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Musket Ball



Musket Ball was a high-density satellite designed to obtain atmospheric density data at low altitudes. The spacecraft was a 30-cm-diameter brass sphere with a 2.5-cm wall thickness. Mounted on the surface were two beacon antennas, spaced 180 deg apart, for a c-band transponder. Internal electronics consisted of the transponder and a silver-cadmium battery pack. The battery, with an expected 12-day lifetime, was the sole source of power for the spacecraft. The spacecraft employed an automatic timing device to turn on the transponder for periodic interrogation. The satellite, which was successfully launched into a polar orbit as part of the payload of OV1-21, performed normally until it reentered the earth's atmosphere on September 19, 1971.

Alternate Names

  • OAR 907
  • Radar Tracked Den Sat
  • 05383
  • SESP 70-2D
  • MusketBall

Facts in Brief

Launch Date: 1971-08-07
Launch Vehicle: Atlas
Launch Site: Vandenberg AFB, United States
Mass: 61.4 kg

Funding Agency

  • Department of Defense-Department of the Air Force (United States)


  • Engineering
  • Earth Science

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Mr. C. H. ReynoldsProject ManagerPhillips Laboratory (nee USAF Geophysics Lab, nee Cambridge Labs)
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