The Commercial Titan III, also known as CT-3 or CT-III, was an American

expendable launch system An expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are destroyed during reentry or impact with Earth, or discarded in space. ELVs typically consist of s ...

, 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 ...

during the late 1980s and flown four times during the early 1990s. It was derived from the

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 ...

, and was originally proposed as a medium-lift expendable launch system for the

US 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 ...

, who selected the

Delta II Delta II was an expendable launch system, originally designed and built by McDonnell Douglas, and sometimes known as the Thorad Delta 1. Delta II was part of the Delta rocket family, derived directly from the Delta 3000, and entered service in ...

instead. Development was continued as a commercial launch system, and the first rocket flew in 1990. Due to higher costs than contemporary rockets such as the

Ariane 4 The Ariane 4 was a European expendable rocket, expendable launch vehicle in the Ariane (rocket family), Ariane family, developed by the (CNES), the Government of France, French space agency, for the European Space Agency (ESA). The manufacturi ...

, orders were not forthcoming, and the CT-3 was retired in 1992. The Commercial Titan III differed from the Titan 34D in that it had a stretched second stage, and a larger payload fairing to accommodate dual satellite payloads. All four launches occurred from LC-40 at

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the sta ...

. The first carried two

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a Transponder (satellite communications), transponder; it creates a communication channel between a source transmitter and a Rad ...

s, Skynet 4A and JCSAT-2, and was launched at 00:07 UTC on 1 January 1990, which was 19:07 local time on 31 December 1989. The launch received the International Designator 1990-001, using the UTC date. The second launch occurred on 14 March, and carried the Intelsat 603 satellite. The rocket's second stage failed to separate, and the payload could only be released from the rocket by means of jettisoning its kick motor. It was later visited by , on mission

STS-49 STS-49 was NASA's maiden flight of the Space Shuttle ''Endeavour'', which launched on May 7, 1992. The primary goal of its nine-day mission was to retrieve an Intelsat VI satellite, Intelsat 603, which failed to leave Low Earth orbit two yea ...

. Astronauts attached a new kick motor, which raised the satellite into a

geosynchronous transfer orbit In space mission design, a geostationary transfer orbit (GTO) or geosynchronous transfer orbit is a highly elliptical type of geocentric orbit, usually with a perigee as low as low Earth orbit (LEO) and an apogee as high as geostationary orbit ...

, as had originally been planned. The third launch, on 23 June, carried Intelsat 604, and was successful. There was no Commercial Titan III launch in 1991, due to maintenance work at Launch Complex 40. The final flight of the Commercial Titan III occurred on 25 September 1992, and placed NASA's

Mars Observer The ''Mars Observer'' spacecraft, also known as the ''Mars Geoscience/Climatology Orbiter'', was a Robotic spacecraft, robotic space probe launched by NASA on September 25, 1992, to study the Martian surface, atmosphere, climate and magnetic fie ...

spacecraft into

heliocentric orbit A heliocentric orbit (also called circumsolar orbit) is an orbit around the barycenter of the Solar System, which is usually located within or very near the surface of the Sun. All planets, comets, and asteroids in the Solar System, and the Sun ...

, by means of a

Transfer Orbit Stage The Transfer Orbit Stage (TOS) was an upper stage developed by Martin Marietta for Orbital Sciences Corporation during the late 1980s and early 1990s. The TOS was designed to be a lower-cost alternative to Inertial Upper Stage and Centaur G u ...

Launch history

References

{{Titan rockets Space launch vehicles of the United States Titan (rocket family)