It carried several dozen male rats (possibly 25 or 45), six Russian tortoises(Agrionemys horsfieldii) (each in a separate box), a mushroom bed, flour beetles (Tribolium confusum) in various stages of their life cycle, and living bacterial spores. It provided data on the reaction of mammal, reptile, insect, fungal, and bacterial forms to prolonged weightlessness.
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).