the Soviets, Soyuz 1 being the first (although Soyuz 18a was a ballistic reentry, and Soyuz 24 reportedly also was one). The high G-loads during reentry were a mix of crew error and a design flaw in the autopilot; because the backup engine produced less thrust than the main engine, the autopilot tried to run it until the proper delta V was achieved, but the cosmonauts issued a manual shutoff command after 213 seconds of burn time. This unwise decision resulted in a ballistic reentry. This would have caused the Soyuz to land uprange of the planned landing point, but the low delta-V (as the result of the crew manually shutting off the engine early) resulted in the opposite effect and instead, the capsule touched down very close to the target area. An investigation lasted a month and found that the part that failed had been tested 8,000 times previously without failing, and the Soyuz engine had fired some 2,000 times since 1967, also without a single failure. But the engine was modified for the next flight, and a vacant Soyuz with the newly modified engine, Soyuz 34, was sent to the orbiting Salyut for the crew there to return with. References External links Soyuz 33 chronology at videocosmos.com Crewed Soyuz missions 1979 in the Soviet Union Bulgaria–Soviet Union relations Spacecraft launched in 1979 Spacecraft which reentered in 1979 Spacecraft launched by Soyuz-U rockets