Failed · Failure
A mission NSSDCA describes as intended for a Venus flyby and probe. The SL-6/A-2-e (Molniya + Blok I) launcher successfully achieved Earth orbit on 27 March 1964, but the circuit for the valves of the attitude control system malfunctioned, the spacecraft could not maintain a stable attitude for the burn to head for Venus, and it was left in Earth orbit and designated Cosmos 27. It reentered and burned up in the atmosphere the next day.
- Destinations
- Launch vehicle
- Molniya-M
- Launch site
- Tyuratam (Baikonur Cosmodrome), U.S.S.R
- Countries
- Soviet Union
- Mission types
- Flyby, Atmospheric probe
Chronology
Mission timeline
Launch
Launched into Earth orbit, where the Blok I upper stage failed
Both NSSDCA pages give the launch as 27 March 1964 at 03:24:43 UT. The launch/orbital information page disagrees with itself and the disagreement is recorded rather than resolved: its Earth-orbit row gives an epoch start of 1964-03-27 03:21:00, three minutes and forty-three seconds before the launch date and time printed at the head of the same page. The two catalogues also disagree on which object carries the satellite number: the master catalog lists 00770 among this spacecraft's alternate names, while GCAT gives 00770 to the Molniya 8K78(M) Blok-I stage as S00770, piece 1964-014B, and gives the spacecraft S00772.
EarthMission end
Reentered the day after launch
The master catalog records that the spacecraft reentered and burned up in the atmosphere the next day, and the launch/orbital information page gives a decay date of 1964-03-28.
Earth
Mission architecture
Vehicles
Cosmos 27 · Spacecraft
Destinations: Venus
3MV-1 No. 3 SA · Probe
Trajectory record
Trajectory dataset not yet available
No verified trajectory dataset is committed for this mission, so Mission Atlas renders no path.
Provenance
Sources
Each source is listed once and labeled with the mission, event, trajectory, or destination/body context it supports.
Data verified through September 3, 2026
- Cosmos 27 - NSSDCA Master Catalog (spacecraft 1964-014A), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- Cosmos 27 - NSSDCA launch/orbital information (1964-014A), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- GCAT: General Catalog of Artificial Space Objects (auxiliary catalog), J. McDowell — OTHEROther · Supports: mission claims
- GCAT: General Catalog of Artificial Space Objects (satellite catalog), J. McDowell — OTHEROther · Supports: mission claims · event claims
- Tentatively Identified Missions and Launch Failures - NASA NSSDCA — NSSDCAArchive · Supports: mission claims
- Planet Sizes and Locations in Our Solar System — NASAOther · Supports: destination/body context