In the high heat of a Houston summer, in early August 1973, controllers at the Johnson Space Center were faced with the very real possibility of orchestrating the rescue of three astronauts from the Skylab orbital station. Commander Al Bean, Science Pilot Owen Garriott and Pilot Jack Lousma had launched safely on 28 July and, after several uncomfortable days suffering the effects of space sickness, were beginning to hit their stride as they prepared to break the world endurance record by spending two months off the planet. Then, on the morning of 2 August, as Lousma prepared breakfast in the galley, he saw something strange through the window. He called Garriott over to take a look…and the two men were astonished to behold what looked like a snowstorm brewing outside! At first, Garriott thought he was seeing a beautiful auroral display – they were, after all, flying over New Zealand and through the southern auroral area at the time – but he was left open-mouthed as a flurry of snowflake-like particles (“a real blizzard”, he said later) flooded past the window. It did not take long to ascertain the cause. Shortly after launch, the crew had experienced problems with one of their four ‘quads’ of manoeuvring thrusters, spaced at 90-degree intervals around the circumference of the Apollo spacecraft’s service module. The troublesome unit (known as ‘Quad B’) had been shut down, but now as Bean and Lousma floated to the command module to check its systems they noticed that Quad D – directly opposite Quad B – was displaying erratic data.
Temperatures were plunging rapidly and the crew activated the quad’s backup heaters. An hour later, a further drop in temperature and pressure signified that the astronauts had a second leak on their hands. Garriott and Lousma’s visual observations confirmed this fact. In his NASA oral history, Lousma recalled seeing the oxidiser quantity readings falling on the meters and began shutting off the relevant valves, closing up the plumbing and ensuring that all was secure. But with two of their four quad sets now out of action, Bean and his men were left with only two functional quads…and at this stage the situation turned ugly, for the thrusters sets were a critical manoeuvrability asset and half of them were gone, less than a week into an eight-week mission.
The rate of oxidiser was low – around ten percent of the quad’s nitrogen tetroxide had gone – but Mission Control had no idea how quickly it might increase. Although the crew could use two, or even one, quads to get home, this was not an acceptable condition for re-entry, without further investigation. The questions came thick and fast in the next few hours. Was it a systemic flaw? Would there be a continuous string of failures? Or was it a purely random failure? No one knew. If the entire batch of nitrogen tetroxide used for the mission had been contaminated, a cloud of uncertainty lingered over the other two sets of thrusters, Quads A and C. And if the leak worsened, internal circuits inside the service module might make the entire spacecraft unusable. In a conversation with JSC Director Chris Kraft, Al Bean implored him to allow the mission to continue, but was told that a rescue mission – with a modified Apollo craft – might be attempted if the situation deteriorated. Rescue missions for Skylab had been extensively planned for more than two years; indeed, astronauts Vance Brand and Don Lind had undergone specific training to accomplish it.
On 13 August, Time magazine told its readers the unsettling news: that one of the service module’s four thruster quads had sprung a leak shortly after launch and another quad had proven inoperable a few days later. Not only was Mission Control concerned that all four quads were of similar design, but their fuel – and the fuel for the big Service Propulsion System (SPS) engine – originated from the same batch. If that batch was contaminated, NASA could have a ‘generic’ problem on its hands which might affect the whole spacecraft and prevent Bean, Garriott and Lousma from returning home safely. In theory, Apollo could be controlled with just one quad or even using the thrusters on the command module itself, but the risk of further deterioration prompted the space agency to take steps to implement a rescue. Of course, Skylab’s multiple docking adaptor carried two ports, which might permit a rescue craft to visit. Yet the effort itself to orchestrate a real rescue was an audacious endeavour and called for a second Apollo to be outfitted with five seats; two for its own pilots and three others for Bean, Garriott and Lousma. The stranded crew could then transfer from the station to the rescue vehicle and return to Earth. Assessments of the practicability of such a plan were first made in April 1971 and it was considered possible for NASA and its workforce to launch the mission at any time between ten and 45 days after being given the go-ahead. It was not a simple ‘paper’ exercise: by March 1972, NASA had committed itself firmly to having a rescue capability and sea-based trials, supported by Navy and Air Force helicopters, were undertaken later that year.
With Garriott focused on the scientific side of the mission, Bean and Lousma had been intimately involved in designing the rescue craft. In fact, said Lousma, they provided a rescue capability for the previous Skylab crew and would have ferried Pete Conrad, Joe Kerwin and Paul Weitz home in the event of unsurmountable problems with their own craft. “Al and I worked with Rockwell and the NASA engineers,” Lousma told the NASA oral historian, “in configuring a command module that had two flat couches underneath the three couches on top and that would handle five people. In the centre, between the two people on the very bottom floor, there was enough room to put some of the experimental data and other kinds of things you’d want to bring back for data reduction.”
The biggest concern, he added, was the potential ‘stroking’ of the upper deck of couches. Normally, the standard three couches were designed to ‘stroke’, or have their supports compress, like a shock absorber, in the event of a rough landing. If that happened to the returning rescue craft, the supports might compress…onto the astronaut in the couch below! However, since no couch had ever stroked during any of the previous dozen Apollo splashdowns, NASA considered the risk a minimal one.
Now, in the first half of August 1973, it seemed that a rescue mission might really happen. Preparations at the Kennedy Space Center now shifted into high gear, with efforts to ready Pad 39B for its second Saturn 1B launch in a few days. The spacecraft and booster to be used were those already earmarked to transport the third Skylab crew into orbit in November. On 3 August, the processing schedule was accelerated, with technicians and engineers working around the clock to ready the vehicle for a possible new role. The Apollo (known as ‘Skylab-Rescue’ or ‘SL-R’) would be stripped of stowage lockers in its lower equipment bay to accommodate the three couches and ‘ballasted’ with lead to compensate for centre-of-gravity offsets. Upon receipt of ‘the call’, the ‘field modification kit’ to turn a three-man command module into a five-man expanded ship would commence.
According to NASA documentation from the time, aside from safely returning both crews to Earth, the main objectives were to bring back ‘selected’ experiment data, perform a diagnosis of the failure of the original Apollo craft and configure Skylab for a revisit. In terms of experiments returned to Earth – “ironically”, said Al Bean – frozen urine specimens and dried faeces were of primary interest from a medical perspective, although Earth resources and Apollo Telescope Mount film tapes would also be brought home. Launch of SL-R was scheduled for 5 September, three-quarters of the way through Bean, Garriott and Lousma’s 59-day mission. On 10 August, the SL-R spacecraft was moved to the Vehicle Assembly Building for checkout.
By necessity, this work was abbreviated and it was expected that the spacecraft could be readied for installation onto the Saturn 1B booster and rolled out to the pad in just three days. Flight readiness checks would then be accomplished by 24 August, propellant loading would commence on the 27th and launch would occur a week later. The SL-R mission was expected to last no more than five days, ending with a splashdown in the Pacific on 10 September.
Of course, no daring rescue could possibly go ahead without a heroic team of astronauts. Since January 1972, Vance Brand and Don Lind had been in dedicated training, along with Bill Lenoir, as backups to the second and third Skylan crews. Additionally, Brand and Lind would pull double duty as the SL-R standby crew for both missions, though Lenoir had also trained for the role and was considered equally qualified. (“I was not in the discussion that selected the crew,” Brand told the NASA oral historian. “We just found out. Both were capable of doing that job. Bill was a scientist, but also an excellent engineer and pilot. Everybody cross-trained for everything.”)
However, as the commander of the rescue flight, Brand had his doubts. He had become very familiar with the schedule of launch preparations for both the spacecraft and its Saturn 1B booster and felt that the ‘long pole’ to achieving their 5 September target was getting the vehicle ready within a month. “I think we would have been lucky to be off 30 days after that,” he recalled, “but we were talking about that, aiming for that.”
When the trouble with Bean, Garriott and Lousma’s ship became clear, Brand and Lind spent most of August 1973 “figuring out how to rendezvous with them, where we would dock, outfitting our command module so that it had…padding on the aft bulkhead where people could lie…[to] get five people in the spacecraft”. In addition to the risk of stroking of the couches, the number of bodies inside the command module might also have posed difficulties after splashdown; if the spacecraft entered its ‘Stable 2’ orientation (nose-down in the water) it could prove disorientating for the crew.
On one occasion, Brand and Lind undertook training in the Gulf of Mexico in a mock-up of the command module. For the purposes of the five-man exercise, three other astronauts, including Bill Lenoir, joined them.
“Now,” Lind told Lenoir, “if we get in Stable 2, remember you’re on top of the vehicle, so when you unstrap, make sure you have a hold of a stanchion someplace.”
Lenoir gave him an incredulous look, which read: How dumb do you think I am?
Shortly afterwards, the command module entered the Stable 2 orientation. Lenoir was instructed to unstrap. Without thinking, he released his belt and – wham – fell several feet. He glared at Lind. “If you say one word,” he mouthed, “I’ll kill you!”
Many within NASA, including the astronauts themselves, believed that the rescue would most likely go ahead. The mood was lightened a little when further investigation confirmed that none of the oxidiser batches were contaminated and had not contributed to the leak. It also appeared that Quads A and C were unaffected and a subsequent investigation attributed the failure to undetected loose fittings in oxidiser lines.
Moreover, by identifying work-around procedures, Brand and Lind succeeded in developing an ability for Bean to undock from Skylab and complete re-entry without Quads B and D. The men also worked out a method of running both translational hand controllers simultaneously, and in opposite directions, to achieve translation capability and execute a de-orbit burn with only the command module’s attitude thrusters. “We were so clever as the backup crew,” said Lind, “that we worked ourselves out of a flight! You really didn’t want to have to go rescue them. You really wanted to bring them back safely with all their equipment.” Their workaround, together with the engineering expertise of others on the ground and of the crew in orbit, ensured that Bean’s crew could complete their scheduled 59-day mission. Rather than making a two-stage SPS burn for re-entry, it was decided that the men would perform a single burn, and that if there were no more quad leaks in the meantime the SL-R mission could be stood down.
As the situation began to improve, with the workarounds and the relief that the leaks did not highlight a systemic flaw and the oxidiser batches were not contaminated, plans changed quickly. For the men in space, there was little risk: they had no increased chance of fire or pressure loss aboard Skylab, they had plenty of food stores – even with a voracious eater like Lousma among them – and their only worry was the risk of having to come home early and curtail a mission which had already started later than expected due to space sickness.
The decision to remove SL-R from consideration changed virtually overnight. On 14 August, only days after the transfer of the spacecraft to the Vehicle Assembly Building, NASA announced that the launch vehicle was being retasked for launch no earlier than 25 September; effectively, the agency was removing it from immediate rescue duty, since Bean, Garriott and Lousma were already scheduled to land at around that time. This decision ties in with Lousma’s assertion to the NASA oral historian that “after about ten days or so” into the crisis, the crew was advised that they could stay aboard Skylab and continue their mission. On that same day, 14 August, the Saturn – now reassigned to its original purpose of launching the final Skylab crew – was transferred to Pad 39B to begin its own preparations. Still, when technicians finished loading hypergolic propellants aboard the rocket on 10 September, it remained in a ‘Launch Minus Nine Days’ standby status until Bean’s crew were safely back on Earth.
For Vance Brand and Don Lind, it was a bittersweet experience. “You really feel not just a professional obligation, but also a personal obligation,” Lind remembered, “to the fellows on the crew that you know so well to do that job very well. We did the best job we could and were able to convince management that we had enough redundancy to bring the guys home with the quad problems.” For Brand, who flew aboard Apollo-Soyuz less than two years later, given the choice, he would have preferred the joint flight with the Soviets, rather than having to lead the hairy SL-R mission. Still, commanding the world’s first-ever fully-fledged space rescue would have stood as an intensely rewarding achievement for the rest of his life. Today, almost four decades later, whilst it would have been ‘interesting’ to see Brand and Lind fly their mission, we should perhaps be thankful that they did not have to.
This is part of a series of History articles which will appear each weekend, barring any major news stories. Next week’s article will focus on the Skylab Medical Experiments Altitude Test (SMEAT), a 56-day simulation of a space station mission, completed at the Johnson Space Center in Houston, 40 years ago, this summer.Missions » Apollo »