Editing Soyuz (rocket family) (section)

=== Third stage ===
[[File:Soyuz 19 (Apollo Soyuz Test Project) spacecraft.jpg|thumb|270px|One of the common payloads of the Soyuz rocket family, a Soyuz spacecraft. This one is for [[Apollo Soyuz Test Project]], an international docking mission with [[Apollo (spacecraft)|Apollo spacecraft]] of the United States.]]

There are two variant upper stages in use, the '''Blok-I''' (used on the [[Soyuz-2|Soyuz 2.1a]]) and the '''Improved Blok-I''' (used on the [[Soyuz-2|Soyuz 2.1b]]).<ref>{{Cite book |url=http://www.arianespace.com/site/documents/Soyuz_Users_Manual_Part1.pdf |title=Soyuz at the Guiana Space Centre User's Manual Issue 1 |date=June 2006 |publisher=Arianespace |page=1-7 |access-date=2024-11-26 |archive-url=https://web.archive.org/web/20070927021858fw_/http://www.arianespace.com/site/documents/Soyuz_Users_Manual_Part1.pdf |archive-date=2007-09-27 |url-status=dead}}</ref>

Statistics:
* Height: {{convert|6.7|m|ftin|abbr=off}}
* Diameter: {{convert|2.66|m|ftin|abbr=off}}
* Empty mass: {{convert|2355|kg}}
* Gross mass: {{convert|27755|kg}}
* Propellant mass: {{convert|25400|kg}}
** Oxidizer load (liquid oxygen): {{convert|17800|kg}}
** Fuel load (RP-1): {{convert|7600|kg}}
* Blok-I powered by: 1 × [[RD-0110]] with four main combustion chambers and four vernier thrusters combustion chambers for attitude control. The engine is pump-fed by using gas pressure generated by the vernier thrusters. The propellant tanks are pressurized with oxygen vaporization and generator gases.
** Maximum thrust: {{convert|297.9|kN}}
** Specific impulse: {{convert|325|isp}}
** Chamber pressure 6.8 MPa (986 psi)
** Burn time: 250 seconds
* Improved Blok-I powered by: 1 × [[RD-0124]] with four main combustion chambers, each gimbaling in one axis for attitude control. The engine is pump-fed by using a closed-cycle gas generator. The propellant tanks are pressurized with helium vaporization.
** Maximum thrust: {{convert|297.9|kN}}
** Specific impulse: {{convert|359|isp}}
** Chamber pressure 16.2 MPa (2350 psi)
** Burn time: 270 seconds