_(21649093158).jpg) SOLRAD 4 satellite | |
| Names | GRAB 3 SOLar RADiation 4 SR 4 GREB 3 |
|---|---|
| Mission type | Solar X-Rays |
| Operator | United States Naval Research Laboratory (USNRL) |
| COSPAR ID | 1962-F02 (SR4GREB) |
| Mission duration | Failed to orbit |
| Spacecraft properties | |
| Spacecraft type | SOLRAD |
| Manufacturer | Naval Research Laboratory (NRL) |
| Launch mass | 25 kg (55 lb) |
| Dimensions | 51 cm (20 in) |
| Start of mission | |
| Launch date | 24 January 1962, 09:30 GMT |
| Rocket | Thor-Ablestar |
| Launch site | Cape Canaveral, LC-17B |
| Contractor | Douglas Aircraft Company |
| End of mission | |
| Decay date | Failed to orbit |
| Orbital parameters | |
| Reference system | Geocentric orbit (planned) |
| Regime | Low Earth orbit |
| Perigee altitude | 930 km |
| Apogee altitude | 930 km |
| Inclination | 66.80° |
| Period | 103.00 minutes |
SOLRAD (SOLar RADiation) 4 was a solar X-rays, ultraviolet, and electronic surveillance satellite. Developed by the United States Navy's United States Naval Research Laboratory (USNRL), it was the fourth in both the SOLRAD and the GRAB (Galactic Radiation and Background) programs.
The satellite was to be orbited along with ionospheric study satellite LOFTI-2, the United States Army's range calibration satellite SECOR, Navy surveillance calibration satellite Surcal, and the University of Iowa's Van Allen radiation belts-studying Injun 2 satellite. This unprecedented five-in-one mission, called "Composite 1" and "Buckshot", ended in failure on 24 January 1962 after its Thor-Ablestar's second stage failed to deliver the payloads to orbit.