Part 13B: Все Одновременно (All At Once)
Small Steps, Giant Leaps - Part 13B: Все Одновременно (All At Once)
May 15th, 1976
Apollo-Soyuz Test Project MET 75 hours, 30 minutes
Rehydrated peaches were surprisingly good, all things considered.
Jack Swigert rested by Fortune’s window, idly eating a bag of rehydrated peaches by the spoonful as he watched the planet turn below. Apollo and Soyuz were positioned near-perpendicular to Earth, giving him a decent view of the sunrise over the green-blanketed side of Yupiter. Despite this being his second spaceflight, he’d only ever really witnessed Earth orbital sunrise once, fleetingly on Apollo 8 after TLI.
Behind him, his Command Module Pilot chatted back and forth with Houston on a headset, finishing up the night’s housekeeping before the rest period. With no headset himself, Jack only heard the one side, Fred’s occasional “Okay”s and “Will do”s and the occasional bit of technical talk, the click of a dial or a switch here or there. Jack was really only half-listening; Fred knew what he was doing, he didn’t need a babysitter.
Looking out over the blue world below, Jack thought he spotted an island. They were somewhere over the middle of the Pacific right now, a really beautiful view. He turned back towards Fred to ask for a camera. “Hey Fredo, could ya-”
And that’s when something unexpected happened.
There was a distant bang, like an old car backfiring. Jack felt the whole structure of the spacecraft shudder slightly. He closed his bag of peaches and set it aside, sliding into the center seat.
Sitting in the left seat, Fred looked a bit in shock as he keyed his mic.
"Houston, we've, ah- we've got some kind of situation-"
Jack pulled a headset on and went to key his own mic as well, but a burst of static over the comm cut both him and Fred short. As it dissipated, the voice of CAPCOM Bob Lawrence once again filtered through.
"This is Houston. Say again, please."
Jack took it this time. "Houston, we've got a situation up here."
In moments of unexpected stress, the human brain tends to choose one thing to fix upon in particular - whatever it, in the moment, calculates to be the most likely cause.
In this case, right here and right now, Commander John Leonard "Jack" Swigert Jr.'s mind jumped immediately to the previous night.
‘The Docking Module.’
On the night of May 14th, the crew of Apollo had been awoken an hour into their rest period by a Master Alarm indicating low oxygen pressure in the Docking Module. Though easily fixed by slightly increasing flow, it'd stuck with the Commander as a minor worry, something else to juggle on a busy mission.
And now, in the midst of this crisis, Jack was all but convinced that the DM was the source of the trouble.
"- pretty large bang associated with the Caution and Warning there,"
As Fred continued to relay everything down to Houston, Jack turned to his other crewman, Joe Engle, as he clambered up to join the two of them in the right seat. "Joe, check the DM pressure, I can't help but think it just popped."
Joe reached for the console and flicked a dial. "Pressure looks nominal."
Taking that initial panic about a Docking Module and shoving it to the side, Jack surveyed the situation - Main Bus B undervolt, computer restart, fluctuating O2 tank readings. Not the Docking Module, then; something electrical, something gone funny with the computer or the power system down in the Service Module. Faulty readings.
In the minutes following, the crew aboard Fortune and those in Mission Control would scramble to find an answer to their problem, what’d caused the spacecraft to suddenly panic like this and begin tumbling. Some 5 minutes after the initial issue, with the situation still relatively unclear, NASA’s counterparts in Moscow would join with vital information: reports of “visible damage to Apollo” from the crew aboard Soyuz, themselves wrestling with orientation issues as the spacecraft they remained docked to fired its thrusters erratically.
This perspective from the Soviets changed the conversation immediately - from one of instrumentation failure and computer troubles, to one of physical damage to Fortune’s systems. Theories ranged from a meteor strike or an impact by a piece of orbital debris, to an internal fire or explosion.
What mattered, though, was that the Apollo spacecraft was damaged, and something needed to be done about it. It became abundantly clear early on that the gas seen venting into space by the crew of Soyuz was from an oxygen leak in Fortune’s Service Module, backed up by some of the on-board sensor readings and the failure of Fuel Cells 1 and 3, which used oxygen as a reactant with hydrogen to produce electricity.
Were both the oxygen tanks to empty entirely, the SM’s final Fuel Cell would die, leaving the spacecraft without the power needed to return home. There was only one option left: isolate the Command Module’s “surge tank” supply of oxygen, to ensure that, when the time came, the Command Module itself would have the power and air available for re-entry. In the meantime, the limited remaining oxygen in Tank 1 would either leak into space or be consumed by Fuel Cell 2 - meaning that regardless of what happened next, Fortune’s Service Module would run out of power in the next 3 hours.
This, then, meant an immediate emergency abort - the second in the history of NASA after Gemini 8, and one extremely time-sensitive. Working alongside their counterparts in the Soviet Union, the two space programs formulated a series of small maneuvers with Yupiter’s thrusters to lower the two still-docked spacecraft to a point where Fortune (whose own RCS supply had been depleted somewhat trying to hold steady after the accident) could re-enter on thrusters alone without a need to fire its (very possibly damaged) Service Propulsion System.
The planned third day of joint operations for Apollo-Soyuz, which would have included undocked “formation flying”, solar observation experiments, and an additional docking operation, was canceled entirely. Both Fortune and Yupiter would have their missions cut short, with Soyuz 20 sacrificing much of its own limited orbital propellant supply to save Apollo and subsequently performing its own emergency re-entry on the next orbit.
"- checked those burn parameters and it looks like you've got them in right, Jack. Fortune, you are Go for undocking and deorbit."
"Thanks, Bob- sorry we couldn't keep you busy for longer."
With the Commander keying everything in and Houston giving the final go-ahead for Apollo’s hastily-improvised RCS-only deorbit, Fred Haise now faced perhaps the most daunting task of his entire life, moreso even than walking on the Moon itself: flipping a single switch.
On the console in front of him, just to the left of where he sat center seat, was a switch labeled LM JETT - ‘Lunar Module Jettison’, in this case inaccurately labeled. Once that switch was thrown, Fortune would be free of the Docking Module - and free of Yupiter, thus far their only companions throughout this entire ordeal. In every other harebrained rescue plan Rockwell, Houston, and Moscow had thought over for the short hour they’d had, that Soyuz spacecraft was a key component; everything from abandoning ship entirely and reentering together in Soyuz, injuries be damned, through spending a night aboard and jumpstarting Apollo in the morning. In the end, they’d gone with the simplest option. Relying on a damaged Service Module had its own risks, but Soyuz would at least be flying in close formation until the burn started, ready to lend aid. Even if the entry batteries somehow ran out of power during descent, Fortune's parachutes were already primed to open automatically and the crew’s suits would keep them alive.
With more than a bit of reluctance, Fred flipped the switch, and with a quiet thunk, Apollo and Soyuz finally parted ways.
From the left seat, Jack managed the maneuver with a practiced hand. “We’re clear, I’d put separation at about 1 meter per second. Happy trails, Yupiter- wish we could’ve parted under better circumstances.”
From over the shared comm, the voice of Alexei Leonov. “Good luck, Apollo. We hope to see you on the ground soon, my friends.”
[Fortune with its damaged Service Module, as imaged by Flight Engineer Vitaly Sevastyanov aboard Soyuz 20.]
Reentry felt somewhere in the general region of torture for Docking Module Pilot Joe Engle.
It wasn't just the constant, crushing G-forces, the rattle and shake of the capsule screaming through the atmosphere - though that was admittedly spooky to experience firsthand after years of just hearing about it - but also the distinct awareness that, here inside this little cone of metal, the three of them didn’t know for certain that they were safe. The explosion that’d crippled Fortune could very well have punched through the Service Module and nicked their heat shield, damaging the only thing standing between them and a very quick demise.
Though a trained pilot, it was hard for Joe’s brain not to cling to those animal instincts of fear - every groan of metal, ever rattle of a frantic RCS thruster firing, sounded like the heat shield giving way, the hull breaking apart, the burning plasma surrounding their vehicle clawing its way in to turn the three of them to genuine all-American bar-be-que. In a moment like this, there’s not a hell of a lot a pilot can do. So for those 8 long minutes, Joe simply sat there, braced in his seat, and silently prayed.
Finally, though, the glow around Fortune’s windows began to abate; the eerie will-o-the-wisp glow was replaced slowly but surely by the darkness of the night sky over the Pacific outside. The G-forces let up as well; a dull pop-pop could be nothing other than the mortars firing to deploy the drogue parachutes. Here in the little bubble of his spacesuit helmet, Joe let out a breath he didn’t even know he was holding.
And finally, a crackle over the comm, and the reassuring voice of home, personified by none other than backup Commander Al Bean:
“- is Houston, do you copy? Fortune, this is Houston, do you copy? Over.”
Jack, who’d just removed his own helmet and tossed it down into the Lower Equipment Bay, let out an exhausted laugh.
“Roger, Houston, we read you loud and clear. Boy, is it good to hear you again.”
Immediately following the emergency return of Apollo Fortune (and the subsequent, thankfully nominal landing of Soyuz 20 Yupiter a few hours later in the Kazakh SSR), both NASA and the Soviet space agency began investigations into what exactly went wrong, continuing to communicate with one another to build a picture from both sides. These two entities - the “Apollo-Soyuz Review Board” on the American side and the “Special State Commission on Apollo-Soyuz Mission Incident” on the Soviet side - left no stone unturned, examining the returned capsules extensively; poring through production histories of every mission component; reading and rereading flight recorder data.
As was standard for every spaceflight both Soviet and American, the crews were debriefed afterwards; in this case, however, the astronauts and cosmonauts would be interviewed much more thoroughly to build a more accurate timeline of events.
In the end, after 3 months of investigation, the reports were published and presented to their respective governments in late August, with a smaller companion “joint report” compiling data from both.
NASA’s Apollo-Soyuz Review Board concluded that, in the simplest of terms, the failure of Fortune’s Service Module on May 15th, 1976 was caused by an explosion of Oxygen Tank 2 due to faulty wiring. Service Module-109, originally assigned to Apollo 13, sustained minor damage during a fall in late 1969 during spacecraft assembly operations. SM-109 had been pulled from flight, disassembled, and inspected, with several damaged components being replaced. Not counted among those parts replaced were the two oxygen tanks; an external inspection of both Tank 1 and Tank 2 revealed no damage. This missed damage to the internal fill line in Oxygen Tank 2 formed the first part of the failure. The second part came over half a decade later, during Apollo-Soyuz’ Countdown Demonstration Test in April of 1976, when Oxygen Tank 2 failed to empty completely at the end of the test. NASA ground engineers, not wanting to replace the tank and delay the mission up to a month, elected simply to boil the remaining oxygen out of Tank 2 using the internal heaters and fans - a process with existing precedent in ground testing and in a similar tank issue on a previous launch - and which worked, at the unknown cost of damaging teflon insulation around the wiring for Oxygen Tank 2’s internal fans due to a heater failure caused by an electrical incompatibility. This damage, now “baked in”, would cause the wires to short when the fans were activated to stir the tanks, producing a spark which, in the pressurized pure oxygen environment of the tank, ignited the teflon insulation in a fireball which ruptured the tank and blew an exterior panel off of the Service Module, damaging surrounding systems in the process.
This case of oxygen tank damage was not the first time this sequence of events had occurred - only the first time they had resulted in catastrophic failure. Investigation into similar issues on the ground showed that another tank - initially assigned to Apollo 10 before being removed and switched to Skylab 2 after a similar case of minor damage - failed to drain completely during Skylab 2’s own Countdown Demonstration Test, and was similarly emptied using the heaters to boil off excess oxygen rather than delaying the mission by replacing the tank. This, in turn, would embolden ground crews on Apollo-Soyuz to do the same.
The Apollo-Soyuz Test Project, in historical hindsight, is best regarded as an “abridged success”. The years of preparation and training for the mission gave personnel at NASA and in the Soviet space program experience working with one another, opening unprecedented lines of scientific communication between the two great space powers which would, in some form or another, continue to be utilized throughout the latter half of the 20th century and into the 21st. The explosion of Fortune’s Service Module served as an unexpected test of international cooperation during a crisis, in its own way.
It is impossible to look at Apollo-Soyuz without, to some extent, also examining the problems of Project Apollo as a whole. America’s third crewed spaceflight program was not without its share of issues and glitches over its decade-and-a-half span of development and flight, but none perhaps so serious, so deadly as that which afflicted Apollo-Soyuz. By some cruel stroke of luck, it was only on the final mission of the program, only when Apollo had another spacecraft to rely upon, that such a failure occurred. We exit the realm of history and enter that of speculation when we begin to ask, “What if?”; what if Skylab 2, with an oxygen tank very possibly damaged in a similar fashion, hadn’t dodged the same bullet? What if, in some other world, such a failure had occurred on a lunar mission, days away from home and with no chance at rescue? The answer, in the latter case, is surely one of grim outcome. What might also be said through Apollo-Soyuz about NASA safety culture in the Apollo era, of “Go Fever” and corners cut, shall be left for the reader - and other works - to consider.
Regardless, with the final mission of Project Apollo now consigned to the pages of history, NASA could now, at this point, look forward to the promise of the future; to the Space Shuttle, and all of its potential.