Kosmos 1669

Kosmos 1669

Mission type	Salyut 7 resupply
Operator	OKB-1
COSPAR ID	1985-062A
SATCAT no.	15918
Mission duration	42 days
Spacecraft properties
Spacecraft	Progress s/n 126
Spacecraft type	Progress 7K-TG
Manufacturer	NPO Energia
Launch mass	7280 kg
Dry mass	7020 kg
Payload mass	2500 kg
Dimensions	7.48 m in length and 2.72 m in diameter
Start of mission
Launch date	19 July 1985, 13:05 UTC
Rocket	Soyuz-U s/n B15000-446
Launch site	Baikonur 1/5
Contractor	OKB-1
End of mission
Disposal	Deorbited
Decay date	30 August 1985, 01:20 UTC
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee altitude	298 km
Apogee altitude	358 km
Inclination	51.66°
Period	91.0 minutes
Epoch	19 July 1985
Docking with Salyut 7
Docking port	Aft
Docking date	21 July 1985, 15:05 UTC
Undocking date	28 August 1985, 21:50 UTC
Time docked	38 days
Cargo
Mass	2500 kg

Kosmos-1669 (Russian: Космос-1669) was a Progress spacecraft used to resupply the Salyut 7 space station. It was a Progress 7K-TG spacecraft with the serial number 126.

Mission

Kosmos-1669 was launched by a Soyuz-U carrier rocket from Site 1/5 at the Baikonur Cosmodrome, at 13:05 UTC on 19 July 1985. The spacecraft docked with the aft port of Salyut 7 at 15:05 UTC on 21 July 1985. Following undocking on 28 August 1985, it moved away from the station, before returning and redocking to test the reliability of the docking system.^[1] It undocked for a second time at 21:50 UTC,^[2] and was deorbited on 30 August 1985, with the spacecraft burning up over the Pacific Ocean at 01:20 UTC.

Salyut-7

Kosmos-1669 was the second cargo spacecraft (after Progress 24) to visit Salyut 7 after its reactivation, and also the last Progress flight as part of the Salyut programme. It delivered new spacesuit, to replace ones damaged by cold temperatures whilst Salyut 7 was deactivated,^[3] as well as replacement parts and consumables. This Progress mission was followed by one last cargo mission to Salyut 7, but carried out by an TKS spacecraft: TKS-4, which would become the fourth and last flight of an TKS spacecraft. The next following mission of a Progress cargo spacecraft, Progress 25, flew to Mir.^[1]

As of 2009, Kosmos-1669 is the only Progress spacecraft to have received a Kosmos designation, which are usually reserved for military, experimental and failed spacecraft. It has been reported that this may have been an error due to confusion with a TKS spacecraft which later became Kosmos 1686,^[4] or that the spacecraft may have gone out of control shortly after launch, but then been recovered after the Kosmos designation had been applied.^[1] Alternatively, it could have been given the designation as it was used to test modifications that would be used on future Progress missions.^[3] Some news agencies reported that it was a free-flying Progress-derived spacecraft,^[3] or that it was a new type of spacecraft derived from the Progress.^[5]

See also

• List of Progress flights

References