Zenit-3SL

The Zenit-3SL design began in the late 1980s as the Zenit-3, a proposed replacement for the Proton-K, which would have used a Zenit-2 rocket with a Block D upper stage.

This proposal was shelved after the dissolution of the Soviet Union, as Russia inherited the space programme, however the Zenit was manufactured in Ukrainian SSR.

Of thirty-six rockets launched, three failed, with a fourth placing its payload into an incorrect, but recoverable orbit.

The first failure occurred during the third flight, on 12 March 2000, when a software error resulted in the premature cutoff of the second stage, leaving the ICO F-1 satellite unable to reach orbit.

[6] On 29 June 2004, during the launch of Apstar 5, the upper stage shut down 54 seconds early due to a wiring fault,[7] leaving the satellite in a lower than planned orbit.