Names | IMP-C IMP-3 Interplanetary Monitoring Platform-3 |
---|---|
Mission type | Space physics |
Operator | NASA |
COSPAR ID | 1965-042A |
SATCAT no. | 01388 |
Mission duration | 2 years (achieved) |
Spacecraft properties | |
Spacecraft | Explorer XXVIII |
Spacecraft type | Interplanetary Monitoring Platform |
Bus | IMP |
Manufacturer | Goddard Space Flight Center |
Launch mass | 128 kg (282 lb) |
Dimensions | 71 × 20.3 cm (28.0 × 8.0 in) |
Power | 4 deployable solar arrays and batteries |
Start of mission | |
Launch date | 29 May 1965, 12:00:00 GMT |
Rocket | Thor-Delta C (Thor 441 / Delta 031) |
Launch site | Cape Canaveral, LC-17B |
Contractor | Douglas Aircraft Company |
Entered service | 29 May 1965 |
End of mission | |
Last contact | 12 May 1967 |
Decay date | 4 July 1968 [1] |
Orbital parameters | |
Reference system | Geocentric orbit[2] |
Regime | Low Earth orbit |
Perigee altitude | 32,290 km (20,060 mi) |
Apogee altitude | 227,456 km (141,335 mi) |
Inclination | 53.60° |
Period | 8341.90 minutes |
Instruments | |
Cosmic-Ray Range versus Energy Loss Cosmic Rays Fluxgate Magnetometer Ion Chamber and Geiger–Müller Counters Langmuir probe Plasma and Faraday Cup Retarding Potential Analyzer | |
Explorer 28, also called IMP-C, IMP-3 and Interplanetary Monitoring Platform-3, was a NASA satellite launched on 29 May 1965 to study space physics, and was the third spacecraft launched in the Interplanetary Monitoring Platform program. It was powered by chemical batteries and solar panels. There were 7 experiments on board, all devoted to particle studies. Performance was normal until late April 1967, when intermittent problems began. It stayed in contact until 12 May 1967, when contact was lost. The orbit decayed until it re-entered the atmosphere on 4 July 1968.[1] The spacecraft design was similar to its predecessors Explorer 18 (IMP-A), launched in November 1963, and Explorer 21 (IMP-B), launched in October 1964, though this satellite was a few kilograms lighter. The successor Explorer 33 (IMP-D) began the use of a new design.[3]