Thanks for your explanation. As a lover of scifi, especially hard-er scifi, It would be fantastic if you did go into the future- if only the near future and just go with what you think is plausible. Lockheed and their fusion claim, the work at NIF and more realistically, ITER are great and could really make that push that makes VASIMR more of a possibility, but even, given enough time and serious luck, an alcuburrie drive (tho i get that that goes too ASB for you guys). There's just so many options when you start to get to a technological stand point where getting into space is cheaper and easier and thus things like asteroid mining or mining for helium-3 become a potential reality. The reality is that even the small changes cause huge ripples in the reality of space travel and exploration.
Thanks for your explanation. As a lover of scifi, especially hard-er scifi, It would be fantastic if you did go into the future- if only the near future and just go with what you think is plausible. Lockheed and their fusion claim, the work at NIF and more realistically, ITER are great and could really make that push that makes VASIMR more of a possibility, but even, given enough time and serious luck, an alcuburrie drive (tho i get that that goes too ASB for you guys). There's just so many options when you start to get to a technological stand point where getting into space is cheaper and easier and thus things like asteroid mining or mining for helium-3 become a potential reality. The reality is that even the small changes cause huge ripples in the reality of space travel and exploration.
I forget if I've had occasion to mention my personal favorite potential application of fusion to deep space flight on this thread or not before. MSNW also has their own, quite different, project for a power-generation reactor; the NASA funding they've received is specifically for a rocket. Although this Wikipedia article mentions specific impulses of "up to" 3000 and pulse rate of once a minute, Slough and others have been more optimistic in some publications, suggesting ISP more like 5000 and pulse rates of once every ten seconds or even faster. Taking the more cautious figures, a pulse should produce a reaction of about 11,000 Newton-seconds. The engine itself, they have suggested in a publication, would be about 15 metric tonnes all up, so for the multiple-hundred tonne spacecraft they are talking about it should result in velocity changes of centimeters per second with each pulse, with a pulse coming every minute. For the more optimistic 50,000 m/sec exit speeds of the plasma, Slough has said that would correspond to a factor of 200 energy gain (energy released by fusion divided by the input energy needed to compress the metal ring to trigger the fusion). Getting the pulse rate up would be very nice but it isn't so easy to do.
I don't know how to directly compare this system by the criteria you use to compare VASMIR to Hall thrusters, but judging by the results if it works, namely 3 month or even single month transfers to Mars, and back in the same timeframe, I'd say it is orders of magnitude better than either. That is, as high-ISP systems go, I don't think many work out to be much superior to 3000 without reducing the thrust-mass ratio to horribly low levels, whereas realistic systems that can produce ISP in that range have even lower thrusts by far than this MSNW fusion pulser would. While the thrust is laughably low in some contexts, for an interplanetary drive it is quite good. So they say on the appropriate NASAspaceflight.com thread anyway.
Huh. I was under the impression that Alternate History is essentially a branch of science fiction.
And of course the "hard/soft" spectrum applies, with this thread way over toward the diamond end of "hard" and the more frivolous ASB threads off in the realm of vaporized marshmallows.What I hear you saying is, the "hardness" would be softened as you go beyond provable 2013 OTL state of the art and start betting on opinions as to which promising or exciting new tech that might work actually will. Plus of course the other things you mention--how will humans react to medium gravity, how will we fare under months and years of GCRs, etc--questions that are wide open and unanswerable by current scientific knowledge.
I veer toward optimism about the former--just provide a quarter G or so and humans ought to rehabilitate just fine to full Earth G after indefinite stays in the lighter G with few irreversible consequences) and pessimism about the latter (that radiation can't be good, and we'd need shielding to cut it in half or better to enable space missions spanning years--that is to say, 5 freaking meters thickness of water! To correspond to half of the 10 tonnes of air we currently enjoy shielding us from them, you see). But that of course is just by shoot-from-the-hip opinion. It would be nice to be proven wrong about the radiation, even in a package where I'm also wrong about the medium-G--because we can readily raise a rotating system we hoped would work at 1/4 G to a full G, but we'd need to build the freaking Battlestar Galactica if we wanted 5 meters of radiation protection.
Anyway, while we might have a semantic disagreement about whether or not all of this great stuff you've written so far is already science fiction or not, there can be no doubt its character would change the moment you have to take it beyond proven knowledge and proven technical capabilities.
TheLoneAmigo
Donor
From post #3 in part II... we never discovered the fate of the Soviet Grand Tour probe. Is there any chance that it would ever get launched?
Hello again. Whilst both OTL and TTL featured a Cassini mission to Saturn, there have been significant differences between the two versions. So this week, let's take a look at some of those differences (and similarities).
In both TLs, Cassini took an indirect route to Saturn which includes taking a gravity assist from the homeworld...
In both TLs, Cassini took an indirect route to Saturn which includes taking a gravity assist from the homeworld...
In a difference from OTL, Cassini features an atmospheric probe, which separates from the mothership before arrival at Saturn.
The atmospheric probe means that TTL's mission gains direct knowledge of Saturn's atmosphere which was not possible IOTL.
AFAIK, the delta-v for a hohmann delta-v requirement for going straight from the Earth to Saturn is in the region of 15.7 Km/s - assuming that this is correct.
Small wonder gravity assisted flyby's HAD to be used here, since that number is well and truly beyond the limits of even the Vulkan-Atlas (T) - which I get a peak delta-v of 8.4 Km/s for.
The joys of what could've been. I wonder if they detected He3 in significant quantities there?
Which makes me very angry.
But I can still understand why they would do this. With the atmosphere probe and simply remembering to have all the Cassini receivers on - assuming it's close enough to OTL Cassini/Huygens - something would have to give somewhere to keep it properly plausible.
No, it doesn't. It's just somebody from here recommending it over there. I was kind of hoping it might escape notice, since I'm rather terrified of all the holes that site's esteemed membership of industry professionals and historians might come here and kick in things.means ETS got now knightly accolade by them ?
No, it doesn't. It's just somebody from here recommending it over there. I was kind of hoping it might escape notice, since I'm rather terrified of all the holes that site's esteemed membership of industry professionals and historians might come here and kick in things.
oh my god
This would end as
I've made an update to the Mission List Wiki to include most of the Spacelab missions and the early Freedom missions (up to FOC). I've still got a lot of question marks in these and a few gaps (in particular AARDV missions for both Spacelab and Freedom), and I've probably made some mistakes, so feel free to edit and correct!
Thank you, Nixonshead. I appreciate that--feel free to send me any questions you have. Ditto for anyone else--the more details people catch in old posts and get added to this resource, the less likely those details are to be forgotten, even by the writers.
Part III, Post 10: European launcher development of the 1990s
Good afternoon everyone! It's that time once again, and I think this week's post should interest people. Two weeks ago, we looked at the state of the Russian space program, with a particular focus on the transition from national service to competing in a commercial world. This week, we follow up on that thread a few hundred miles west as we check in on the European launcher program. Unlike IOTL, it's not unchallenged nor dominating by default, and the result is a sharp question: how to position for the new millennium?
Eyes Turned Skyward, Part 3: Post #10
The dawn of the 1990s arrived disconcertingly for the European Space Agency. At the beginning of the European international program, the partners had gathered to lay out a roadmap to develop a substantial program, capable of matching even the superpowers. On the manned side, a long-running and highly successful, if sometimes contentious, partnership with NASA had been key, while unmanned astronomy and planetary science missions had depended on partnerships not just with the Americans, but with Japan and Russia as well. However, the key of the endeavor had been the ongoing development of a string of commercially-aimed launch vehicles: Europa. Despite their troubled birth, by the introduction of the Europa 4 series in the late 1980, ESA had forged Europa into a very successful family of rockets. Covering a wide range of capabilities, Europa was well-suited to European needs and enjoyed considerable success for European governmental and commercial payloads. Despite the success of the rockets in serving the European market, the core of commercial satellite development remained in the United States, where a plethora of launch options, many covering similar payload capacities as Europa, were offered by competing manufacturers. With little differentiation between Europa and American rockets on price--indeed, the new ALS Carracks promised to be cheaper than the lighter Europas whose payload it matched--it was a challenge to win American launch contracts, and with very few exceptions American payloads flew on American rockets while European payloads flew on Europas. The battleground was thus markets like India, South Korea, Vietnam, and the Middle East--all wealthy, industrialized nations looking to build satellite networks, but as yet unable or unwilling to build their own launch vehicles. Currently without a launcher development program for the first time in their history, ESA had already been debating how to position to build market share in these areas when the fall of the Soviet Union sent shockwaves through the industry. The end of the Cold War meant that Russian manufacturers, desperately hungry for hard cash, were now free to bring their low costs and proven histories to Western markets--indeed, they were virtually required to by the chaos spreading throughout Russia. At the same time, the Chinese were also opening their own low-cost industry up to foreign payloads, opening yet another front that European manufacturers would need to hold.
To compete in this newly complicated marketplace, Europa would need to change. However, unlike in the past where the requirement had usually been for a more capable launcher to keep up with growing payloads, here the requirement was for a more competitive rocket, able to hold its own against a flood of low-cost competitors from the East and high-tech ones from the West. Unfortunately, this was not a problem solvable with more development funds and engineering--in fact, sometimes quite the opposite. The problems of Europa were largely administrative and logistic, and these required solutions that no combination of strap-ons could solve. Despite the strength that ESA’s financial support gave it, Europa’s operations were limited by this same support. For one, the necessity of having vehicles available to meet ESA member’s scientific and national defense needs meant that Europa’s schedule was somewhat limited. In addition, the direct control of Europa’s operations budget by the ESA members meant that flexibility to invest in launch site improvements or to make modifications to the vehicles to reduce operations was lacking, replaced with extremely formal contracting and byzantine governmental budgeting processes. In addition, the structure of ESA’s logistics train meant high built-in costs, which in turn only further discouraged potential customers from selecting Europa for their launch needs.
With the need to compete internationally clearly requiring a shakeup, the British and French, exercising new muscle thanks to reduced German funding of the combined agency, proposed a potential solution: instead of the government directly supporting and operating Europa, Europa’s suppliers would instead be grouped together under a new semi-private company, which the ESA member governments would hold stakes in. This separation would give the new company greater freedom to alter its operations to minimize costs and build commercial market share while still ensuring continued ESA access to native launchers. This new consortium--announced in March 1991 as EuropaSpace--set about its improvements with gusto. However, given the ongoing changes in the market and the potential improved technologies available as new Russian technologies were being examined and replicated by European companies like Rolls-Royce, the company initially focused not on new launchers, but on streamlining contracts and supply chain for their existing families. With moves thus underway to reduce overhead and trim costs to lower the price at which commercial payloads could be offered, the main limiting factor on selling slots was the facilities at Kourou. With only a single launch pad available for the Europa 4 family, the maximum number of launches that could be performed of the type was roughly 8 per year. Thus, a 4 ton and a 2 ton pair of satellites (the most common sizes for satellites--”full” and “half” sized busses, respectively) launched independently would require nearly a quarter of a year’s launches on a Europa 44 and Europa 42 respectively. In the past, this had been somewhat typical as launches were allocated as flights were sold. However, EuropaSpace, following on the track blazed by commercial Titans, moved to instead pair such payloads into larger dual-launched pairs aboard the larger Europas: 42u and 44u. A “full” and a “half” would fit reasonably well on a 42u, while slightly heavier pairings could be slotted in on the until-then almost unused 44u configuration originally planned for manned Minotaur or future space laboratories and probe missions. In doing so, not only could twice as many commercial payloads be launched per year, but the cost of each would decrease. While a 44 and 42 would have required a total of two Griffin cores, six Blue Streak boosters, and a pair of Aurore upper stages, dual-launching on a 42u would cut that to just one, two, and two respectively--a substantial savings in hardware costs with only minor launch timing changes to the customer.
However, even as the benefits of this focus on dual-launching was being reaped, the future of European launchers was being discussed at the highest levels, both by the ESA partner governments and by representatives of EuropaSpace. The Europa family, built on the legacy going back to the 1950s missile programs, was still something of a “second generation” launcher, with large levels of craft work and extensive analogue steps involved in production thanks to tooling and facilities that had been in service since before the information revolution--some of the jigs, stands, and metalworking techniques used in assembling RZ.2 engines for Blue Streaks and Griffins (not to mention the engines themselves) had originally been designed and constructed based on calculations carried out by slide rules, with tubes being bent and welded by hand for the regenerative nozzles. In an era when automotive and aerospace engineering was increasingly making use of the benefits of automation and electronic controls, it was an anachronism. Thus, like the Americans and Russians, the Europeans too were looking towards the future and the potential for an overhauled “ELV3” third generation to incorporate the latest launch technologies and production improvements. The question, then, was what this third generation would look like. In the summer of 1993, this question came to a head in a series of technical conferences sponsored by ESA.
The lead entry, supported by EuropaSpace, was a continuation of the past successes with expendable rockets, but updated to use the latest in manufacturing techniques and engine technologies. The proposals for such “Europa 5” concepts resembled in some ways the multicore families of the Russians and Americans--instead of a large-diameter core and separately designed boosters, the new family would instead be based on a single lower stage which would be clustered to meet the required payload capacities. EuropaSpace proposed this class to meet the existing Europa 4 ability to dual-launch current satellites, while also future-proofing against the growing number of 6 mt “supersized’ busses by designing for an upper payload to GEO of no less than 10 mT--enough to dual launch 4 mT full busses, or a potentially expanding to dual-launch 4 ton class or 4 and 6 ton birds. With new staged-combustion engines, improved production techniques, and pad updates, EuropaSpace promised that the new vehicle would be able to match or beat American launch providers on cost, while meeting the capabilities of all competing launchers (even commercial Vulkan). (Meanwhile, EuropaSpace would receive ESA funding for all new toolings, pad improvements, and more--which they wouldn’t for any less ambitious modifications, and thus a benefit for the company.) However, while this was popular with the French and British governments, it was less so with Germany. The Germans had already suffered trims to the Minotaur program as a result of their reduced funding caused by diversion of resources to rebuilding the old East German territories. Now the new Europa 5 proposals promised to shift even more of the money involved in Europa--already limited mostly to the Astris third stage--to France and Britain in the name of “minimizing overhead.” However, the reasons for this were hard to argue against: Britain and France were the nations with the largest existing foundation for any new hydrogen or kerosene expendable rocket. Thus, German support ended up falling behind less “conventional” proposals, mostly involving some degree of reuse--particularly types divergent enough from conventional expendables that German aerospace manufacturers would be no less advanced than French or British companies.
The main German support was behind their own native Sanger II project, which had examined a fully reusable two-stage-to-orbit system since the mid 1980s. The first stage was to have been a turboramjet-powered aircraft, which would have lifted the second stage up to Mach 6 and nearly 25 km before dropping it and returning to base. This would then have enabled the Horus second stage, a reusable delta-wing spaceplane, to continue on to orbit on hydrogen/oxygen rockets carrying a reasonable payload. The designs--both with the spaceplane upper stage and an expendable higher-payload version--had reached advanced conceptual stages, and the proposed turbo-rocket cycle for the carrier plane had been seen initial demonstration on the ground in 1991. With such a design, Germany argued, Europe would be able to compete not just on a level playing field against the Americans, but to beat them by a wide margin--perhaps even beat the Russians and Chinese to make Europe the leader in spaceflight. However, support for such ambitious proposals didn’t break down entirely by national lines--there had been low-level French studies continuing on from the rejected spaceplane designs for the European cargo vehicle, while the Uk had seen a program run by Rolls-Royce on a cooled turborocket of their own for use in a single-stage spaceplane called HOTOL. However, neither set of proposals had gained much traction in their native countries, and the Germans provided a strong backer for these programs which otherwise were nearing abandonment.
However, such revolutionary vehicles would require substantial investment to show any results at all, while also carrying huge development risks. Many of the proposals had very limited payload margins, meaning any overruns risked preventing them from making orbit, while the technical readiness of such hypersonic aerospace vehicles was much, much lower than conventional rockets or even existing supersonic aircraft--limited to computer simulations and sounding rocket testing to serve as pathfinders for basic information. Given these, even under the most optimistic development timelines, such a vehicle could not be in service before the mid 2000s. Thus, no matter Germany’s fierce advocacy and interest expressed by many individuals within the main ESA and EuropaSpace leadership and rank-and-file engineers, in the end Europa 5 was given the go-ahead, with a targeted entry-into-service of 1999. However, since the risk reduction was much less expensive than full-scale development, Germany was able to secure a roughly 6:1 ratio of funding for Europa 5 development to development for an “X-plane” program under the Sanger name. This would be devoted to a subscale demonstrator of a Mach 6 turborocket vehicle called the Hypersonic Engine Demonstrator (HED) to prove out the carrier aircraft’s systems and development of a “stagelike” spaceplane similar to a subscale Sanger Horus upper stage. This could be tested with subsonic captive carry and drop testing, and potentially even supersonic carry and drop from a Concorde-derived carrier aircraft. While Germany had not achieved the full program they might have dreamed for, even this was enough to make them the center of European RLV development--a more than satisfactory outcome.
The Europa 5 program proceeded fairly rapidly once approved. The Aurore upper stages of earlier Europas would be retained, though the HM-7B would see an improved vacuum extension and an overhaul to reduce part count and minimize manual assembly steps. Similar process improvements were applied to the stage structure--the number of separate welding operations on the assembly of the domes and barrels was reduced, and the remaining welds confined to fewer specifications to minimize reset times--reducing production costs and enabling a higher throughput of stages if needed. The major element, though, was the new first stage. Built using new 3.5m tooling, it would be based on a pair of the new Rolls-Royce staged-combustion kerosene engine, the RZ.4. This engine, designed with the benefits of Russian insight into staged-combustion cycle design, was roughly the size and form factor of the existing RZ.2 but produced substantially more thrust and had significant improvements in specific impulse. With three cores clustered into a Europa 53u configuration, it would be able to launch more than 8 mT to GTO, allowing for either a 4-and-4 configuration or a 6-and-2. Single core and 5-core configurations would enable it to support both the old Europa 4 range and expand the upper end to match the capabilities of the single-core Saturn Multibody and Vulkan. With conceptual design complete in 1994 and the final design approved, work began to bend metal. In order to avoid introducing hassles into the carefully-leaned launch operations at Kourou, EuropaSpace was able to secure funding for an entire new integration and launch complex. This facility would enable Europa 5 to be brought online in parallel with Europa 4’s final launches, but was to be located so that once Europa 4 was retired, the old Europa 4 site could be re-activated to support Europa 5 as well if needed to open up even more launch slots for sale at the launcher’s internationally competitive prices.
Meanwhile, the Sanger program was proceeding along parallel tracks. The first was the construction of the Hypersonic Engine Demonstrator, a vehicle designed to be air-dropped from the back of a custom-modified A340 at altitude. It would then ignite its engine for a brief demonstration of hypersonic controls and thrust before burning out and falling into the sea. A successful series of these flights (using, of course, multiple vehicles) would demonstrate the basic principles behind the Sanger design in flight, a critical first step for justifying the approval of a full-scale vehicle. At the same time, work was proceeding on a “flight like” mockup of the orbiter, which was scheduled for a series of captive carry tests and drop gliding tests to demonstrate vehicle control and verify weight projections, as well as on other associated required technology such as the new higher specific impulse Vulcain upper stage engine from Snecma, the same firm building the then-current HM-7B. Conceptual design work on the two vehicles was completed in early 1995, and metal began to be bent on the four HEDs and the mockup Horus second stage vehicle. By the start of 1997, the first carry flights of the HED were beginning and construction of the Horus was nearly complete. However, the start of the HED program put the entire program into jeopardy. The first firing of a HED resulted in a partial success, though a seriously qualified one. While the drop was nominal, the engine lit, and the initial burn went as planned, after roughly a minute of flight the vehicle lost communications with the carrier and chase planes. After months of reviewing the data from the thousands of sensors onboard the HED, the issue was traced to a faulty seal between the engine and the exhaust of the vehicle which had failed to hold up under the full running engine’s load, venting combustion gasses into the body of the vehicle. Not designed to withstand high-pressure gasses at hundreds of degrees Celsius, the avionics had melted moments before the fuel tank gave in and the entire vehicle ignited. Even as the Horus mockup began captive carry testing, the next few HED tests proved no more successful, with control issues and a compressor stall, respectively, dooming the vehicles to a watery grave before they could complete successful extended flights.
With only one HED remaining and generally negative results thus far, 1998 saw a sharp re-evaluation of the Sanger program. The hypersonic carrier vehicle proved a weak link, while the orbiter was beginning to look more plausible. The question was if it was replaceable, and suggestions abounded. The simplest would be a subsonic drop from the same modified A340 that had carried the drop-test vehicle--with such a launch, the vehicle would be capable of making orbit, though with virtually no payload, making it little more than a technology demonstrator. Alternately, the orbiter could be used to replace the Aurore second stage on Europa 5, which would enable downmass capability and could offer an alternative to man-rating the existing Minotaur for crew transport to station. In a third option, a supersonic carrier, potentially Concorde-derived, would enable a meager but potentially worthwhile payload with full reusability. However, modifications to the Concorde in order to enable it to carry a large external payload would be technically demanding given the age and sophistication of the type, and the expense could easily run to billions of dollars, leaving the existing Sanger budget far in the rear-view mirror. Even though most of the benefits and funding would ultimately flow back to British and French companies, the dominant Anglo-French coalition was cool to the cost, and the idea withered on the vine. Another option was the ambitious proposal of the British Rolls-Royce team, which had moved from HOTOL to Sanger, to start largely from scratch on a new HOTOL-like design that would be single-stage-to-orbit capable, completely eliminating the cost of the carrier vehicle, albeit at the cost of increased expense on the orbital portion. However, their proposed engine was still in very early development, and key areas including the heat exchangers would require advances well beyond the state of the art to reach even bench-testing. While work had proceeded far enough that giving up entirely, especially given the potential and competition from across the Atlantic, seemed not to be an option, the exact trajectory of the Sanger program into the new millennium and reality was very much up in the air.
Eyes Turned Skyward, Part 3: Post #10
The dawn of the 1990s arrived disconcertingly for the European Space Agency. At the beginning of the European international program, the partners had gathered to lay out a roadmap to develop a substantial program, capable of matching even the superpowers. On the manned side, a long-running and highly successful, if sometimes contentious, partnership with NASA had been key, while unmanned astronomy and planetary science missions had depended on partnerships not just with the Americans, but with Japan and Russia as well. However, the key of the endeavor had been the ongoing development of a string of commercially-aimed launch vehicles: Europa. Despite their troubled birth, by the introduction of the Europa 4 series in the late 1980, ESA had forged Europa into a very successful family of rockets. Covering a wide range of capabilities, Europa was well-suited to European needs and enjoyed considerable success for European governmental and commercial payloads. Despite the success of the rockets in serving the European market, the core of commercial satellite development remained in the United States, where a plethora of launch options, many covering similar payload capacities as Europa, were offered by competing manufacturers. With little differentiation between Europa and American rockets on price--indeed, the new ALS Carracks promised to be cheaper than the lighter Europas whose payload it matched--it was a challenge to win American launch contracts, and with very few exceptions American payloads flew on American rockets while European payloads flew on Europas. The battleground was thus markets like India, South Korea, Vietnam, and the Middle East--all wealthy, industrialized nations looking to build satellite networks, but as yet unable or unwilling to build their own launch vehicles. Currently without a launcher development program for the first time in their history, ESA had already been debating how to position to build market share in these areas when the fall of the Soviet Union sent shockwaves through the industry. The end of the Cold War meant that Russian manufacturers, desperately hungry for hard cash, were now free to bring their low costs and proven histories to Western markets--indeed, they were virtually required to by the chaos spreading throughout Russia. At the same time, the Chinese were also opening their own low-cost industry up to foreign payloads, opening yet another front that European manufacturers would need to hold.
To compete in this newly complicated marketplace, Europa would need to change. However, unlike in the past where the requirement had usually been for a more capable launcher to keep up with growing payloads, here the requirement was for a more competitive rocket, able to hold its own against a flood of low-cost competitors from the East and high-tech ones from the West. Unfortunately, this was not a problem solvable with more development funds and engineering--in fact, sometimes quite the opposite. The problems of Europa were largely administrative and logistic, and these required solutions that no combination of strap-ons could solve. Despite the strength that ESA’s financial support gave it, Europa’s operations were limited by this same support. For one, the necessity of having vehicles available to meet ESA member’s scientific and national defense needs meant that Europa’s schedule was somewhat limited. In addition, the direct control of Europa’s operations budget by the ESA members meant that flexibility to invest in launch site improvements or to make modifications to the vehicles to reduce operations was lacking, replaced with extremely formal contracting and byzantine governmental budgeting processes. In addition, the structure of ESA’s logistics train meant high built-in costs, which in turn only further discouraged potential customers from selecting Europa for their launch needs.
With the need to compete internationally clearly requiring a shakeup, the British and French, exercising new muscle thanks to reduced German funding of the combined agency, proposed a potential solution: instead of the government directly supporting and operating Europa, Europa’s suppliers would instead be grouped together under a new semi-private company, which the ESA member governments would hold stakes in. This separation would give the new company greater freedom to alter its operations to minimize costs and build commercial market share while still ensuring continued ESA access to native launchers. This new consortium--announced in March 1991 as EuropaSpace--set about its improvements with gusto. However, given the ongoing changes in the market and the potential improved technologies available as new Russian technologies were being examined and replicated by European companies like Rolls-Royce, the company initially focused not on new launchers, but on streamlining contracts and supply chain for their existing families. With moves thus underway to reduce overhead and trim costs to lower the price at which commercial payloads could be offered, the main limiting factor on selling slots was the facilities at Kourou. With only a single launch pad available for the Europa 4 family, the maximum number of launches that could be performed of the type was roughly 8 per year. Thus, a 4 ton and a 2 ton pair of satellites (the most common sizes for satellites--”full” and “half” sized busses, respectively) launched independently would require nearly a quarter of a year’s launches on a Europa 44 and Europa 42 respectively. In the past, this had been somewhat typical as launches were allocated as flights were sold. However, EuropaSpace, following on the track blazed by commercial Titans, moved to instead pair such payloads into larger dual-launched pairs aboard the larger Europas: 42u and 44u. A “full” and a “half” would fit reasonably well on a 42u, while slightly heavier pairings could be slotted in on the until-then almost unused 44u configuration originally planned for manned Minotaur or future space laboratories and probe missions. In doing so, not only could twice as many commercial payloads be launched per year, but the cost of each would decrease. While a 44 and 42 would have required a total of two Griffin cores, six Blue Streak boosters, and a pair of Aurore upper stages, dual-launching on a 42u would cut that to just one, two, and two respectively--a substantial savings in hardware costs with only minor launch timing changes to the customer.
However, even as the benefits of this focus on dual-launching was being reaped, the future of European launchers was being discussed at the highest levels, both by the ESA partner governments and by representatives of EuropaSpace. The Europa family, built on the legacy going back to the 1950s missile programs, was still something of a “second generation” launcher, with large levels of craft work and extensive analogue steps involved in production thanks to tooling and facilities that had been in service since before the information revolution--some of the jigs, stands, and metalworking techniques used in assembling RZ.2 engines for Blue Streaks and Griffins (not to mention the engines themselves) had originally been designed and constructed based on calculations carried out by slide rules, with tubes being bent and welded by hand for the regenerative nozzles. In an era when automotive and aerospace engineering was increasingly making use of the benefits of automation and electronic controls, it was an anachronism. Thus, like the Americans and Russians, the Europeans too were looking towards the future and the potential for an overhauled “ELV3” third generation to incorporate the latest launch technologies and production improvements. The question, then, was what this third generation would look like. In the summer of 1993, this question came to a head in a series of technical conferences sponsored by ESA.
The lead entry, supported by EuropaSpace, was a continuation of the past successes with expendable rockets, but updated to use the latest in manufacturing techniques and engine technologies. The proposals for such “Europa 5” concepts resembled in some ways the multicore families of the Russians and Americans--instead of a large-diameter core and separately designed boosters, the new family would instead be based on a single lower stage which would be clustered to meet the required payload capacities. EuropaSpace proposed this class to meet the existing Europa 4 ability to dual-launch current satellites, while also future-proofing against the growing number of 6 mt “supersized’ busses by designing for an upper payload to GEO of no less than 10 mT--enough to dual launch 4 mT full busses, or a potentially expanding to dual-launch 4 ton class or 4 and 6 ton birds. With new staged-combustion engines, improved production techniques, and pad updates, EuropaSpace promised that the new vehicle would be able to match or beat American launch providers on cost, while meeting the capabilities of all competing launchers (even commercial Vulkan). (Meanwhile, EuropaSpace would receive ESA funding for all new toolings, pad improvements, and more--which they wouldn’t for any less ambitious modifications, and thus a benefit for the company.) However, while this was popular with the French and British governments, it was less so with Germany. The Germans had already suffered trims to the Minotaur program as a result of their reduced funding caused by diversion of resources to rebuilding the old East German territories. Now the new Europa 5 proposals promised to shift even more of the money involved in Europa--already limited mostly to the Astris third stage--to France and Britain in the name of “minimizing overhead.” However, the reasons for this were hard to argue against: Britain and France were the nations with the largest existing foundation for any new hydrogen or kerosene expendable rocket. Thus, German support ended up falling behind less “conventional” proposals, mostly involving some degree of reuse--particularly types divergent enough from conventional expendables that German aerospace manufacturers would be no less advanced than French or British companies.
The main German support was behind their own native Sanger II project, which had examined a fully reusable two-stage-to-orbit system since the mid 1980s. The first stage was to have been a turboramjet-powered aircraft, which would have lifted the second stage up to Mach 6 and nearly 25 km before dropping it and returning to base. This would then have enabled the Horus second stage, a reusable delta-wing spaceplane, to continue on to orbit on hydrogen/oxygen rockets carrying a reasonable payload. The designs--both with the spaceplane upper stage and an expendable higher-payload version--had reached advanced conceptual stages, and the proposed turbo-rocket cycle for the carrier plane had been seen initial demonstration on the ground in 1991. With such a design, Germany argued, Europe would be able to compete not just on a level playing field against the Americans, but to beat them by a wide margin--perhaps even beat the Russians and Chinese to make Europe the leader in spaceflight. However, support for such ambitious proposals didn’t break down entirely by national lines--there had been low-level French studies continuing on from the rejected spaceplane designs for the European cargo vehicle, while the Uk had seen a program run by Rolls-Royce on a cooled turborocket of their own for use in a single-stage spaceplane called HOTOL. However, neither set of proposals had gained much traction in their native countries, and the Germans provided a strong backer for these programs which otherwise were nearing abandonment.
However, such revolutionary vehicles would require substantial investment to show any results at all, while also carrying huge development risks. Many of the proposals had very limited payload margins, meaning any overruns risked preventing them from making orbit, while the technical readiness of such hypersonic aerospace vehicles was much, much lower than conventional rockets or even existing supersonic aircraft--limited to computer simulations and sounding rocket testing to serve as pathfinders for basic information. Given these, even under the most optimistic development timelines, such a vehicle could not be in service before the mid 2000s. Thus, no matter Germany’s fierce advocacy and interest expressed by many individuals within the main ESA and EuropaSpace leadership and rank-and-file engineers, in the end Europa 5 was given the go-ahead, with a targeted entry-into-service of 1999. However, since the risk reduction was much less expensive than full-scale development, Germany was able to secure a roughly 6:1 ratio of funding for Europa 5 development to development for an “X-plane” program under the Sanger name. This would be devoted to a subscale demonstrator of a Mach 6 turborocket vehicle called the Hypersonic Engine Demonstrator (HED) to prove out the carrier aircraft’s systems and development of a “stagelike” spaceplane similar to a subscale Sanger Horus upper stage. This could be tested with subsonic captive carry and drop testing, and potentially even supersonic carry and drop from a Concorde-derived carrier aircraft. While Germany had not achieved the full program they might have dreamed for, even this was enough to make them the center of European RLV development--a more than satisfactory outcome.
The Europa 5 program proceeded fairly rapidly once approved. The Aurore upper stages of earlier Europas would be retained, though the HM-7B would see an improved vacuum extension and an overhaul to reduce part count and minimize manual assembly steps. Similar process improvements were applied to the stage structure--the number of separate welding operations on the assembly of the domes and barrels was reduced, and the remaining welds confined to fewer specifications to minimize reset times--reducing production costs and enabling a higher throughput of stages if needed. The major element, though, was the new first stage. Built using new 3.5m tooling, it would be based on a pair of the new Rolls-Royce staged-combustion kerosene engine, the RZ.4. This engine, designed with the benefits of Russian insight into staged-combustion cycle design, was roughly the size and form factor of the existing RZ.2 but produced substantially more thrust and had significant improvements in specific impulse. With three cores clustered into a Europa 53u configuration, it would be able to launch more than 8 mT to GTO, allowing for either a 4-and-4 configuration or a 6-and-2. Single core and 5-core configurations would enable it to support both the old Europa 4 range and expand the upper end to match the capabilities of the single-core Saturn Multibody and Vulkan. With conceptual design complete in 1994 and the final design approved, work began to bend metal. In order to avoid introducing hassles into the carefully-leaned launch operations at Kourou, EuropaSpace was able to secure funding for an entire new integration and launch complex. This facility would enable Europa 5 to be brought online in parallel with Europa 4’s final launches, but was to be located so that once Europa 4 was retired, the old Europa 4 site could be re-activated to support Europa 5 as well if needed to open up even more launch slots for sale at the launcher’s internationally competitive prices.
Meanwhile, the Sanger program was proceeding along parallel tracks. The first was the construction of the Hypersonic Engine Demonstrator, a vehicle designed to be air-dropped from the back of a custom-modified A340 at altitude. It would then ignite its engine for a brief demonstration of hypersonic controls and thrust before burning out and falling into the sea. A successful series of these flights (using, of course, multiple vehicles) would demonstrate the basic principles behind the Sanger design in flight, a critical first step for justifying the approval of a full-scale vehicle. At the same time, work was proceeding on a “flight like” mockup of the orbiter, which was scheduled for a series of captive carry tests and drop gliding tests to demonstrate vehicle control and verify weight projections, as well as on other associated required technology such as the new higher specific impulse Vulcain upper stage engine from Snecma, the same firm building the then-current HM-7B. Conceptual design work on the two vehicles was completed in early 1995, and metal began to be bent on the four HEDs and the mockup Horus second stage vehicle. By the start of 1997, the first carry flights of the HED were beginning and construction of the Horus was nearly complete. However, the start of the HED program put the entire program into jeopardy. The first firing of a HED resulted in a partial success, though a seriously qualified one. While the drop was nominal, the engine lit, and the initial burn went as planned, after roughly a minute of flight the vehicle lost communications with the carrier and chase planes. After months of reviewing the data from the thousands of sensors onboard the HED, the issue was traced to a faulty seal between the engine and the exhaust of the vehicle which had failed to hold up under the full running engine’s load, venting combustion gasses into the body of the vehicle. Not designed to withstand high-pressure gasses at hundreds of degrees Celsius, the avionics had melted moments before the fuel tank gave in and the entire vehicle ignited. Even as the Horus mockup began captive carry testing, the next few HED tests proved no more successful, with control issues and a compressor stall, respectively, dooming the vehicles to a watery grave before they could complete successful extended flights.
With only one HED remaining and generally negative results thus far, 1998 saw a sharp re-evaluation of the Sanger program. The hypersonic carrier vehicle proved a weak link, while the orbiter was beginning to look more plausible. The question was if it was replaceable, and suggestions abounded. The simplest would be a subsonic drop from the same modified A340 that had carried the drop-test vehicle--with such a launch, the vehicle would be capable of making orbit, though with virtually no payload, making it little more than a technology demonstrator. Alternately, the orbiter could be used to replace the Aurore second stage on Europa 5, which would enable downmass capability and could offer an alternative to man-rating the existing Minotaur for crew transport to station. In a third option, a supersonic carrier, potentially Concorde-derived, would enable a meager but potentially worthwhile payload with full reusability. However, modifications to the Concorde in order to enable it to carry a large external payload would be technically demanding given the age and sophistication of the type, and the expense could easily run to billions of dollars, leaving the existing Sanger budget far in the rear-view mirror. Even though most of the benefits and funding would ultimately flow back to British and French companies, the dominant Anglo-French coalition was cool to the cost, and the idea withered on the vine. Another option was the ambitious proposal of the British Rolls-Royce team, which had moved from HOTOL to Sanger, to start largely from scratch on a new HOTOL-like design that would be single-stage-to-orbit capable, completely eliminating the cost of the carrier vehicle, albeit at the cost of increased expense on the orbital portion. However, their proposed engine was still in very early development, and key areas including the heat exchangers would require advances well beyond the state of the art to reach even bench-testing. While work had proceeded far enough that giving up entirely, especially given the potential and competition from across the Atlantic, seemed not to be an option, the exact trajectory of the Sanger program into the new millennium and reality was very much up in the air.
So would I be correct in the belief that the LOX/LH2 upper stages are simply getting improvements to their manufacture? And their main engines? With no real change in their shape?
Is it just me? Or is everyone here switching to the CCB Design?
Which I suppose shouldn't be all that surprising, seeing at it makes for a great way of trimming the total costs by having fewer unique parts to be built for a given LV.
And being able to match the low end - payload-wise - of Saturn MultiBody and Vulkan? I like the sound of that.
Any new Rocket would be radical in hardware or Design, compare to old Europa-2/3/4 design.
Is it just me? Or is everyone here switching to the CCB Design?
Which I suppose shouldn't be all that surprising, seeing at it makes for a great way of trimming the total costs by having fewer unique parts to be built for a given LV.
And being able to match the low end - payload-wise - of Saturn MultiBody and Vulkan? I like the sound of that.
CCB are Cheap if produce in mass and flexibie adaptable for mission by clustering the booster.
i look into concept, first with skepticism, now i'm a advocate for it.
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