The Thor-Delta, also known as Delta DM-19 or just Delta was an early 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 ...

used for 12

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

al launches in the early 1960s. A derivative of the Thor-Able, it was a member of the

Thor Thor (from ) is a prominent list of thunder gods, god in Germanic paganism. In Norse mythology, he is a hammer-wielding æsir, god associated with lightning, thunder, storms, sacred trees and groves in Germanic paganism and mythology, sacred g ...

family of rockets, and the first member of the

Delta Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...

family. The first stage was a

missile in the DM-19 configuration (DM-18A / MB-3-I engine). The second stage was the

( AJ-10-142 engine), which had been derived from the earlier Able stage. An

Altair Altair is the brightest star in the constellation of Aquila (constellation), Aquila and the list of brightest stars, twelfth-brightest star in the night sky. It has the Bayer designation Alpha Aquilae, which is Latinisation of name ...

solid rocket motor (X-248A-7) was used as a third stage. The basic design of the original

Vanguard The vanguard (sometimes abbreviated to van and also called the advance guard) is the leading part of an advancing military formation. It has a number of functions, including seeking out the enemy and securing ground in advance of the main force. ...

upper stages, featuring a pressure-fed nitric acid/

UDMH Unsymmetrical dimethylhydrazine (abbreviated as UDMH; also known as 1,1-dimethylhydrazine, heptyl or Geptil) is a chemical compound with the formula H2NN(CH3)2 that is primarily used as a rocket propellant. At room temperature, UDMH is a colorle ...

, regeneratively cooled engine, was kept in place, but with an improved AJ10-118 engine. More significantly, the Delta stage featured cold gas attitude control jets allowing it to be stabilized in orbit for restart and more precise burns. The Thor-Delta was the first rocket to use the combination of a Thor missile and a Delta upper stage. This configuration was reused for many later rockets, and a derivative, 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 ...

, remained in service until 2018.

Thor-Delta launches

The Thor-Delta launched a number of significant payloads, including the first

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 ...

, Echo 1A; the first British satellite, Ariel 1; and the first active direct-relay communications satellite, Telstar 1. All 12 launches occurred from

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 ...

Launch Complex 17. The launch of Telstar 1 used pad B, while all other launches were from pad A. All launches were successful except the maiden flight, which failed to place Echo 1 into orbit due to a problem with the second stage.

Launch list

Gallery

File:Launch of TIROS II Spac0047-repair.jpg, Thor 245 Delta 3 launching TIROS-2 File:Thor-Delta TIROS III launch.jpg, Thor 286 Delta 5 launching TIROS-3 File:Thor Delta with Explorer 10 (Mar. 25, 1961).gif, Thor 295 Delta 4 launching Explorer 10 File:Thor Delta with Telstar 1 Jul 10 1962.jpg, Thor 316 Delta 11 launching Telstar 1 File:Thor Delta with Tiros 4 (Feb. 8 1962)-repair.jpg, Thor 317 Delta 7 launching TIROS-4 File:Thor Delta with Ariel 1 (Apr. 26, 1962).jpg, Thor 320 Delta 9 launching Ariel 1

References

{{Thor and Delta rockets Thor (rocket family)

Thor-Delta launches

Launch list

Gallery

See also

References