S-45 (satellite)


S-45 1.jpg
S-45 before launch
Mission typeIonospheric
Mission durationFailed to orbit
Spacecraft properties
Launch mass33.6 kilograms (74 lb)
Start of mission
Launch date25 February 1961, 00:13:16 (1961-02-25UTC00:13:16Z) UTC
RocketJuno II AM-19F
Launch siteCape Canaveral LC-26B
Orbital parameters
Reference systemGeocentric
RegimeHighly elliptical

S-45 was an American satellite, which was lost in a launch failure in 1961. The satellite was intended to operate in a highly elliptical orbit, from which it was to have provided data on the shape of the ionosphere,[1] and on the Earth's magnetic field.[2] It was part of the Explorer programme, and would have been designated Explorer 10 had it reached orbit. A second identical satellite, S-45A, also failed to achieve orbit when it was launched.[2]

S-45 was launched aboard a Juno II rocket, serial number AM-19F. The launch took place from Launch Complex 26B at the Cape Canaveral Air Force Station at 00:13:16 UTC on 25 February 1961.[3] The rocket malfunctioned after the second stage separated, and contact with the payload was lost.[4] The third and fourth stages subsequently failed to ignite, resulting in the satellite failing to achieve orbit.[5]


  1. ^ "Explorer S45". NSSDC Master Catalog. NASA. Retrieved 14 July 2010.
  2. ^ a b Wade, Mark. "P-14". Encyclopedia Astronautica. Archived from the original on 13 June 2010. Retrieved 14 July 2010.
  3. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 14 July 2010.
  4. ^ Krebs, Gunter. "Explorer: S-45". Gunter's Space Page. Retrieved 14 July 2010.
  5. ^ "Explorer Program". Mission and Spacecraft Library. NASA. Archived from the original on 27 January 2008. Retrieved 14 July 2010.