Names | GRAB 1 SOLar RADiation SR 1 GREB 1 |
---|---|
Mission type | Solar X-rays |
Operator | Naval Research Laboratory (NRL) |
Harvard designation | 1960 Eta 2 |
COSPAR ID | 1960-007B |
SATCAT no. | 00046 |
Mission duration | 10 months (achieved) 64 years, 7 months and 3 days (in orbit) |
Spacecraft properties | |
Spacecraft type | SOLRAD |
Manufacturer | Naval Research Laboratory |
Launch mass | 19.05 kg (42.0 lb) |
Dimensions | 51 cm (20 in) of diameter |
Power | 6 watts |
Start of mission | |
Launch date | 22 June 1960, 05:54 GMT |
Rocket | Thor-Ablestar |
Launch site | Cape Canaveral, LC-17B |
Contractor | Douglas Aircraft Company |
End of mission | |
Deactivated | April 1961 |
Orbital parameters | |
Reference system | Geocentric orbit[1] |
Regime | Low Earth orbit |
Perigee altitude | 614 km (382 mi) |
Apogee altitude | 1,061 km (659 mi) |
Inclination | 66.69° |
Period | 101.7 minutes |
SOLRAD (SOLar RADiation) 1 is the public designation for SOLRAD/GRAB 1, a combination science and surveillance satellite launched into orbit on 22 June 1960. It was the first satellite to successfully observe solar X-rays, the first to conduct surveillance from orbit, and the first to be launched with another instrumented satellite (the unrelated navigation satellite, Transit 2A).
Developed by the United States Navy's Naval Research Laboratory (NRL), the satellite was in many ways a direct successor to NRL's Project Vanguard, the first American satellite program. The satellite's scientific mission was a success, sending useful data until November 1960 that determined normal solar X-ray output and confirmed the connection between increased solar X-ray activity and radio fade-outs.
The SOLRAD scientific package aboard the satellite provided cover for the Galactic Radiation and Background (GRAB) electronic surveillance package, whose mission was to map the Soviet Union's air defense radar network. The GRAB mission was also successful, operating until 22 September 1960, and revealing that the Soviet air defense radar network was more extensive than had been expected. SOLRAD/GRAB 1 was switched off in April 1961, making it the first satellite to be remotely deactivated.