Zenit 3 SL
Launch vehicle Zenit 3-SL/Block DM-SL
Launch site International Waters, Pacific Ocean
Date/Time 2000-03-12
Description Second stage partial failure
Cause Ground software logic error
Payload ICO F1 (Telephone satellite, ICO)
Desired orbit Geostationary transfer orbit

According to the Sea Launch Failure Review Oversight Board, all data presented indicate a ground software logic error as single root cause. A ground software command failed to close a pneumatic system valve on the second stage of the vehicle prior to lift-off.

As a result of launching with this valve in the incorrect position, a sequence of events followed, involving excessive loss of helium. Ultimately, the rocket did not reach orbital velocity, leading to a premature shutdown of second-stage engine and termination of the flight at approximately 8 minutes into the mission.

The Board received independent reports and presentations from the Sea Launch partners, as well as from representatives from a joint Russian and Ukrainian commission.

See also:

Launch Failures Chronology