Versions
There are two versions of Soyuz-U in current use, Soyuz-U/Ikar and Soyuz-U/Fregat.
Soyuz-U/Ikar uses Ikar as its 3rd stage, produced by the Progress State Research and Production Rocket Space Center, TsSKB-Progress. Ikar is used to deliver various payloads with masses of 750 kg to 3920 kg to heights 250 km to 1400 km. The performance of the Ikar upper stage is lower than that of the Fregat upper stage, but it is more precise in maneuvering and it can operate autonomously longer.
Soyuz-U/Fregat uses Fregat as its 3rd stage, developed and produced by Lavochkin Association in Khimki.
An older variant of Soyuz-U, the Soyuz-U2 launcher, had the same hardware as the basic Soyuz-U. Instead of standard RP-1, it used a high energy, synthetic version, Syntin, as the first stage fuel. This variant, mainly used for reconnaissance satellites, last flew in 1996, after production of Syntin ended due to cost reasons.
Soyuz-U was the basic platform for the development of the Soyuz-FG launch vehicle, which uses an all-new first stage.
In the future both Soyuz-U and Soyuz-FG will be replaced by the Soyuz-2 launch vehicle.
Read more about this topic: Soyuz-U
Famous quotes containing the word versions:
“The assumption must be that those who can see value only in tradition, or versions of it, deny man’s ability to adapt to changing circumstances.”
—Stephen Bayley (b. 1951)