Cosmos 27

Launch Notes

The Blok L stage and probe reached Earth orbit successfully, but the attitude control system failed to operate and so the stage could not be oriented properly for main engine start. It reentered the atmosphere one day after launch and burned up. Examination of telemetry data found that the failure was due to a design flaw in the circuitry of the BOZ unit, which resulted in power not being transferred to the attitude control jets on the Blok L stage.