Twenty years ago, in 1990, the Space Shuttle Atlantis was in orbit on mission STS-36. It had launched on the Department of Defense mission on February 28, during a classified launch window.
(Plymouth Colony in Massachusetts, taken from Atlantis on STS-36. NASA image.)
Astronauts John O. Creighton, John H. Casper, David C. Hilmers, Richard M. Mullane, and Pierre J. Thuot deployed a classified payload shortly after reaching orbit, and landed at Edwards Air Force Base on March 4th.
(Personal note: We were still at Edwards AFB at the time, but I don’t remember if I saw that landing. I was not on the recovery team for it.)
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