Interlude: Challenger
John F Kennedy Space Center, Florida, USA
3rd June 1986, 2020hrs
Madeline Ninfa pushed up her glasses and rubbed her eyes as she prepared to watch the Space Shuttle Challenger launch for the fifteenth time that evening. Mission STS-24 had taken off from Kennedy Space Center almost three hours ago, putting Challenger and her crew of six safely into orbit. For Madeline, the shuttle would rise at least another ten times before she would call it a night and head home.
A couple of years back, there would have been a team of at least four experienced engineers doing the post-launch footage review, but the last couple of budget rounds had been brutal. Now it was just Madeline. The most junior engineer on the Mission Assurance team, and therefore the cheapest to pay for overtime. In spite of the unfairness of the situation, she nonetheless took her duties seriously, as her supervisor knew well. She’d get the job done.
Pulling her glasses back down, Madeline reached for the next tape cassette on the review pile and pushed it into the machine. This one was from a telescopic tracking camera. For the sixteenth time, Madeline saw the shuttle stack rise into the early evening sky. She leaned in towards the CRT display, her right hand on the video controller, studying for any anomalies. The video machine was far more sophisticated than her home VCR, and she could change the speed and direction of the playback with ease.
Slowing the image to one-fifth speed, she scrutinised the O-ring seals on the left Solid Rocket Booster in more detail. Good. Still no sign of smoke. No return of the minor burn-throughs that had plagued the Shuttle during its early years. Hardly surprising, after the very public chewing-out former NASA Administrator Borman had given the contractor when the issue had been brought to his attention. Redesigned seals had been introduced on STS-9 back in ‘83, since when the MA team had only seen one reoccurrence of the issue. Still, it had to be checked. Madeline didn’t believe in taking chances with such things.
Satisfied, she ejected the tape and then reached for the next, taking a sip of flat, warm Pepsi as she did so. Ever since NASA had been pressured into agreeing to fly a Coke machine on a future shuttle mission, KSC had been swamped with Cola-Cola hats, T-shirts and other branded paraphernalia. Madeline didn’t particularly like Pepsi, even when it wasn’t flat, but choosing the other cola brand was her own small protest against the creeping commercialisation of the space programme. Pepsi: The Choice of Bloody-Minded Contrarians…
Tape number seventeen was from a camera on the launch tower, somewhere near the top. Madeline watched the nose of the orbiter ride its orange-clad External Tank past the screen, followed by the wings-
What was that?!
Madeline quickly paused and rewound the tape, then watched again in slow-motion.
There! Just as the right wing root entered the frame, something flashed past the camera and hit the wing, just below the leading edge. It was gone just two frames later, but to Madeline it looked like the object had broken apart or shattered as it left the screen. The shape of the object was concealed by motion blur, but it was at least a couple of feet across, and orange.
“Shit”.
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Low Earth Orbit
5th June 1986
Christ, this thing is big!
Astronaut Thomas Ormston, Mission Specialist for STS-24/Skylab-14, peered over the lip of Challenger’s payload bay to look across an expanse of silver radiators and the wing beyond. To his left was the Shuttle’s crew cabin; to his right, the white fabric of a Spacelab can; and above, the slowly moving sphere of the Earth. Amongst these artefacts, Ormston was a tiny white fly, buzzing around in his MMU, trying not to get squashed.
“Vertical translation complete,” he reported into his headset as he thumbed the Z+ thrusters and killed his motion. “Beginning payload bay egress.”
“Copy that, Tom,” came the voice of mission commander Robert “Hoot” Gibson over the radio. “We still have visual on you. Take care out there.”
“Roger,” Tom replied. Taking care was at the very top of his priority list. This was only the fourth untethered spacewalk in NASA history, and the first where it was planned for the astronaut to be out of sight of the rest of the crew. If he got into trouble while underneath the orbiter, his crewmates would have to move Challenger slowly away before rotating and coming back to help him. That shouldn’t pose a problem… unless his motion kept him close enough that the orbiter’s turn clipped him as he floated unseen. On any ordinary mission, taking such a risk would never have been sanctioned. But this was turning out to be no ordinary mission.
Tom was now well beyond the payload bay, drifting off Challenger’s starboard side, just above the wing root. Using the MMU’s cold gas thrusters, he spun to face the orbiter and stopped his outward motion. He could see the concerned faces of his crewmates in the orbiter cabin windows. Tom gave a stiff-armed wave to them, before gripping the translation controls again and began to sink downwards. Or was that upwards? Above him, the coast of south-west Africa was sliding by. So was he really drifting downwards, or rather hanging upside-down as he ascended?
Stop it!
Ignoring the Earth, Tom fixed his eyes on the tiled skin of the orbiter, re-establishing his frame of reference. As the second shuttle to fly, Challenger was missing the flexible thermal blankets of the later orbiters, with brick-like tiles covering almost all of the ship. Most of the orbiters had suffered a couple of tiles coming loose at some point - or more than a couple, in the case of Columbia’s first mission. This problem had been largely fixed with a new adhesive after the first year of operations. Even when it did occasionally happen, the underlying substrate provided enough protection for re-entry, but it had made for some nervous landings. If the engineers at KSC were right, this time there could be a real cause for concern.
“Tom, Challenger. We’ve lost visual on you.”
“Copy, Challenger.” Tom had now travelled below the level of the wings and was too low for his crewmates to see him through the windows.
“I’m starting my inspection run now, Challenger,” Tom reported, pushing his MMU forward, then rotating to get a better look at the ship’s belly as he drifted past. Houston said the suspected impact area was just behind the starboard wing root-
“Oh shit!”
“Tom, you okay?”
“Sorry, Challenger. I’m okay. But we have one beat-up bird here. I see damage to multiple tiles. Eight, maybe ten, grouped just behind the leading edge. Maybe some damage to the carbon-carbon too.”
“Any tiles lost?” Hoot asked.
“I don’t think so, but a couple are definitely loose. Others have got big bites taken out of them.” Tom came to a halt and grimly surveyed the damage, making sure to take lots of pictures to send back to Houston.
“I don’t think we’re taking this ride home.”
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NBC Nightly News, 5th June 1986
“NASA officials have today confirmed that the Space Shuttle Challenger, which was damaged during lift-off, is not expected to be able to return its crew of seven to Earth. A spacewalk by astronaut Thomas Ormston confirmed that the damage the shuttle’s protective heat shield is too great to guarantee a safe re-entry into Earth’s atmosphere.
“Here with the details is our science correspondent, Robert Bazell.”
CUT TO: Footage of the Mission Control Room at Johnson Space Center
“Following confirmation that a piece of insulating foam had hit Challenger’s wing during take-off, Mission Control here in Houston ordered Mission Specialist Thomas Ormston to undertake a rare untethered space-walk to survey the damage. His assessment revealed that several heat resistant tiles protecting the shuttle’s right wing had been damaged or removed by the foam strike. Although there is no immediate danger to the crew, analysis of the footage led to NASA engineers deciding that it would be too risky for Challenger to attempt to re-enter Earth’s atmosphere. This leaves the five men and two women of Challenger’s crew stranded in space until a rescue mission can be launched.
“That rescue is expected to come from Challenger’s sister-ship, Enterprise. Despite being the most recent addition to NASA’s operational shuttle fleet, Enterprise is actually the oldest of the orbiters, having been used as part of a flight test program during development of the shuttle. Following a successful first launch last December, Enterprise was scheduled to lift off again next month with a prototype moon capsule, on a test flight as part of the Freedom lunar program. That mission has now been cancelled as the shuttle is instead made ready for a rendezvous with Challenger to bring her crew back home. NASA have not yet confirmed the crew for this mission, called “STS-500” in internal planning, but it is expected to be piloted by only two astronauts, in order to leave room for the Challenger’s crew of seven.
“Despite the urgency of the situation, NASA says that it will be a minimum of four weeks before the Enterprise can be launched. In the meantime, Challenger will dock at the Skylab space station, which was her planned destination before disaster struck. Once at the station, the crew will shut down all non-essential equipment in order to preserve their resources for as long as possible. Instead of supporting a scientific mission, Skylab will now become a safe harbour for the astronauts while they await rescue.”
“For NBC Nightly News, this is Robert Barzell.”
CUT TO: NBC Studio
“In related news, the White House has confirmed that Soviet leader Mikhail Gorbachev today called President Reagan with an offer to assist the astronauts in any way possible. President Reagan reportedly thanked Mr Gorbachev, but indicated that, for now, no such assistance was necessary…”
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Skylab-B, Low Earth Orbit
7th June 1986
“Okay, we’re all set here. Shut it down, Gert”.
Through the narrow connecting tunnel, Tom watched as the Belgian astronaut double-checked the procedure print-out in his hand before flipping the breakers that would put the Spacelab module into a “hibernation” mode. The main lights immediately went out, leaving a few LED blinkies on one rack panel as the only source of illumination. The ventilators sighed as they slowed their spinning, finally stopping altogether. Slowly, Gert Hendrik dragged himself into the tunnel, then turned and pulled the hatch closed.
“All those experiments…” the ESA astronaut lamented as he and Tom headed back towards the docking module. “I spent three years training to operate them, and now…”
“Yeah. Nothing on this mission has gone how it was supposed to,” Tom replied. “But if we’re going to hang on up here until Enterprise can get to us, we need to ration everything, including power from the fuel cells.”
The pair passed through the transfer tunnel to the Exterior Airlock. As Tom sealed the hatch to the tunnel, he was startled by a sudden shout from above him: “Make a hole!”
Tom and Hendrik quickly flattened themselves against the airlock wall as Judith Resnick appeared head-first through the docking tunnel from Skylab, her hair wild as she grabbed a handhold to arrest her motion. She executed a ninety-degree twist, then kicked herself through the remaining hatch into Challenger’s Mid-Deck, with a “Thanks, guys” as she departed.
“Hey, Judith, anything we can help with?” Hendrik called after her, but the Mission Specialist was already gone. Tom shrugged at Hendrik, and indicated the hatch Resnick had entered through. “I’m sure we can find something to keep us busy back in the ‘Lab,” he said, and pulled himself through the top hatch, with Hendrik close behind.
If they’d visited the station a year earlier (If, if, if! Tom thought), they would have been entering Skylab’s Docking Module. That had changed last October, when the shuttle Discovery had delivered Skylab’s first expansion module, the Power and Docking Node. The new module was the same diameter as the Spacelab module they’d just been working in, but about half as long. It nevertheless felt roomy, with neat rows of storage racks flush along the walls. The new module hadn’t yet had time to accumulate the clutter that inevitably began to fill rooms aboard the station, and the white locker doors were mostly free of greasy handprints and scuff-marks.
As its name suggested, the Node was intended as the centrepiece for further expansion, and there were pits in the ‘floor’ and ‘ceiling’ containing hatches that would, one day, lead through to, a lab/hab module and a lifeboat capsule, if and when NASA finally got round to making Skylab permanently habitable. In one of those pits, Challenger’s pilot, Charles Bolden, was crouched, holding a camera up against the hatch window.
“Hey, Charlie,” Tom called out. “How’s she looking?”
Bolden looked up from his camera and grimaced. “Not much to see from here,” he admitted with a wave at the window. Through it, Tom and Hendrik could make out the bright, sunlit hull of Challenger, with a pitch-black slash of Skylab’s shadow cutting across one wing. “No sign of damage to the upper surface, just like you said, Tom. But Houston wants the pictures to prove it.”
“It makes no difference to us either way,” Hendrik grumbled.
“True,” Bolden admitted. “But it might help the next crew, if we spot a problem they can fix on future launches.”
“Hey, Tom!” came a sudden feminine shout.
The three men looked over to see Kathryn Maguire calling from the old Docking Module. “Hoot wants a word with you in the Workshop,” Maguire went on. “You too, Gert.” Without waiting for a reply, Maguire flipped over and headed back into the main body of the station.
With a quick farewell to Bolden, Hendrik and Tom both scrambled to follow her, first through the narrow, gloomy Docking Module, then into the Airlock Module. As they passed through, being careful not to damage the two stowed EMU spacesuits, Tom couldn’t help rolling his eyes at the airlock door. This part of the station had been left pretty much unmodified from the original Skylab-A configuration, meaning that door was actually a repurposed, cone-section Gemini hatch, jammed awkwardly into the wall. Every time he saw it, Tom thought, it looked more ridiculous. Like buying a brand new TransAm and welding on the door from a 1950s Oldsmobile.
He didn’t dwell on it, as he and Hendrik followed Maguire into the main body of the station, the Orbital Workshop. Where the previous modules had varied from petit to claustrophobic, the Workshop was cavernous. Four years of hosting periodic visitors had not even begun to fill the enormous volume of the old Saturn V S-IVB hydrogen tank. The walls were cluttered with cables and storage bags, the two grid-floor decks scattered with bulky pieces of hardware, tables and partitions, but the vast interior of the tank remained open, bright and airy.
“Tom! Gert! Over here!” Robert L. “Hoot” Gibson, commander of the STS-24/Skylab-14 mission, called the two astronauts over to where he was perched on gridwork of the Upper Deck, surrounded by a flock of Flight Operations Manual ring binders. Maguire had already descended to the Lower Deck, where she got busy storing trays of vittles ferried over from Challenger. Hendrik and Tom glided through the empty space of the upper dome to join Gibson on the deck, re-orienting themselves to their commander’s local vertical and clipping the triangle-patterned grips of their shoes into the gridwork for stability.
“Houston is looking into options for clearing the docking port for when our rescuers arrive,” Gibson started without preamble. Tom noted that Hoot had said “when”, not “if”. He approved of such optimism.
“As you know,” Gibson went on, “Plan A is to rig Challenger to support an undocking manoeuvre under ground command. Judith’s looking at what it would take to wire up the MAIN-B bus to allow the docking latches to be opened via radio command. The guys in Housten think it’s possible, but just in case, we need a back-up plan.”
“Which would be a manual undocking, right?” Tom asked.
“Right,” Gibson confirmed. “Someone would have to be aboard Challenger to unlatch her, wait until she’s clear, then EVA back to Skylab. You’re our designated EVA specialist, Tom. What’s your view?”
“Risky,” Tom replied at once. “I’d have to get the EMU buttoned up alone, with no-one to help.”
“Could there not be two people on the Shuttle, to assist one another?” Hendrik asked.
Tom thought it over before answering. “Maybe,” he finally conceded. “We’ve only got the one MMU. I’d have to tow the second person on an untethered EVA across - what? Say, five-hundred feet of empty space? Enterprise should be able to come get us if we hit trouble, as long as it’s not too close to Challenger or Skylab. Still, I’d hate to have to try it in practice.”
“Think about it,” Hoot ordered. “If we can’t get Challenger clear of the port, the alternative is ferrying us over one at a time through the old Gemini airlock, bringing back the empty EMU for use on the next trip. Or, God help us, being pulled along in rescue balls.”
“All while Enterprise keeps station for however many hours it takes to get us all out,” Tom noted. Hoot nodded once in agreement. “OK, skipper,” Tom said. “Give me a couple of hours to think it over.”
With a sketched salute, Tom drifted away from Gibson and Gert, his mind already mulling over EVA procedures and contingency options. In one small corner of his mind, he realised that there was very little chance he’d actually have to put these plans into action. Resnick was an electronics whizz, and the modifications she had to make were not especially challenging. The automated undock would almost certainly work. It was far more likely that Gibson, as a good leader, was simply assigning them all tasks to keep them occupied, so they didn’t have time to dwell on their predicament.
Still, it was an interesting problem…
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”Marooned: The Inside Story of the Challenger Accident”, by James R. Hansen, published by Simon and Schuster, New York, 1995.
With Challenger safely docked at Skylab, NASA had bought the crew some breathing space, but the danger was still very real. For its mission to the space station, Challenger had been carrying a Spacelab module with an Extended Duration Orbiter (EDO) pallet, carrying enough supplies for a normal mission of a month, with some margin. By shutting down as many of the shuttle’s systems as possible, this could be stretched by perhaps another 15 days, but it was still too short a window for comfort.
The next shuttle mission on the schedule had been Enterprise, which was preparing for only its second mission, carrying a prototype of the Freedom return capsule on a test flight in late July. As soon as NASA confirmed that Challenger would be unable to return to Earth, Enterprise was pulled from its regular workflow and started preparations for a rescue mission. In order to fit in all seven of Challenger’s crew, Enterprise would launch with only two astronauts on board: Commander Gordon Fullerton and Pilot Michael Coats. Two extra jumpseats were added to Enterprise’s mid-deck, bringing the total number of seats to nine. In its payload bay, Enterprise would carry an EDO,a number of vacuum-sealed packages with air, water and food, and two Manned Maneuvering Unit (MMU) “jetpacks”. The MMUs would allow the crew to ferry additional supplies to the Challenger astronauts through Skylab’s small payload airlock, in case the rescue effort took longer than expected. Although not publicly admitted at the time, Enterprise would also carry seven body bags, in case the worst should happen. One way or another, NASA was determined to bring their people home.
In addition to retrieving the crew, NASA had not yet given up on the possibility of bringing Challenger herself back home. The shuttle fleet had only recently reached its operational size of five orbiters, and reducing this back down to four would place an enormous strain on the fleet. The late 1980s was expected to see an increasing number of flights launched in support of Freedom, first for testing, then for operational missions. This was in addition to the expansion and greater utilisation of Skylab, requiring a minimum of six flights per year. Commercial Atlas and Titan rockets were starting to come on-line by 1986, but NASA still had a significant backlog of commercial satellites slated to launch on the shuttle, plus scientific missions that relied on the orbiters’ unique capabilities. To meet all these demands, a five-orbiter fleet was not a luxury, but a necessity.
Unfortunately, simply building a replacement orbiter was not an option, even if Congress could have been persuaded to pay. With the delivery of Atlantis and Enterprise in 1985, shuttle manufacturer Rockwell had shut down their highly specialised production facilities and downsized their workforce with a focus on maintaining the existing fleet. It was a similar story up and down the complex shuttle supply chain, making it impractical to restart production. In 1981, Rockwell had proposed establishing a stock of spares which could be assembled into a new orbiter in the event of a shuttle loss, but this had been rejected as too costly following the approval of plans to refit Enterprise for orbital flight. With none of the remaining shuttle test articles suitable for conversion to orbital flight, this meant that replacing Challenger was simply not feasible. The only way to continue to operate five orbiters was to somehow recover Challenger, and NASA started to look into the possibility as soon as the crisis hit.
Within days of Challenger’s launch, NASA engineers at the Johnson Space Center, led by astronaut Joe Engle and in coordination with Rockwell International, had been working on a plan for the astronauts to repair or replace the damaged Thermal Protection System (TPS) tiles. It was quickly decided that trusting the astronaut’s lives to such a patch was too risky, but it could point the way to recovering the orbiter in an unmanned configuration.
The need to perform on-orbit TPS repairs had been identified by NASA well before the first orbital flight. The effort had stalled by 1981, due to a perceived lack of need and problems with bubble formation in the Cure In Place Ablator (CIPA) paste proposed for the job. The Mattingly Report on shuttle safety had triggered a re-start of the TPS repair project, and a test of the repair procedure and CIPA applicator equipment was carried out on Challenger’s maiden flight, STS-8, in June 1983. Although difficult to apply with accuracy when untethered in an MMU, the ablative itself performed well, and the CIPA applicator was afterwards carried as standard on all shuttle missions.
Assuming the TPS could be repaired, Challenger would have to be brought home in an unmanned configuration. This would require the astronauts to make a small number of switch configurations on the flight deck before departing, to enable Mission Control in Houston to command the deorbit burn. The Orbital Maneuvering System (OMS) and Reacation Control System (RCS) would be pressurized for a burn, the OMS engines would be armed, and the onboard computer system would be configured to allow ground command of the necessary actions.
This would bring Challenger out of orbit, but landing her would require additional modifications. By default, Mission Control had no capability to command the orbiter to start the Auxiliary Power Units (APUs) needed to power the aerodynamic control surfaces, nor to deploy air data probes or the landing gear. To make this possible, significant additional rewiring would have to be done by the crew, together with a number of software patches uplinked from the ground.
Fortunately for NASA, in Judith Resnick they had an expert electronics engineer on the spot. Together with support teams in Houston and Palmdale, Resnick devised a plan to rewire the shuttle to trick the on-board General Purpose Computers (GPCs) into thinking that the necessary switches were being flipped when Houston gave the signal.
This would involve prying off the panel covers, and replacing selected switches that would otherwise need to be thrown by hand with solenoids. These solenoids would be controlled via a tangle of cables running up to the GPCs, which would receive an emergency software patch containing the activation logic. When the computer sent the signal, the solenoid would effectively "flip the switch" it replaced, electro-mechanically tying the circuits to the GPC even though they weren't truly designed for it. It wasn't pretty, but in theory it should work.
Meanwhile, on the ground, a debate was raging over where Challenger should make touch-down. The Shuttle Landing Facility at Kennedy Space Centre was quickly ruled out due to the need to overfly large parts of the country before touch-down. This was deemed too risky in case anything should go wrong and the shuttle broke up in mid-air. Edwards Air Force Base, the landing site for the early shuttle missions, was considered, but in the end the 15,000 foot runway at Vandenberg Air Force Base was chosen for the attempted recovery. This had the advantage of being right on the coast, cutting down the risk of injuring bystanders, as well as having shuttle processing facilities on-site, simplifying the process of making the orbiter safe and assessing its status post-landing.
Raiding the Spacelab module for the necessary wiring and components, Resnick and ESA astronaut Gert Hendrick had completed the necessary modifications by June 20th, and then supported a further week of patching and testing to give confidence that it would work. With Thomas Ormston making a tile repair EVA on July 1st, the crew had done everything they could to make Challenger ready to return home without them. The focus on the station now turned to preparations for the arrival of Enterprise.
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Space Shuttle Enterprise, OV-101, Low Earth Orbit
12th July 1986
“Houston, Enterprise. Confirm we are at 500 feet from Skylab and holding. We still have eyes on Challenger. Range now showing three-three-one-seven feet, continuing to recede at one-three feet per second. Over.”
“Enterprise, Houston. We confirm your readings, Gordo. Skylab reports the docking port reset is completed and they’re ready to receive you. You can start final approach once Challenger reaches five thousand feet.”
“Copy that, Houston. Enterprise standing by.”
“You think she’ll make it home?” Coats asked his commander, gazing at the white arrowhead that was Challenger.
“The odds aren’t great,” Fullerton admitted. “But Hoot and his team have done all they can for her. It’s in God’s hands now…”
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Challenger felt nothing. It was just a vehicle. A machine. It did not have a soul.
Engines fired, velocity slowed. The long fall homewards had begun.
Many people tracked its progress as the shuttle descended towards the atmospheric interface. Mission controllers in Houston sat nervously over their consoles, sifting telemetry and tracking data, trying to anticipate all possibilities. At Vandenberg, landing support teams checked and re-checked their equipment, pausing now and then to gaze towards the westward sky, even knowing there would be nothing to see yet. In space, the astronauts aboard Skylab listened to updates, and prayed.
But the ship itself merely carried out its program.
The first touch of atmosphere caressed Challenger’s belly. A gentle tug which soon became a firm push, as molecules piled up in front of the speeding ship. Air compressed, hot with anger at this intruder into their realm, that ripped them asunder with its passage. Pushing, slowing, heating, the plasma fought against the shuttle.
As the shuttle passed over the Pacific and the plasma sheath around it grew larger, the TDRSS satellites and ground stations lost contact with Challenger. Tracking was easy to maintain visually, as the bright fireball streaked across the sky. So far, everything seemed to be going to plan, but so far everything was proceeding as it would on a normal re-entry. The modifications to the orbiter’s wiring had yet to be activated, and before then peak heating would reveal whether the repairs to the TPS were sufficient.
Here, on the wing, a weakness! The raging plasma flowed eagerly around the rough patch of cured CIPA paste on the right wing, and began to prise it away. Flake by flake, the protective material was worn away, carrying with it some of the airflow’s viscous heat… but at the price of thinning the shield between the ship and the plasma. It was a race, the outcome of which was life or death to the orbiter.
As peak atmospheric heating passed, the shuttle remained on a nominal trajectory. The ionisation layer that had cut Challenger off from communications began to thin, and Houston sent the command to trigger Resnick’s modified switches. The solenoids activated exactly as intended, signalling the computers to activate the automatic landing program.
A signal! A switch had been thrown in the cockpit which had never been designed for automation. Challenger had a crew! The shuttle scrambled to respond, powering up the APUs and deploying sensors. Filled with renewed purpose, she flexed her control surfaces and felt them bite into the raging airflow, using their pressure to bend the ship’s path to the design in its memory banks. The ship had but one duty now: to get her crew home.
As Challenger performed the standard approach S-curves over the Pacific, controllers in Housten began to relax a little. The TPS patch had held through its toughest challenge, and the software and hardware hacks that the crew had applied appeared to have worked as planned. Some of the older heads began to feel again the spirit of Apollo 13, bringing a mission home with a can-do, failure-is-not-an-option attitude that many had thought NASA had lost. The shuttle was now 200km from Vandenberg, still 45km high, but telemetry confirmed the computers had locked on to the air base’s TANS beacon and was homing in for landing. The worst seemed past.
It was a tiny gap. The last, desperate blow struck by fading ionised gasses against their tormentor. A gap had been opened in the ablator, and beneath, the aluminium skin of the orbiter had been briefly exposed to the hot airflow. The hole that had burned through was just a few square centimetres in area, and posed no problems to the aerodynamics of the glider as the computer steered for home. For just a few seconds, the wing interior had been lit by the last fluorescent fire of re-entry, before that fire had faded. Now a cooler draft flowed intermittently through the gap, dancing teasingly amongst the struts and wires of the wing box. A victory dance.
40km from the runway, as Challenger’s autopilot reached the point at which it would normally pass control to its human commander, the patched software triggered to keep the ship under computer control. Tracking cameras on the ground and in spotter planes monitored carefully as Challenger traced a descending circle 5km across and lined up on the 4500m runway at Vandenberg Air Force Base. The approach remained nominal.
Almost home! Challenger flexed her control surfaces and steepened her descent, eager to feel the touch of the Earth upon her wheels once again. There had been no more stray signals from the flight deck, even now, when the crew should have taken control. Still, the orbiter knew her duty. It would keep those she carried safe from a hostile universe. She would carry them to the stars, then bring them back to the mother planet. That was her purpose. Her destiny. Her challenge.
Altitude 2000 feet. Pull up now, slow the descent. The runway is directly ahead. Time to deploy landing gear… Deploy landing gear..!
++++++++++++++++++++
Vandenberg Air Force Base, 20th July 1986
Thomas Ormston looked on as the final pieces of Challenger were removed from alongside the runway and stacked on a flatbed truck. They would join the rest of the orbiter’s remains in the large hanger that had been cleared for the purpose. Over the next few months, the parts of Challenger would be analysed piece by piece for their story. Only once that process had been completed would a final report be published confirming the cause of her destruction.
Whatever that report finally concluded, Tom already knew the answer. His repair job had simply not been good enough. He had failed her.
He and the rest of the combined STS-24/500 crew had still been aboard Skylab as Challenger descended, making final preparations for their own departure. Everyone had paused their own work and gathered around the air-to-ground radio in the Lab to listen to the updates from Houston, relayed to them via the TDRSS network. As the orbiter entered blackout, Tom, acting on a strange urge, had reached out and touched the laminated copy of High Flight that had been left by the Skylab 5 crew. This instinctive invocation of good luck at first appeared to have worked, as Challenger made an almost flawless approach. But then, at the final moment, the right landing gear - housed just a few feet from where Thomas had patched the TPS - had failed to deploy. The voice from Housten described how the right wing had contacted the runway at more than 200 miles per hour, dragging the orbiter off the runway, where she had flipped and skidded to a halt. Any hopes that Challenger might fly again died in that moment.
Tom knew that he, too, would remain Earthbound from now on. Hoot had told him he‘d keep him on the flight roster, but even assuming that wasn‘t over-ridden by management, Tom just couldn’t face the idea of going up again. The Program would go on, he was sure. There was too much pride at stake, especially with the Soviets crowing over how their own shuttle had made flawless automated landings, and how, by placing the orbiter at the top of its launcher, their shuttle was immune to the sort of impact that had doomed Challenger. NASA would learn lessons and be flying again within a year. Not long after that, the Stars and Stripes would be raised again on the Moon.
But not by Tom. He‘d made up his mind before they‘d landed at KSC. Challenger would never fly again, and so neither would he.
Getting some flashbacks to Archibald's old "Columbia Rescue" timeline from a decade ago - in a good way, of course.
