A British military satellite communications network developed with American
assistance. With the launch of Skynet 1A in 1969, Britain became the third
entity after the United States and Intelsat to orbit a geostationary satellite.
Skynet 1B, launched in August 1970, was stranded in a transfer orbit when
its apogee kick motor failed to fire. Then Skynet 1A failed prematurely,
and it was not until 1974 that the first Skynet 2 was launched. Unfortunately
this too was stranded in a useless orbit. Skynet 2B, however, was successfully
placed in an orbit over the Indian Ocean at 42° E and, remarkably, was still
working 20 years later. Skynet 3 was never developed, and the next launch
was the first of the Skynet 4 series in 1988. Skynet 4, with an on-orbit
mass of 800 kg, has one experimental EHF (extremely high frequency) channel,
two UHF (ultrahigh frequency), and four X-band channels. The fifth and last
Skynet 4, and a replacement for Skynet 4C was launched by an Ariane on Feb.
26, 1999. The first satellite in the Skynet 5 series was launched atop an
Ariane 5-ECA rocket on Mar. 11, 2007.
| Skynet 5
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