Vela

The Vela (meaning "watchman" in Spanish) series of spacecraft were designed to monitor worldwide compliance with the 1963 nuclear test ban treaty. The satellites were so successful, each operating for at least 5 years, that a planned acquisition of a fourth and fifth pairs was cancelled. Instead, TRW was awarded afurther contract in March 1965 for an Advanced Vela spacecraftseries. The Vela series was the first spacecraft procurement toutilize a fixed price incentive contract.

Spacecraft
Spin stabilized at 120 rpm. 20-sided polyhedrons with body mounted solar cells generating 90 W. During launch, 2 satellites were connected by a central cylinder containing an apogee motor.

Payload
Twelve external X-ray detectors and 18 internal neutron and gamma-ray detectors. The third pair (F5, 6) carried an improved detector package, including an optical nuclear flash instrument.

Country of Origin	United States
Customer/User	USAF
Manufacturer(s)	TRW
Size	1.4 m diameter
Orbit	Average 102000 km, incl. = 38 deg., two spacecraft in the same plane with 180 deg separation
Design Life	6 months

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Vela 1	1963-039A	10/17/63	ESMC	Atlas Agena D	VHO	220
Vela 2	1963-039C	10/17/63	ESMC	Atlas Agena D	VHO	220
Vela 3	1964-040A	7/17/64	ESMC	Atlas Agena D	VHO	220
Vela 4	1964-040B	7/17/64	ESMC	Atlas Agena D	VHO	220
Vela 5	1965-058A	7/20/65	ESMC	Atlas Agena D	VHO	235
Vela 6	1965-058B	7/20/65	ESMC	Atlas Agena D	VHO	235