 The identicalExplorer 9 satellite | |
| Names | NASA S-56 |
|---|---|
| Mission type | Air density research |
| Operator | NASA |
| COSPAR ID | EXS-56 |
| Mission duration | Failed to orbit |
| Spacecraft properties | |
| Spacecraft | Explorer S-56 |
| Spacecraft type | Air Density Explorer |
| Bus | S-56 |
| Manufacturer | Langley Research Center |
| Launch mass | 7 kg (15 lb) |
| Dimensions | 3.66 m (12.0 ft) diameter |
| Power | solar cells and rechargeable batteries |
| Start of mission | |
| Launch date | 4 December 1960, 21:14GMT |
| Rocket | Scout X-1 (ST-3) |
| Launch site | Wallops Flight Facility,LA-3 |
| Contractor | Vought |
| End of mission | |
| Destroyed | Failed to reach orbit |
| Orbital parameters | |
| Reference system | Geocentric orbit (planned) |
| Regime | Medium Earth orbit |
| Perigee altitude | 545 km (339 mi) |
| Apogee altitude | 2,225 km (1,383 mi) |
| Inclination | 38.91° |
| Period | 118.6 minutes |
Explorer Program | |
Explorer S-56 was aNASA satellite launched on 4 December 1960, at 21:14GMT as part of theExplorer program.[1] The satellite was composed of a 3.66 m (12.0 ft) diameter inflatable sphere, and was intended to study the density of the upper atmosphere. TheScout X-1 rocket used to launch Explorer S-56 failed in flight, and the satellite never reached orbit.[2]
The spacecraft consisted of alternating layers ofaluminium foil andMylarpolyester film. Uniformly distributed over the aluminium surface were 5.1 cm (2.0 in)-diameter dots of white paint for thermal control. The sphere was packed in a tube 21.6 cm (8.5 in) in diameter and 48.3 cm (19.0 in) long and mounted in the nose of the fourth stage of itsScout X-1 launch vehicle.[2]
Upon separation of the fourth stage, the sphere will be inflated by a nitrogen gas bottle, and a separation spring will eject it out into its own orbit. The two hemispheres of aluminium foil will be separated with a gap of Mylar at the spacecraft's equator and will serve as the antenna. A 136MHz, 15mW beacon will be carried for tracking purposes, the beacon and the SAOBaker-Nunn camera network will be relied upon for tracking. Power will be supplied bysolar cells andrechargeable batteries.
Explorer S-56 was launched, at 21:14 GMT on 4 December 1960, fromLaunch Area 3 at theWallops Flight Facility (WFF), atop aScout X-1 launch vehicle with the serial number ST-3. It was the first attempt to place a satellite in orbit using anall-solid propellant launch vehicle and the first orbital attempt made from NASA's Wallops Island facility. It was the first spacecraft launched fromWallops Island, but failed to reach orbit due to the second stage not igniting and impacting in theAtlantic Ocean, at 130 km (81 mi) at east of Wallops Island.[3] It was replaced by the identicalExplorer 9 (1961-004A) spacecraft.[4]
The first of six identicalair density research satellites to be launched.[2]
This article incorporates text from this source, which is in thepublic domain.