Kosmos 1686

Kosmos 1686

Kosmos 1686 (top) docked to Salyut 7, imaged by Range-Doppler radar.
Salyut program insignia
Station statistics
Call sign	Salyut 7
Launch	1985-09-27 02:01:00 UTC Docked to Salyut 7 on 1985-10-02.
Launch pad	Baikonur Cosmodrome, USSR
Reentry	February 7, 1991
Mass	20,000 kg
Length	15 m
Width	16 m
Diameter	4.15 m
Perigee	219 km (118.25 nmi)
Apogee	278 km (150.1 nmi)
Orbital inclination	51.6 degrees
Orbital period	89.2 minutes
Orbits per day	16.14
Days in orbit	1959 days
Statistics as of deorbit & reentry References:
Configuration
Combined Kosmos 1686-Salyut 7 space station complex

Kosmos 1686 (Russian: Космос 1686 meaning Cosmos 1686), also known as TKS-4, was a heavily modified TKS spacecraft which docked unmanned to the Soviet space station Salyut 7 as part of tests to attach scientific expansion modules to stations in Earth orbit. The module which docked to the station was the FGB component of a TKS vehicle launched on September 27, 1985, and was designed to test systems planned for use on the Mir Core Module. The spacecraft docked with Salyut 7 on October 2, 1985, during the long-duration stay of the cosmonauts of its fifth principal expedition, which arrived on Soyuz T-14. It was the last flown TKS spacecraft.