The Soviet Union launches Soyuz 29 on a mission to berth at space station Salyut 6 for a period of around four months. Cosmonauts Vladimir Kovalyonok and Aleksandr Ivanchenkov are aboard, and they eventually set a new space endurance record, remaining in orbit for 139 days. Numerous material science experiments are carried out, as well as a spacewalk to retrieve samples of various materials left exposed to space outside the station. The crew is also assigned to take on a more rigorous exercise program. They will return to Earth in November after swapping vehicles with the crew of Soyuz 31.