Wikipedia page on (OTL of course) U.S military spy satellites, the Keyholes. It is a fascinating program - as big as Apollo, but it ran much longer, and was hidden. And of course ITTL it will be impacted, because of the Agena connection - and Big Gemini.
https://en.wikipedia.org/wiki/Key_Hole
Gambit versus
Dorian: the NRO quixotic choice.
The KH-11 Kennan, first flown in 1976, marked the beginning of a conceptual revolution for the National Reconnaissance Office. Unlike all the spysats before it, the KH-11 beamed pictures electronically to the ground, real-time. All previous spysats had dropped rolls of film into reentry capsules snatched over the Pacific and brought back to the NRO headquarters, a cumbersome process that took days of time. Among those earlier satellites was the KH-8 Gambit.
As of 1971 the initial plan was for KH-8 to remain in service for years even after the KH-11 became operational in 1976. The reason was Gambit still provided high resolution photos of a quality that the KH-11 could not achieve from its higher orbit even with its bigger mirror.
But the KH-11 could provide photographs of fairly high quality nearly instantaneously. It was used to cover many more of the GAMBIT’s targets, and the KH-8 was then used much more carefully to photograph only those targets where its high resolution could be of greatest value.
But the Gambit had a major issue: it was based on an Agena.
In 1972 NASA picked up two major projects. One was Big Gemini for crew transportation. The other was to use Lockheed Agena as a versatile space tug.
Unbestknown to the civilian world, these two decisions had a major impact on the National Reconnaissance Office.
The NRO already massively used the Agena long before NASA. All Key Hole satellites from KH-1 to KH-8 were designed around an Agena bus. No less than 144 Coronas were launched, plus 82 Gambits and a handful of KH-5 and KH-6, for a grand total of
240 Agenas.
Corona was tasked with broad mapping at medium resolution. Gambit by contrast focused on the highest resolution, as small as a couple of inches.
Interestingly, NASA decision of using the Agena as a civilian space tug happened at a time when the NRO gave up the Agena bus for its future spy satellites. The KH-9, KH-10 and KH-11 were entirely different beasts.
Even with hindsight it is hard to guess what impact the civilian Agenas had on the KH-8 Gambit. Perhaps the massive production of civilian Agenas made KH-8 cheaper to build. But the civilian missions also inevitably attracted attention on the military Agenas, making the NRO bosses very nervous.
There was however another area where the civilian and NRO programs clashed.
The KH-10 Dorian, or Manned Orbiting Laboratory (MOL) concept was that two Air Force astronauts would look through the viewfinder and if they saw something interesting, like a Soviet X-plane on an airfield, they would press a shutter button and take a picture. In the mid-1960s, an American reconnaissance satellite overflew the Soviet submarine construction facility at Severodvinsk and got lucky: a Soviet submarine was out of the water, up on rails, and in plain sight, providing a rare view of its propeller. Normally when submarines are in the water their propellers are not visible, and knowing the number of blades on a propeller is useful information for knowing how fast a submarine is moving. Sonar operators on ships or other submarines can count the number of times the blades beat the water and estimate a vessel’s speed. So this photo was a real coup. Not too long after it was taken, it was used by an instructor who was then training Air Force astronauts. He showed it to them as an example of the kind of opportunities that they might find as they orbited the Earth, peering down on the Soviet Union.
MOL therefore had two acquisition optical systems, one per astronaut. The astronauts would work side by side, with their backs towards Earth. Each could peer through his own eyepiece that showed the terrain coming up ahead, as well as through another eyepiece that showed what the KH-10 optical system was seeing at that precise moment. These acquisition optics essentially looked over the astronauts’ shoulders to the ground below. The KH-10 had a primary and secondary eyepiece so that each astronaut could see the powerful view of the ground, good enough to see people walking on a city street.
Right from its beginning in 1964 the manned MOL clashed with the unmanned KH-8 for the high resolution missions. The KH-8 was a straight development of the KH-7 that flew since 1963, the year MOL was started. The first KH-8 was flown in 1966. By contrast with that very fast development, the MOL lagged behind, plagued by delays and cost overruns.
So one may ask, why was the KH-10 pursued for so long – until 1969, with a first flight in 1972 – when the KH-8 was doing the very same job since 1966, and at a much lower cost ?
One reason why MOL was pursued after the KH-8 went into service was simply a paradigm thing.
According to former NRO boss Alexander Flax "The Air Force generals were stuck on the idea that they could have an asset where a reconnaissance of any given location under the groundtrack could be ordered up on the basis of "Hey, guys, we think something odd is happening at Site Whatever, take a look and take shots of anything you find interesting." The way the MOL paradigm worked, you didn't take pictures of everything, you had human judgment deciding what merited the high-res imagery. When you get into a paradigm that, whatever else happens, it is always best to have a trained person selecting your imaging targets real-time, you pursue MOL even when it doesn't make sense.
So as early as 1966 the KH-8 and KH-10 clashed over the very high resolution mission. The battle was over in 1969, when the KH-10 was canned.
But in 1972 a chain of events brought back the old rivalry.
The MOL was reborn from the ashes in the shape of a military Big Gemini. Incredibly, a lot of MOL hardware had already been build at the time of its cancellation in 1969, and it went into storage in Area 51. among hardware build were a handful of extremely powerful cameras, with a 1.8 m diameter mirror.
What the Air Force wanted was to fly MOL hardware on Big Gemini ships borrowed from NASA and called Blue Helios. That would be much less expensive than building MOL from a clean sheet of paper.
As we saw earlier the initial plan was for KH-8 to remain in service for some years even after the KH-11 became operational in 1976. The reason was Gambit still provided high resolution photos of a quality that the KH-11 could not achieve from its higher orbit even with its bigger mirror. But the KH-11 could provide photographs of fairly high quality nearly instantaneously. It was used to cover many more of the GAMBIT’s targets, and the KH-8 was then used much more carefully to photograph only those targets where its high resolution could be of greatest value.
But that reasonning also applied to Blue Helios. Just like the KH-8, the KH-10 camera system provided very high resolution photos of a quality that the KH-11 could not achieve from its higher orbit even with its bigger mirror.
So the NRO had to chose between the two systems. On paper the KH-8 had many advantages over Blue Helios – it was much less expensive and worked fine. But there was a major drawback with the system. NASA and civilian space companies were using Agena massively in the space tug role. Inevitably that drew attention to the military Agenas, making the NRO extremely nervous. Relations with NASA and Lockheed were extremely tensed. At the end of the day the NRO preferred to remove the Agena-based Gambit from service and fly a handful of Blue Helios missions instead. Blue Helios missions were flown at slow rate – one every 18 months, and worked in tandem with KH-11 satellites.