Hughes Builds Two TV Satellites for Norway
| Height stowed: | 3.32 m (10 ft 6 in) |
|---|---|
| Width stowed: | 2.16 m (7 ft 1 in) |
| Height deployed | 7.76 m (25 ft 3 in) |
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| Weight in orbit: | 646.5 kg (1422 lb) beginning of life |
Hughes Space and Communications International, Inc., under contract to Telenor of Oslo, Norway, provided powerful satellites to deliver direct-to-home television programming to Scandinavia and northern Europe.
In November 1995, Hughes was awarded the contract for Thor II, a high-powered version of Hughes' spin-stabilized 376 model. Thor II was successfully launched in May 1997. That same month, Telenor announced the award of a follow-on contract to Hughes for a second high-powered Hughes 376 satellite, Thor III, which was successfully launched in June 1998. In October 2000, The Boeing Company acquired three units within Hughes Electronics Corporation: Hughes Space and Communications Company, Hughes Electron Dynamics, and Spectrolab, Inc., in addition to Hughes Electronics' interest in HRL, the company's primary research laboratory. The four are now part of Boeing's newest subsidiary, Boeing Satellite Development Center.
Both contracts required Hughes to provide the spacecraft, launch services on a McDonnell Douglas (now Boeing) Delta II rocket, earth station upgrades at various sites, including the main site in Nittedal, Norway, and training. The satellites are built at the Integrated Satellite Factory of Hughes Space and Communications Company, now Boeing Satellite Development Center, in El Segundo, Calif.
Although Thor II is Telenor's second satellite, it was the first satellite designed specifically for Norway. Telenor's first satellite, also a Hughes 376 model, was originally built for British Sky Broadcasting. In 1992 Telenor bought the satellite in orbit and changed its name from Marcopolo II to Thor I.
The popular and versatile Hughes 376, now Boeing 376, spin-stabilized spacecraft is one of the world's most-purchased commercial communications satellites. Thor II was the 48th HS 376 model to be launched.
Since the launch of the first Hughes 376 in 1980, Hughes has continued to enhance and improve the design of this spin-stabilized satellite. Improvements in propulsion and power extend the life and increase the power capability in order to match heightened customer requirements. Through the use of gallium arsenide solar cells, today's high-power HS 376 model features a 50% increase in power over its predecessor.
The HS 376 has two telescoping cylindrical solar panels and antennas that fold for compactness during launch. The basic bus accommodates a wide range of customized payloads, and the satellite can be boosted by any of the world's major launch vehicles.
Telenor's three-satellite fleet will deliver television and telephony/data services to Scandinavia and Northern Europe, with western offshore beams to the Faroes, Iceland, and Greenland. Thor II and Thor III will be collocated at Telenor's Nordic Hot-Bird position at 1° West longitude. Thor II covers five zones stretching from Scandinavia across the north Atlantic to Greenland, with the primary zone comprising Norway, Denmark, Sweden, Finland, and the Baltic states. The Ku-band effective isotropic radiated power (EIRP) is 52 dBW in the primary zone. Thor III will cover three zones stretching from Scandinavia across the north Atlantic to Greenland and into eastern Europe. The EIRP for Thor III will be 50 dBW.
The Thor antennas have shaped surface octagonal reflectors of approximately 2 meters diameter, with single offset feeds. These antennas have three surfaces: one for horizontally polarized signals, one for vertically polarized signals, and one for on-station tracking and command. Both spacecraft will use a bipropellant propulsion system for greater stationkeeping and attitude control efficiency.
Boeing Satellite Development Center is the leading manufacturer of commercial communication satellites,and is also a major supplier of spacecraft and scientific instruments to the U.S. government, and builder of weather satellites for the United States and Japan.