Outposts on the Frontier: A Fifty-Year History of Space Stations (Outward Odyssey: A People's History of Spaceflight)

by Jay Chladek

  The principal backer of AAP was NASA associate administrator for the Office of Manned Spaceflight George Mueller (pronounced Miller). Mueller was an electrical engineer with a doctorate in physics. He had twenty-three years of experience in research and teaching positions, along with a good eye for both management and practical engineering solutions. Mueller was a very capable manager, helping to organize the Office of Manned Spaceflight in Washington DC and establishing the pecking order of the other NASA centers based on what roles they would play in the development of hardware for manned spaceflight.

  George Mueller had already wielded his authority in mandating the use of “all-up” testing in the Saturn V rocket program. Prior to that point, rocket stages had been test-flown individually to verify their systems. He sensed that the Apollo program was most certainly going to fall behind schedule if the original rocket-testing process were used. So going against the wishes of the NASA centers, Mueller came up with the radical solution that all the Saturn V rocket stages should be stacked and tested live during one launch. The gamble would prove to be a successful one, as the two unmanned test flights of the Saturn V performed well with relatively few problems in 1967 and 1968.

  Mueller made some additional decisions regarding the Apollo program, as he wanted to see the capabilities of the spacecraft expanded and made “multimission” capable with the ability to do more than just fly to the moon and land on it. As production of the hardware got better, performance would improve. With these improvements, missions could be extended and more capabilities could be added.

  15. George Mueller charted the course of NASA’s post-Apollo future. Courtesy NASA.

  NASA astronaut selection was also looking toward the future. In June 1965 the fourth class of astronauts selected was made up exclusively of scientists. Many in NASA and Congress considered these appointments to simply be a political stunt to appease the National Academy of Sciences in their concerns that NASA should be doing more for science, but several of the new astronaut candidates had backgrounds and experience that were considered potentially important to NASA’s post-Apollo future.

  Of the six scientist-astronauts selected, only Harrison Schmitt had a scientific background that had a direct benefit to Apollo’s lunar-mission goals: geology. The others were either physicists or physicians. Almost all were required to take undergraduate pilot training once they joined NASA to qualify for jet flight, so it would be about a year before they could contribute in specific assignments as astronauts.

  The AAP office first opened its doors in August 1965. George Mueller’s intention for the program was to keep NASA’s work in spaceflight continuing at the conclusion of Apollo’s lunar program. Complex programs typically require a minimum of five years to get from drawing board to flight hardware. This time is needed for hardware design, systems testing, integration, and possible flight-testing before an operational mission can fly. Off-the-shelf hardware can reduce some of the work, but not by much since equipment still needs to be modified and tested to see if it works in its new role.

  If work did not start on what NASA would do next soon, there was a real chance that a large time gap would form between the last Apollo mission and the next manned spaceflight; the likely result would be program layoffs and budget cuts. Mueller knew that a great team of civil servants and contract workers had been established in the creation of Apollo, and he wanted to see that workforce kept intact after Apollo’s conclusion.

  But there was a catch with AAP. Since Apollo’s goal of landing a man on the moon was driving NASA’s budget, it meant there was practically no money left over for a follow-on program. There was also the question of what the mission of AAP would be. Building a space station seemed like a logical goal, but the exact roadmap to pursue for a station design was unclear. If AAP began work on a station, which path should it choose? Should it be all new or use off-the-shelf hardware as much as possible?

  Origins of the Wet Lab

  At the Marshall Spaceflight Center (MSFC) in Huntsville, Alabama, center director Wernher von Braun was also concerned about the future. Located on the grounds of the U.S. Army’s Redstone Arsenal, the job of this NASA center was to design and develop the Saturn family of boosters for NASA’s lunar program. It was the Saturn that got von Braun’s team transferred from the army to NASA, leading to the MSFC’s creation in 1960.

  By 1965, work was progressing steadily on the Saturn V as the MSFC was responsible for designing and testing the S-IC stage of the Saturn V and its F-1 engines. There were still many problems to overcome, but things were progressing steadily. Work was also finishing up on the Saturn IB booster being built for the Earth-orbit testing of the Apollo spacecraft. All this work was possible thanks to the original Saturn I two-stage rocket, which up to that point had been used for early testing of Apollo hardware and the launching of three Pegasus micrometeoroid detection satellites. With some tweaks to the Saturn I design, it might be possible to do other things with it.

  Engineers at Marshall had conducted studies to see if a spent S-IV rocket stage (the upper stage of the Saturn I) left in orbit could be converted into a space laboratory as a workshop of sorts. The Pegasus program already had proved that an S-IV-based spacecraft was possible. The Pegasus satellite payload remained attached to the spent rocket stage, and the resulting vehicle looked almost like a space station itself.

  The idea was a novel one. A Saturn I would launch an S-IV into orbit. The S-IV’s fuel tank would provide fuel to the rocket engines as normal. But at the front of the rocket stage would be an airlock assembly with a docking port for an Apollo spacecraft. The exterior of the rocket stage would be reinforced with insulation shielding to protect the interior. An Apollo CSM would be launched next, and it would dock with the spent S-IV stage. The astronauts would conduct space walks to drain the remaining liquid hydrogen (LHX) out of the S-IV’s large fuel tank and then repressurize it with gaseous oxygen to turn it into a space habitat for experiments. The idea of converting a spent rocket stage into a living space became known as the “wet lab” concept.

  Additional proposals and studies were done with the S-IVB rocket stage of the improved Saturn IB design. The Saturn IB was also facing the prospect of being a short-lived program, as there were no plans for its use once the unmanned and manned Earth-orbit testing for the Apollo program had been completed. The S-IVB offered even more potential for conversion into a space laboratory, as its internal volume was greater than that of the original S-IV stage. It was also more lightweight than the S-IV, meaning the S-IVB could potentially haul more equipment into orbit.

  Von Braun considered these proposals very carefully. His primary concern was to find a way to expand the role of the Marshall Spaceflight Center, and he wanted to do it for two reasons. First, he knew that without any follow-up rocket-stage development, contracts after Apollo and the role of the MSFC and its rocketry team would likely be broken up and sent to other NASA centers once the lunar program had concluded. Like George Mueller, but on a smaller scale, he wanted to keep the Marshall team intact. Secondly, von Braun also knew that in order for Marshall to survive, it would have to diversify its role in manned spaceflight and do much more than just design and develop rocket boosters.

  Douglas Aviation in California, the prime contractor for the S-IVB rocket stage, had also done similar proposals for a wet lab workshop, as they had been hoping to expand their role in manned spaceflight for many years. They saw space as the future of their company. They had bid on and won many contracts for both the DoD and NASA, including the U.S. Air Force MOL project; yet they had enjoyed only limited success. The MOL program was also classified, so they couldn’t share much of its development with any NASA programs. The relationship between Douglas and the Marshall Spaceflight Center was a healthy one, so each group bounced many ideas off one another to help flesh out a plan for the shape of what NASA’s first space station should look like.

  Eventually, a merging of the minds took place between Mueller, von Braun, and
Douglas Aviation. Personnel from the Manned Spacecraft Center in Houston (MSC, what would eventually become known as the Johnson Space Center, or JSC, after President Johnson’s death in 1973) also provided their input into the project and were encouraged by what they saw. MSC put together its own team of engineers to study the wet lab proposals, but there were many roadblocks that these proposals would have to overcome before becoming an operational program.

  The biggest factor to any AAP station proposal coming from Marshall, MSC, or Douglas moving forward was that it could not interfere with work being done on the lunar program, regarding either engineering or budget. Everything had to be conducted in parallel, because for all intents and purposes, it was a separate program in much the same way that Gemini and Apollo were parallel programs of one another. With luck, AAP missions might take place concurrently with the later Apollo missions, but the lunar program still took priority in mission planning and budget circles. Some provisions were made in NASA’s 1967 budget to fund AAP studies, but in the end, this only came to $42 million, which was little more than a drop in the very large bucket of what was needed.

  The Apollo Telescope Mount, a Mission for AAP

  As for what AAP would do with a lab once it got into orbit, a key piece of the puzzle began to fall into place in 1966. Observations of the sun from telescopes on the ground charted that the next peak of solar activity would take place in 1969–70. It would be nice if a solar observation telescope of some sort were ready to fly in orbit by then. Solar observations from ground-based telescopes share many of the same problems with telescopes observing other areas of the sky, thanks to the filtering properties of the atmosphere.

  Getting a telescope and other instruments to fly above the atmosphere could pay off big with scientific data about the star at the center of our solar system. Having a crew on orbit to operate the telescope could allow for data to be collected and analyzed in real time, as opposed to a remotely operated system where data would have to be beamed back and analyzed before new instructions were radioed up. Changes can take place on the sun very rapidly, and a manned system could adjust more quickly as needed.

  NASA’s Office of Space Science and Applications (OSSA) was moving forward with plans to fly such a telescope, but there were questions of what form it should take. Homer Newell, the head of the OSSA, began talks with Mueller in 1966 to see if such a telescope could fly as part of AAP. The OSSA was in favor of flying a small telescope in the service module of an Apollo spacecraft. The space intended for it was already being developed for later Apollo missions, and it would eventually become known as the SIM (scientific instrument module) bay. Mueller wanted to develop a more capable instrument, perhaps built into a modified lunar module (LM) with the idea being that a bigger telescope could accomplish potentially greater results. In August 1966, NASA deputy administrator Robert Seamans authorized the project to move forward and went with Mueller’s idea.

  The Apollo Telescope Mount (ATM) plan seemed like an elegant one. It would be built in a heavily modified LM descent module. The LM would not fly to or land on the moon. Instead, it would be flown in Earth orbit. The landing legs of the LM would be replaced with a large solar array that would generate power for the ATM. Additional sensors and detection equipment would also be fitted. Astronauts would fly the ATM from the LM’s ascent stage, using the onboard maneuvering thrusters. Astronauts would aim the ATM at specific regions of the sun during each orbit to collect data on points of interest. When done, an Apollo command and service module (CSM) would redock with the ATM, and the astronauts would reenter the CSM and come home. The ATM would fly free in orbit either to burn up on reentry or wait for another crew, depending on how it was outfitted. There was also the option of using the ATM for unmanned solar observations after the crew departed.

  There were some drawbacks to the design, though. First of all, a Saturn IB could launch either an Apollo CSM or LM (in original configuration or ATM configuration), but typically not both, unless the weight was kept down to a bare minimum. Secondly, Houston had concerns about using the LM in this manner because of the risk of astronauts being stranded in orbit with no way to return home, since it had no heat shield. Plus, with such a lightweight spacecraft, there were concerns that movement of astronauts inside the LM ascent stage would jostle the instruments and potentially corrupt the data. There was also a concern that the work required to turn a LM into an ATM would run the risk of putting Grumman Aerospace, the LM contractor, even further behind in their delivery schedule of the first LMs for flight-testing.

  Even with these roadblocks, work continued on the ATM, enough for a full-size mock-up to be built. Acknowledging the problems himself, Mueller proposed that it might be better to dock the ATM with the proposed wet lab orbiting workshop. The ATM still could fly free to conduct its observations, but it would remain tethered so that the astronauts would at least have a lifeline to get back to the workshop if a problem developed. In the end, the free-flying ATM concept was kept in reserve while other AAP mission ideas were considered.

  Things were moving along well until 27 January 1967. On that day, a fire at Cape Canaveral in the Apollo 1 spacecraft killed the crew of Gus Grissom, Ed White, and Roger Chaffee during a dress rehearsal a few weeks before launch. How and why the fire took place would have broad repercussions for the future of American manned spaceflight.

  A pure-oxygen system was used in Apollo, since it was easier to develop than a two-gas oxygen-and-nitrogen system. Earth’s atmosphere is made up of about 30 percent oxygen and 70 percent nitrogen, along with a few trace gases. During launch and ascent, the cabin pressure would bleed down to only 5 psi. At this pressure, the astronauts would still get the same amount of oxygen as they would receive on Earth. The use of 5 psi also meant that it was easier to design space suits that could operate during EVAs without blowing up like a balloon. The same practice had been used for both Mercury and Gemini with no problems. No one at NASA suspected that it might be a problem during Apollo.

  On the launchpad, in order to seal the cabin properly once the hatch had been closed, the capsule was pressurized to 15 psi, which is a little over atmospheric pressure at sea level (14.7 psi). At 15 psi in pure oxygen, materials that don’t normally burn will do so. When the fire broke out, it spread rapidly, and the internal pressure of the cabin went up even higher. The astronauts were unable to get out because the entry hatch of the block 1 Apollo command module was designed to open inward, not outward.

  With the loss of the Apollo 1 crew, the entire manned space program was put on an indefinite hold while the fire was investigated. For a large portion of 1967, all the NASA centers devoted many hours to investigating the cause of the fire and taking steps to prevent it from ever happening again. AAP’s goals were set aside temporarily. To help prevent a similar disaster from happing in the future, the spacecraft cabin would be pressurized at launch with an oxygen-nitrogen mixture, while astronaut crews sealed in their space suits would continue to breathe pure oxygen. As the cabin environment bled down to 5 psi on ascent, pure oxygen would replace the nitrogen for the rest of the mission.

  AAP Becomes a Space Program

  In 1968 AAP was given its own line item in NASA’s budget, which was the first major step to becoming an actual program. Astronauts were also being assigned to AAP. However, there were storm clouds on the budget horizon as opposition in Congress to the Apollo program had been brewing for years. Money had been funneled to NASA for a program that had yet to fly astronauts into space, let alone to the moon. The loss of the Apollo 1 astronauts didn’t help matters either. NASA’s budget for fiscal year 1968 was due for a major slash.

  Support for AAP was not going to come from NASA’s chief administrator, either. The man in charge of NASA at the time, James Webb, was not in favor of AAP. He let the preliminary work progress, but he also saw it ultimately as an obstacle. Webb’s primary responsibility for NASA, as he saw it, was to safeguard the lunar program. That meant that any program that intended to use
Apollo hardware was going to take a backseat to the lunar program in terms of financial and hardware support. Webb was rather vocal in expressing his disdain for AAP and never put forth any efforts to champion it to Congress. Even when AAP got funding, Webb treated it as a hedge fund to help keep development on the lunar program going without financial interruption.

  When the 1968 budget came out, there were cuts across the board by the House of Representatives. The Senate considered many of those cuts to be a bit too deep and reinstated some of the funding, but the damage was still done. A primary component of making AAP a robust follow-up program to Apollo was keeping the Saturn IB and Saturn V production lines going. Without more rocket boosters, AAP was shaping up to be a short program. Unfortunately, budget cuts forced the Saturn IB production line to shut down. So AAP would have to make do with already-built Saturn IBs to launch the wet lab and fly three manned missions to it, with a fifth rocket acting as a backup. The Saturn V remained in production, but it was exclusively intended for the lunar program and not AAP.

  AAP itself didn’t get all the funding needed to pursue its initial goals either, as it only received three-fifths of the budget that was requested. So grandiose plans featuring many spaceflights in support of an orbital workshop, a free-flying ATM, and other Earth science–based experiments were scaled back to a more modest proposal that could be done with fewer flights. Rather than becoming a major program in its own right, AAP was instead becoming a bridge from Apollo to whatever came next, whenever it might be. At least AAP was now an official program. With this funding and a mission mandate, work could now get underway to start building and testing hardware with a goal of flying the Orbital Workshop (OWS), a module that functioned as NASA’s first space station.