Millions remember the countdowns, launchings, splashdowns and parades as the U.S. raced the USSR to the Moon in the 1960s, but few know that both superpowers also ran parallel covert space programs to launch military astronauts on spying missions.

For the first time, an elite corps of ex-U.S. military astronauts tells the story of this other, top-secret space race, which might easily have turned into a shooting war in orbit. While the Apollo astronauts enjoyed ticker-tape parades, U.S. astrospies trained in total obscurity. Meanwhile, the Soviets actually built three manned spy stations. NOVA gains first-time access to a surviving Almaz station in a restricted Russian space facility, where an ex-cosmonaut demonstrates the high-powered spy cameras that were trained on U.S. cities. With a cannon designed to destroy hostile satellites—or attack American astrospies—Almaz was probably the only manned spacecraft ever equipped for space war.