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ORS Mk.2 (ERS)

TRS Mk3, Mk2, Mk1, OV3, ORS Mk1, Mk2, Mk3 (left to tight) [NASA]

From 1962 the US Air Force launched a series very small technology satellites called ERS (Environmental Research Satellites). The satellites were built by TRW Systems Group for the United States Air Force Office of Aerospace Research (AFOAR). Depending on the shape, these satellites are also referred to as the Tetrahedral Research Satellite (TRS) or Octahedral Research Satellite (ORS).

The basic configuration of the ORS Mk.2 spacecrafts was a regular octahedron measuring 23 cm on a side. Solar cells mounted on each side of the faces provide sufficient electrical power to operate the experiments and the telemetry system when the satellite is illuminated by the sun. No internal battery or command system were provided. The satellite subsystems consisted of electrical power, antenna, telemetry, experiments, and mechanical structure.


  • ORS 1 (ERS 15): carried out cold welding experiments using eight different material combinations which were fused using actuators, 5 kg
  • ORS 2 (ERS 16): carried a cold welding experiment consisting of five metal to metal tests using actuators, 5 kg
  • ERS 23: Classified
  • ERS 24: Classified
  • ERS 25: Classified
Nation: USA
Type / Application: Experimental
Operator: US Air Force (USAF)
Contractors: TRW Systems Group
Equipment: various: see above
Configuration: Octahedron (ORS Mk.2)
Propulsion: None
Power: Solar cells
Mass: 5 kg (#1, 2)
Satellite COSPAR Date LS Launch Vehicle Remarks
ORS 1 (ERS 15) 1966-077C 19.08.1966 Va SLC-3E Atlas-SLV3 Agena-D with RTS-1 2, SECOR 7
ORS 2 (ERS 16) 1966-051C 09.06.1966 Va PALC-1-2 P Atlas-SLV3 Agena-D with RTS-1 1, SECOR 6
ORS ? (ERS 23) - cancelled ?
ORS ? (ERS 24) - cancelled ?
ORS ? (ERS 25) - cancelled ?


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