Thor-Delta
Thor 320 Delta 9 rocket with UK first satellite Ariel 1, 26 April 1962 | |
| Function | Expendable launch system |
|---|---|
| Country of origin | United States |
| Capacity | |
| Payload to LEO | 270 kg |
| Launch history | |
| Status | Retired |
| Launch sites | Cape Canaveral, LC-17 |
| Total launches | 12 |
| Success(es) | 11 |
| Failure(s) | 1 |
| First flight | 13 May 1960 |
| Last flight | 18 September 1962 |
| First stage - Thor DM-19 | |
| Engines | DM-18A / MB-3-I |
| Second stage Delta | |
| Engines | AJ-10-142 |
| Third stage | |
| Engines | X-248A-7 |
The Thor-Delta, also known as Delta DM-19 or just Delta was an early American expendable launch system used for 12 orbital launches in the early 1960s. A derivative of the Thor-Able, it was a member of the Thor family of rockets, and the first member of the Delta family.
The first stage was a Thor missile in the DM-19 configuration (DM-18A / MB-3-I engine). The second stage was the Delta (AJ-10-142 engine), which had been derived from the earlier Able stage. An Altair solid rocket motor (X-248A-7) was used as a third stage.
The basic design of the original Vanguard upper stages, featuring a pressure-fed nitric acid/UDMH, 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, remained in service until 2018.