The Ace Moving Company

company. It offered, for the first time, rooftop-to-rooftop voice, data and video business communications, as well as Canadian television and other broadcast services.

Although its name implies that it was the third ANIK-C-series satellite to be placed into orbit, this was actually the first to be launched! Two others, ANIK-C1 and ANIK-C2, had been placed in storage until a suitable date could be established for their launch. By coincidence, ANIK-C3's completion occurred at the same time as Telesat's first contracted flight opportunity on the Shuttle, so it was decided to take it straight from the factory to the launch pad. The other two ANIK-Cs were launched on later Shuttle missions in 1983 and 1985.

Both SBS-3 and ANIK-C3 were cylindrical drums, measuring 2.7 m tall and 2.1 m wide when stowed on board Columbia, but increasing to more than twice that height in their final configuration. Both were coated with black 'skins' of 14,000 solar cells, which generated 1,100 watts of DC power to operate them over decade-long lifespans and also carried their own supplies of hydrazine fuel for station-keeping. Each had an onboard power system, including rechargeable batteries, to run its communications equipment. SBS-3 covered the entire contiguous United States and ANIK-C3 virtually all of Canada, including its remote northern regions.

SBS-3 was equipped with 10 transponder channels; ANIK-C3 had 16. Attached to the top of each satellite was a 1.7-m-wide shared-aperture grid antenna with two reflecting surfaces to provide both 'transmission' and 'reception' beams. In the case of ANIK-C3, which operated in the high-frequency radio bands at 14 and 12 GHz, a combination of high transmission power and high-frequency band usage meant that much smaller antennas just 1.2 m across could now be situated on rooftops or office blocks. This marked a significant reduction in size from the 3.6-m-wide reception dishes used previously, which had been viable only for hotels and office buildings.

Not only were commercial satellites new to the Shuttle, but so were the Payload Assist Module (PAM)-Ds, built by McDonnell Douglas, which were used by satellites on board both the Shuttle and the expendable Delta rocket. In essence, they and the payload bay-mounted cradle provided portable launch platforms, fitted with spin motors and deployment springs and could deliver satellites of up to 1,250 kg into geosynchronous transfer orbits.

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