Satellites that keep on working

Satellites that keep on working: "

The US Air Force’s Defense Satellite Communications System III constellation has bragging rights as the longest-serving on-orbit military communications system in US history.

Built by Lockheed Martin, the system has surpassed 200 years of uninterrupted secure voice and high-data rate communications for Defense Department users worldwide. In all, 14 DSCS III spacecraft have been built at the company’s Sunnyvale, Calif., facility.''

Their design life is 10 years but smart management of station keeping fuel, plus a solid design and construction, mean that 10 of them have provided a total of 71 years beyond their design life.'

There are nine operating currently, beginning with B12 launched on July 2, 1992, through the latest, B6 launched August 29, 2003'

Alas, all good things come to an end.''

DSCS’ replacement, the Boeing-built Wideband Global Satcom constellation,'is on its way. WGS-1 is in operation; WGS-2 is due for launch Mar. 13 and WGS-3 in July. The new spacecraft take advantage of innovations in commercial comsat technology and are more capable than the older DSCS III design.'

Phase-out of DSCS III is expected in 2011 after the launch of WGS-5. The network will grow to six satellites in 2013.'

Meanwhile, LockMart is busy on the Advanced Extremely High Frequency program, a replacement for the Milstar constellation. The first AEHF is to be delivered to the Air Force nest year. AEHF will increase data rates by a factor of five over Milstar and double the number of possible connections.'

Milstar will pass its 50^th year of on orbit operations in April.

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(Via On Space.)