Kovalyonok

Ryumin

---

9 October 1977 02:40 GMT. Landing Date: 1977-10-11 03:24:45 PM. Flight Time: 2.03 days. Flight Up: Soyuz 25. Flight Back: Soyuz 25. Call Sign: Foton (Photon). Crew: Kovalyonok, Ryumin. Backup Crew: Ivanchenkov, Romanenko. Program: Salyut 6.

What went wrong: Failed to dock with station due to damage to spacecraft's docking mechanism. Manned two crew. Unsuccessful mission. Failed to dock with Salyut 6. Recovered October 11, 1977 3:25 GMT.

Narrative (adapted from D S F Portree's Mir Hardware Heritage, NASA RP-1357, 1995)

Soyuz 25 achieved soft dock with the new Salyut 6 station, inserting its probe apparatus into the conical drogue of the Salyut 6 front port. Hard docking involved retracting the probe to pull the station and spacecraft docking collars together. However, the docking collars would not latch. Cosmonauts Vladimir Kovalyonok and Valeri Ryumin had to return to Earth before their ferry’s batteries became depleted. Engineers theorized that the Salyut 6 forward port might have been damaged during ascent, or that the Soyuz 25 docking unit was at fault. If the latter was true (and they could not be certain, because the docking unit was discarded before reentry, along with the Soyuz 25 orbital module), then it was possible that the several hard docking attempts had damaged the Salyut 6 forward port, making it unfit for future dockings.

• 1977 Oct 9 - Soyuz 25  Crew: Kovalyonok, Ryumin. Spacecraft: Soyuz 7K-T. Payload: Soyuz 7K-T s/n 42. Mass: 6,860 kg (15,120 lb). Launch Site: Baikonur. Launch Vehicle: Soyuz. Duration: 2.03 days. Perigee: 194 km (120 mi). Apogee: 240 km (140 mi). Inclination: 51.60 deg. Period: 88.80 min.

  Manned two crew. Unsuccessful mission. Failed to dock with Salyut 6.

• 1977 Oct 11 - Landing of Soyuz 25 

  Soyuz 25 landed at 03:24 GMT.