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Hitchhiker 1, 2 (P-11 4051, 4201, 4202)

Hitchhiker [USAF]

The Hitchhiker satellites were prototype satellites in the P-11 program, which served scientific purposes. Later P-11 satellites were built as classified SIGINT subsatellites.

These subsatellites were deployed from the propulsion rack of the Agena-D stage of KH-4 Corona, KH-6 Lanyard and KH-7 Gambit-1 reconnaissance satellites.

Hitchhiker 1 was put into an elliptical orbit to measure the energy and pitch-angle distribution of protons and electrons. The intrumenttation was provided by the Massachusetts Institute of Technology (MIT) and by American Science and Engineering. The instrument suit consisted of:

  • a Faraday cup plasma probe
  • an electrostatic analyser consisting of a plastic scintilator on a photomultiplier for 4-100 keV electrons
  • an electrostatic analyser consisting of a plastic scintilator on a photomultiplier for 4-100 keV protons
  • an electron detector to count 0.3-5.0 MeV electrons
  • a proton detecor to count 0.7-5.3 MeV protons
  • a Geiger tube for wide-field detection of protons with E > 40 MeV and electrons with E > 4 MeV
Nation: USA
Type / Application: Experimental
Operator: USAF
Contractors: Lockheed (bus)
Equipment: ?
Configuration: P-11 bus
Propulsion: ?
Power: Solar cells, batteries
Orbit: 331 km × 4125 km, 82.14 (#1); 271 km × 3724 km, 95.69 (#2)
Satellite COSPAR Date LS Launch Vehicle Remarks
Hitchhiker (1) (P-11 4051) 1963-F03 18.03.1963 Va 75-3-4 F Thor-SLV2A Agena-D with KH-6 1
Hitchhiker 1 (P-11 4201) 1963-025B 27.06.1963 Va 75-1-2 Thor-SLV2A Agena-D with KH-4 22
Hitchhiker 2 (P-11 4202, OPS 3316) 1964-045B 14.08.1964 Va PALC-2-4 Atlas-SLV3 Agena-D with KH-7 10