The Delta-K was an American

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...

stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Sta ...

, developed by McDonnell Douglas and Aerojet. It was first used on 27 August 1989 as the second stage for the

Delta 4000 The Delta 4000 series was an American expendable launch system which was used to conduct two orbital launches in 1989 and 1990. It was a member of the Delta family of rockets. Although several variants were put forward, only the Delta 4925 was la ...

series. It continued to serve as the second stage for subsequent variants of the

Delta rocket Delta is an American versatile family of expendable launch systems that has provided space launch capability in the United States since 1960. Japan also launched license-built derivatives ( N-I, N-II, and H-I) from 1975 to 1992. More than 300 ...

. It was propelled by a single AJ10-118K rocket engine, fueled by

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

and

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

,Delta K
, ''Encyclopedia Astronautica'', date 30 Jan 1997, accessed 2011-02-01. which are

hypergolic A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. The ...

. The Delta-K had a long heritage to the first Able stage used in

Project Vanguard Project Vanguard was a program managed by the United States Navy Naval Research Laboratory (NRL), which intended to launch the first artificial satellite into low Earth orbit using a Vanguard rocket. as the launch vehicle from Cape Canaveral ...

. The AJ-10 engine was first used in the Able second stage of the

Vanguard rocket The Vanguard rocket was intended to be the first launch vehicle the United States would use to place a satellite into orbit. Instead, the Sputnik crisis caused by the surprise launch of Sputnik 1 led the U.S., after the failure of Vanguard TV-3 ...

, as the AJ10-118 configuration. It was initially fueled by

nitric acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...

and

UDMH Unsymmetrical dimethylhydrazine (UDMH; 1,1-dimethylhydrazine, НДМГ or codenamed Geptil) is a chemical compound with the formula H2NN(CH3)2 that is used as a rocket propellant. It is a colorless liquid, with a sharp, fishy, ammonia-like smell ...

. An AJ10 engine was first fired in flight during the third Vanguard launch, on 17 March 1958, which successfully placed the

Vanguard 1 Vanguard 1 (Harvard designation: 1958-Beta 2, COSPAR ID: 1958-005B ) is an American satellite that was the fourth artificial Earth-orbiting satellite to be successfully launched, following Sputnik 1, Sputnik 2, and Explorer 1. It was laun ...

satellite into orbit. As of 25 May 2008, 138 have been launched, and excluding one which was destroyed by the explosion of a lower stage, none have failed. The Delta-K was used as the second stage of the

Delta II Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 va ...

rocket from 1989 to 2018. This second stage was retired at conclusion of the

ICESat-2 ICESat-2 (Ice, Cloud, and land Elevation Satellite 2), part of NASA's Earth Observing System, is a satellite mission for measuring ice sheet elevation and sea ice thickness, as well as land topography, vegetation characteristics, and clouds. ICES ...

launch on 15 September 2018.

References

Rocket stages {{rocket-stub

See also

References