Transtage rocket stage.jpg
A Transtage
ManufacturerMartin Marietta
Country of originUnited States
Used onTitan III
General characteristics
Height4.57 meters (15.0 ft)
Diameter3.05 meters (10.0 ft)
Gross mass12,247 kilograms (27,000 lb)
Engine details
Powered by2 AJ10-138
Maximum thrust8,000 lbf (36 kN) each[1]
Specific impulse311 seconds (3.05 km/s)
Burn time440 seconds
PropellantAerozine 50 / N2O4

Transtage, given the United States Air Force designation SSB-10A, was an American upper stage used on Titan III rockets, developed by Martin Marietta and Aerojet.


Transtage was developed in anticipation of a requirement to launch military payloads to geostationary orbit; a contract for development of the stage was issued on 20 August 1962.[2] Transtage used a pressure-fed two-chamber configuration, using Aerozine 50 fuel and nitrogen tetroxide as oxidizer; the thrust chambers were gimbaled for steering and each produced 8,000 lbf (36 kN) of thrust. The design specification required up to three restarts during the first six hours of a mission.[3]

Forty-seven Titan III launches are known to have used Transtage upper stages; of those, three are known to have suffered launch failures.[4] The first launch, boosted by a Titan IIIA, occurred on 1 September 1964; the Transtage failed to pressurize, resulting in premature engine cutoff, and a failure to reach orbit.[4] The second launch, on 10 December, was successful, and all ensuing launches used the Titan IIIC launch vehicle. The last launch of a Transtage was on 4 September 1989, boosted by a Titan 34D rocket.[4]

See also



  1. ^ Wade, Mark. "AJ10-138". Encyclopedia Astronautica. Archived from the original on December 28, 2016. Retrieved 2019-07-24.
  2. ^ Foradori, Giacomoello and Pascolini 2017, pp.56-57
  3. ^ Hunley 2007, p. 168.
  4. ^ a b c Heyman 2003


  • Foradori, Paolo; Giampiero Giacomello; Alessandro Pascolini (2017). Arms Control and Disamament: 50 Years of Experience in Nuclear Education. London: Palgrage Macmillan. ISBN 978-3-319-62258-3.
  • Heyman, Jos (17 March 2003). "Martin Marietta SSB-10 Transtage". Directory of U.S. Military Rockets and Missilesm Appendix 3: Space Vehicles. Designation-Systems. Retrieved 2017-12-17.
  • Hunley, J.D. (2007). The Development of Propulsion Technology for U.S. Space-Launch Vehicles, 1926-1991. College Station, TX: Texas A&M University Press. ISBN 978-1-58544-588-2.