Mission highlights

Soyuz T-13 was the 8th expedition to Salyut 7.
Vladimir Dzhanibekov could have had no notion that he would so soon  visit Salyut 7 after his Soyuz T-12 flight, and what more on the  first Soyuz flight to dock manually with an inert space station, as  Salyut 7 had been crippled by a solar array problem. For this  purpose modifications were made to the Soyuz spacecraft to include  control levers for proximity operations. Viktor Savinykh's and  Vladimir Dzhanibekov's mission was successful and they were able to  salvage the Salyut 7 station. Savinykh remained aloft for 169 days,  returning to Earth in Soyuz T-14; Dzhanibekov returned to Earth in  Soyuz T-13 with Grechko after spending 110 days on Salyut 7. Before  deorbiting, Soyuz T-13 spent about 30 hours conducting rendezvous  and docking tests.

Salvaging Salyut 7

The effort to salvage Salyut 7 was, in the words of author David S.  F. Portree, "one of the most impressive feats of in-space repairs in  history". As the crew approached the inert station, they saw that  its solar arrays were pointing randomly as it rolled slowly about  its long axis. They used a handheld laser rangefinder to judge their  distance, and conducted a fly-around inspection to be certain the  exterior was intact. Dzhanibekov noted that the thermal blankets on  the transfer compartment had turned a dull gray from prolonged  exposure to sunlight.
Dzhanibekov piloted his ship to intercept the forward port of Salyut  7, matched the station's rotation and achieved soft dock with the  station. Upon achieving hard dock—the only time a spacecraft has  docked with an inert space station—the crew confirmed through the  electrical connectors in the docking collars that the Salyut 7  electrical system was dead. They carefully sampled the air in the  station before opening the hatch. The station air was very cold, but  breathable. Frost covered the walls and apparatus. The cosmonauts  wore winter garb, including fur-lined hats, as they entered the  station.
The first order of business was to restore electric power. Two of  the eight batteries were destroyed, the rest fully discharged.  Dzhanibekov determined that a sensor in the solar array pointing  system had failed, preventing the batteries from recharging. A  telemetry radio problem prevented the TsUP (mission control center)  from detecting the problem. Salyut 7 had quickly run down its  batteries, shutting down all its systems and accounting for the  break in radio contact.[citation needed] The cosmonauts set about  recharging the batteries and used Soyuz T-13 to turn the station in  order to point its solar arrays to the sun.
On June 10 they turned on the air heaters. The cosmonauts relied on  the Soyuz T-13 air regeneration system until they could get the  Salyut 7 system back in order. On June 13 the attitude control  system was successfully reactivated. This was cause for jubilation,  as it meant Kosmos 1669 (a Progress supply spacecraft) bearing  replacement parts could dock with Salyut 7. The station’s water  tanks thawed by the end of June – freezing had destroyed the water  heater, so the cosmonauts used a powerful television light to heat  fluids. Wall heaters were turned on only after all the frost had  evaporated, in order to prevent water from entering equipment.  Normal atmospheric humidity was achieved only at the end of July,  nearly two months after docking.