Tim Furniss/CAPE CANAVERAL
The UK's Skynet 4D military-communications satellite was lofted into orbit by a three-stage Boeing Delta 2 booster from Cape Canaveral, Florida, on 10 January.
The launch was the first of 18 planned by the Delta this year and the first of 11 Matra Marconi Space (MMS)-built satellites scheduled to be launched in 1998.
The Skynet satellites provide secure military communications for the UK Ministry of Defence and the three UK military services, using receivers ranging from portable to fixed terminals and are operated and controlled by Royal Air Force Oakhanger, Hampshire.
The Skynet 4D is the first of three enhanced communications satellites ordered by the MoD under a $520 million contract, which includes the spacecraft, three launches and additional ground-station equipment. The Delta launch cost about $50 million. The Skynet 4E and F will be launched on Ariane 4 boosters from Kourou, French Guiana, by Arianespace in September 1998 and in 1999.
Following its in-orbit check-out at 6¹E in geostationary orbit, the Skynet 4D will be moved to replace the ageing Skynet 4B - the first Skynet 4-series spacecraft to be launched, in 1988 - at 53¹E in geostationary orbit. The Skynet 4A and 4C satellites were launched in 1990.
Compared with the Skynet 4s, "80%of the Skynet 4D-F payloads have been modified as a result of changes in the worldwide military environment, requiring much greater service flexibility", according to David Cross, MMS Skynet spacecraft manager. These improvements include improved UHF and SHF spot-beam coverage and antenna capability.
The Skynet launch was also the first to take place from Boeing's Pad 17B since its modification to accommodate launches of the new Delta 3 booster.
Two Delta 3 launches are planned this year, the first in June, as well as eight Delta 2 launches. Six are planned from Vandenberg AFB, California.
Source: Flight International
