You think with all the hints I dropped earlier that there won't be a second astronomy-focused post? All of your questions will be answered in due time...
You think with all the hints I dropped earlier that there won't be a second astronomy-focused post? All of your questions will be answered in due time...
Well, I wondered if those were really hints...
Well, you've got me a little more excited now. The possibilities for astronomical observation from the lunar surface (especially on Farside) really are tremendous, once you've got a presence there.
Part IV, Post 16: ESA's unmanned space missions
Good evening, everyone! We're running a bit late, so I'll just get right to why you're all here, as this week we take another look at the unmanned aspects, this time from someplace a hair closer to home than Russia. Be on the lookout for something you'll be seeing more and more of as Eyes draws to a close: the present tense! Hope you all enjoy...
Eyes Turned Skyward, Part IV: Post #16
As Piazzi left its launch pad in early 1993, the attention of Europe’s scientists and engineers began to turn towards the missions that would follow it and the rapidly developing International Infrared Observatory into space. With its scientific program maturing into operations, and the geopolitical and financial conditions it had been created under ceasing to exist, it was clear that the Vision 2000 strategic plan that had been developed in the early 1980s to rationalize the hodgepodge of “national champion” programs that ESA had been saddled with had run its course and needed to be replaced. As they had a decade earlier, the managers and bureaucrats at the agency’s Parisian headquarters began to reach out to the continent’s scientific community, mediated by the European Science Foundation, to draw up a map for the agency’s next ten years of operations.
Much as they had previously, the scientists responsible for planning out the agency’s scientific program began by trying to crystallize the vague concept of the “community consensus” on what missions ought to take place next into concrete ideas. With Odysseus and Telemachus having recently completed their first solar polar passes, and the power and danger of the Sun having been dramatically demonstrated in Quebec just four years earlier, further solar research seemed a sure bet for investment and a rich area for further research. At the same time, the detection by the Soviet RELIKT satellite a few years earlier of anisotropies in the cosmic microwave background, or CMB, opened up the exciting possibility of directly probing the properties and behavior of the early universe, even as other astronomical opportunities beckoned. Finally, the recent conclusion of the Kirchhoff comet mission, the rapidly advancing Cassini and “Grand Tour” missions, both with significant European involvement, and Piazzi’s steady if slow movement towards Vesta tantalized with the vision of European spacecraft cruising the solar system’s planets and moons and--given discussions with the United States on European involvement in Project Constellation--European boots stepping for the first time onto another celestial body. Balancing space, sun, and planets would be no easy task, and neither would be prioritizing the plethora of attractive mission opportunities in each area, but it needed to be done.
The first result of the series of meetings that began following Piazzi’s launch was a simple recognition of this wide variety of attractive targets, and a first effort to restrict the range of spacecraft considered. The new plan--already named Cosmos 2010--would have three major scientific tracks, each tailored to justify missions in these three areas of research. First would be Cosmic Origins, seeking to explore the beginnings of the universe itself through a new, more sensitive exploration of the CMB. By leveraging European leadership in cryogenic instruments and cryogenic spacecraft, essential to explore the low-energy radiation left behind by the Big Bang, the new Cosmic Origins Probe that had been proposed just as the construction of Cosmos 2010 started would be able to go far beyond the 1980s technology behind RELIKT, let alone the 1970s designs powering NASA’s earlier, unsuccessful Cosmic Microwave Background Explorer, engaging in precision measurements of the anisotropy of the cosmic microwave background and studying its fine structure at unprecedented detail. At the same time, continued development of the infrared telescopes the ESA had developed and mastered could support and supplement the primary CMB measurements, allowing exploration of distant, early galaxies and bodies.
Second, there was Living Sun, born from discussions of cooperation between the American, Japanese, and European space programs in solar research in the wake of the damaging 1989 solar flare. Combined with the developing scientific consensus around global warming, and growing interest in historical climates--many of which were subject to different solar environments than the present--there had been a renaissance in interest in the physical processes behind solar activity, and in understanding and predicting solar behavior. By launching a massive campaign to study the Sun across a wide range of wavelengths and with a wide range of tools, the joint effort hoped to catalyze a revolution in scientific understanding of the Sun. Although precise details had not been worked out, European spacecraft were expected to form an important part of the program, working in conjunction with their American and Japanese counterparts to create an interlocking scientific machine for producing data on solar behavior.
Finally, there would be Early Planets, like Cosmic Origins a purely scientific track focusing on the last remnants of the early solar system. From the battered and cratered surface of the Moon, one of the last traces of the violence of the Late Heavy Bombardment that terminated the early solar system, to the comets and asteroids frozen forever between condensation of the solar nebula into solid particles and combination into planets, a wealth of information still lay beyond Piazzi and other, past missions. With the prospect of discovering the first extrasolar planets becoming increasingly realistic, interest in planetary formation had been growing among astronomers, and a new campaign to explore these areas attracted significant interest and support as a major initiative, one that could tap into public excitement over discovering the very origins of the planets.
With these general areas of interest identified and confirmed by the scientists of Europe, the next step was to actually plan out the missions that would advance them into the future. As it had driven the selection of the Cosmic Origins track, the first of these missions to be formally proposed and approved was the Cosmic Origins Probe in 1995, just months after the Cosmos 2010 plan was formally approved and without any sort of open submission process. This would be, as the name suggested, the flagship of the Cosmic Origins track, utilizing modern technology and instruments to explore the CMB in detail far beyond what previous missions had allowed. In conjunction with balloon-borne and surface instruments, it would allow astronomers to begin a new era of precision cosmology, extending RELIKT’s CMB observations to begin choosing between different models of the universe shortly after the Big Bang.
Although it had been clear from the beginning that the Cosmic Origins Probe was virtually guaranteed selection, what was less clear was which missions would accompany it into space. With declining aerospace spending due to the end of the Cold War and downwards pressure on ESA’s budget (especially from Germany, which was both rapidly shrinking its military and having to deal with the multibillion mark cost of bringing its newly integrated east up to developed standards), it had been an accepted fact that fewer missions would be started during Cosmos 2010 than during Vision 2000, especially since the confusing melange of national-origin missions that had been brought under the Vision 2000 banner had, by and large, vanished. How many fewer did not, however, become clear until later in 1995, as the ESA’s governing council finalized the anticipated budget for the Cosmos 2010 program. In an attempt to balance both scientific ambition and national interests, the council opted to prioritize smaller, cheaper spacecraft like the ones that had cemented ESA’s position in space science, while still allowing the development of larger, more complex, but more scientifically ambitious and productive probes like the ones that NASA’s program had been built on. Beside the Cosmic Origins Probe, there would be enough budgetary room for three other smaller missions, costing no more than a few hundred million European Currency Units (a predecessor to the euro used as a unit of accounting for pan-European organizations) each, and a single larger spacecraft, with a less well-defined cost cap that might reach as high a billion ECUs.
With the limitations of politics and finance clear, the initiative returned to the scientists, who now had to decide which of the many proposals that had been developed over the past several years would fly. There was, as ever, no shortage of attractive missions, with proposals ranging from Mercury orbiters to Pluto flybys, and from outwards-looking radio telescopes to Sun-observing gamma ray observatories to decide between. Guided by the Cosmos 2010 scientific program, however, over the next several years the European scientific community was able to boil the mass of paper missions into just the right number of, if not quite artifacts of aluminium and composites ready to fly into space just yet, then at least better-realized spacecraft ready for construction.
First on the list, and taking the large mission slot, would be the Solar Probe, a spacecraft designed to achieve, or at least approach, the by-now decades old mission of reaching the Sun itself. Flagship of Living Sun, the Solar Probe would, after a series of Venus flybys, eventually pass through the solar corona just 6,000,000 kilometers above the Sun’s photosphere, where solar radiation would heat it to a blistering 1,400 degrees Celsius, affording the first direct look at the region of the solar atmosphere where the solar wind is accelerated into the rest of the solar system. By exploring this region of the solar atmosphere, scientists hoped to crystallize theoretical speculation on the origins of the corona’s extreme and unusual temperature, and the solar wind itself, helping to better understand the flow of material outwards from the Sun and, perhaps, the solar flares and coronal mass ejections that could affect life on Earth.
Although an ambitious leap forwards by the European space program, ESA was perhaps the best placed of the International Solar Program partners to carry out such a mission, with its experience building and operating the Helios 1, 2, and Encke spacecraft in the 1970s and early 1980s. While far less ambitious than Solar Probe, with perihelions barely inside Mercury’s orbit, they were still the closest any previous spacecraft had come to the solar furnace, affording valuable practical experience in the challenges faced by close-in operation. By taking advantage of advances in technology during the 1980s and 1990s, in particular high-temperature materials to protect the spacecraft from the blazing fury of the Sun and powerful computers to calculate possible gravitational assist trajectories, the Solar Probe spacecraft would be able to approach much closer than the Helios probes possibly could have, without requiring an impractically large launch vehicle or difficult Jupiter flyby (and the use of expensive radioisotope thermal generators), while the relatively narrow focus of the mission on particles and fields experiments would keep costs down compared to more widely-ranging NASA proposals that also would have delved into optical observations and gravitational research.
Complementing the Solar Probe would be the Solar Composition Probe, a mission to collect material from the solar wind and return it to Earth. By greatly improving knowledge of solar composition, it would not only allow for better understanding of the behavior of the Sun itself, but greater insight into the differences between the primordial material of the solar nebula and the modern solar system, and hence into how the solar system evolved--a topic of rapidly increasing scientific interest given the recent discovery of the first extrasolar planets orbiting ordinary stars. By appealing simultaneously to two of Cosmos 2010’s tracks, the Solar Composition Probe won considerable support and easy acceptance as one of ESA’s smaller missions, especially given the relative technical simplicity of resting in space and collecting material blowing past on a solar breeze.
Just as the Solar Composition Probe would complement the Solar Probe in its efforts to explore the solar corona, so the Far-InfraRed and Sub-millimetere Space Telescope would go hand-in-glove with the Cosmic Origins Probe in unraveling the beginnings of the universe. By pushing the limits of cryogenic detector technology, FIRST would be the first space telescope to cover the far infrared and submillimeter bands that the coldest objects in the universe, like nebulae collapsing into protostars or galaxies on the cusp of formation, radiate in, allowing FIRST to explore the composition of some of the oldest and youngest objects anywhere. A direct descendent of an identically-named predecessor that had been proposed during the creation of Vision 2000, the relative technical immaturity of the necessary technology had led to FIRST being delayed while research was carried out to prove the basic design concepts. With those results in hand and verifying the concept, the Cosmos 2010 planners were as enthusiastic about moving FIRST into the list of approved missions as they had been a few years earlier about the Cosmic Origins Probe, making it an easy approval.
Rounding out the list of new scientific missions would be Ceres Orbiter, an unambitious yet scientifically valuable mission that would build on the legacy of Piazzi and explore one of the last of the solar system’s protoplanets. While Piazzi had been unable to visit the largest of the asteroids thanks to celestial mechanics, continuing Earth-based observations had kept it a puzzle, showing an apparently water-rich and relatively undisturbed composition, similar to what it might have had at the formation of the solar system. Given the extensive chemical and geophysical changes that had taken place on Vesta, a smaller body, since its formation (as revealed by Piazzi during its visit in 1995), it seemed strange that the larger and only slightly more distant from the Sun Ceres would have remained in its primordial state. Therefore, many scientists were eager to explore Ceres and try to determine why Ceres and Vesta had ended up so different after four and a half billion years of evolution in a similar environment and coming from a similar starting point. Finally, just as the howardite-eucrite-diogenite meteorites had originated on Vesta, it was hoped that other meteorites in Earth’s collections might ultimately be pieces of Ceres launched into space by ancient impacts. Although the spectroscopic evidence that had led scientists to suspect the Vestan origin of the howardite-eucrite-diogenites even before Piazzi’s launch was lacking in the case of Ceres, there were plausible explanations for this, and it was far from unreasonable that observations might simply have missed the points of origin for as-yet unknown Cerean meteorites.
As the machinery of mission selection worked, however, construction of the Cosmic Origins Probe was underway across Europe, with instruments and support equipment flowing to the integration center in Germany as technical issues were debugged, performance goals were reached, and hardware was built. The greatest struggle faced by engineers was keeping the probe’s weight down, in order to keep it within the payload envelope of the planned Europa 50a launch vehicle, with significant efforts being undertaken to keep the probe’s mass within that rocket’s approximately one-ton capacity to its operational orbit around the second Sun-Earth Lagrangian point, SEL-2. By late 1999, just over four years after it had initially been selected, the spacecraft had reached French Guiana, where a last round of tests awaited before it was loaded with liquid helium and mounted onto its Europa booster. Ironically, earlier in the year the decision had been made to “trade up” to the more powerful Europa 52, rendering the weight-trimming efforts of the probe’s engineers pointless. Along the way, it had also gained a proper name, Georges Lemaître, after the Belgian physicist who had first proposed the idea of the Big Bang his namesake was about to investigate. After a series of delays caused by poor weather and minor technical glitches, Georges Lemaître finally lifted off from Kourou early in the new year, followed by a flawless injection into its initial trans-lunar trajectory later in the day. During the lunar flyby, the spacecraft itself executed another burn, putting itself on its final trans-SEL-2 trajectory. For the next few months, as it slowly cruised for SEL-2, the spacecraft began cooling down its primary instruments and carrying out calibration and engineering checks, so that once it entered its circum-SEL-2 orbit in March it was fully checked out and ready to begin observation, looking outwards to observe the faint ripples of the Universe’s beginnings.
Over the course of the next year, the spacecraft built up its first all-sky map, with scientists on the ground carefully removing the far brighter signature of nearby objects before announcing, in the middle of 2001, the results of the probe’s primary mission. As expected, it had confirmed the RELIKT result with flying colors, agreeing with the new generation of ultra-sensitive Earth-based instruments that there was, indeed, significant anisotropy in the cosmic microwave background. More than that, however, the scientists behind the spacecraft were able to compare its results to those of the newest generation of cosmological theories, mathematical constructs that aimed to predict nothing less than the evolution of the universe itself. After careful analysis, the best match went to the new but popular “C2CDM,” or “Cosmological Constant-Cold Dark Matter” hypothesis, which had been proposed only a few years earlier to explain the apparent acceleration of the expansion of the universe. Besides the by this point standard idea that the bulk of the universe’s matter is in the form of “cold,” or slow-moving, invisible “dark” matter, C2CDM adds the theory that the universe is pervaded by an invisible and nearly undetectable “dark energy” field that slightly modifies Einstein’s field equations, introducing the “cosmological constant” of its name and causing a gradual acceleration in the universe’s rate of expansion. Compared to alternate theories like quintessence or modified Newtonian dynamics, C2CDM seemed to have a better fit with Georges Lemaître’s observational data, especially when supplemented with other observations, both of the cosmic microwave background and of other aspects of the universe. Beyond cosmology, other areas of science also benefited from the spacecraft’s data. Particle physicists, in particular, learned that there did not seem to be a fourth kind, or “flavor” of neutrino in the universe, with the data instead favoring the existence of only the three types that had been observed in the laboratory. Although not enough to rule out the existence of a fourth neutrino “flavor,” it showed that astronomical observations could still inform terrestrial science just as well as the opposite.
Even before the publication of its first batch of results, the spacecraft had already earned an indefinite mission extension on the back of its still-good condition, lower than expected consumption of liquid helium, and the scientific value of further data in refining the probe’s results. For four and a half more years, Georges Lemaître continued to scan the skies, building up four more full all-sky maps and about a quarter of a sixth, before it finally exhausted its helium supply. While they did not have the impact of its first data release, the annual corrections and updates issued by the Lemaître team using this additional data continually refined and improved Lemaître’s measurements of key cosmological parameters, greatly narrowing the scope of permissible theories of physical cosmology and providing additional support for the C2CDM model. Once the probe exhausted its liquid helium supply, a brief additional engineering mission was undertaken to observe how the performance characteristics of its instruments changed as they heated back up, then it executed a final burn to throw itself away from SEL-2 and into a heliocentric graveyard orbit, before being remotely shut down in April 2006, just shy of five and a half years after launch.
As Georges Lemaître was shutting down, however, Solar Probe--now named Aristarchus, after the Greek philosopher who was the first person in history to propose a heliocentric cosmos--was just getting started. Originally (and optimistically) planned for a launch in 2002, just six years after approval, it had been slipped first to 2004, then on to 2005, driven by the severe difficulties encountered by its French builders in pushing the state-of-the-art in thermal protection systems and high-temperature solar cells. Multiple shield designs failed under the rigorous inspection of the Haute Température Installation d'Essai, or High Temperature Test Facility, a new installation built on the outskirts of the spacecraft’s manufacturing plant, stressed beyond their limits by the extreme temperatures the probe would encounter during its close solar passes, leading many to wonder if a less ambitious objective--passing just a bit farther away from the Sun--might not be all that was achievable. Nevertheless, the French persisted in their efforts, and by the originally planned launch date had come up with a sunshield built out of carbon-carbon, the same composite material used to make high-performance brake pads for race cars, which combined with a new and highly advanced reflective coating on its front face seemed able to protect the spacecraft from extremes of temperature that would be encountered during the close encounters.
With this crucial part of Aristarchus finally lined up, the rest of the spacecraft began quickly falling into place, such that by the middle of 2005 it was able to follow in its predecessor’s footsteps on the journey into space, traveling to French Guiana for a short layover and check-up before being mated to its Europa 54u launch vehicle for its ride into orbit in November. After an uneventful launch, its Aurore-B upper stage gave it the final push needed on its way to Venus, which it reached after a cruise mostly consumed by instrument check-out and deployment just before the end of the year, swinging past in its first perihelion-lowering pass. In early February, just as Lemaître was being decommissioned, Aristarchus finally reached its first perihelion, swinging past the Sun at an altitude of just 25,000,000 kilometers, handily breaking the record set by the Helios probes twenty years earlier. Although this pass was only a warm-up, well within the probe’s design enveloped, its operators were still relieved when it rose back out from the depths of its orbit, bearing a cargo of scientific data and none the worse for wear, as far as could be determined from Earth.
With no fatal flaws having shown themselves, Aristarchus was clear to continue its primary mission. Over the next several years, it dipped repeatedly within the orbit of Mercury, swinging closer and closer to the Sun as its encounters with Venus sapped its orbit’s energy bit by bit and allowed it to penetrate further and further into the Sun’s domain. As this was going on, scientists were poring over what data was returned on each orbit, combining it with the returns of the flock of remote sensing spacecraft around and near Earth to build a new picture of the Sun’s behavior. As had often been the case in the space age, the new information provided by Aristarchus both confirmed and challenged old concepts and theories; for example, although it quietly provided updated information for helioscientists seeking to predict the evolution of the solar wind from near-solar regions out into interplanetary space, it also produced a major blow to those same scientists, providing strong evidence against the then-popular theory that the wind originates from intermittent, pulsed sources in the corona, a theory which also nicely explained a number of observations of structures in the solar wind near Earth and in the solar atmosphere. Instead, Aristarchus’ data seemed to favor a relatively steady, smooth outflow of plasma from the Sun’s atmosphere, punctuated by occasional outbursts of activity. Perhaps this was, as some suggested, merely the result of the slow decline in activity from the Sun as it descended towards a solar minimum, but at the least it sent many scientists back to their offices, considering how to incorporate Aristarchus’ observations into a new, stronger theory of solar behavior.
Besides Aristarchus, their work was also constrained by the samples returned several years earlier by the Solar Composition Probe. Operating under the far more benign conditions of near-Earth space, and with a relatively technically undemanding mission, it had taken just two years to go from approval in early 1997 to launch towards the end of summer 1999, barely nosing out Georges Lemaître to become the first of the Cosmos 2010 spacecraft to make it into space for its cruise to the first Sun-Earth Lagrangian point, on the opposite side of the Earth to Lemaître’s SEL-2 position. Once it reached the Lagrangian point and settled into its orbit among the other Sun-observing spacecraft stationed there, it opened wide, allowing the invisible wind of particles blowing past it to collect on its outspread “wings”. For the next several years it patiently waited, collecting pieces of the solar wind atom-by-atom, until in 2002, after nearly three years of operation, it closed up and began its return to the Earth, which it reached several weeks later.
Here began the most daunting and technically challenging phase of the mission. Due to the physics of ion deposition, the spacecraft’s solar wind collectors had had to be made thin--or, in other words, fragile. So fragile, as a matter of fact, that if the return capsule landed normally, without taking special precautions, they could be damaged or destroyed, ruining the probe’s scientific value and wasting tens of millions of euros (which since 1999 had replaced ECUs) in the process. A range of options had been explored to counterbalance this, from an elaborate mixed retrorocket-airbag system reminiscent of the old Soyuz landings that would cushion even the blow of a land landing to a daring aerial stunt capture that would have seen specially modified aircraft pull the capsule out of mid-air while still descending--a technique perfected by the United States in the 1960s and 1970s to recover similar capsules full of exposed spy satellite film, but never before tried in Europe--but ultimately the best option, or at least the one selected, had been to switch, at least for this one mission, to a water landing, combined with a retrorocket system similar to that of the Soyuz or Longxing capsules for reducing terminal velocity to nearly zero. Between the cushioning effect of the sea and the low impact velocity, it was hoped that there would be little, if any, damage, maximizing the probability of returning intact samples.
As such, when the Solar Collection Probe came streaking in over Earth’s sky, headed straight for the landing zone off of French Guiana, the mission’s scientists were holding their breath and wondering whether the complex braking system would work properly, even as French Navy helicopters and recovery teams were taking off to secure the capsule as quickly as possible following landing. Tensions dropped slightly when parachute deployment was confirmed by observers, but the real test wasn’t passed until the retros ignited, just a few moments before the sample capsule hit the water. With smoke billowing around it, the capsule slowed to a hover only meters above the sea’s surface, before they burned out and it fell the rest of the distance, dropping gently into the ocean. Within minutes, the recovery personnel had winched the capsule aboard one of the helicopters detailed to support the recovery, and within hours it, along with the precious samples contained within, was traveling across the Atlantic for the Extraterrestrial Curation Facility in London. There, scientists began the careful and delicate process of teasing out the captured ions from the wafers of silicon holding them, identifying their chemical species, and putting them together into an image of the Sun’s composition.
As expected, their results were not especially shocking or novel; the Sun’s composition had after all been an object of study for the past century and a half, ever since the invention of the spectroscope. Instead, the painstaking work of the next several years would be in refining, not overturning, that carefully gathered data from generations of astronomers. Combined with Aristarchus’ in-situ data, it provided information about both the initial and final conditions that any new model of the solar wind would need to match to correspond with reality. Perhaps more importantly, it served as a new base to model the chemical evolution of the solar nebula during the early stages of the solar system. Combined with new dynamical models of the system’s evolution developed using new, more powerful computers, the Solar Composition Probe’s data has helped give rise to the latest version of the standard solar system evolution model, and helped to develop general theories for the behavior of young solar systems.
While scientists in London were studying samples of the Sun, astronomers elsewhere on the continent were poring over the data coming in from FIRST, the last of the Cosmos 2010 spacecraft to launch, early in 2006. The delay was due less to technical difficulties than to budgetary priorities, given the limited amount of funding that each ESA member nation was willing to provide and the other budgetary priorities that the agency faced. Matters were not helped by the fact that, though of a relatively well-understood design, FIRST would nevertheless be a large, complex spacecraft, straining the budgetary limitations that Headquarters had set out for the Cosmos 2010 program. Combining a large, cryogenically cooled mirror and sophisticated scientific instruments on a budget drew out spacecraft development over nearly a decade, leaving FIRST to slowly come together. Despite fears that it might end up being scooped, no competition materialized and FIRST was smoothly lifted by a Europa rocket towards its operational orbit around SEL-2. Initial commissioning tests soon showed that all of the spacecraft’s instruments were working as planned, and it settled into a steady routine of observations, gathering spectra and images of targets ranging from galaxies to the dusty nebulae surrounding still-forming stars until it ran out of cryocoolant in late 2009, after three and a half years of operation.
During its observations, FIRST greatly extended and refined observations of the molecular and chemical structure of interstellar and circumstellar objects, showing that many simple biological molecules are common in interstellar gas clouds such as the Orion Nebula and helping, like the Solar Composition Probe, to set new limits on the conditions that new stars face as they are born. Its long-wavelength capability and orbital position also gave it the valuable capability of tracking water, a common and important molecule, but hard to detect from Earth through our water-logged atmosphere. By detecting the spectral signature of water in balls of gas and dust on the cusp of collapsing into new star systems, in debris disks surrounding young stars, and even in our own solar system, supporting Ceres Orbiter and Cassini in their exploration of the minor planet and Saturn, respectively, FIRST was able to improve the scientific understanding of how water behaves during stellar formation, much like its other observations assisted in the construction of new models of stellar formation. It also helped support observations by Ceres Orbiter and Cassini of water emissions--geysers--from Ceres and Enceladus, respectively, providing an additional capability to track the movement of water from those bodies through the space around them. Finally, FIRST’s sensitivity to emissions in the far-infrared allowed it to make the first observations of the cosmic galaxy background, the most distant and ancient galaxies visible from Earth, penetrating the veils of dust and extreme redshifts that had prevented them from previously being visible and providing the first information on these most ancient structures.
Last but not least, the first decade of the 21st century also saw Ceres Orbiter leave Earth for its destination, the largest of the asteroids. Ceres Orbiter was designed to build on its predecessor Piazzi, extending the latter’s admittedly limited survey of the asteroid belt to another, unusual object, one that besides being one of the asteroids appeared to be one of the last protoplanets, a type of planetary body intermediate between the minor planets and full-fledged planets, but mostly consumed during the process of planetary formation. Due to the gravitational influence of Jupiter, those protoplanets which had formed in the asteroid belt--Ceres, Vesta, Pallas, and perhaps others--had never had the chance to aggregate into planets, leaving them exposed to remote observation and opening the way for an investigation into the crucial but brief period of the solar system’s history where protoplanets were forming and merging. Although previously interesting, of course, this question had taken on new urgency since the discovery in the mid-1990s of the first planets around other stars, causing a tremendous upswing in interest in planetary formation and the dynamics of early solar systems and protoplanetary discs.
Compared to the rocky and relatively dry Vesta, which Piazzi had visited, observations had shown that Ceres was wet and rich in volatile materials, more similar to the C-type asteroids 313 Chaldaea and 415 Palatia, which Piazzi had flown past in 1996 and 1997, respectively, or 449 Hamburga, which it had reached in 1998, or to the Galilean moons of Jupiter that Galileo had observed than to Vesta. However, Chaldaea, Palatia, and Hamburga had been too small for their own gravity to pull them into a spherical shape, or for their internal heat to result in differentiation--the separation of the rock and ice within them into distinct layers based on their density. By contrast, the Galilean moons were so large that they were essentially planets, with all the same geological complexities and foibles. By investigating Ceres, just large enough that it had probably differentiated like Vesta but not so large or near a source of tidal energy that it had likely had much internal activity since its formation, scientists would extend the observations of Piazzi to new types of object, more similar to what proto-gas giants or the Galilean moons might have looked like early in their history.
The design of Ceres Orbiter was based on a scaled-down version of the Piazzi bus, taking advantage of the development of so-called “electric” satellite busses in the decade since its development to speed development and cut costs. Although a ballistic mode had been considered, since the spacecraft was only intended to visit a single asteroid instead of conducting a Piazzi-like tour, analysis of the electric versus ballistic modes showed that ballistic spacecraft would require larger retro and trans-Cerean injection stages than electric rockets, in turn requiring the use of larger, more costly launch vehicles. By contrast, an electric spacecraft could be launched on a Europa 50a, saving tens of millions of euros.
Thus, after Ceres Orbiter--now named Gauss, after the mathematician and scientist, who had played an important role in early asteroidal studies, in particular by calculating the orbits of several of the first asteroids to be discovered--was lifted into space and thrown onto an escape trajectory in mid-2003, it quietly unfurled its solar panels and began thrusting away from Earth, gradually building up speed and raising its inclination over the next several years to match with Ceres’ orbit. By late 2005, after nearly two and a half years of thrusting, Gauss was closing in on Ceres, and early in the new year was able to settle into a stable, low orbit around the body. In conjunction with occasional observations from FIRST as it finished commissioning, Gauss quickly plunged into detailed observations of the body. Besides a high-resolution visible light camera for mapping the asteroid, Gauss carried an array of spectrometers for measuring the composition and mineralogy of its surface in significant detail and a laser altimeter for precisely measuring its topography and shape. Together with FIRST’s instruments, this added up to an impressive scientific payload for ferreting out all but the minutest details of the protoplanet.
The first task of this payload was to begin studying Cerean surface geography, especially in comparison to the crude surface maps that had produced over the past twenty years from Earth-based observations. Although many of the features “detected” by those instruments proved to be illusory or amalgamations of multiple nearby structures, a few--in particular, the giant dark spot that had been named “Piazzi” after the asteroid’s discoverer--stood up to scrutiny, in most cases proving to be large impact craters. As with most bodies in the Solar System, craters defined Ceres’ surface, creating a rugged terrain marked by overlapping crater walls, with only the rare relatively unmarked interior or a handful of mysterious flat plains remaining relatively untouched. The greatest of these craters was Piazzi itself, as had been theorized before the probe’s arrival, a giant of a crater that rivaled some of those on Vesta for depth, and appeared to reach to the boundary of the protoplanet’s mantle. As on Vesta, or in the Moon’s South Pole-Aitken Basin, this offered the exciting possibility of observing material from deeper within the asteroid than could possibly have been reached otherwise, and the probe’s observation program was duly modified to put more priority on observing Piazzi early and often.
Interest in the region was only magnified by the discovery by FIRST during supporting operations of significant amounts of water and water byproducts in near-Ceres space above several specific locations on the surface, in particular one of the dark spots observed along with Piazzi. The obvious explanation for these gases being present, and one that came to mind readily for anyone who had noticed the discovery of ice crystals in the lunar regolith during Artemis 9 the previous year, was that there was some subsurface ice source, slowly sublimating away as the regolith heated up during the day, a conclusion supported by the observation of bright spots at the bottom of several particularly deep craters, spots which turned out to be made mostly of water ice. A few quick calculations indicated that even a fairly thick solid layer of ice under the surface would be depleted entirely in a geologically short period of time, far less than the the length of time since the asteroid’s formation. Hence, scientists concluded, there had to be a source: geological activity continually bringing ice from some deep subsurface reservoir closer to the surface where it could sublimate and escape into the thin Cerean atmosphere. The most popular theory posits a nearly continuous layer of ice deep under the rocky Cerean surface, slowly churning upwards due to its lower density like lava on Earth, but minority views hold that part of the reservoir, perhaps even the majority, could be liquid, a solution of water and ammonia that could stay fluid even at extremely low temperatures.
In light of these discoveries, Gauss’ observation program was further modified; although the spacecraft had not been designed for gravity measurements, careful tracking of the signal from the probe to its receiving antennas on Earth could allow at least a crude measurement of the gravity anomaly and perhaps even the gravity gradient, providing a simplistic map of the protoplanet’s structure; additionally, careful measurements might be able to detect changes in the speed of Ceres’ rotation stemming from the outer crust and inner core being coupled through a fluid instead of solid rock. Unfortunately, both measurements were inconclusive, giving results that were consistent with either model. Many scientists lamented the lack of a magnetometer, an instrument that had been planned but omitted in a cost and mass-saving effort; had it been present, the magnetic field that would have been induced by movement through the solar magnetic field in the probably salty ocean might have been detectable, a sure signature of whether or not an ocean was present.
Besides these ice-related measurements, Gauss also examined the composition of the surface in fine detail, showing it to mostly resemble the C-type asteroids that Piazzi had visited, as expected. As had been hoped, a few meteorites--a handful of the carbonaceous chondrites that had been discovered over the past few centuries--were found to match the composition of specific locations on the Cerean surface, and thus to have most likely come from its surface. Even more interestingly, observations also confirmed that minerals such as carbonates and brucites that are believed to only form in the presence of water could be found on Ceres’ surface. Although this was seized on by advocates of the ocean model as supporting their theory, opponents pointed out that several alternative explanations, none of which needed Ceres to be partially melted, could be advanced, leaving the situation confused.
By the time Gauss was nearing the end of its first Cerean year in 2011, work on the successor program to Cosmos 2010 was well underway, with the first missions already in space and returning data. Buoyed by the successes of the Cosmos 2010 and Vision 2000 strategic plans, when European scientists and engineers began meeting in 2003 and 2004 to begin charting out ESA’s next scientific program--now modified to incorporate Earth science and therefore to bring all of ESA’s scientific activities under a single overarching strategic plan--they saw little reason to change what had been a winning formula. Drawing on the rapid discovery of new extrasolar planets, beginning with 70 Virginis b in 1996, and the recent reinstitution of the so-called “cosmological constant” to cosmological models from Georges Lemaître data and ground-based observations indicating an apparent acceleration in the rate of the universe’s expansion, they developed a program containing four distinct scientific tracks.
The first, “Dark Universe,” would seek to investigate dark matter and the cosmological constant, or dark energy, which together appeared to make up the vast majority of the universe’s mass-energy content, and about which very little was or is known except through indirect observations. Moving to a topic slightly closer Earth in time and space, the second track, “Planetary Universe,” would mark a major push to discover and, hopefully, characterize extrasolar planets, or exoplanets, on a massive scale, expanding catalogs of hundreds of discoveries to thousands or tens of thousands, and answering the question of whether the Solar System, and in particular Earth, were “normal” or, somehow, strange and unusual among planetary systems, something that was feared from the proportion of so-called “hot Jupiters” and planets in highly elliptical orbits that had been discovered by that time. Of course, the greatest discovery would be learning that one of these planets supported--or supports--life, the dream of thinkers for centuries. To investigate this possibility, there was the “Living Universe” track, aimed at discovering whether any extrasolar planets might support life through characterizing (and, perhaps, discovering life in) potential habitable environments in the Solar System. Finally, there was “Human Universe,” a program aimed at directly applying space technology to Earth’s problems.
Each of these tracks was designed to support both a larger, so-called “flagship” mission and smaller, supporting missions, another sign of the expansion of ESA’s ambitions. Much as with Cosmos 2010 a decade earlier, by the time Universe 2020 was approved strong candidate proposals had already been developed for each track, both for flagships and supporting missions, and soon the program had been fleshed out and finalized. Leading the Dark Universe track is Eddington, a mission designed to scan a large region of the sky for so-called “weak gravitational lensing” events, a method of statistically measuring the mass of objects in the universe by tracking the distortion they cause as an effect of Einstein’s general theory of relativity on background light sources, named after the British astrophysicist who was one of the first and strongest proponents of the theory, and who organized an expedition to detect lensing caused by the Sun in 1919. Through Eddington’s survey, scientists are creating a map of the dark matter content of the universe, and study how it associates with “light,” or baryonic matter, as well as how it changes over time in conjunction with spectroscopic data to identify redshifts, and collaborative observations with other telescopes. Launched in 2012 after five years of development, Eddington has already significantly improved models of dark matter distributions, in particular by discovering several clusters where mass concentrations, as revealed by the lensing events, and baryon concentrations, as shown by conventional observations, have separated during inter-cluster interactions, strong evidence for dark matter models as against modified dynamics alternatives. It is expected that once the full survey is completed in the next several years, that a map associating baryonic and dark matter through a wide volume and far back in time will be completed, allowing the next generation of telescopes to conduct a more focused study. 2009’s Wide Field Gamma Telescope is also supporting this track, both by searching for possible signs of dark matter-dark matter interactions and by helping to characterize the properties of potential confounders, like quasars, black holes, and neutron stars.
Leading the Planetary Universe track, Giordano Bruno, launched only a few months ago, is expected to revolutionize exoplanetary astronomy through its industrial-scale approach to planet detection. By using an array of small telescopes, Bruno will be able to scan an enormous field of well over 1,000 square degrees continuously for tiny brightness fluctuations caused by the passage of planets in front of stars--planetary transits. While dependent on the chance alignment of the star’s ecliptic plane and Earth, it is one of the best methods of planetary detection presently available, and, based on the results of NASA’s EPIC mission last decade, will allow the discovery of a truly massive planetary sample, enough to allow scientists to start drawing statistical conclusions about planetary properties. Planetary candidates from Bruno, once it begins its observational phase, are expected to be premiere targets for NASA’s Spitzer Space Telescope and the next generation of ground-based megatelescopes. Bruno’s photometric capabilities will also be used to support a search for microlensing candidates in the data and research into asteroseismology, the study of stellar interiors through surface oscillations much like earthquakes.
The first independent ESA outer planets mission, Herschel, was selected in 2006 to lead the Living Universe track, designed to take advantage of Cassini’s discovery of massive plumes of water erupting from Saturn’s moon Enceladus to conduct a relatively cheap yet capable mission that may be the first to indicate life on another celestial body. By avoiding the need to operate in powerful radiation belts like those around Jupiter’s moon Europa, Herschel will be far simpler and cheaper to design than a Europa spacecraft, while the powerful eruptions from Enceladus’ south pole carry water, possibly laced with organic compounds, into space for easy capture and analysis compared to Mars or Titan-bound missions. As Saturn orbits ten times farther away from the Sun as Earth, making solar power generation difficult and nigh-impractical, Herschel will also be the second European mission to use radioisotope thermal generators, and the first to use European-designed and built versions. Using a novel design using americium-241--the isotope used in smoke detectors around the world--instead of the plutonium-238 used in American designs, the European Common RTG marks a major advance in ESA capabilities. Unfortunately, it has also suffered technical difficulties, and the probe has recently been delayed from an originally scheduled 2015 launch date to 2018 due to problems experienced by France’s Commissariat à l'Énergie Atomique and Britain’s National Nuclear Laboratory in safely manufacturing and assembling the spacecraft’s fuel elements. Besides this major mission, the Mars Rare Gas Orbiter, launched in 2013 and only recently having reached Mars, is intended to investigate data from NASA’s MACO mission indicating the presence of a small amount of methane in Mars’ atmosphere, a possible sign of life.
Finally, the Human Universe track is being led by the Earth Observation System, a collection of satellites from multiple countries intended to work in concert to study all aspects of Earth’s environment, from core to crust and beyond. Consisting not of a single mission but of multiple smaller ones designed to work together, it is hoped that the EOS will provide unprecedented, nearly-continuous data on a wide variety of phenomena, ranging from global rainfall measurements to the slow movement of magma in the Earth’s interior to a precision map of global carbon dioxide emissions and absorptions, revolutionizing climate science. Multiple spacecraft from ESA, CNES, ASI, NASA, JAXA, and ISRO have already been launched under the EOS banner, and data is being incorporated from Chinese and Russian missions as well. In support of this track, ESA has been encouraging applications research in its Freedom research programs and in proposals for its portion of Orion lunar surface time, besides its other research programs.
Looking ahead, the next phase of ESA’s science program--its strategic plan to 2030--is already under construction, with discussions taking place on what scientific goals seem most relevant for the next decade. Beyond Herschel, there could be missions to Titan or even past Saturn, to Uranus or Neptune, in either case performing significant fundamental planetology, while further research into dark matter--especially if ongoing direct detection experiments yield a signal--or the cosmological constant promise potentially exciting results. Gravitational waves, the subject of an impressive number of paper studies by ESA, NASA, and JAXA over the years, could also be a major focus of a new mission. And, if Bruno finds an Earth-sized planet not too close and not too far from a star of the right size, and it is confirmed...or better yet, discovered to have an oxygenated atmosphere...Nothing is yet set in stone, and whatever occurs, the next decade is sure to be an exciting and productive one.
Eyes Turned Skyward, Part IV: Post #16
As Piazzi left its launch pad in early 1993, the attention of Europe’s scientists and engineers began to turn towards the missions that would follow it and the rapidly developing International Infrared Observatory into space. With its scientific program maturing into operations, and the geopolitical and financial conditions it had been created under ceasing to exist, it was clear that the Vision 2000 strategic plan that had been developed in the early 1980s to rationalize the hodgepodge of “national champion” programs that ESA had been saddled with had run its course and needed to be replaced. As they had a decade earlier, the managers and bureaucrats at the agency’s Parisian headquarters began to reach out to the continent’s scientific community, mediated by the European Science Foundation, to draw up a map for the agency’s next ten years of operations.
Much as they had previously, the scientists responsible for planning out the agency’s scientific program began by trying to crystallize the vague concept of the “community consensus” on what missions ought to take place next into concrete ideas. With Odysseus and Telemachus having recently completed their first solar polar passes, and the power and danger of the Sun having been dramatically demonstrated in Quebec just four years earlier, further solar research seemed a sure bet for investment and a rich area for further research. At the same time, the detection by the Soviet RELIKT satellite a few years earlier of anisotropies in the cosmic microwave background, or CMB, opened up the exciting possibility of directly probing the properties and behavior of the early universe, even as other astronomical opportunities beckoned. Finally, the recent conclusion of the Kirchhoff comet mission, the rapidly advancing Cassini and “Grand Tour” missions, both with significant European involvement, and Piazzi’s steady if slow movement towards Vesta tantalized with the vision of European spacecraft cruising the solar system’s planets and moons and--given discussions with the United States on European involvement in Project Constellation--European boots stepping for the first time onto another celestial body. Balancing space, sun, and planets would be no easy task, and neither would be prioritizing the plethora of attractive mission opportunities in each area, but it needed to be done.
The first result of the series of meetings that began following Piazzi’s launch was a simple recognition of this wide variety of attractive targets, and a first effort to restrict the range of spacecraft considered. The new plan--already named Cosmos 2010--would have three major scientific tracks, each tailored to justify missions in these three areas of research. First would be Cosmic Origins, seeking to explore the beginnings of the universe itself through a new, more sensitive exploration of the CMB. By leveraging European leadership in cryogenic instruments and cryogenic spacecraft, essential to explore the low-energy radiation left behind by the Big Bang, the new Cosmic Origins Probe that had been proposed just as the construction of Cosmos 2010 started would be able to go far beyond the 1980s technology behind RELIKT, let alone the 1970s designs powering NASA’s earlier, unsuccessful Cosmic Microwave Background Explorer, engaging in precision measurements of the anisotropy of the cosmic microwave background and studying its fine structure at unprecedented detail. At the same time, continued development of the infrared telescopes the ESA had developed and mastered could support and supplement the primary CMB measurements, allowing exploration of distant, early galaxies and bodies.
Second, there was Living Sun, born from discussions of cooperation between the American, Japanese, and European space programs in solar research in the wake of the damaging 1989 solar flare. Combined with the developing scientific consensus around global warming, and growing interest in historical climates--many of which were subject to different solar environments than the present--there had been a renaissance in interest in the physical processes behind solar activity, and in understanding and predicting solar behavior. By launching a massive campaign to study the Sun across a wide range of wavelengths and with a wide range of tools, the joint effort hoped to catalyze a revolution in scientific understanding of the Sun. Although precise details had not been worked out, European spacecraft were expected to form an important part of the program, working in conjunction with their American and Japanese counterparts to create an interlocking scientific machine for producing data on solar behavior.
Finally, there would be Early Planets, like Cosmic Origins a purely scientific track focusing on the last remnants of the early solar system. From the battered and cratered surface of the Moon, one of the last traces of the violence of the Late Heavy Bombardment that terminated the early solar system, to the comets and asteroids frozen forever between condensation of the solar nebula into solid particles and combination into planets, a wealth of information still lay beyond Piazzi and other, past missions. With the prospect of discovering the first extrasolar planets becoming increasingly realistic, interest in planetary formation had been growing among astronomers, and a new campaign to explore these areas attracted significant interest and support as a major initiative, one that could tap into public excitement over discovering the very origins of the planets.
With these general areas of interest identified and confirmed by the scientists of Europe, the next step was to actually plan out the missions that would advance them into the future. As it had driven the selection of the Cosmic Origins track, the first of these missions to be formally proposed and approved was the Cosmic Origins Probe in 1995, just months after the Cosmos 2010 plan was formally approved and without any sort of open submission process. This would be, as the name suggested, the flagship of the Cosmic Origins track, utilizing modern technology and instruments to explore the CMB in detail far beyond what previous missions had allowed. In conjunction with balloon-borne and surface instruments, it would allow astronomers to begin a new era of precision cosmology, extending RELIKT’s CMB observations to begin choosing between different models of the universe shortly after the Big Bang.
Although it had been clear from the beginning that the Cosmic Origins Probe was virtually guaranteed selection, what was less clear was which missions would accompany it into space. With declining aerospace spending due to the end of the Cold War and downwards pressure on ESA’s budget (especially from Germany, which was both rapidly shrinking its military and having to deal with the multibillion mark cost of bringing its newly integrated east up to developed standards), it had been an accepted fact that fewer missions would be started during Cosmos 2010 than during Vision 2000, especially since the confusing melange of national-origin missions that had been brought under the Vision 2000 banner had, by and large, vanished. How many fewer did not, however, become clear until later in 1995, as the ESA’s governing council finalized the anticipated budget for the Cosmos 2010 program. In an attempt to balance both scientific ambition and national interests, the council opted to prioritize smaller, cheaper spacecraft like the ones that had cemented ESA’s position in space science, while still allowing the development of larger, more complex, but more scientifically ambitious and productive probes like the ones that NASA’s program had been built on. Beside the Cosmic Origins Probe, there would be enough budgetary room for three other smaller missions, costing no more than a few hundred million European Currency Units (a predecessor to the euro used as a unit of accounting for pan-European organizations) each, and a single larger spacecraft, with a less well-defined cost cap that might reach as high a billion ECUs.
With the limitations of politics and finance clear, the initiative returned to the scientists, who now had to decide which of the many proposals that had been developed over the past several years would fly. There was, as ever, no shortage of attractive missions, with proposals ranging from Mercury orbiters to Pluto flybys, and from outwards-looking radio telescopes to Sun-observing gamma ray observatories to decide between. Guided by the Cosmos 2010 scientific program, however, over the next several years the European scientific community was able to boil the mass of paper missions into just the right number of, if not quite artifacts of aluminium and composites ready to fly into space just yet, then at least better-realized spacecraft ready for construction.
First on the list, and taking the large mission slot, would be the Solar Probe, a spacecraft designed to achieve, or at least approach, the by-now decades old mission of reaching the Sun itself. Flagship of Living Sun, the Solar Probe would, after a series of Venus flybys, eventually pass through the solar corona just 6,000,000 kilometers above the Sun’s photosphere, where solar radiation would heat it to a blistering 1,400 degrees Celsius, affording the first direct look at the region of the solar atmosphere where the solar wind is accelerated into the rest of the solar system. By exploring this region of the solar atmosphere, scientists hoped to crystallize theoretical speculation on the origins of the corona’s extreme and unusual temperature, and the solar wind itself, helping to better understand the flow of material outwards from the Sun and, perhaps, the solar flares and coronal mass ejections that could affect life on Earth.
Although an ambitious leap forwards by the European space program, ESA was perhaps the best placed of the International Solar Program partners to carry out such a mission, with its experience building and operating the Helios 1, 2, and Encke spacecraft in the 1970s and early 1980s. While far less ambitious than Solar Probe, with perihelions barely inside Mercury’s orbit, they were still the closest any previous spacecraft had come to the solar furnace, affording valuable practical experience in the challenges faced by close-in operation. By taking advantage of advances in technology during the 1980s and 1990s, in particular high-temperature materials to protect the spacecraft from the blazing fury of the Sun and powerful computers to calculate possible gravitational assist trajectories, the Solar Probe spacecraft would be able to approach much closer than the Helios probes possibly could have, without requiring an impractically large launch vehicle or difficult Jupiter flyby (and the use of expensive radioisotope thermal generators), while the relatively narrow focus of the mission on particles and fields experiments would keep costs down compared to more widely-ranging NASA proposals that also would have delved into optical observations and gravitational research.
Complementing the Solar Probe would be the Solar Composition Probe, a mission to collect material from the solar wind and return it to Earth. By greatly improving knowledge of solar composition, it would not only allow for better understanding of the behavior of the Sun itself, but greater insight into the differences between the primordial material of the solar nebula and the modern solar system, and hence into how the solar system evolved--a topic of rapidly increasing scientific interest given the recent discovery of the first extrasolar planets orbiting ordinary stars. By appealing simultaneously to two of Cosmos 2010’s tracks, the Solar Composition Probe won considerable support and easy acceptance as one of ESA’s smaller missions, especially given the relative technical simplicity of resting in space and collecting material blowing past on a solar breeze.
Just as the Solar Composition Probe would complement the Solar Probe in its efforts to explore the solar corona, so the Far-InfraRed and Sub-millimetere Space Telescope would go hand-in-glove with the Cosmic Origins Probe in unraveling the beginnings of the universe. By pushing the limits of cryogenic detector technology, FIRST would be the first space telescope to cover the far infrared and submillimeter bands that the coldest objects in the universe, like nebulae collapsing into protostars or galaxies on the cusp of formation, radiate in, allowing FIRST to explore the composition of some of the oldest and youngest objects anywhere. A direct descendent of an identically-named predecessor that had been proposed during the creation of Vision 2000, the relative technical immaturity of the necessary technology had led to FIRST being delayed while research was carried out to prove the basic design concepts. With those results in hand and verifying the concept, the Cosmos 2010 planners were as enthusiastic about moving FIRST into the list of approved missions as they had been a few years earlier about the Cosmic Origins Probe, making it an easy approval.
Rounding out the list of new scientific missions would be Ceres Orbiter, an unambitious yet scientifically valuable mission that would build on the legacy of Piazzi and explore one of the last of the solar system’s protoplanets. While Piazzi had been unable to visit the largest of the asteroids thanks to celestial mechanics, continuing Earth-based observations had kept it a puzzle, showing an apparently water-rich and relatively undisturbed composition, similar to what it might have had at the formation of the solar system. Given the extensive chemical and geophysical changes that had taken place on Vesta, a smaller body, since its formation (as revealed by Piazzi during its visit in 1995), it seemed strange that the larger and only slightly more distant from the Sun Ceres would have remained in its primordial state. Therefore, many scientists were eager to explore Ceres and try to determine why Ceres and Vesta had ended up so different after four and a half billion years of evolution in a similar environment and coming from a similar starting point. Finally, just as the howardite-eucrite-diogenite meteorites had originated on Vesta, it was hoped that other meteorites in Earth’s collections might ultimately be pieces of Ceres launched into space by ancient impacts. Although the spectroscopic evidence that had led scientists to suspect the Vestan origin of the howardite-eucrite-diogenites even before Piazzi’s launch was lacking in the case of Ceres, there were plausible explanations for this, and it was far from unreasonable that observations might simply have missed the points of origin for as-yet unknown Cerean meteorites.
As the machinery of mission selection worked, however, construction of the Cosmic Origins Probe was underway across Europe, with instruments and support equipment flowing to the integration center in Germany as technical issues were debugged, performance goals were reached, and hardware was built. The greatest struggle faced by engineers was keeping the probe’s weight down, in order to keep it within the payload envelope of the planned Europa 50a launch vehicle, with significant efforts being undertaken to keep the probe’s mass within that rocket’s approximately one-ton capacity to its operational orbit around the second Sun-Earth Lagrangian point, SEL-2. By late 1999, just over four years after it had initially been selected, the spacecraft had reached French Guiana, where a last round of tests awaited before it was loaded with liquid helium and mounted onto its Europa booster. Ironically, earlier in the year the decision had been made to “trade up” to the more powerful Europa 52, rendering the weight-trimming efforts of the probe’s engineers pointless. Along the way, it had also gained a proper name, Georges Lemaître, after the Belgian physicist who had first proposed the idea of the Big Bang his namesake was about to investigate. After a series of delays caused by poor weather and minor technical glitches, Georges Lemaître finally lifted off from Kourou early in the new year, followed by a flawless injection into its initial trans-lunar trajectory later in the day. During the lunar flyby, the spacecraft itself executed another burn, putting itself on its final trans-SEL-2 trajectory. For the next few months, as it slowly cruised for SEL-2, the spacecraft began cooling down its primary instruments and carrying out calibration and engineering checks, so that once it entered its circum-SEL-2 orbit in March it was fully checked out and ready to begin observation, looking outwards to observe the faint ripples of the Universe’s beginnings.
Over the course of the next year, the spacecraft built up its first all-sky map, with scientists on the ground carefully removing the far brighter signature of nearby objects before announcing, in the middle of 2001, the results of the probe’s primary mission. As expected, it had confirmed the RELIKT result with flying colors, agreeing with the new generation of ultra-sensitive Earth-based instruments that there was, indeed, significant anisotropy in the cosmic microwave background. More than that, however, the scientists behind the spacecraft were able to compare its results to those of the newest generation of cosmological theories, mathematical constructs that aimed to predict nothing less than the evolution of the universe itself. After careful analysis, the best match went to the new but popular “C2CDM,” or “Cosmological Constant-Cold Dark Matter” hypothesis, which had been proposed only a few years earlier to explain the apparent acceleration of the expansion of the universe. Besides the by this point standard idea that the bulk of the universe’s matter is in the form of “cold,” or slow-moving, invisible “dark” matter, C2CDM adds the theory that the universe is pervaded by an invisible and nearly undetectable “dark energy” field that slightly modifies Einstein’s field equations, introducing the “cosmological constant” of its name and causing a gradual acceleration in the universe’s rate of expansion. Compared to alternate theories like quintessence or modified Newtonian dynamics, C2CDM seemed to have a better fit with Georges Lemaître’s observational data, especially when supplemented with other observations, both of the cosmic microwave background and of other aspects of the universe. Beyond cosmology, other areas of science also benefited from the spacecraft’s data. Particle physicists, in particular, learned that there did not seem to be a fourth kind, or “flavor” of neutrino in the universe, with the data instead favoring the existence of only the three types that had been observed in the laboratory. Although not enough to rule out the existence of a fourth neutrino “flavor,” it showed that astronomical observations could still inform terrestrial science just as well as the opposite.
Even before the publication of its first batch of results, the spacecraft had already earned an indefinite mission extension on the back of its still-good condition, lower than expected consumption of liquid helium, and the scientific value of further data in refining the probe’s results. For four and a half more years, Georges Lemaître continued to scan the skies, building up four more full all-sky maps and about a quarter of a sixth, before it finally exhausted its helium supply. While they did not have the impact of its first data release, the annual corrections and updates issued by the Lemaître team using this additional data continually refined and improved Lemaître’s measurements of key cosmological parameters, greatly narrowing the scope of permissible theories of physical cosmology and providing additional support for the C2CDM model. Once the probe exhausted its liquid helium supply, a brief additional engineering mission was undertaken to observe how the performance characteristics of its instruments changed as they heated back up, then it executed a final burn to throw itself away from SEL-2 and into a heliocentric graveyard orbit, before being remotely shut down in April 2006, just shy of five and a half years after launch.
As Georges Lemaître was shutting down, however, Solar Probe--now named Aristarchus, after the Greek philosopher who was the first person in history to propose a heliocentric cosmos--was just getting started. Originally (and optimistically) planned for a launch in 2002, just six years after approval, it had been slipped first to 2004, then on to 2005, driven by the severe difficulties encountered by its French builders in pushing the state-of-the-art in thermal protection systems and high-temperature solar cells. Multiple shield designs failed under the rigorous inspection of the Haute Température Installation d'Essai, or High Temperature Test Facility, a new installation built on the outskirts of the spacecraft’s manufacturing plant, stressed beyond their limits by the extreme temperatures the probe would encounter during its close solar passes, leading many to wonder if a less ambitious objective--passing just a bit farther away from the Sun--might not be all that was achievable. Nevertheless, the French persisted in their efforts, and by the originally planned launch date had come up with a sunshield built out of carbon-carbon, the same composite material used to make high-performance brake pads for race cars, which combined with a new and highly advanced reflective coating on its front face seemed able to protect the spacecraft from extremes of temperature that would be encountered during the close encounters.
With this crucial part of Aristarchus finally lined up, the rest of the spacecraft began quickly falling into place, such that by the middle of 2005 it was able to follow in its predecessor’s footsteps on the journey into space, traveling to French Guiana for a short layover and check-up before being mated to its Europa 54u launch vehicle for its ride into orbit in November. After an uneventful launch, its Aurore-B upper stage gave it the final push needed on its way to Venus, which it reached after a cruise mostly consumed by instrument check-out and deployment just before the end of the year, swinging past in its first perihelion-lowering pass. In early February, just as Lemaître was being decommissioned, Aristarchus finally reached its first perihelion, swinging past the Sun at an altitude of just 25,000,000 kilometers, handily breaking the record set by the Helios probes twenty years earlier. Although this pass was only a warm-up, well within the probe’s design enveloped, its operators were still relieved when it rose back out from the depths of its orbit, bearing a cargo of scientific data and none the worse for wear, as far as could be determined from Earth.
With no fatal flaws having shown themselves, Aristarchus was clear to continue its primary mission. Over the next several years, it dipped repeatedly within the orbit of Mercury, swinging closer and closer to the Sun as its encounters with Venus sapped its orbit’s energy bit by bit and allowed it to penetrate further and further into the Sun’s domain. As this was going on, scientists were poring over what data was returned on each orbit, combining it with the returns of the flock of remote sensing spacecraft around and near Earth to build a new picture of the Sun’s behavior. As had often been the case in the space age, the new information provided by Aristarchus both confirmed and challenged old concepts and theories; for example, although it quietly provided updated information for helioscientists seeking to predict the evolution of the solar wind from near-solar regions out into interplanetary space, it also produced a major blow to those same scientists, providing strong evidence against the then-popular theory that the wind originates from intermittent, pulsed sources in the corona, a theory which also nicely explained a number of observations of structures in the solar wind near Earth and in the solar atmosphere. Instead, Aristarchus’ data seemed to favor a relatively steady, smooth outflow of plasma from the Sun’s atmosphere, punctuated by occasional outbursts of activity. Perhaps this was, as some suggested, merely the result of the slow decline in activity from the Sun as it descended towards a solar minimum, but at the least it sent many scientists back to their offices, considering how to incorporate Aristarchus’ observations into a new, stronger theory of solar behavior.
Besides Aristarchus, their work was also constrained by the samples returned several years earlier by the Solar Composition Probe. Operating under the far more benign conditions of near-Earth space, and with a relatively technically undemanding mission, it had taken just two years to go from approval in early 1997 to launch towards the end of summer 1999, barely nosing out Georges Lemaître to become the first of the Cosmos 2010 spacecraft to make it into space for its cruise to the first Sun-Earth Lagrangian point, on the opposite side of the Earth to Lemaître’s SEL-2 position. Once it reached the Lagrangian point and settled into its orbit among the other Sun-observing spacecraft stationed there, it opened wide, allowing the invisible wind of particles blowing past it to collect on its outspread “wings”. For the next several years it patiently waited, collecting pieces of the solar wind atom-by-atom, until in 2002, after nearly three years of operation, it closed up and began its return to the Earth, which it reached several weeks later.
Here began the most daunting and technically challenging phase of the mission. Due to the physics of ion deposition, the spacecraft’s solar wind collectors had had to be made thin--or, in other words, fragile. So fragile, as a matter of fact, that if the return capsule landed normally, without taking special precautions, they could be damaged or destroyed, ruining the probe’s scientific value and wasting tens of millions of euros (which since 1999 had replaced ECUs) in the process. A range of options had been explored to counterbalance this, from an elaborate mixed retrorocket-airbag system reminiscent of the old Soyuz landings that would cushion even the blow of a land landing to a daring aerial stunt capture that would have seen specially modified aircraft pull the capsule out of mid-air while still descending--a technique perfected by the United States in the 1960s and 1970s to recover similar capsules full of exposed spy satellite film, but never before tried in Europe--but ultimately the best option, or at least the one selected, had been to switch, at least for this one mission, to a water landing, combined with a retrorocket system similar to that of the Soyuz or Longxing capsules for reducing terminal velocity to nearly zero. Between the cushioning effect of the sea and the low impact velocity, it was hoped that there would be little, if any, damage, maximizing the probability of returning intact samples.
As such, when the Solar Collection Probe came streaking in over Earth’s sky, headed straight for the landing zone off of French Guiana, the mission’s scientists were holding their breath and wondering whether the complex braking system would work properly, even as French Navy helicopters and recovery teams were taking off to secure the capsule as quickly as possible following landing. Tensions dropped slightly when parachute deployment was confirmed by observers, but the real test wasn’t passed until the retros ignited, just a few moments before the sample capsule hit the water. With smoke billowing around it, the capsule slowed to a hover only meters above the sea’s surface, before they burned out and it fell the rest of the distance, dropping gently into the ocean. Within minutes, the recovery personnel had winched the capsule aboard one of the helicopters detailed to support the recovery, and within hours it, along with the precious samples contained within, was traveling across the Atlantic for the Extraterrestrial Curation Facility in London. There, scientists began the careful and delicate process of teasing out the captured ions from the wafers of silicon holding them, identifying their chemical species, and putting them together into an image of the Sun’s composition.
As expected, their results were not especially shocking or novel; the Sun’s composition had after all been an object of study for the past century and a half, ever since the invention of the spectroscope. Instead, the painstaking work of the next several years would be in refining, not overturning, that carefully gathered data from generations of astronomers. Combined with Aristarchus’ in-situ data, it provided information about both the initial and final conditions that any new model of the solar wind would need to match to correspond with reality. Perhaps more importantly, it served as a new base to model the chemical evolution of the solar nebula during the early stages of the solar system. Combined with new dynamical models of the system’s evolution developed using new, more powerful computers, the Solar Composition Probe’s data has helped give rise to the latest version of the standard solar system evolution model, and helped to develop general theories for the behavior of young solar systems.
While scientists in London were studying samples of the Sun, astronomers elsewhere on the continent were poring over the data coming in from FIRST, the last of the Cosmos 2010 spacecraft to launch, early in 2006. The delay was due less to technical difficulties than to budgetary priorities, given the limited amount of funding that each ESA member nation was willing to provide and the other budgetary priorities that the agency faced. Matters were not helped by the fact that, though of a relatively well-understood design, FIRST would nevertheless be a large, complex spacecraft, straining the budgetary limitations that Headquarters had set out for the Cosmos 2010 program. Combining a large, cryogenically cooled mirror and sophisticated scientific instruments on a budget drew out spacecraft development over nearly a decade, leaving FIRST to slowly come together. Despite fears that it might end up being scooped, no competition materialized and FIRST was smoothly lifted by a Europa rocket towards its operational orbit around SEL-2. Initial commissioning tests soon showed that all of the spacecraft’s instruments were working as planned, and it settled into a steady routine of observations, gathering spectra and images of targets ranging from galaxies to the dusty nebulae surrounding still-forming stars until it ran out of cryocoolant in late 2009, after three and a half years of operation.
During its observations, FIRST greatly extended and refined observations of the molecular and chemical structure of interstellar and circumstellar objects, showing that many simple biological molecules are common in interstellar gas clouds such as the Orion Nebula and helping, like the Solar Composition Probe, to set new limits on the conditions that new stars face as they are born. Its long-wavelength capability and orbital position also gave it the valuable capability of tracking water, a common and important molecule, but hard to detect from Earth through our water-logged atmosphere. By detecting the spectral signature of water in balls of gas and dust on the cusp of collapsing into new star systems, in debris disks surrounding young stars, and even in our own solar system, supporting Ceres Orbiter and Cassini in their exploration of the minor planet and Saturn, respectively, FIRST was able to improve the scientific understanding of how water behaves during stellar formation, much like its other observations assisted in the construction of new models of stellar formation. It also helped support observations by Ceres Orbiter and Cassini of water emissions--geysers--from Ceres and Enceladus, respectively, providing an additional capability to track the movement of water from those bodies through the space around them. Finally, FIRST’s sensitivity to emissions in the far-infrared allowed it to make the first observations of the cosmic galaxy background, the most distant and ancient galaxies visible from Earth, penetrating the veils of dust and extreme redshifts that had prevented them from previously being visible and providing the first information on these most ancient structures.
Last but not least, the first decade of the 21st century also saw Ceres Orbiter leave Earth for its destination, the largest of the asteroids. Ceres Orbiter was designed to build on its predecessor Piazzi, extending the latter’s admittedly limited survey of the asteroid belt to another, unusual object, one that besides being one of the asteroids appeared to be one of the last protoplanets, a type of planetary body intermediate between the minor planets and full-fledged planets, but mostly consumed during the process of planetary formation. Due to the gravitational influence of Jupiter, those protoplanets which had formed in the asteroid belt--Ceres, Vesta, Pallas, and perhaps others--had never had the chance to aggregate into planets, leaving them exposed to remote observation and opening the way for an investigation into the crucial but brief period of the solar system’s history where protoplanets were forming and merging. Although previously interesting, of course, this question had taken on new urgency since the discovery in the mid-1990s of the first planets around other stars, causing a tremendous upswing in interest in planetary formation and the dynamics of early solar systems and protoplanetary discs.
Compared to the rocky and relatively dry Vesta, which Piazzi had visited, observations had shown that Ceres was wet and rich in volatile materials, more similar to the C-type asteroids 313 Chaldaea and 415 Palatia, which Piazzi had flown past in 1996 and 1997, respectively, or 449 Hamburga, which it had reached in 1998, or to the Galilean moons of Jupiter that Galileo had observed than to Vesta. However, Chaldaea, Palatia, and Hamburga had been too small for their own gravity to pull them into a spherical shape, or for their internal heat to result in differentiation--the separation of the rock and ice within them into distinct layers based on their density. By contrast, the Galilean moons were so large that they were essentially planets, with all the same geological complexities and foibles. By investigating Ceres, just large enough that it had probably differentiated like Vesta but not so large or near a source of tidal energy that it had likely had much internal activity since its formation, scientists would extend the observations of Piazzi to new types of object, more similar to what proto-gas giants or the Galilean moons might have looked like early in their history.
The design of Ceres Orbiter was based on a scaled-down version of the Piazzi bus, taking advantage of the development of so-called “electric” satellite busses in the decade since its development to speed development and cut costs. Although a ballistic mode had been considered, since the spacecraft was only intended to visit a single asteroid instead of conducting a Piazzi-like tour, analysis of the electric versus ballistic modes showed that ballistic spacecraft would require larger retro and trans-Cerean injection stages than electric rockets, in turn requiring the use of larger, more costly launch vehicles. By contrast, an electric spacecraft could be launched on a Europa 50a, saving tens of millions of euros.
Thus, after Ceres Orbiter--now named Gauss, after the mathematician and scientist, who had played an important role in early asteroidal studies, in particular by calculating the orbits of several of the first asteroids to be discovered--was lifted into space and thrown onto an escape trajectory in mid-2003, it quietly unfurled its solar panels and began thrusting away from Earth, gradually building up speed and raising its inclination over the next several years to match with Ceres’ orbit. By late 2005, after nearly two and a half years of thrusting, Gauss was closing in on Ceres, and early in the new year was able to settle into a stable, low orbit around the body. In conjunction with occasional observations from FIRST as it finished commissioning, Gauss quickly plunged into detailed observations of the body. Besides a high-resolution visible light camera for mapping the asteroid, Gauss carried an array of spectrometers for measuring the composition and mineralogy of its surface in significant detail and a laser altimeter for precisely measuring its topography and shape. Together with FIRST’s instruments, this added up to an impressive scientific payload for ferreting out all but the minutest details of the protoplanet.
The first task of this payload was to begin studying Cerean surface geography, especially in comparison to the crude surface maps that had produced over the past twenty years from Earth-based observations. Although many of the features “detected” by those instruments proved to be illusory or amalgamations of multiple nearby structures, a few--in particular, the giant dark spot that had been named “Piazzi” after the asteroid’s discoverer--stood up to scrutiny, in most cases proving to be large impact craters. As with most bodies in the Solar System, craters defined Ceres’ surface, creating a rugged terrain marked by overlapping crater walls, with only the rare relatively unmarked interior or a handful of mysterious flat plains remaining relatively untouched. The greatest of these craters was Piazzi itself, as had been theorized before the probe’s arrival, a giant of a crater that rivaled some of those on Vesta for depth, and appeared to reach to the boundary of the protoplanet’s mantle. As on Vesta, or in the Moon’s South Pole-Aitken Basin, this offered the exciting possibility of observing material from deeper within the asteroid than could possibly have been reached otherwise, and the probe’s observation program was duly modified to put more priority on observing Piazzi early and often.
Interest in the region was only magnified by the discovery by FIRST during supporting operations of significant amounts of water and water byproducts in near-Ceres space above several specific locations on the surface, in particular one of the dark spots observed along with Piazzi. The obvious explanation for these gases being present, and one that came to mind readily for anyone who had noticed the discovery of ice crystals in the lunar regolith during Artemis 9 the previous year, was that there was some subsurface ice source, slowly sublimating away as the regolith heated up during the day, a conclusion supported by the observation of bright spots at the bottom of several particularly deep craters, spots which turned out to be made mostly of water ice. A few quick calculations indicated that even a fairly thick solid layer of ice under the surface would be depleted entirely in a geologically short period of time, far less than the the length of time since the asteroid’s formation. Hence, scientists concluded, there had to be a source: geological activity continually bringing ice from some deep subsurface reservoir closer to the surface where it could sublimate and escape into the thin Cerean atmosphere. The most popular theory posits a nearly continuous layer of ice deep under the rocky Cerean surface, slowly churning upwards due to its lower density like lava on Earth, but minority views hold that part of the reservoir, perhaps even the majority, could be liquid, a solution of water and ammonia that could stay fluid even at extremely low temperatures.
In light of these discoveries, Gauss’ observation program was further modified; although the spacecraft had not been designed for gravity measurements, careful tracking of the signal from the probe to its receiving antennas on Earth could allow at least a crude measurement of the gravity anomaly and perhaps even the gravity gradient, providing a simplistic map of the protoplanet’s structure; additionally, careful measurements might be able to detect changes in the speed of Ceres’ rotation stemming from the outer crust and inner core being coupled through a fluid instead of solid rock. Unfortunately, both measurements were inconclusive, giving results that were consistent with either model. Many scientists lamented the lack of a magnetometer, an instrument that had been planned but omitted in a cost and mass-saving effort; had it been present, the magnetic field that would have been induced by movement through the solar magnetic field in the probably salty ocean might have been detectable, a sure signature of whether or not an ocean was present.
Besides these ice-related measurements, Gauss also examined the composition of the surface in fine detail, showing it to mostly resemble the C-type asteroids that Piazzi had visited, as expected. As had been hoped, a few meteorites--a handful of the carbonaceous chondrites that had been discovered over the past few centuries--were found to match the composition of specific locations on the Cerean surface, and thus to have most likely come from its surface. Even more interestingly, observations also confirmed that minerals such as carbonates and brucites that are believed to only form in the presence of water could be found on Ceres’ surface. Although this was seized on by advocates of the ocean model as supporting their theory, opponents pointed out that several alternative explanations, none of which needed Ceres to be partially melted, could be advanced, leaving the situation confused.
By the time Gauss was nearing the end of its first Cerean year in 2011, work on the successor program to Cosmos 2010 was well underway, with the first missions already in space and returning data. Buoyed by the successes of the Cosmos 2010 and Vision 2000 strategic plans, when European scientists and engineers began meeting in 2003 and 2004 to begin charting out ESA’s next scientific program--now modified to incorporate Earth science and therefore to bring all of ESA’s scientific activities under a single overarching strategic plan--they saw little reason to change what had been a winning formula. Drawing on the rapid discovery of new extrasolar planets, beginning with 70 Virginis b in 1996, and the recent reinstitution of the so-called “cosmological constant” to cosmological models from Georges Lemaître data and ground-based observations indicating an apparent acceleration in the rate of the universe’s expansion, they developed a program containing four distinct scientific tracks.
The first, “Dark Universe,” would seek to investigate dark matter and the cosmological constant, or dark energy, which together appeared to make up the vast majority of the universe’s mass-energy content, and about which very little was or is known except through indirect observations. Moving to a topic slightly closer Earth in time and space, the second track, “Planetary Universe,” would mark a major push to discover and, hopefully, characterize extrasolar planets, or exoplanets, on a massive scale, expanding catalogs of hundreds of discoveries to thousands or tens of thousands, and answering the question of whether the Solar System, and in particular Earth, were “normal” or, somehow, strange and unusual among planetary systems, something that was feared from the proportion of so-called “hot Jupiters” and planets in highly elliptical orbits that had been discovered by that time. Of course, the greatest discovery would be learning that one of these planets supported--or supports--life, the dream of thinkers for centuries. To investigate this possibility, there was the “Living Universe” track, aimed at discovering whether any extrasolar planets might support life through characterizing (and, perhaps, discovering life in) potential habitable environments in the Solar System. Finally, there was “Human Universe,” a program aimed at directly applying space technology to Earth’s problems.
Each of these tracks was designed to support both a larger, so-called “flagship” mission and smaller, supporting missions, another sign of the expansion of ESA’s ambitions. Much as with Cosmos 2010 a decade earlier, by the time Universe 2020 was approved strong candidate proposals had already been developed for each track, both for flagships and supporting missions, and soon the program had been fleshed out and finalized. Leading the Dark Universe track is Eddington, a mission designed to scan a large region of the sky for so-called “weak gravitational lensing” events, a method of statistically measuring the mass of objects in the universe by tracking the distortion they cause as an effect of Einstein’s general theory of relativity on background light sources, named after the British astrophysicist who was one of the first and strongest proponents of the theory, and who organized an expedition to detect lensing caused by the Sun in 1919. Through Eddington’s survey, scientists are creating a map of the dark matter content of the universe, and study how it associates with “light,” or baryonic matter, as well as how it changes over time in conjunction with spectroscopic data to identify redshifts, and collaborative observations with other telescopes. Launched in 2012 after five years of development, Eddington has already significantly improved models of dark matter distributions, in particular by discovering several clusters where mass concentrations, as revealed by the lensing events, and baryon concentrations, as shown by conventional observations, have separated during inter-cluster interactions, strong evidence for dark matter models as against modified dynamics alternatives. It is expected that once the full survey is completed in the next several years, that a map associating baryonic and dark matter through a wide volume and far back in time will be completed, allowing the next generation of telescopes to conduct a more focused study. 2009’s Wide Field Gamma Telescope is also supporting this track, both by searching for possible signs of dark matter-dark matter interactions and by helping to characterize the properties of potential confounders, like quasars, black holes, and neutron stars.
Leading the Planetary Universe track, Giordano Bruno, launched only a few months ago, is expected to revolutionize exoplanetary astronomy through its industrial-scale approach to planet detection. By using an array of small telescopes, Bruno will be able to scan an enormous field of well over 1,000 square degrees continuously for tiny brightness fluctuations caused by the passage of planets in front of stars--planetary transits. While dependent on the chance alignment of the star’s ecliptic plane and Earth, it is one of the best methods of planetary detection presently available, and, based on the results of NASA’s EPIC mission last decade, will allow the discovery of a truly massive planetary sample, enough to allow scientists to start drawing statistical conclusions about planetary properties. Planetary candidates from Bruno, once it begins its observational phase, are expected to be premiere targets for NASA’s Spitzer Space Telescope and the next generation of ground-based megatelescopes. Bruno’s photometric capabilities will also be used to support a search for microlensing candidates in the data and research into asteroseismology, the study of stellar interiors through surface oscillations much like earthquakes.
The first independent ESA outer planets mission, Herschel, was selected in 2006 to lead the Living Universe track, designed to take advantage of Cassini’s discovery of massive plumes of water erupting from Saturn’s moon Enceladus to conduct a relatively cheap yet capable mission that may be the first to indicate life on another celestial body. By avoiding the need to operate in powerful radiation belts like those around Jupiter’s moon Europa, Herschel will be far simpler and cheaper to design than a Europa spacecraft, while the powerful eruptions from Enceladus’ south pole carry water, possibly laced with organic compounds, into space for easy capture and analysis compared to Mars or Titan-bound missions. As Saturn orbits ten times farther away from the Sun as Earth, making solar power generation difficult and nigh-impractical, Herschel will also be the second European mission to use radioisotope thermal generators, and the first to use European-designed and built versions. Using a novel design using americium-241--the isotope used in smoke detectors around the world--instead of the plutonium-238 used in American designs, the European Common RTG marks a major advance in ESA capabilities. Unfortunately, it has also suffered technical difficulties, and the probe has recently been delayed from an originally scheduled 2015 launch date to 2018 due to problems experienced by France’s Commissariat à l'Énergie Atomique and Britain’s National Nuclear Laboratory in safely manufacturing and assembling the spacecraft’s fuel elements. Besides this major mission, the Mars Rare Gas Orbiter, launched in 2013 and only recently having reached Mars, is intended to investigate data from NASA’s MACO mission indicating the presence of a small amount of methane in Mars’ atmosphere, a possible sign of life.
Finally, the Human Universe track is being led by the Earth Observation System, a collection of satellites from multiple countries intended to work in concert to study all aspects of Earth’s environment, from core to crust and beyond. Consisting not of a single mission but of multiple smaller ones designed to work together, it is hoped that the EOS will provide unprecedented, nearly-continuous data on a wide variety of phenomena, ranging from global rainfall measurements to the slow movement of magma in the Earth’s interior to a precision map of global carbon dioxide emissions and absorptions, revolutionizing climate science. Multiple spacecraft from ESA, CNES, ASI, NASA, JAXA, and ISRO have already been launched under the EOS banner, and data is being incorporated from Chinese and Russian missions as well. In support of this track, ESA has been encouraging applications research in its Freedom research programs and in proposals for its portion of Orion lunar surface time, besides its other research programs.
Looking ahead, the next phase of ESA’s science program--its strategic plan to 2030--is already under construction, with discussions taking place on what scientific goals seem most relevant for the next decade. Beyond Herschel, there could be missions to Titan or even past Saturn, to Uranus or Neptune, in either case performing significant fundamental planetology, while further research into dark matter--especially if ongoing direct detection experiments yield a signal--or the cosmological constant promise potentially exciting results. Gravitational waves, the subject of an impressive number of paper studies by ESA, NASA, and JAXA over the years, could also be a major focus of a new mission. And, if Bruno finds an Earth-sized planet not too close and not too far from a star of the right size, and it is confirmed...or better yet, discovered to have an oxygenated atmosphere...Nothing is yet set in stone, and whatever occurs, the next decade is sure to be an exciting and productive one.
Twice over. Piazzi, which we saw in Part III, was a multi-asteroid probe that visited Vesta as part of its mission. That would be a better analogue to Dawn than this spacecraft, which is very Ceres-focused.
ESA's been busy with the unmanned probes (and dealing with all the issues that arise from financing and developing them) and I noticed that Bruno (telescope) is using a number of small telescopes to find candidate Earth-like Planets, I'll assume they're fixed to the same basic platform to make keeping them in place a lot easier.
I see the use of present tense, particularly towards the end of this Post.
I see the use of present tense, particularly towards the end of this Post.
Bruno is basically a clone of PLATO or TESS, so yes. They're very small telescopes, so they don't take up a large amount of room.
I also had to modify this one after Dawn got to Ceres to add the bright spots
We'll see if those are water ice or not...I was puzzled not to see a Ceres lander included in the 2030 wish list. I actually was frustrated Gauss did not already include, along with its "mothership" main body, a lander not unlike the one that bounced around Phobos earlier in the timeline. Looking up and comparing the escape velocities of the two bodies I see Ceres is a different order of magnitude of problem in approaching, landing on and moving about on, having an escape velocity of 510 m/sec compared to Phobos's and surface gravity of 28 cm/sec^2 compared to Phobos's .6.
Still, landing there from a close orbit should take no more than 12 percent of the mass of a craft using a rocket thruster with an ISP in the ballpark of 300, such as hypergolic propellants could give. It would even be possible to pick up samples and return to the orbiting bus with less than a third of the total lander mass being propellant; I'd think making a wheeled or alternately hopping lander would allow mission controllers to choose from a wide variety of terrain near the initial landing zone, itself chosen by them for good opportunities. I'm thinking maybe 100 kg for the whole thing.
There's no sense in sample return if the main probe is not going to return to Earth orbit from Ceres, of course and I don't suppose Gauss was designed to do that.
All the more reason then to expect a Ceres lander on the 2030 wish list.
Unless the reasoning is that by then there surely would be a human-crewed mission to Ceres.
Still, landing there from a close orbit should take no more than 12 percent of the mass of a craft using a rocket thruster with an ISP in the ballpark of 300, such as hypergolic propellants could give. It would even be possible to pick up samples and return to the orbiting bus with less than a third of the total lander mass being propellant; I'd think making a wheeled or alternately hopping lander would allow mission controllers to choose from a wide variety of terrain near the initial landing zone, itself chosen by them for good opportunities. I'm thinking maybe 100 kg for the whole thing.
There's no sense in sample return if the main probe is not going to return to Earth orbit from Ceres, of course and I don't suppose Gauss was designed to do that.
All the more reason then to expect a Ceres lander on the 2030 wish list.
Unless the reasoning is that by then there surely would be a human-crewed mission to Ceres.
Morning all. For this week's image we take a look at the Georges Lemaître space probe.
Well, I never said they weren't studying a Ceres lander for the next strategic plan. But the process is against returning to Ceres quite so soon, given that ESA has to accommodate the interests of scientists who want to launch other spacecraft to other places. Especially since ESA (unlike NASA) has a unified system for astronomical and planetary science missions, so that they end up competing for funding.
Basically, scientists who want to land on Ceres are going to have to wait their turn, which probably means waiting until after 2030. Ceres is interesting, but it's not a huge priority the way, say, a life-bearing Mars or Europa or Enceladus would be. It's not like it's going anywhere.
100 kg is probably an underestimate, considering that Huygens, a rather minimal lander, weight around that (discounting the heat shield and parachute, of course). A lander would be pretty heavy, which would mean that the whole spacecraft would have to bump up a class or two of launchers and have an upgraded ion propulsion system.
In any case, Gauss was far too early to be thinking about a Ceres lander. The trouble you're not accounting for is that you need to be able to decide where to land before anyone is actually going to go along with the idea of putting a lander up, because otherwise you could end up traveling all the way to Ceres only to find that your lander costing hundreds of millions of Euros has some fatal design flaw for the circumstances it has to deal with. You need an orbiter, or at least a close flyby mission, to provide an initial site reconnaissance before you can even think about landing anywhere.
Additionally, Gauss was specifically chosen because it was a cheap but scientifically useful mission--an S-class mission, in OTL ESA parlance. Adding a lander would have destroyed this case for the spacecraft and quite probably pushed it outside of the desired budget box.
No, of course not. It would have entailed a fair amount of extra expense for no real purpose.
Morning all. For this week's image we take a look at the Georges Lemaître space probe.
Nice work, as always, Nixon.
Part IV, Post 17: Orion Expedition 1
Good evening, everyone! This week, I'm pleased to bring you a special treat. Today, we're finally following the crew of Orion Expedition 1 on their way to their mission in the first semi-permanent outpost on the Moon. However, Workable Goblin and I wanted to make sure you all could get a feel for life onboard the outpost and make it more than "just another mission," so we turned to someone who's a past contributor to the TL, and better with narrative writing than seems quite fair given his other talents. Today's post is thus brought to you by none other than nixonshead, and I hope you'll all enjoy this as much as I did!
Eyes Turned Skyward, Part IV: Post #17
This is it!
Edward Boxall, ESA astronaut, moved his booted left foot down to the final rung of the ladder and leaned backwards. Above him, the bulk of Clarke’s Descent Stage loomed brightly, contrasted against the black sky. No starlight made it through the layer of golf filter on his helmet visor, and the Earth, huddling close to the polar horizon, was hidden out of sight behind the lander.
Leaning to look downwards, Ed could see dark streaks in the grey gray lunar regolith where the lander’s rockets had exposed the underlying bedrock. Small stones scattered around the landing site cast long shadows in the almost horizontally slanting sunlight, whilst the bootprints of his crewmates looked like black holes in the world. Soon, his own bootprints would be joining them.
“Hey, Ed, you gonna join us today?”
Ed smiled at the voice of the Mission Science Officer, always adept at breaking the tension in any situation.
“On my way, Winch,” Ed called back over the radio. “Just one small step…”
Ed’s right foot pressed into the gritty surface, quickly followed by his left.
“For the people of the United Kingdom, the member nations of the European Space Agency and the world, may our mission here herald the beginning of a new phase of human exploration and habitation on our nearest neighbor.”
"One-two, one-two. How're you reading me, Anne?" Ed Boxall, the first British astronaut on the Moon, tapped the side of his Snoopy cap experimentally as he stood in his Thermal Control Garment next to ALES-1's suit lock.
"Loud and clear, Ed," Anne Holcomb confirmed from the other side of the room. "Are you getting me through your headphones?"
"Affirmative, I've got good reception," Ed reported. "How about you, Phil?"
Mission Commander Phil Whitt, similarly attired to Ed, gave a thumbs up as he replied. "Also a good signal. Let's hope it's just as good at a range greater than five feet!"
"Anne and I had no problems yesterday," Mission Science Officer Winchell Chung told the pair. "It got a little scratchy when relaying through Mesyat, but line-of-sight was clear as a bell. In any case, you're not going far today, so if you run into any problems just wave at a camera and we can come get you."
On the communications workstation, Holcomb double-checked her read-out before reporting in to Mission Control. "Houston, Orion. Please confirm you have good Alice-1 and -2 comms relay, over." Following a brief but noticeable lightspeed delay, the voice of Capcom came back through both the console speakers and Boxall's and Whitt's headsets: "Orion, Houston, that's a roger on our side, we have good signal on both Phil and Ed. You have a go for EVA at your leisure."
"Okay guys, time to get your shells on," said Chung. "Just like in training, you trigger the hatches and I'll confirm the seal before you undock, okay?"
"No problem," said Whitt as he grabbed the handhold above the suitlock hatch and swung his legs into the waiting suit. Ed followed suit, easily managing to lift himself into position in the 1/6th gravity of the Moon. Like Phil, Ed slid in legs first through the open backpack of the Articulated Lunar Excursion Suit, slipping into the suit's legs before pulling in his arms and pushing them through the holes in front of him until his fingers hit the ends of the gloves. "This reminds me of putting my son into his romper suit when he was a toddler," Ed commented as he pulled his torso and head fully into the suit.
"You don't squirm around half as much as my daughter did when I tried to dress her!" Chung replied. "Okay, Phil, you look good in there. Go ahead and close the backpack."
"Okay Winch," Phil responded. Ed heard a few clicks through the open back of his suit, but otherwise just hung in place waiting for Phil to get to him. With the protective cover still over ALES-2's helmet, there wasn't even a view to enjoy yet. As he waited, Ed started to hum randomly.
"Jeez, Ed, you didn't take that blasted kazoo into the suit did you?" came Holcomb's plaintive question.
Ed laughed. "No, that's pure Edward Boxall, unplugged!"
"You'd better not have anything unplugged," Chung put in. "Otherwise this EVA is liable to be scrubbed". The American astronaut was now behind Ed in the cabin. "Nope, looks like you're all wired up as you should be. Ready for seal?"
"Ready," replied Ed. He triggered the closure mechanism, and with a quiet "thunk!" the background noises of the Orion cabin, which Ed hadn't even noticed up to now, abruptly ceased. Alone in the dark, with just the low whirl of the helmet fan, Ed was unpleasantly reminded of the sensory deprivation tests he'd undergone at Cologne when he'd first been selected as an astronaut. This time though, the silence didn't last long as Holcomb's voice came through his headphones: "Alice-1, Alice-2, Orion. Comms check."
"Alice-1 comms okay," came Whitt's voice, before Ed responded "Alice-2, comms are good."
"Okay guys," Holcomb replied, "It's all looking good from here. Lift up your dust covers and stand by for undock.
"Roger, lifting cover now" Ed reported as he slowly moved the stiff, unresponsive arms of his moonsuit to bring his gloved right hand up to the fabric covering over his helmet. Moving carefully in the unfamiliar suit, he pushed wire hoop attached to the cover upwards and looked out upon the harsh, raw beauty of the lunar surface. Just as it had on his earlier EVAs in the old pressure suits, the view took his breath away, and he sent up a silent prayer of thanks to God that he was lucky enough to be alive at a time when such miracles were possible that he could walk upon the Moon.
"Visual on Alice-2," came Whitt's voice through the radio, and Ed turned his head to see Phil's suit clinging by its backpack to the cabin wall next to him. Whitt's sun visor was down, so Ed couldn't make out his face, but the other astronaut gave him a cheery wave of recognition. Ed returned the wave. "Hi Phil, fancy meeting you here. It's a small world, eh?"
"Smaller than Earth, that's for sure!"
Just then Holcomb's voice broke in over the radio. "If you two have finished your comedy routine, we’ve confirmed a good seal on our side. You can undock when you’re ready."
"Thanks, Anne," Whitt replied. "Alice-1 undocking... now!"
Ed watched as Whitt's suit jerked forward, the rear half of his backpack emerging from the recessed suitlock as he held on to the twin railings either side of him for balance. "I have a good separation," Whitt told Holcomb. "I'm free standing on the platform."
"Roger, Phil. Ed, ready to go for Alice-2 undock."
“Roger.” Ed forced the stiff gloves of his suit to grip the side rails and pulled sharply forward. There was a brief resistance and a loud click as the backpack disconnected from its berth. “I’m out,” Ed called through the radio. Wow, I really am, he reminded himself. Outside on the Moon...
Standing at the edge of the platform that topped Orion’s descent module, Ed looked out across the bleak landscape in awe. If he leaned over the railing and looked downwards (something that was much easier in his articulated Turtle-suit than it would have been in the old A9L), he could see the scars where the base’s descent had disturbed the top layer surface dust. A tangle of footprints and wheel tracks surrounded the lander, along with various boxes and equipment unpacked by Holcomb and Chung on their previous EVA, but out beyond a couple of hundred meters the ground was undisturbed. Primordial. Where no man has gone before...
“Hey, Anne,” Whitt’s voice came over the radio. “Kill the lights for a second, will ya?”.
“What’s that?” Ed asked nervously, tightening his grip on the handrail.
“I just want to try something out,” came the commander’s enigmatic reply.
“Okay, Phil,” Anne called from inside. “Shutting down the floods now.”
As the hab’s external lights winked out, Ed found himself plunged into darkness. Both the sun and the Earth, neither of which ever rose more than a few degrees above the horizon here, were on the other side of the hab, so the only natural light was that reflected from the dusty surface of Shackleton Crater’s rim. Ed moved to switch on his helmet lamp, but Whitt said “Hold on a second. Push up your sun visor and let your eyes adapt.”
Ed did as he was told, sliding the gold-coated visor upwards. Looking over to the silhouette of Whitt in Alice-1, Ed could see the commander using his arms to shield his eyes from the surface moonlight, his body tilted backwards.
“Just take a look at that,” Whitt breathed.
As Ed’s eyes turned skyward, he finally saw why Whitt had ordered the lights off. Shielded from the glare of the sun, with the bulk of the lunar surface hidden from view by the Hab’s descent stage and unfiltered by his protective visor, the full glory of the night’s sky could at last be seen.
“My God. It’s full of stars…”
After two days in the pressurized rover’s tiny cabin, Ed Boxall was longing for the wide, open spaces of the hab module. He and Anne Holcomb had driven almost sixty kilometers around the rim of Shackleton crater, mostly sticking to the peaks but occasionally dipping into the shadowed depression of the crater itself. Ed had never enjoyed road trips, and especially disliked camping. But with no motorway service stations or roadside motels within a quarter-million miles, the camped two-person cabin had to do duty as cockpit, bedroom and bathroom all in one. The dust - which had gotten into the cabin somehow despite the use of suitlocks - was bad enough, but the smell… Maybe I should try describing the smell in my next blog entry, Ed thought to himself. Just to see if the PR guys in Houston let it through…
As if the thought was enough to summon them, the radio crackled into life. “Rover, Houston, how do you read?”
Holcomb toggled the set and replied “Houston, rover, we read you fine. We’re about four kilometers out from Orion and heading back.”
“That’s our estimate too, Anne,” the response came a couple of seconds later. “Ah, we have a request from the science team to make another small diversion.” Even from this distance, Ed could hear the nervousness in the CapCom’s voice at raising the topic. “They’ve identified another potential LITT site close to your track and, ah, they’d appreciate a little ground truth survey.”
Holcomb rolled her eyes and turned to Ed. “Another survey! You want this one?”
“Hey, I got the last one!” he protested.
“Yeah, but I got the two before that, plus I’m designated driver for the next two hours.”
“Rover, Houston, did you read my last?”
“We heard you, Houston,” Anne replied testily. “We’re working through a tasking issue, will advise shortly.”
The two astronauts looked at each other. It was Holcomb who spoke first: “Rock-Paper-Scissors?”
After a best-of-three, it was Ed who reluctantly twisted around in the cockpit to pull himself into the rover’s second Alice suit. If the cabin was beginning to smell like a sports locker room, the suits were closer to a pair of ski boots after a week in the Alps. The Orion hab included a supply of deodorant spray cans in its inventory, but for some reason NASA and its partner agencies had failed to include these in the rovers. The cans weren’t rated for transfer through vacuum, so they hadn’t brought them across before leaving. Ed was planning to raise this issue prominently in the post-mission “Lessons Learned” debriefings. Given his time again, he would have smuggled one over inside his suit, regulations be damned!
Doing his best to ignore the odour, Ed methodically ran through the suit checks. This would be, what, his eighth EVA of the trip? By this point Ed was sure he’d be able to recite the checklist letter-perfect from memory fifty years from now, but the careful attention to detail drummed into all astronauts meant that he used the hardcopy on his wrist and took his time to make sure every point was covered. Checks completed, he disengaged from the suitlock and stepped off of the rover’s small platform and onto the lunar regolith.
The view was familiar after three days of driving, but still stunning. The rover was perched on the rim of Shackleton, currently in sunlight but not in one of the Peaks of Eternal Light such as like the one hosting Orion. Looking down slope, Ed could see for a hundred meters or so before the crater plunged into darkness like a shore disappearing into the ocean. Even with his sun filter up, no details were visible in that inky pool. To the left and right he could see the occasional outcrop of rock as sections of the rim breached the terminator, but directly ahead there was just the pitch-black curve of the horizon blotting out the stars.
But there was work to be done. Reaching up to activate his helmet lamp, Ed began headed down into the darkness with bounding strides. Over the past three weeks each member of the Orion team had settled on their own preferred means of extravehicular locomotion. Holcomb was a bunny-hopper, but Ed found he preferred this gentle lope, springing from one foot to the other. He found he could build up a surprisingly rapid pace if all he needed was to go in a straight line, as now, and it only took a couple of minutes to reach the edge of the sunlit region. It was only as he approached the shadow zone and started pushing back with each step to slow down that the full inertia of his body plus the suit made itself felt. Also making themselves felt were the blisters he’d earned on the ball of each foot from making exactly this maneuver over the past few days.
Wincing slightly at the pain, Ed radioed back to Holcomb in the rover. “I’m at the edge of the shadow now.”
“Roger that, I’ve got visual on you,” came her reply. “The map says the permanent shadow zone is about fifty meters further down, a little to your right. There should be a crater about twenty meters across almost directly ahead of you. If you skim the right side of that and keep going, you should get there.”
Ed moved cautiously into the shadow, swinging his helmet light around slowly as he advanced, trying to spot a landmark in its dim puddle of light.
“I don’t see... Ah, there it is! Okay, bearing right.” Now sure of his direction, Ed set off once more, this time keeping to a pace slow enough to be sure of spotting any potential trip-hazards. Fortunately, there seemed to be few rocks in this area larger than his fist, and the gentle slope was at a reasonably constant grade. Not much risk of making a Little Step here, Ed thought to himself, but better safe than sorry.
“Okay, you can stop about there, Ed,” Holcomb told him. “You’re about at the right spot. How’s it looking?”
“Unremarkable,” Ed responded, looking around. “The slope’s shallow enough for LITT. Should be no problem setting up the tripods.” He kicked experimentally at the surface. “Regolith is moderately thick, about four, five centimeters... Oh wow!”
“What’s up, Ed?”
Ed looked down at the shallow trench he had scuffed in the dirt, rocking slightly to change the angle of his lamp. Was that sparkle..?
“I think we’ve got ice here! Just a few grains, but very close to the surface. I’m going to grab a sample.”
The long handled scoop was back at the rover, so kneeling down in the articulated suit, Ed dug his gloves into the regolith and grabbed two big handfuls of the dirt. A couple of sample bags were still attached to the waist of his ALES, so he dropped both handfuls into one and popped the seal closed.
“What do you think,” Holcomb asked. “Is there more here than over at Bussey Wells?”
“Could be,” said Ed, scuffing his way around the site. “It’s certainly closer to the surface, and seems to be all over this area. Only four klicks out from the hab, too. Looks like this area could have more value than simply a place to put a telescope.”
“Hold on,” said Holcomb, “I’ll bring the rover in closer and join you. We should get some more samples before we start calling this place ‘Boxall’s Brook’ or something.”
Ed mulled that over for a few moments, before remembering how he had knelt down in the ALES to get his first sample. That wouldn’t have been possible in the old A9L suits. Maybe that should be commemorated somehow.
“You know, I think I’d prefer the name ‘Alice Springs’...”
“Jeez, I’d almost forgotten how awkward these things are to put on,” Chung groused from the airlock as he fought to lock the pants of his A9L moonsuit to the torso. “Hey Phil, you sure we can’t take the Turtles with us?”
“Forget it, Winch,” Commander Whitt replied. “This is a base now, not a sortie outpost. We can’t tell the next crew they have to stick to their A9ls just because you’re having trouble fitting your beer gut back into your old suit.”
Ed listened to the banter with half an ear as he finished clearing his bunk area in Orion’s dome. No, not his area, not anymore. As Phil had pointed out, the small metal and fabric hut they’d called home for the past month would soon be left empty, waiting to host a new crew. Someone else would be sleeping here next year, and probably someone else again the year after. This was never going to be more than a temporary home for Ed, no different really from the endless anonymous hotel rooms he’d used over his years of training.
No, of course that wasn’t true. Orion was more than a place to sleep. It was their protector and comforter in a barren, hostile, beautiful land. Outside of this Hab and the Clarke, there was no-where else on this entire world where a human being could survive and thrive. The Apollo pioneers had proven the Moon could be reached, whilst the first Artemis sorties had shown how it could be explored. With Orion, humans had finally demonstrated that they could settle down and live on this, the rocky shore of the interplanetary ocean. Whilst Orion was crewed, humanity had two homes in the solar system.
The crews that followed would build on that legacy, extending their stays until finally settling permanently on the Moon. But for the crew of the first Orion expedition, it was time to return to the mother-world.
Eyes Turned Skyward, Part IV: Post #17
This is it!
Edward Boxall, ESA astronaut, moved his booted left foot down to the final rung of the ladder and leaned backwards. Above him, the bulk of Clarke’s Descent Stage loomed brightly, contrasted against the black sky. No starlight made it through the layer of golf filter on his helmet visor, and the Earth, huddling close to the polar horizon, was hidden out of sight behind the lander.
Leaning to look downwards, Ed could see dark streaks in the grey gray lunar regolith where the lander’s rockets had exposed the underlying bedrock. Small stones scattered around the landing site cast long shadows in the almost horizontally slanting sunlight, whilst the bootprints of his crewmates looked like black holes in the world. Soon, his own bootprints would be joining them.
“Hey, Ed, you gonna join us today?”
Ed smiled at the voice of the Mission Science Officer, always adept at breaking the tension in any situation.
“On my way, Winch,” Ed called back over the radio. “Just one small step…”
Ed’s right foot pressed into the gritty surface, quickly followed by his left.
“For the people of the United Kingdom, the member nations of the European Space Agency and the world, may our mission here herald the beginning of a new phase of human exploration and habitation on our nearest neighbor.”
"One-two, one-two. How're you reading me, Anne?" Ed Boxall, the first British astronaut on the Moon, tapped the side of his Snoopy cap experimentally as he stood in his Thermal Control Garment next to ALES-1's suit lock.
"Loud and clear, Ed," Anne Holcomb confirmed from the other side of the room. "Are you getting me through your headphones?"
"Affirmative, I've got good reception," Ed reported. "How about you, Phil?"
Mission Commander Phil Whitt, similarly attired to Ed, gave a thumbs up as he replied. "Also a good signal. Let's hope it's just as good at a range greater than five feet!"
"Anne and I had no problems yesterday," Mission Science Officer Winchell Chung told the pair. "It got a little scratchy when relaying through Mesyat, but line-of-sight was clear as a bell. In any case, you're not going far today, so if you run into any problems just wave at a camera and we can come get you."
On the communications workstation, Holcomb double-checked her read-out before reporting in to Mission Control. "Houston, Orion. Please confirm you have good Alice-1 and -2 comms relay, over." Following a brief but noticeable lightspeed delay, the voice of Capcom came back through both the console speakers and Boxall's and Whitt's headsets: "Orion, Houston, that's a roger on our side, we have good signal on both Phil and Ed. You have a go for EVA at your leisure."
"Okay guys, time to get your shells on," said Chung. "Just like in training, you trigger the hatches and I'll confirm the seal before you undock, okay?"
"No problem," said Whitt as he grabbed the handhold above the suitlock hatch and swung his legs into the waiting suit. Ed followed suit, easily managing to lift himself into position in the 1/6th gravity of the Moon. Like Phil, Ed slid in legs first through the open backpack of the Articulated Lunar Excursion Suit, slipping into the suit's legs before pulling in his arms and pushing them through the holes in front of him until his fingers hit the ends of the gloves. "This reminds me of putting my son into his romper suit when he was a toddler," Ed commented as he pulled his torso and head fully into the suit.
"You don't squirm around half as much as my daughter did when I tried to dress her!" Chung replied. "Okay, Phil, you look good in there. Go ahead and close the backpack."
"Okay Winch," Phil responded. Ed heard a few clicks through the open back of his suit, but otherwise just hung in place waiting for Phil to get to him. With the protective cover still over ALES-2's helmet, there wasn't even a view to enjoy yet. As he waited, Ed started to hum randomly.
"Jeez, Ed, you didn't take that blasted kazoo into the suit did you?" came Holcomb's plaintive question.
Ed laughed. "No, that's pure Edward Boxall, unplugged!"
"You'd better not have anything unplugged," Chung put in. "Otherwise this EVA is liable to be scrubbed". The American astronaut was now behind Ed in the cabin. "Nope, looks like you're all wired up as you should be. Ready for seal?"
"Ready," replied Ed. He triggered the closure mechanism, and with a quiet "thunk!" the background noises of the Orion cabin, which Ed hadn't even noticed up to now, abruptly ceased. Alone in the dark, with just the low whirl of the helmet fan, Ed was unpleasantly reminded of the sensory deprivation tests he'd undergone at Cologne when he'd first been selected as an astronaut. This time though, the silence didn't last long as Holcomb's voice came through his headphones: "Alice-1, Alice-2, Orion. Comms check."
"Alice-1 comms okay," came Whitt's voice, before Ed responded "Alice-2, comms are good."
"Okay guys," Holcomb replied, "It's all looking good from here. Lift up your dust covers and stand by for undock.
"Roger, lifting cover now" Ed reported as he slowly moved the stiff, unresponsive arms of his moonsuit to bring his gloved right hand up to the fabric covering over his helmet. Moving carefully in the unfamiliar suit, he pushed wire hoop attached to the cover upwards and looked out upon the harsh, raw beauty of the lunar surface. Just as it had on his earlier EVAs in the old pressure suits, the view took his breath away, and he sent up a silent prayer of thanks to God that he was lucky enough to be alive at a time when such miracles were possible that he could walk upon the Moon.
"Visual on Alice-2," came Whitt's voice through the radio, and Ed turned his head to see Phil's suit clinging by its backpack to the cabin wall next to him. Whitt's sun visor was down, so Ed couldn't make out his face, but the other astronaut gave him a cheery wave of recognition. Ed returned the wave. "Hi Phil, fancy meeting you here. It's a small world, eh?"
"Smaller than Earth, that's for sure!"
Just then Holcomb's voice broke in over the radio. "If you two have finished your comedy routine, we’ve confirmed a good seal on our side. You can undock when you’re ready."
"Thanks, Anne," Whitt replied. "Alice-1 undocking... now!"
Ed watched as Whitt's suit jerked forward, the rear half of his backpack emerging from the recessed suitlock as he held on to the twin railings either side of him for balance. "I have a good separation," Whitt told Holcomb. "I'm free standing on the platform."
"Roger, Phil. Ed, ready to go for Alice-2 undock."
“Roger.” Ed forced the stiff gloves of his suit to grip the side rails and pulled sharply forward. There was a brief resistance and a loud click as the backpack disconnected from its berth. “I’m out,” Ed called through the radio. Wow, I really am, he reminded himself. Outside on the Moon...
Standing at the edge of the platform that topped Orion’s descent module, Ed looked out across the bleak landscape in awe. If he leaned over the railing and looked downwards (something that was much easier in his articulated Turtle-suit than it would have been in the old A9L), he could see the scars where the base’s descent had disturbed the top layer surface dust. A tangle of footprints and wheel tracks surrounded the lander, along with various boxes and equipment unpacked by Holcomb and Chung on their previous EVA, but out beyond a couple of hundred meters the ground was undisturbed. Primordial. Where no man has gone before...
“Hey, Anne,” Whitt’s voice came over the radio. “Kill the lights for a second, will ya?”.
“What’s that?” Ed asked nervously, tightening his grip on the handrail.
“I just want to try something out,” came the commander’s enigmatic reply.
“Okay, Phil,” Anne called from inside. “Shutting down the floods now.”
As the hab’s external lights winked out, Ed found himself plunged into darkness. Both the sun and the Earth, neither of which ever rose more than a few degrees above the horizon here, were on the other side of the hab, so the only natural light was that reflected from the dusty surface of Shackleton Crater’s rim. Ed moved to switch on his helmet lamp, but Whitt said “Hold on a second. Push up your sun visor and let your eyes adapt.”
Ed did as he was told, sliding the gold-coated visor upwards. Looking over to the silhouette of Whitt in Alice-1, Ed could see the commander using his arms to shield his eyes from the surface moonlight, his body tilted backwards.
“Just take a look at that,” Whitt breathed.
As Ed’s eyes turned skyward, he finally saw why Whitt had ordered the lights off. Shielded from the glare of the sun, with the bulk of the lunar surface hidden from view by the Hab’s descent stage and unfiltered by his protective visor, the full glory of the night’s sky could at last be seen.
“My God. It’s full of stars…”
After two days in the pressurized rover’s tiny cabin, Ed Boxall was longing for the wide, open spaces of the hab module. He and Anne Holcomb had driven almost sixty kilometers around the rim of Shackleton crater, mostly sticking to the peaks but occasionally dipping into the shadowed depression of the crater itself. Ed had never enjoyed road trips, and especially disliked camping. But with no motorway service stations or roadside motels within a quarter-million miles, the camped two-person cabin had to do duty as cockpit, bedroom and bathroom all in one. The dust - which had gotten into the cabin somehow despite the use of suitlocks - was bad enough, but the smell… Maybe I should try describing the smell in my next blog entry, Ed thought to himself. Just to see if the PR guys in Houston let it through…
As if the thought was enough to summon them, the radio crackled into life. “Rover, Houston, how do you read?”
Holcomb toggled the set and replied “Houston, rover, we read you fine. We’re about four kilometers out from Orion and heading back.”
“That’s our estimate too, Anne,” the response came a couple of seconds later. “Ah, we have a request from the science team to make another small diversion.” Even from this distance, Ed could hear the nervousness in the CapCom’s voice at raising the topic. “They’ve identified another potential LITT site close to your track and, ah, they’d appreciate a little ground truth survey.”
Holcomb rolled her eyes and turned to Ed. “Another survey! You want this one?”
“Hey, I got the last one!” he protested.
“Yeah, but I got the two before that, plus I’m designated driver for the next two hours.”
“Rover, Houston, did you read my last?”
“We heard you, Houston,” Anne replied testily. “We’re working through a tasking issue, will advise shortly.”
The two astronauts looked at each other. It was Holcomb who spoke first: “Rock-Paper-Scissors?”
After a best-of-three, it was Ed who reluctantly twisted around in the cockpit to pull himself into the rover’s second Alice suit. If the cabin was beginning to smell like a sports locker room, the suits were closer to a pair of ski boots after a week in the Alps. The Orion hab included a supply of deodorant spray cans in its inventory, but for some reason NASA and its partner agencies had failed to include these in the rovers. The cans weren’t rated for transfer through vacuum, so they hadn’t brought them across before leaving. Ed was planning to raise this issue prominently in the post-mission “Lessons Learned” debriefings. Given his time again, he would have smuggled one over inside his suit, regulations be damned!
Doing his best to ignore the odour, Ed methodically ran through the suit checks. This would be, what, his eighth EVA of the trip? By this point Ed was sure he’d be able to recite the checklist letter-perfect from memory fifty years from now, but the careful attention to detail drummed into all astronauts meant that he used the hardcopy on his wrist and took his time to make sure every point was covered. Checks completed, he disengaged from the suitlock and stepped off of the rover’s small platform and onto the lunar regolith.
The view was familiar after three days of driving, but still stunning. The rover was perched on the rim of Shackleton, currently in sunlight but not in one of the Peaks of Eternal Light such as like the one hosting Orion. Looking down slope, Ed could see for a hundred meters or so before the crater plunged into darkness like a shore disappearing into the ocean. Even with his sun filter up, no details were visible in that inky pool. To the left and right he could see the occasional outcrop of rock as sections of the rim breached the terminator, but directly ahead there was just the pitch-black curve of the horizon blotting out the stars.
But there was work to be done. Reaching up to activate his helmet lamp, Ed began headed down into the darkness with bounding strides. Over the past three weeks each member of the Orion team had settled on their own preferred means of extravehicular locomotion. Holcomb was a bunny-hopper, but Ed found he preferred this gentle lope, springing from one foot to the other. He found he could build up a surprisingly rapid pace if all he needed was to go in a straight line, as now, and it only took a couple of minutes to reach the edge of the sunlit region. It was only as he approached the shadow zone and started pushing back with each step to slow down that the full inertia of his body plus the suit made itself felt. Also making themselves felt were the blisters he’d earned on the ball of each foot from making exactly this maneuver over the past few days.
Wincing slightly at the pain, Ed radioed back to Holcomb in the rover. “I’m at the edge of the shadow now.”
“Roger that, I’ve got visual on you,” came her reply. “The map says the permanent shadow zone is about fifty meters further down, a little to your right. There should be a crater about twenty meters across almost directly ahead of you. If you skim the right side of that and keep going, you should get there.”
Ed moved cautiously into the shadow, swinging his helmet light around slowly as he advanced, trying to spot a landmark in its dim puddle of light.
“I don’t see... Ah, there it is! Okay, bearing right.” Now sure of his direction, Ed set off once more, this time keeping to a pace slow enough to be sure of spotting any potential trip-hazards. Fortunately, there seemed to be few rocks in this area larger than his fist, and the gentle slope was at a reasonably constant grade. Not much risk of making a Little Step here, Ed thought to himself, but better safe than sorry.
“Okay, you can stop about there, Ed,” Holcomb told him. “You’re about at the right spot. How’s it looking?”
“Unremarkable,” Ed responded, looking around. “The slope’s shallow enough for LITT. Should be no problem setting up the tripods.” He kicked experimentally at the surface. “Regolith is moderately thick, about four, five centimeters... Oh wow!”
“What’s up, Ed?”
Ed looked down at the shallow trench he had scuffed in the dirt, rocking slightly to change the angle of his lamp. Was that sparkle..?
“I think we’ve got ice here! Just a few grains, but very close to the surface. I’m going to grab a sample.”
The long handled scoop was back at the rover, so kneeling down in the articulated suit, Ed dug his gloves into the regolith and grabbed two big handfuls of the dirt. A couple of sample bags were still attached to the waist of his ALES, so he dropped both handfuls into one and popped the seal closed.
“What do you think,” Holcomb asked. “Is there more here than over at Bussey Wells?”
“Could be,” said Ed, scuffing his way around the site. “It’s certainly closer to the surface, and seems to be all over this area. Only four klicks out from the hab, too. Looks like this area could have more value than simply a place to put a telescope.”
“Hold on,” said Holcomb, “I’ll bring the rover in closer and join you. We should get some more samples before we start calling this place ‘Boxall’s Brook’ or something.”
Ed mulled that over for a few moments, before remembering how he had knelt down in the ALES to get his first sample. That wouldn’t have been possible in the old A9L suits. Maybe that should be commemorated somehow.
“You know, I think I’d prefer the name ‘Alice Springs’...”
“Jeez, I’d almost forgotten how awkward these things are to put on,” Chung groused from the airlock as he fought to lock the pants of his A9L moonsuit to the torso. “Hey Phil, you sure we can’t take the Turtles with us?”
“Forget it, Winch,” Commander Whitt replied. “This is a base now, not a sortie outpost. We can’t tell the next crew they have to stick to their A9ls just because you’re having trouble fitting your beer gut back into your old suit.”
Ed listened to the banter with half an ear as he finished clearing his bunk area in Orion’s dome. No, not his area, not anymore. As Phil had pointed out, the small metal and fabric hut they’d called home for the past month would soon be left empty, waiting to host a new crew. Someone else would be sleeping here next year, and probably someone else again the year after. This was never going to be more than a temporary home for Ed, no different really from the endless anonymous hotel rooms he’d used over his years of training.
No, of course that wasn’t true. Orion was more than a place to sleep. It was their protector and comforter in a barren, hostile, beautiful land. Outside of this Hab and the Clarke, there was no-where else on this entire world where a human being could survive and thrive. The Apollo pioneers had proven the Moon could be reached, whilst the first Artemis sorties had shown how it could be explored. With Orion, humans had finally demonstrated that they could settle down and live on this, the rocky shore of the interplanetary ocean. Whilst Orion was crewed, humanity had two homes in the solar system.
The crews that followed would build on that legacy, extending their stays until finally settling permanently on the Moon. But for the crew of the first Orion expedition, it was time to return to the mother-world.
I loved that update.
Nice job nixonshead! For some reason, I misread "spray cans" as "spray cats" when I first read it, and had the image of a cat on the moon...
For the Artemis/Orion lander/hab module, I may have missed it, but was it mentioned as to how it was powered? Sort of interested in that based off where they are landed.
Nice job nixonshead! For some reason, I misread "spray cans" as "spray cats" when I first read it, and had the image of a cat on the moon...
For the Artemis/Orion lander/hab module, I may have missed it, but was it mentioned as to how it was powered? Sort of interested in that based off where they are landed.
It was a birthday gift! I'm not sure if the site is butterflied, but somehow I suspect so.You gave him an awesome cameo !
Both are solar, with a GH2/GOX fuel cell reserve. It's designed for the 14-day missions and lunar nights of more equatorial sites, so it's actually more than sufficient for the selected base site, which sees 85% illumination--about 3 days of dark a month.
Nixonshead did a great job with this post. And Winchell Chung being on the Moon? That I didn't see coming. And being able to see all the stars by being in the shadow and with the lights off, that has to be a sight you wouldn't be able to forget.
But it's the last sentence that really hits home:
It makes it appear that eventually, there will be permanent Human Presence on our closest celestial neighbour. I can't describe that with mere words.
And Winchell Chung being on the Moon? That I didn't see coming. And being able to see all the stars by being in the shadow and with the lights off, that has to be a sight you wouldn't be able to forget. But it's the last sentence that really hits home:
It makes it appear that eventually, there will be permanent Human Presence on our closest celestial neighbour. I can't describe that with mere words.
I loved that update.
Nice job nixonshead! For some reason, I misread "spray cans" as "spray cats" when I first read it, and had the image of a cat on the moon...
For the Artemis/Orion lander/hab module, I may have missed it, but was it mentioned as to how it was powered? Sort of interested in that based off where they are landed.
Can you imagine the level of desperation that would drive a man to consider smuggling cats in his spacesuit? To improve the smell!?!