Kosmos 557

Kosmos 557 (Russian: Космос 557 meaning Cosmos 557) was the designation given to DOS-3, the third space station in the Salyut program. It was originally intended to be launched as Salyut-3, but due to its failure to achieve orbit on May 11, 1973, three days before the launch of Skylab, it was renamed Kosmos-557.

Kosmos 557 (DOS-3)

Salyut programme insignia
Station statistics
COSPAR ID	1973-026A
SATCAT no.	06498
Crew	3
Launch	11 May 1973 00:20:00 UTC
Launch pad	LC-81/24, Baikonur Cosmodrome, USSR
Reentry	22 May 1973
Mass	19,400 kg
Periapsis altitude	218 km
Apoapsis altitude	266 km
Orbital inclination	51.6 degrees
Orbital period	89.1 minutes
Days in orbit	11 days (22 May 1973)
Days occupied	0 days (22 May 1973)
No. of orbits	~175 (22 May 1973)
Statistics as of 11 May 1973 (Unless noted otherwise)
Configuration
The planned orbital configuration of DOS-3.

Due to errors in the flight control system while out of the range of ground control, the station fired its altitude thruster until it consumed all of its altitude control fuel and became uncontrollable before raising its orbit to the desired altitude. Since the spacecraft was already in orbit and had been registered by Western radar, the Soviets disguised the launch as "Kosmos 557" and quietly allowed it to reenter Earth's atmosphere and burn up a week later. It was revealed to have been a Salyut station only much later.