 Explorer 24 satellite | |
| Names | AD-B Air Density experiment-B |
|---|---|
| Mission type | Air density |
| Operator | NASA |
| COSPAR ID | 1964-076A |
| SATCATno. | 00931 |
| Mission duration | 1426 days (achieved)[1] |
| Spacecraft properties | |
| Spacecraft | Explorer XXIV |
| Spacecraft type | Explorer |
| Bus | AD |
| Manufacturer | Langley Research Center |
| Launch mass | 8.6 kg (19 lb) |
| Dimensions | 3.6 m (12 ft) diameter |
| Power | Solar cells and rechargeable batteries |
| Start of mission | |
| Launch date | 21 November 1964, 17:09:39GMT[2][3] |
| Rocket | Scout X-4 (S-135R)[4] |
| Launch site | Vandenberg,PALC-D |
| Contractor | Vought |
| Entered service | 21 November 1964 |
| End of mission | |
| Decay date | 18 October 1968 |
| Orbital parameters | |
| Reference system | Geocentric orbit[5] |
| Regime | Low Earth orbit |
| Perigee altitude | 525 km (326 mi) |
| Apogee altitude | 2,498 km (1,552 mi) |
| Inclination | 81.40° |
| Period | 116.30 minutes |
| Instruments | |
| Nonsystematic Changes of Air Density Systematic Changes of Air Density | |
Explorer program | |
Explorer 24 (also calledAD-B,Air Density experiment-B andS-56C) was aNASA satellite designed foratmospheric studies. Explorer 24 was launched on 21 November 1964 fromVandenberg Air Force Base,Lompoc, California, with aScout X-4. Explorer 24 was launched along with its successor satellite,Explorer 25.[6]
Explorer 24 was placed in orbit together withExplorer 25 from a single launch vehicle. Explorer 24 was identical in configuration to the previously launched balloon satellitesExplorer 9 andExplorer 19. The spacecraft was 3.6 m (12 ft) in diameter, was built of alternating layers ofaluminum foil andplastic film, and was covered uniformly with 5.1 cm (2.0 in) white dots for thermal control. It was designed to yield atmospheric density nearperigee as a function of space and time from sequential observations of the sphere's position in orbit. To facilitate ground tracking, the satellite carried a 136-MHz tracking beacon.[6]
This experiment was designed to determine nonsystematic changes of the density of the upper atmosphere from studies of the drag on a 3.6 m (12 ft) diameter low-density sphere caused by short-term differences in solar activity. Density values near perigee were deduced from sequential observations of the spacecraft position, using optical (Baker-Nunn camera network) and radio and/or radar tracking techniques. This experiment resulted in the successful determination of reasonable density values until spacecraft re-entry.[7]
This experiment was designed to determine systematic changes of air density as a function of altitude, latitude, and time of day, by measuring the drag on a 3.6 m (12 ft) diameter low-density sphere with ground tracking.[8]
Explorer 24 helped determine the variation in density between the day and night of theEarth and gave rise to studies on the zone winds in theexosphere, at an altitude of between 450 km (280 mi) and 620 km (390 mi).[9][10]
The satellitereentered theEarth's atmosphere on 18 October 1968.[6]
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.
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