Explorer 23


Explorer 23
S-55 model
Mission typeEarth science
COSPAR ID1964-074A[1]
SATCAT no.924
Mission duration1 year
Spacecraft properties
Launch mass133.8 kg (295 lb)
Start of mission
Launch date6 November 1964, 12:00 (1964-11-06UTC12) UTC[2]
RocketScout X-1
Launch siteWallops LA-3
End of mission
Last contact7 November 1965
Decay date29 June 1983 (1983-06-30)
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude451 km (280 mi)[1]
Apogee altitude865 km (537 mi)[1]
Period97.9 minutes[1]
Epoch6 November 1964[1]

Explorer 23 (also called S-55C) was the last of three S-55 micrometeoroid satellites launched as part of NASA's Explorers program. Its purpose was to obtain data on the near-earth meteoroid environment, thus providing an accurate estimate of the probability of penetration in spacecraft structures by meteoroids and allowing a more confident definition of the penetration flux-material thickness relation to be derived.

The cylindrically shaped spacecraft, about 61 by 234 centimetres (24 in × 92 in), was built around the burned-out fourth stage of the Scout launch vehicle, which remained as part of the orbiting satellite. Explorer 23 carried stainless steel pressurized-cell penetration detectors, impact detectors, and cadmium sulfide cell detectors to obtain data on the size, number, distribution, and momentum of dust particles in the near-earth environment. In addition, the spacecraft was designed to provide data on the effects of the space environment on the operation of capacitor penetration detectors and solar cell power supplies. The spacecraft mass, neglecting the fourth stage vehicle hardware and motor, was 96.4 kilograms (213 lb).

The spacecraft operated satisfactorily during its 1-year life (November 6, 1964, through November 7, 1965), and all mission objectives were accomplished, except for the cadmium sulfide cell detector experiment, which was damaged on liftoff and provided no data.[1]

See also


  1. ^ a b c d e f g h "S 55C". NSSDC Master Catalog. NASA Goddard Space Flight Center. This article incorporates text from this source, which is in the public domain.
  2. ^ "Launch Log". Jonathan's Space Page. Retrieved June 9, 2018.