|Operator||Institute of Biomedical Problems|
|Mission duration||18.5 days|
|Launch mass||6,000 kg (13,000 lb)|
|Start of mission|
|Launch date||29 September 1979,|
|Rocket||Soyuz-U 11A511U (s/n Zh15000-193)|
|Launch site||Plesetsk, Site 41/1|
|End of mission|
|Recovered by||Soviet Space Forces|
|Landing date||14 October 1979, 02:24 UTC|
near Oktyabr'skoe, Kazakhstan, Soviet Union
|Reference system||Geocentric orbit|
|Regime||Low Earth orbit|
|Perigee altitude||226 km (140 mi)|
|Apogee altitude||406 km (252 mi)|
Bion 5, or also Kosmos 1129 (in Russian: Бион 5, Космос-1129) was a Bion satellite. It was a biomedical research mission involving scientists from nine countries, launched on 29 September 1979, at 15:30:00 UTC. Among the experiments was the first attempt to breed mammals in space, which proved unsuccessful. The mission ended after 18.5 days, on 14 October 1979, at 02:24 UTC. The mission had the cooperation of the Bulgaria, Czechoslovakia, East Germany, France, Hungary, Poland, Romania, the United States and the Soviet Union.
Organisms studied included:
Bion 5 mission consisted of various biological studies, including the first mammalian reproduction attempts (rats) in space, which ended up not succeeding. Experiences NASA were designed to study the effects of radiation on mice, quail embryos and some plant specimens.
Studies on the effect of microgravity were also performed on the muscles and bones of rats and avian embryogenesis was studied in space. the effects of microgravity on plant tissues were investigated using carrots and carrot cancerous tissue to study the effects of space flight on the growth and development of plants. As in the previous mission, 30 rats for the species Rattus norvegicus were sent physiological studies; Seven additional rats were used in embryological experiments.