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Today's Moon

Moon Missions to Moon Asiasat 3/HGS 1

Missions to Moon - Asiasat 3/HGS 1

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Asiasat 3/HGS 1 | image: http://sse.jpl.nasa.gov

Country : Hong Kong, People's Republic of China
Research Org : Asia Satellite Telecommunications Co. Ltd.
(AsiaSat)/Peoples Republic of China
Mission launch : Launched 224 December 1997


Asiasat 3 was an accidental Moon mission. A communications satellite launched for China, a booster rocket malfuntion failed to put Asiasat 3 in a stable Earth orbit

Asiasat 3 was a communications satellite launched by Hong Kong, People's Republic of China. It was to be used primarily for television distribution and telecommunications services throughout Asia, the Middle East, and Australasia, with multiple spot beams for selected areas.

The body-stabilized satellite was 26.2 m tip-to-tip along the axis of the solar arrays and 10 m across the axis of the antennas. The bus was essentially a cube, roughly 4 m on a side.

Power to the spacecraft was generated using two sun-tracking, four-panel solar wings covered with Ga-As solar cells, providing up to 9900 watts A 29-cell Ni-H battery provided power to the spacecraft during eclipse operations. A bipropellant propulsion system, consisting of twelve conventional bi-propellant thrusters, was used for stationkeeping.

Two 2.72 m diameter Gregorian shaped-surface antennas were mounted on opposing sides of the bus, perpendicular to the axis along which the solar arrays were mounted. One of these antennas operated in C-band, the other in Ku-band. Focused area coverage was provided by a 1.3 m diameter, dual-gridded shaped reflector operating in the Ku-band. A 1 m diameter Ku-band steerable spot-beam antenna provided the spacecraft with the ability to direct 5 degree coverage of any area on the Earth's surface visible to the spacecraft from its orbit location. Both of these antennas were mounted on the nadir side of the spacecraft.

The satellite was to be placed into a geosynchronous orbit, but a malfunction in the fourth (DM 3) stage resulted in a short life and a dysfunctional orbit. Later investigation revealed that the DM 3 may have been designed only for a maximum payload of 2.4 metric tonnes and had previously mislaunched two earlier payloads which exceeded this limit (as did Asiasat 3).

Following its failure to achieve the proper orbit, the manufacturer (Hughes Global Services) purchased the spacecraft back from the insurers and renamed it HGS 1. HGS 1 was then successfully maneuvered into two successive flybys of the Moon to place it into geosynchronous orbit, the first time such a maneuver was performed by a commercial satellite.



Last Updated ( Friday, 11 September 2009 07:34 )