There weren't any, believe it or not. The Outer Space Treaty put the kibosh on most of the development. Things also got a lot more compact and tidy when satellites became capable of doing most of the stuff we were using capsules for. Our runup with the MOL/DORIAN talked the Soviets into Almaz, which had the tailgun out of a Tu-22 in it: The Soviets flew these three times, took some pictures of US ground installations, test fired the cannon to see what would happen (results were mixed) and gave up. Mostly. Until SDI. That's a 1mW CO2 laser heading up into orbit... until someone made a sign error on the programming and it rolled too much and launched into the sea. 'twould have been deeply destabilizing in that halcyon era of 1987. I'm still not convinced the CIA had nothing to do with that.