Delta B

The Delta B, or Thor-Delta B was an American expendable launch system used for nine orbital launches between 1962 and 1964.^[3] A derivative of the Thor-Delta, it was a member of the Delta family of rockets.^[4]

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)[1]
Payload to Earth escape trajectory
Mass	130 pounds (59 kg)[1]
Launch history
Status	Retired[2]
Launch sites	Cape Canaveral LC-17[3]
Total launches	9
Success(es)	8
Failure(s)	1
First flight	13 December 1962
Last flight	19 March 1964

The first stage was a Thor missile in the DM-21 configuration, and the second stage was the AJ10-118,^[1] which was derived from the earlier Delta-A.^[4] An Altair solid rocket motor was used as a third stage.^[1]

All nine launches occurred from Cape Canaveral Air Force Station Launch Complex 17.^[3] Most of the launches carried communications satellites, including Syncom-1^[2] and Syncom-2.^[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.^[5] Syncom-2 subsequently became the first geosynchronous satellite,^[5] and was placed at 55° west of the Greenwich Meridian. The final launch failed due to third stage underperformance,^[6] all other launches were successful.^[3]

Delta B launches

Delta B was launched nine times:^[3]

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)