Delta B prior to the launch of TIROS-8 | |
| Function | Expendable launch system |
|---|---|
| Country of origin | United States |
| Capacity | |
| Payload to LEO | |
| Altitude | 350 nautical miles (650 km; 400 mi) |
| Mass | 800 pounds (360 kg) |
| Payload to Earth escape trajectory | |
| Mass | 130 pounds (59 kg) |
| Launch history | |
| Status | Retired |
| Launch sites | Cape Canaveral LC-17 |
| Total launches | 9 |
| Success(es) | 8 |
| Failure | 1 |
| First flight | 13 December 1962 |
| Last flight | 19 March 1964 |
The Delta B, or Thor-Delta B was an American expendable launch system used for nine orbital launches between 1962 and 1964. A derivative of the Thor-Delta, it was a member of the Delta family of rockets.
The first stage was a Thor missile in the DM-21 configuration, and the second stage was the AJ10-118, which was derived from the earlier Delta-A. An Altair solid rocket motor was used as a third stage.
All nine launches occurred from Cape Canaveral Air Force Station Launch Complex 17. Most of the launches carried communications satellites, including Syncom-1 and Syncom-2. Syncom-1 was intended to be the first satellite to be placed into a geosynchronous orbit, however the spacecraft malfunctioned prior to reaching this orbit. Syncom-2 subsequently became the first geosynchronous satellite, and was placed at 55° west of the Greenwich Meridian. The final launch failed due to third stage underperformance, all other launches were successful.
Delta B was launched nine times:
| Date | Ser. | Launch site | Payload |
|---|---|---|---|
| 13.12.1962 | Thor 355 Delta 15 | LC-17A | Relay 1 |
| 14.02.1963 | Thor 358 Delta 16 | LC-17B | Syncom 1 |
| 03.04.1963 | Thor 357 Delta 17 | LC-17B | Explorer 17 |
| 07.05.1963 | Thor 366 Delta 18 | LC-17B | Telstar 2 |
| 19.06.1963 | Thor 359 Delta 19 | LC-17B | TIROS 7 |
| 26.07.1963 | Thor 370 Delta 20 | LC-17A | Syncom 2 |
| 21.12.1963 | Thor 371 Delta 22 | LC-17B | TIROS 8 |
| 21.01.1964 | Thor 373 Delta 23 | LC-17B | Relay 2 |
| 19.03.1964 | Thor 391 Delta 24 | LC-17A | Explorer S-66 (failed) |