One of the problems with the early series of spy satellites was simply this: Every photo frame counts. And many of the photographic frames returned by the early CORONA satellites were of cloud-covered sites. It was accepted as a risk that the weather wouldn't always cooperate. The automatic control worked well enough that pictures were only taken during daylight, but whether the actual meteorological conditions would allow collection of useful intelligence was something that would only be known once the film capsules were recovered and developed.
What they really needed was a way to determine -- in real time -- if a target's lighting and cloud cover would allow a useful picture to be taken. And in the early 1960s, the only way that was known to actually do that was to have a man on the scene to make that call.
This was the genesis of the project that became known to the public as the military's Manned Orbital Laboratory. To the public, it was a military space station for scientific research and experiments.
It also had another designation, one kept a close secret for many years. Its actual payload was called Key Hole 10, or DORIAN. It was in development from 1963 to 1969, when it was cancelled.
Why was it cancelled? Not necessarily because it was big and heavy -- its successor, KH-11, wasn't exactly slim or cheap. It was because computers and communications had become good enough that the "man on the scene" could be a technician in Sunnyvale, California; as opposed to an astronaut in orbit.
Details were few and far between. Even up to a few years ago very little was known about its actual layout. Little by little, that began to change.
First came the leaks. Nothing says locked up forever. Alert enthusiasts pored over publicly-available pictures -- there always were some -- and made some educated guesses based on what was known about its size and weight. The external dimensions were known, for example. And the payload capacity of its Titan IIIC booster were also fairly well-documented. From that, you can figure out what it could and couldn't lift into a Sun-synchronous orbit from Vandenberg AFB. Little by little, more information came out.
And then, NRO recently declassified a whole bunch of material.
This makes for fascinating reading.
For one, even nearly fifty years later, there are labels and even whole pages still redacted. We can speculate why, but the obvious conclusion is that even so many years down the road, those might give away currently-relevant capabilities.
For another, even though they settled fairly early on an entry hatch through the modified Gemini heat shield, and even did a flight test to make sure it would work, they always had a "Plan B" for the astronauts to get back in the return capsule.
Yet another, the original MOL was just the beginning. There were follow-on plans for version capable of being resupplied in-orbit, using uprated Large Diameter Core (LDC) Titan boosters.
In the end, though, the Nixon Administration decided the juice just wasn't worth the squeeze. A TV camera and an encrypted radio link could let a ground-based technician decide what was worth spending a frame of film on, obviating the need for a crew. Soon the film capsules themselves would be rendered obsolete.
But that wasn't the end of the military space station. As the Soviets often did, they decided that anything the Americans spent that much money on was worth trying at least once. The space stations Salyut 2, 3, and 5 were actually Almaz military reconnaissance stations. The two key differences between Almaz and MOL were that the Almaz stations were serviced by Soyuz capsules launched separately, and that the Almaz stations were armed. Not that it made that much difference. Having lost one station to launch failure, and finding that the two flown versions didn't actually do that much, they dropped the idea as well.
In the end, though, the longest-lasting legacy of the MOL program were the men selected to fly it. Seven of them were selected by NASA when the project was cancelled. Six of them became Space Shuttle pilots and commanders, one became a mission specialist. One of them, Richard Truly, became Administrator of NASA between 1989 and 1992. One of the MOL astronauts not selected by NASA, James Abrahamson, would go on to run the Strategic Defense Initiative from 1984 to 1989.
