Mars 1969B

Mars 1969B, also known as Mars 69BA in Soviet documentation, was one of two identical probes (the other being Mars 1969A), each consisting of an orbiter and an atmospheric probe. The mission was never officially announced by the Soviet government.

After a two-year development program, Mars 69B was launched on April 2, 1969 on top of a Proton rocket, model SL-12. Problems began almost immediately, when one of the six first-stage rocket motors exploded. The control systems attempted to automatically compensate and the rocket continued to lift from the pad on five engines. At 25 seconds into the launch, however, proper vehicle attitude could not be maintained, with the rocket reaching the horizontal attitude. The remaining engines shut down, and the launch vehicle and payload impacted the ground 41 seconds after launch, approximately 3 km away.

The probe was intended to image the Martian surface using three cameras that shot film directly and then encoded the images for television transmission back to Earth. Other instruments included a radiometer, water vapor detector, and a series of spectrometers.

External links

* [http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=MARS69b NASA (NSSDC) information on Mars 69B]
* [http://athena.cornell.edu/mars_facts/past_missions_60s.html Cornell University's Mars Missions page]