Mission type Test flight Spacecraft type Soyuz 7K-OK Period 1.5 hours Rocket Soyuz | Mission duration approximately 48hr Manufacturer OKB-1 Dates 7 Feb 1967 – 9 Feb 1967 | |
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Launch mass 6,450 kilograms (14,220 lb) Launch date 7 February 1967, 03:21 (1967-02-07UTC03:21Z) UTC | ||
Kosmos 140 (Russian: Космос 140 meaning Cosmos 140) was an unmanned flight of the Soyuz spacecraft. It was the third attempted test flight of the Soyuz 7K-OK model, after orbital (Kosmos 133) and launch (Soyuz 11A511) failures of the first two Soyuz spacecraft.
The followup to Cosmos 133 was planned for 14 December, but ended disastrously. At liftoff, the Blok A core stage of the 11A57 booster ignited, but not the strap-ons. A shutdown command was immediately sent and pad crews began to move the service towers back in place and drain the propellants. This task was completed for the core stage and strap-ons, and then about 30 minutes after the attempted launch, the escape tower suddenly fired. Its exhaust caused the Blok I third stage propellant tanks to overheat and explode, killing one person on the ground and damaging the Soyuz and core stage/strap-ons beyond repair. LC-1 was also badly damaged and took a month of repair work in the frigid Kazakh winter to be restored to use. The reason for the LES firing was thought to be either a timer being activated due to the Earth's rotation affecting the gyroscope package in the launch vehicle or perhaps one of the service towers bumping it.
In February 1967, the backup booster and spacecraft were set up at LC-1 and the planned mission could be carried out.
The spacecraft suffered attitude control problems and excessive fuel consumption in orbit, but remained controllable. An attempted maneuver on the 22nd orbit still showed problems with the control system. It malfunctioned yet again during retrofire, leading to a steeper than planned ballistic reentry and a 300 mm (12 in) hole being burned in the heat shield.
Although the event would have been lethal to any human occupants, the capsule's recovery systems operated and the capsule crashed through the ice of the frozen Aral Sea, hundreds of kilometers short of its landing zone. The spacecraft finally sank in 10 meters of water and had to be retrieved by divers. The test performance was nonetheless deemed "good enough"; the manned docking missions of Soyuz 1 and Soyuz 2 were approved for the next flight.