Syncom IV/Leasat

Author(s): DaveBowman2001

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The Leased Satellite (Leasat) program, also known as Syncom-IV, were the first satellites designed to be specifically launched by a Space Shuttle. Weighing 3.4 tons and measuring 6.17 m when fully deployed, these satellites provided communications for the US military and its allies during the later years of the Cold War. Designated internally as HS-381 satellites, a total of four were built (with an additional spare) by Hughes Communications, each one launching from 1984 to 1990. All satellites were decommissioned into their respective graveyard orbits since 2015


  • Requires the Space Shuttle addon installed for this addon to work
  • Shuttle missions STS-41-D, STS-51-A, STS-51-D, STS-51-I, and STS-32 will be modified by this addon upon installation

Mission Start End
Leasat 2 (Syncom IV-2) 1984-Aug-301996
Launched from STS-41-D (Discovery)
Leasat 1 (Syncom IV-1) 1984-Nov-081994
Launched from STS-51-A (Discovery)
Leasat 3 (Syncom IV-3) 1985-Apr-121996
Launched from STS-51-D (Discovery), stranded in LEO before being repaired by the crew of STS-51-I (Discovery)
Leasat 4 (Syncom IV-4) 1985-Aug-271985-Sept
Launched from STS-51-I (Discovery), failed shortly afterwards
Leasat 5 (Syncom IV-5) 1990-Jan-092015-Sept-24
Launched from STS-32 (Columbia)

Bill Fisher repairing the crippled Leasat 3 satellite during STS-51-I (Discovery), 1985-Sept-1

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