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astronautix.com Microstar


Class: Technology. Type: Communications. Nation: USA. Agency: U.S. Air Force.

Small satellite bus used for Orbcomm LEO network for global communications and related spacecraft.


Specification

Total Mass: 25 kg.


Microstar Chronology


17 July 1991 Microsat 1 Program: Orbcomm. Launch Site: Edwards . Launch Vehicle: Pegasus. FAILURE: Partial Failure. A problem at first stage separation caused a guidance error and the payload ended up in an orbit with half the intended perigee altitude. Mass: 22 kg. Perigee: 356 km. Apogee: 454 km. Inclination: 82.0 deg.

Test of LEO network for global communications.


03 April 1995 Orbcomm F1 Program: Orbcomm. Launch Site: Vandenberg . Launch Vehicle: Pegasus. Mass: 40 kg. Perigee: 728 km. Apogee: 747 km. Inclination: 70.0 deg.

Commercial communications testbed. Plane F. Ascending node 199.1 degrees.


23 December 1997 Orbcomm A1 Program: Orbcomm. Launch Site: Wallops Island . Launch Vehicle: Pegasus XL. Perigee: 812 km. Apogee: 823 km. Inclination: 45.0 deg.

Plane A. Ascending node 297.7 degrees.


10 February 1998 Orbcomm G1 Program: Orbcomm. Launch Site: Vandenberg . Launch Vehicle: Taurus . Perigee: 781 km. Apogee: 874 km. Inclination: 108.0 deg.

Plane G. Ascending node 297.9 degrees.


18 May 1999 MUBLCOM Launch Site: Vandenberg . Launch Vehicle: Pegasus XL. Perigee: 770 km. Apogee: 775 km. Inclination: 97.7 deg.

After deploying the TERRIERS satellite, the conical Payload Adapter Fitting (1998-26E) was jettisoned at 05:21 GMT, leaving the disk-shaped MUBLCOM satellite attached to the Pegasus XL PRIMEX HAPS-Lite stage. The second HAPS burn at 05:22 GMT raised apogee to 775 km, followed by a third, apogee burn at 06:10 GMT which circularised the orbit. MUBLCOM was deployed to a 769 km x 776 km x 97.7 degree orbit. The final HAPS burn then placed the depleted HAPS stage in a lower 388 km x 722 km x 97.1 degree disposal orbit. MUBLCOM (Multiple beam Beyond Line-of-sight Communications) was an experimental satellite funded by DARPA and managed by the US Army's Communications-Electronics Command (CECOM) at Ft Monmouth, New Jersey. It was built by Orbital Sciences using the Microstar (Orbcomm type) bus and carries a payload testing hand-held radio satellite communications for the armed forces.



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Last update 12 March 2001.
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© Mark Wade, 2001 .