Thor

Marcopolo redirects here. For the explorer, see Marco Polo. For any other, please see Marco Polo (disambiguation)

Thor (previously known as Marcopolo) is a family of satellites designed, launched and tested by Hughes Space and Communications (now part of Boeing Satellite Systems) for British Satellite Broadcasting, and were used for Britain's Direct Broadcast Service. It is owned by Telenor.

Thor is available throughout the UK, Iceland, Ireland, Scandinavia, Greenland, and the North Atlantic.

^[1] Marcopolo 1 launched on August 27, 1989 on the 187th launch of a Delta rocket, and Marcopolo 2 on August 17, 1990, by a Delta II rocket.^[2] Marcopolo I had a Hughes designation as HS376.^[3]

Although the satellites worked perfectly, BSB ^[4] merged with Sky Television to form British Sky Broadcasting and the BSB satellites were sold off and renamed. This also resulted in the obsoletion of the Squarial which was designed to operate with Marcopolo 1 & 2 only.

Thor 1

Marcopolo 1

Marcopolo 1 was introduced in 27th August 1989. It was Hughes Space and Communications's first satellite launched. Marcopolo 1 was sold off in December 1993 to Nordic Satellite AB of Sweden and operated until 2000 as Sirius 1 at 5°E. It was then moved to 13°W, and renamed Sirius W, although it is not currently transmitting any services. It had 5 Ku-band transponders

Marcopolo 2

Marcopolo 2 was launched in 18th August 1990. It had 5 Ku-band transponders.

Marcopolo 2 was sold in July 1992 to Telenor of Norway and renamed Thor 1. It was located at 0.8°W until it was switched off in January 2002. In November 2002, it was moved to 7.4°W and reactivated with digital test signals broadcasting towards Scandinavia. Marcopolo 2 was sent up to the junk orbit in early January 2003.

Thor 2

Thor 2 was launched in 21st May 1997. Both Thor 2 and 3 had a lifetime of 11 years. It was 1467kg. It has 15 active Ku-band transponders, with 3 spares, powered by 40-watt traveling-wave tube amplifiers (TWTAs).

Thor 3

Thor 3 was launched in 9th June 1998. It has 14 active Ku-band transponders powered by 47-watt traveling-wave tube amplifiers (TWTAs).

Thor 3 will be replaced by Thor 6, by 2010, and Thor 3 will be retired.

Note: There was no Thor 4.

Thor 5

Thor 5 was launched in 11th February 2008. They planned that it would have been called as Thor 2R, but they finally and normally called it Thor 5. It has 24 Ku-band transponders.

Thor 6

Thor 6 will be launched in Summer 2009. It will have 36 active Ku-band transponders. 16 transponders will point to the Nordic countries, and 20 transponders will be positioned to serve the growing broadcasting demands within Central and Eastern Europe.

Thor 6 is the final satellite in Telenor Satellite Broadcasting's replacement programme for Thor 2 and Thor 3. Thor 6 will replace Thor 3, which is set to retire in 2010. The order calls for a 26 month in-orbit delivery schedule, and is expected to start services in summer 2009 with an operational lifetime of 15 years.

Specifications^[5]

• Prime contractor: Hughes
• Platform: HS-376
• Mass at launch: 1250 kg
• Mass in orbit: 660 kg
• Payload mass: 100 kg: transponders: 90 kg, antennas: 10 kg
• Diameter: 2.16 m
• Height: 2.7 m (7.2 m deployed)
• Stabilization: Spin stabilized
• DC power: BOL: 1024 W
• Design lifetime: 10 years
• Beacon: 12.494 or 12.495 GHz

References

1. ^ BSB History by Boeing
2. ^ "Boeing Launch Services Mission Record". Boeing. http://www.boeing.com/defense-space/space/bls/missions/index.html. 
3. ^ [1] NASM's Herbert Stephen Desind Collection,p.36
4. ^ BSB1
5. ^ BSB Specs