| Country-Origin: | United States | ||||||||||
| Manufacturer: | Martin Marietta | ||||||||||
| Rockets: | Titan III | ||||||||||
| Height: | 4.57m (14.99feet) | ||||||||||
| Diameter: | 3.05m (10.01feet) | ||||||||||
| Mass: | 12247kg (27,000lb)
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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 8000adj=onNaNadj=on of thrust.[3] The design specification required up to three restarts during the first six hours of a mission.[4]
Forty-seven Titan III launches are known to have used Transtage upper stages;[5] of those, three are known to have suffered launch failures.[6] The first launch, boosted by a Titan IIIA, occurred on 1 September 1964;[7] the Transtage failed to pressurize, resulting in premature engine cutoff, and a failure to reach orbit. 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.