Delta 2000 series
Launch of IUE on a Delta 2914 J-8
FunctionExpendable launch system
Country of originUnited States
Height35 m (114 ft)
Diameter2.44 m (8 ft)
Mass130,392 kg (287,465 lb)
Payload to GTO (Geostationary transfer orbit)
Mass724 kg
Launch history
Launch sitesCape Canaveral, LC-17
Vandenberg, SLC-2W
Total launches44
First flight19 January 1974
Last flight6 October 1981
Booster stage
Powered by9 x Castor 2
Maximum thrust258.915 kilonewtons (58,206 lbf)
Burn time37 seconds
First stage
Powered by1 x Delta-Thor RS-27
Maximum thrust1,030.218 kilonewtons (231,602 lbf)
Burn time223 seconds
Second stage
Powered by1 x Delta P
Maximum thrust41.923 kilonewtons (9,425 lbf)
Burn time322 seconds
Third stage
Powered by1 x Burner II
Maximum thrust43.551 kilonewtons (9,791 lbf)
Burn time42 seconds

The Delta 2000 series was an American expendable launch system which was used to conduct forty-four orbital launches between 1974 and 1981. It was a member of the Delta family of rockets, sometimes called Thorad Delta. Several variants existed, which were differentiated by a four digit numerical code. The Delta 1000, 2000 and 3000 series used surplus NASA Apollo program rockets engines for its first and second stages.

The first stage was an Extended Long Tank Thor, re-engined with the Rocketdyne RS-27 replacing the earlier MB-3-III engine. The RS-27 engine was a rebranded H-1 engine used in the Saturn 1B with minor changes. Three or nine Castor-2 solid rocket boosters were attached to increase thrust at lift-off. The Delta-P second stage used the TRW TR-201 engine. The TR-201 engine was a Lunar Module Descent Engine reconfigured for fixed thrust output. Launches which required a three-stage configuration in order to reach higher orbits used the Thiokol Star-37D or Star-37E upper stage as an apogee kick motor.

Delta 2000 launches occurred from Space Launch Complex 2W at Vandenberg AFB and both pads of Launch Complex 17 at Cape Canaveral. Forty-three out of forty-four launches were successful. The single failure being the maiden flight, 19 January 1974, which placed Skynet 2A into a useless orbit. A short circuit in an electronics package circuit board (on second stage) left the upper stages and satellite in an unstable low orbit (96 x 3,406 km x 37.6°) that rapidly decayed. An investigation revealed that a substandard coating had been used on the circuit board.[1]

The cost of each launch was estimated on average at $28.52 million, depending on the combination of carrier rocket.


  1. ^ Kyle, Ed (9 April 2010). "Delta 2000 series - Extended Long Tank Delta". Space Launch Report. Retrieved 7 June 2012.