Milestones in Space Exploration: The Manned Orbiting Laboratory

Throughout the 1960’s, television audiences around the world watched as the United States launched Mercury, Gemini and Apollo space ships in a race towards the Moon. But at the same time, in total secrecy, another set of astronauts was carrying out another space race with an entirely different purpose.

MOL Gemini B test capsule at the US Air Force Museum, Dayton OH


When the Cold War broke out in the late 1940’s, the US was completely dependent upon air reconnaissance to learn what was going on inside the Soviet Union. When Francis Gary Powers’ U-2 was shot down, that put an end to manned overflights of the USSR. The Americans rushed a number of photo-reconnaissance satellites into space, but they often brought back photos of nothing but cloud cover. The satellite cameras, moreover, used high-resolution photographic film (capable of seeing objects only 2-3 feet wide) that had to be returned to earth from space for developing and inspection. By February 1962, the Air Force decided that what it really needed was a manned space satellite, which could overfly the Soviet Union without fear of being shot down, and which had people on hand to take and develop pictures and make on-the-spot decisions about interpretation and target selection.

In December 1963, President Lyndon Johnson announced that the Air Force would be taking up a new manned space program, independent from NASA, which would use military astronauts to perform experiments in low earth orbit, as part of an effort to understand how humans could live and work in space. Three groups of astronaut trainees, 17 in total, were soon selected for the project–8 in 1965, 5 in 1966, and 4 in 1967.

It was a cover story. The real purpose of the Manned Orbiting Laboratory (MOL–pronounced “mole”) was to spy on the Russians. The core of the satellite was the supersecret Keyhole KH-10 “Dorian” camera. Essentially a large reflector telescope that was aimed down at the earth rather than out into space, the KH-10 could detect objects the size of a softball. At launch the MOL would be placed on a Titan III rocket. Above it would be a modified version of NASA’s Gemini space capsule known as the Gemini B, which had an exit hatch built into its heat shield. This allowed the two spy-astronauts to crawl through a tunnel into the 25-foot long MOL module where the Keyhole telescope/camera was. They would spend the next 30 days in polar orbit, watching through a viewscope and photographing everything below them that looked significant or interesting. The Gemini B would then return them to Earth. The MOL would remain in orbit, to be re-occupied later by another Gemini B crew. After a time, the MOL module would be intentionally de-orbited and burn up in the atmosphere, to be replaced by another launch.

Immediately, there were technical challenges. The first question to be tackled was how to transfer the spy astronauts from the Gemini B capsule to the MOL module. At first it was assumed that each component would be given a hatch opening to the outside, and the astronauts would simply “space walk” from one to the other. But this carried a large risk that the Air Force couldn’t afford, since any accident would subject its secret program to unwanted scrutiny. Next, a flexible pressurized tube was proposed that could be attached to each craft. That would require too many modifications to the spacecrafts, though. The solution that was finally adopted was to put an exit hatch in the bottom of the Gemini capsule, through the external heat shield, which would open into the MOL module and allow easy transfers.

The next problem was finding a power source. The computers needed to run the Keyhole camera system as well as the space ships would require significant amounts of electricity. Batteries added too much weight, and wouldn’t provide enough longterm power. Solar panels would be too bulky and unwieldy on such a small ship. So it was decided that the MOL would use the same hydrogen-oxygen fuel cell that NASA was planning for its Gemini and Apollo spacecraft. But these were not yet operational, and the Air Force had to assume that they would be flight-ready by the time the MOL was to be launched.

Finally, there was the problem of the launch-escape system, to rescue the astronauts if the rocket booster exploded on the pad. In Mercury, a small solid-fueled rocket had been mounted to the nose of the spacecraft: if the booster rocket malfunctioned, the escape rocket would pull the Mercury capsule off the rocket and carry it a safe distance away. In NASA’s Gemini, this system was abandoned in favor of two rocket-propelled ejection seats that would fire if there was a problem with the booster rocket, landing the astronauts by parachute a safe distance away. But the Titan III rocket being used for the MOL, with its two attached solid-rocket boosters, was significantly larger than the Titan II used for Gemini, and the ejection seats were not powerful enough to carry the astronauts far enough away. So the Air Force was forced to compromise by using an escape rocket at the base of the mating ring to push the capsule clear of the booster, then use the ejection seats to blow the astronauts out to a safe distance.

All of these requirements were adding weight and complexity to the system. Since it wasn’t certain that the integrity of the heat shield would not be compromised by putting a hatch through it, a test flight was necessary. In November 1966, a test module was launched from Cape Canaveral under the cover story of a “technical test flight”. It contained a Gemini B with the hatch installed in its heat shield, and a mockup of the MOL module made from a Titan II fuel tank. The Gemini B was only intended to make a suborbital flight, separating from the MOL mockup as it reached space and re-entering to splashdown. The MOL mockup continued to orbit, where it deployed three military satellites. When the Gemini B was recovered, the heat shield was still intact and had worked perfectly. The MOL concept was technically workable.

Meanwhile, the 17 MOL astronaut spies were, like their NASA counterparts, heavily involved in the planning and design of the spacecraft’s components, as well as constant training for their missions. Like the NASA astronauts, they divided up tasks between them: some of the group were involved with the design of the Gemini B capsule, some took on the task of helping to design the MOL module which housed the Keyhole camera. One of the group, Navy pilot Robert Crippen, had applied to both NASA and the MOL programs, and when he was accepted by both and had to make the choice, he chose the Air Force MOL, deciding that it would give him a better chance of actually getting a spaceflight. He was assigned to monitor the development of the training simulators used by the group.

An entire new launch complex was built at Vandenberg Air Force Base in California for Titan III MOL launches. Air Force technicians developed a Manned Maneuvering Unit (MMU), a backpack-like device with small jets that could be used to travel untethered through space, piloted like a tiny spaceship. It was intended to allow MOL crewmen to secretly fly over to any nearby Soviet military satellites and give them a close inspection.

Technically, despite some setbacks and difficulties, the MOL program was coming together. But by 1969, the biggest problems were financial and political. The program had nearly doubled its projected cost: it had already spent $3 billion and still needed at least another three years before being flight-ready. NASA was afraid that the project would not only duplicate its own efforts, but would blur the line between the civilian and military space programs. The CIA had opposed the MOL from the beginning, arguing that the four-inch photographic resolution planned for the KH-10 Dorian camera was unnecessary for intelligence purposes and just added cost and complexity. The US was also already working on the newer Keyhole KH-11 “Kennan” camera system, which would be more capable than the KH-10 (it had a three-inch photographic resolution, and could also send digital photos back to earth by radio) and could be operated from an unmanned satellite, removing the costs and risks of sending a manned crew into space.

The writing was now on the wall. The MOL project was viewed as an expensive and unnecessary duplication of effort, and was cancelled in July 1969.

But parts of the program lived on. The MMU, originally designed to secretly inspect Soviet satellites, was adopted by NASA and used as part of its Space Shuttle program for satellite repair in orbit. The launch complex at Vandenberg was modified and used for placing Space Shuttles into polar orbit. Under an agreement with NASA, those MOL astronaut trainees who were age 35 or under were offered slots in the civilian space program: in all, seven of the fourteen MOL astronauts joined NASA, and all of them flew on Space Shuttle missions. Robert Crippen flew on the first Shuttle test flight, and became Director of the Kennedy Space Center. His partner on the first Shuttle flight was Richard Truly, another former MOL trainee who would go on to become Director of Naval Space Operations and then Director of NASA.

When the Soviet Union learned about the MOL program, meanwhile, they decided that they had to have one too. So in 1970 they began a series of spacecraft under the Almaz program, which used the new Soyuz crew vehicle and space hardware modules being developed for use in the Salyut space stations. Three Almaz manned-telescopes were launched, under cover of the civilian Salyut series. But the Soviets learned, as the Americans had before them, that unmanned spy satellites were just as capable as manned systems, and they cancelled the Almaz program.

Today, one of the test mockups of the Gemini B space capsule developed for the MOL is on display at the US Air Force Museum in Dayton OH.

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