UK DBS; 31 deg W. Direct broadcasting system. Expected operational life 12.5 yr. Owner/operator: British Sky Broadcasting Ltd, 6 Centaurs Business Park, Grant Way, Isleworth, Middlesex TW7 5QD. Sold on-orbit in 1992 to Telenor Norway and redesignated Thor 1.
Geosynchronous. Stationed over 0.8W
The spacecraft was delivered to its final orbit in a complex series of five engine burns by three rocket stages. The Delta's second stage demonstrated its restart capability in 4 burns: Burn 1 placed the rocket and payload into a low circular orbit; Burn 2 raised the apogee to 1400 km; Burn 3 circularised the orbit at 1400 km. The second stage then separated, and Burn 4 lowered the spent stage's perigee to a low altitude to ensure the stage would decay quickly and not add to the space junk already on orbit. Stage 3 burned once to place the payload and its kick motor into a high 1400 km perigee geosynchronous transfer orbit. The Stage 4 Star 30 apogee kick motor circularised the spacecraft's orbit at geostationary altitude. Geostationary at 0.8 degrees W.