Zenit (, ; meaning
Zenith) is a family of space
launch vehicles designed by the
Yuzhnoye Design Bureau of
Soviet Union, and since the early 1990s by the same design bureau but now a part of
Ukraine. Zenit was built in the 1980s for two purposes: as a
liquid rocket booster for the
Energia rocket and, equipped with a second stage, as a stand-alone up-middle launcher greater than 7-ton payload
Soyuz and smaller than 20-ton payload
Proton. The last rocket family developed by the USSR, the Zenit was intended as an eventual replacement for the dated R-7 and Proton families, moreover it would employ cryogenic propellants which were safer and less toxic than the Proton's nitrogen tetroxide/UDMH mix. Moreover Zenit was planned to take over manned spaceship launches from Soyuz, but these plans were abandoned after the
dissolution of the Soviet Union in the early 1990s.