Bion 5 (Cosmos 1129) was a Bion satellite. It was a biomedical research mission involving scientists from nine countries. Among the experiments was the first attempt to breed mammals in space, which proved unsuccessful. The mission ended after 18.5 days.
Payloads are separated by bullets ( · ), launches by pipes ( | ). Manned flights are indicated in bold text. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in (brackets).