Korabl-Sputnik 3 ( meaning Ship-Satellite 3) or Vostok-1K No.3, also known as Sputnik 6 in the West, was a Soviet spacecraft which was launched in 1960. It was a test flight of the Vostok spacecraft, carrying two dogs: Pcholka and Mushka ("little bee" and "little fly"; affectionate diminutives of "pchela" and "mukha", respectively), mice, rats, rabbits, flies, plants, as well as a television camera and scientific instruments.
Soviet space plans for the next several months were ambitious and included Vostok missions, planetary probes, military reconnaissance, and scientific satellites but the first were given priority. However, the Mars shots ended up going first in October and only after those missions flew could the next Vostok test took place. There was still wrangling over the exact design of the Vostok ejection system, and it was eventually decided to eject the cosmonaut using an ejection seat from a relatively low altitude instead of an enclosed capsule as it had been originally envisioned. There was also the possibility that the Vostok's retrorocket could fail and leave the cosmonaut stuck in orbit. It was too late in the spacecraft's design phase to add a backup retrorocket, but the problem could be solved by putting the Vostok into a low enough orbit that it would decay in ten days; the spacecraft had enough consumables onboard to last that long.
Korabl-Sputnik 3 was launched at 07:30:04 UTC on 1 December 1960, atop a Vostok-L carrier rocket flying from Site 1/5 at the Baikonur Cosmodrome. Both Pchyolka and Mushka were killed in the resulting disintegration.