The Centaur Upper Stage Vehicle

The high-energy Centaur upper stage has evolved to become a very reliable and versatile vehicle. The Centaur program began in 1958, with its first successful flight in 1963. Centaur was flown on Atlas for NASA in the 1960’s. The design of the vehicle evolved in the 70’s into the D-1A (Atlas) and D-1T (Titan) with improved avionics. The D-1T configuration was built to fly long planetary missions on the Titan IIIE (TC-1 through TC-7). Titan Centaur evolved following the Challenger accident. The wide body Centaur being developed for shuttle began modification to fly on the Titan IV booster (TC-8 through TC-23) in 1985, incorporating features to reliably perform long-coast, 3-burn missions. The Titan Centaur program wi ll conclude after the flights of the last two Titan Centaur missions in 2003. The Atlas program has successfully launched 62 consecutive Atlas Centaur missions. The latest Centaur upgrade was in support of the Atlas V family of launch vehicles. The Common Centaur builds on the Single Engine Centaur (SEC) program that flew successfully on an Atlas IIIA in May 2000. It stretches the propellant tanks 66 inches from the SEC version to carry more propellant, yielding increased performance, and also incorporated long-coast, 3-burn mission capability. The maiden flight of the Atlas V included a Common Centaur to successfully deploy a commercial satellite on August 21 2002. Using 30+ years and over 160 previous flights of lessons learned, additional enhancements were made to major vehicle systems to improve reliability, operability, performance, and flexibility of this latest Centaur. The Common Centaur offers an improved high-energy upper stage at exceptional value to end-users. Centaur History The Centaur program began in 1958 with its first successful flight in 1963. Centaur was flown on Atlas for NASA in the 60s, then modified with improved avionics into the D-1A (Atlas) and D-1T (Titan) configurations during the 70s. The D-1T configuration was built to fly longer park orbit coasts for inter-planetary missions on the Titan IIIE (TC-1 through 7). In the 80s, a wide body Centaur was developed to be integrated into the Shuttle, however, the program was canceled following the Challenger accident in 1986. In 1985, work had already begun to modify the larger Shuttle/Centaur design to fly on the Titan IV. A fleet of 16 Titan/Centaur vehicles has been produced for the U. S. Air Force, with one of these vehicles launching the NASA Cassini Interplanetary mission to Saturn. The Titan IV Centaur missions flown are the same long coast, 3 burn mission capability that is designed into the Atlas V. To date, 14 of these Titan/Centaurs have been launched with the two remaining flights scheduled through 2003. There have been over 160 Centaurs launched between Titan and Atlas boosters. As of September 2002, there have been 62 consecutive Atlas Centaur vehicles successfully launched. The Atlas IIIB and V Family The Atlas IIIB and V family of launch vehicles provides a wide selection of performance capabilities to our customers to accommodate a variety of needs. The Atlas IIIB program is an evolutionary step from the Atlas IIIA program, providing additional performance with relatively low risk. The Atlas booster is the same, but the Centaur II upper stage has been replaced with the Common Centaur in either a single engine or a dual engine configuration. Both versions receive the benefit of the Common Centaur improvements to reliability and operability. In addition, the dual engine option can be selected for additional performance. All Atlas IIIB launch vehicles use the flight-proven Atlas 14-ft diameter payload fairing in either large or extended versions. Titan Centaur launch vehicle in the tower with Cassini mission (NASA photo)  Copyright 2002 Lockheed Martin Corporation Upper: A Common Centaur tank is shown in San Diego below a Centaur II tank. Lower: A Common Centaur tank leaves San Diego bound for final assembly in Denver. The upper stage configuration choices for the Atlas V are essentially the same as for the Atlas IIIB. All Atlas V launch vehicles use the newly developed Common Core Booster®, which uses a structurally stable 12 1⁄2-ft diameter tank and the Atlas III flightproven RD-180 engine. The Atlas V-400 series uses the Common Centaur in either the single or dual engine version, and incorporates the 4-m (14-ft) diameter payload fairing mounted atop the Centaur, similar to all previous Atlas/Centaur versions. Up to three solid rocket boosters (SRB) can be attached to the booster for additional performance. The Atlas V500 series is the same as the 400, with the exception of using a large 5-m diameter payload fairing, which encapsulates both the Common Centaur and the spacecraft similar to Titan Centaur. Up to five SRBs can be attached to the 500 series booster for additional performance. The third variant is the Atlas V Heavy Lift Vehicle, which uses three Common Core Boosters strapped together for additional thrust for heavy payloads. A longer 5-m payload fairing encapsulates the Common Centaur and the spacecraft, similar to the 500 series. This variant was brought to the critical design review level of maturity in September of 2002, and will be implemented upon customer request. Atlas V (400 Series) Atlas V (500 Series) (0-5 SRBs) Atlas V (HLV) Single