Mission Type: Flyby
Launch Vehicle: 8K78 (no. L1-5M)
Launch Site: NIIP-5 / launch site 1
Spacecraft Mass: 480 kg
-Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
Like its predecessor, this spacecraft never reached Earth orbit. During the launch trajectory, there was a failure in the third stage engine at T+290 seconds as a result of frozen kerosene in the pipeline feeding its turbopump (which prevented a valve from opening).
The third and fourth stages, along with the payload, burned up over Earth's atmosphere over eastern Siberia.
The Mars flyby had been planned for 15 May 1961.