| Kosmos 1129 | |
| Names List: | Bion-5 Biocosmos 5 |
| Mission Type: | Bioscience |
| Operator: | Institute of Biomedical Problems |
| Cospar Id: | 1979-083A |
| Satcat: | 11536 |
| Spacecraft Type: | Bion |
| Spacecraft Bus: | Zenit 12KS |
| Manufacturer: | TsSKB |
| Launch Date: | 29 September 1979, 15:30:00 UTC |
| Launch Rocket: | Soyuz-U |
| Launch Site: | Plesetsk 41/1 |
| Launch Contractor: | TsSKB |
| Recovery By: | Soviet Space Forces |
| Landing Date: | 14 October 1979, 02:24 UTC |
| Landing Site: | near Oktyabr'skoe, Kazakhstan, USSR |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Low Earth orbit |
| Orbit Inclination: | 62.80° |
| Orbit Period: | 90.50 minutes |
| Apsis: | gee |
| Programme: | Bion programme |
| Previous Mission: | Bion 4 |
| Next Mission: | Bion 6 |
| Programme2: | Kosmos (satellites) |
| Previous Mission2: | Kosmos 1128 |
| Next Mission2: | Kosmos 1130 |
Bion 5, also known as Kosmos 1129 (in Russian: Бион 5, Космос-1129) was a Bion satellite. It was an international 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 14.5 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.