Bion-M2: Russia’s New Space Biology Mission and the Secret History of Soviet Monkeys in Orbit

On August 20, 2025, at 17:13 UTC, Russia’s Bion-M2 spacecraft lifted off successfully, carrying 75 mice, over a thousand fruit flies, plant specimens, and cell cultures into orbit. The mission’s goal is to study the effects of spaceflight on living organisms in preparation for the assembly of the future Russian Orbital Service Station (ROSS) in a polar orbit — a path that will repeatedly cross regions of intense Van Allen radiation.

LAUNCH! Soyuz-2-1b launches Bion-M No.2 from site 31/6 at the Baikonur Cosmodrome.

Overview by P. Katin:https://t.co/60sDQ8aht0 pic.twitter.com/sMg1lipw3Y
— NSF – NASASpaceflight.com (@NASASpaceflight) August 20, 2025

It’s the latest chapter in a long and surprisingly little-known history: the Soviet Bion program, which once sent not only mice and fish into space — but also monkeys.

Assembly of the Bion-M2 spacecraft. Credit: Roscosmos — *Assembly of the Bion-M2 spacecraft. Credits: Roscosmos*

From Salyut to “flying laboratories”

In 1971, after launching the Salyut orbital station, the Soviet Union realized that sustaining a human presence in space would require a systematic, scientific approach to studying the effects of weightlessness on living organisms. On the proposal of the Institute for Biomedical Problems (IMBP), modified Vostok capsules were adapted for longer autonomous orbital flights. Thus was born Bion — a series of unmanned biological satellites, packed not with astronauts, but with… very lively payloads.

The first flight, Kosmos-605 (1973), carried rats, turtles, insects, and fungi. Later missions expanded the passenger list to guinea pigs, rabbits, bird embryos, seeds, and microorganisms, aiming to study adaptation to microgravity, reproduction in orbit, and radiation shielding.

The macaque monkey Zabnyaka in the cockpit of Bion-9 (Kosmos-2044) in 1989. Credit: Roscosmos — *The macaque monkey Zabnyaka in the cockpit of Bion-9 (Kosmos-2044) in 1989. Credits: Roscosmos*

Moving up the evolutionary ladder: monkeys

After five missions, Soviet scientists aimed higher — primates. The U.S. had used them extensively during the Mercury program tests, but in the USSR a dedicated primate center was built at the IMBP facility in Khimki. Young, healthy, and docile rhesus macaques were carefully selected from the Sukhumi monkey nursery.

For years, they trained on treadmills, in centrifuges, and in zero-gravity pools. Their reward for following commands correctly? Drops of rosehip syrup. Their tails were docked to make life inside the cramped capsules easier, and electrodes and telemetry packs were implanted to transmit real-time biomedical data.

It was, in effect, a secret squadron of tailed cosmonauts.

The missions

Bion-6 / Kosmos-1514 — 14 December 1983: Abrek and Bion became the first Soviet monkeys in space. The mission ended on day five after Abrek tried to tear off his head-mounted telemetry pack. Both landed safely in Kazakhstan.
Bion-7 / Kosmos-1667 — 10 July 1985: Verny (nicknamed Omka) and Gordy spent a week in orbit alongside rats, amputated newts, guppies, seeds, and 1,500 fruit flies. The mission was a success.
Bion-8 / Kosmos-1887 — 1987: Droma and Erosh endured a shortened flight due to technical problems. After landing 1,500 km off course in the Yakutian taiga, the capsule was found in the snow, lights off, with all animals alive except the fish. Droma, suffering from a cold, was treated and later “retired” to Cuba, where Fidel Castro personally welcomed him.
Bion-9 / Kosmos-2044 — 1989: Zhakonya and Zabnyaka spent a record 13 days and 17 hours in orbit, participating in 80 experiments, most of them European.
Bion-10 — 1992: Krosh and Ivasha flew in the penultimate Soviet monkey mission.
Bion-11 — 1996: Lapik and Multik completed the final macaque flight. While the mission was technically successful, Multik died after landing due to an adverse reaction to anesthesia during a biopsy. Lapik survived and returned to the Adler nursery.

All the other “tailed cosmonauts” lived out their days at the primate center, each with a plaque recording their name and flight date. Only two never came back: Multik, the scientific martyr, and Droma, the honorary retiree in Havana.

*The Bion spacecraft inside the fairing of a Soyuz 2.1a launcher. Credit: Roscosmos/Russianspaceweb*

After the monkeys

Following Multik’s death, mounting international pressure and the withdrawal of U.S. funding ended primate spaceflights. The Bion program continued with other species — mice, geckos, crustaceans, and snails — but never again monkeys.

The last mission before Bion-M2 was Bion-M1 in 2013. And while macaques no longer ride rockets, around 20 rhesus monkeys still take part in centrifuge experiments at the Moscow primatology center. According to a running joke, they do so under contract — signed, of course, by a representative of the Bioethics Committee.