Transtage, given the

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

designation SSB-10A, was an American

upper stage A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own Rocket engine, engines and Rocket propellant, propellant. A ''tandem'' or ''serial'' stage is mounted on top of anoth ...

used on

Titan III Titan was a family of United States expendable rockets used between 1959 and 2005. The Titan I and Titan II were part of the US Air Force's intercontinental ballistic missile (ICBM) fleet until 1987. The space launch vehicle versions contribu ...

rockets, developed by

Martin Marietta The Martin Marietta Corporation was an American company founded in 1961 through the merger of Glenn L. Martin Company and American-Marietta Corporation. In 1995, it merged with Lockheed Corporation to form Lockheed Martin. History Martin Marie ...

and

Aerojet Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas. Aerojet was owned by GenCorp, ...

History

Transtage was developed in anticipation of a requirement to launch military payloads to

geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular orbit, circular geosynchronous or ...

; a contract for development of the stage was issued on 20 August 1962. Transtage used a pressure-fed two-chamber configuration, using

Aerozine 50 __NOTOC__ Aerozine 50 is a 50:50 mix by weight of hydrazine and unsymmetrical dimethylhydrazine (UDMH), developed in the late 1950s by Aerojet General Corporation as a storable, high-energy, hypergolic fuel for the Titan II ICBM rocket engines ...

fuel and

nitrogen tetroxide Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russian rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium ...

oxidizer An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ''electron donor''). In ot ...

; the thrust chambers were gimbaled for steering and each produced of thrust. The design specification required up to three restarts during the first six hours of a mission. Forty-seven Titan III launches are known to have used Transtage upper stages; of those, three are known to have suffered launch failures. The first launch, boosted by a

Titan IIIA The Titan IIIA or Titan 3A was an American expendable launch system, launched four times in 1964 and 1965, to test the Transtage upper stage which was intended for use on the larger Titan IIIC. The Transtage was mounted atop two core stages deriv ...

, occurred on 1 September 1964; 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 The Titan IIIC was an expendable launch system used by the United States Air Force from 1965 until 1982. It was the first Titan (rocket family), Titan booster to feature large solid rocket motors and was planned to be used as a launcher for the D ...

launch vehicle. The last launch of a Transtage was on 4 September 1989, boosted by a

Titan 34D The Titan 34D was a United States expendable launch vehicle used to launch a number of satellites for military applications. Service history Derived from the Titan III, the Titan 34D featured Stage 1 and Stage 2 stretched with more powerful ...

rocket.

References

{{Upper stages Rocket stages Titan (rocket family)

History

See also

References