Failure reason: Approximately 90 seconds before the intended launch, a bad valve caused nitrogen pressurization gas to enter the RP-1 turbopump of the Blok B strap-on. The pump began spinning up, but with no propellant in it, RPM speeds quickly exceeded its design limits which caused it to rupture and allow RP-1 to leak out and start a fire which quickly engulfed the base of the launch vehicle.

Soyuz T-10a, also known as T-10-1, was supposed to be the third long-duration expedition to the Salyut 7 space station. The mission would have launched Commander Vladimir Titov and Flight Engineer Gennady Strekalov on September 26, 1983, 19:37:49 UTC, however the launch vehicle was destroyed on the launch pad by fire. The launch escape system in the Soyuz spacecraft fired two seconds before the launch vehicle exploded, saving the crew. It is so far the only case in which a launch escape system has been fired with a crew aboard.

Mission type: Human Exploration · Orbit: Low Earth Orbit

Rocket: Soyuz U · Provider: Soviet Space Program