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 (BSB), and were used for Britain's Direct Broadcast Service. Thor is owned by Telenor. Marcopolo 1 launched on 27 August 1989 on the 187th launch of a Delta rocket, and Marcopolo 2 launched on 17 August 1990, on a Delta II rocket. Marcopolo I had the Hughes designation HS376.
Although the satellites performed as designed, BSB 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 satellite-reception antenna, which was designed to operate with Thor 1 only.
Sirius W, previously known as Sirius 1, was launched on 27 August 1989. It was Hughes Space and Communications's first satellite. Marcopolo 1 was sold 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. It had 5 Ku band transponders.
Marcopolo 2 was launched on 18 August 1990. It had 5 Ku band transponders. It was sold in July 1992 to Telenor of Norway and renamed Thor 1. It was located at 0.8°W. It was switched off in January 2002, and in November of that year it was moved to 7.4°W and reactivated with digital test signals broadcasting toward Scandinavia. Marcopolo 2 was sent up to the junk orbit in early January 2003.