Anik C is Canada's first dedicated spacecraft to offer point-to-point commercial
services in the 14/12 GHz Ku-band frequencies. The satellite triples the power output of
the Hughes-built Anik A, the country's first communications
satellite. Anik C also allows a significant increase in telecommunications capacity over
Anik A.
Telesat Canada awarded the contract to Hughes Aircraft Company's Space and
Communications Group, today known as Boeing Satellite Systems, in April 1978. The contract
called for three communications satellites to serve Canada's expanding telecommunications
network.
Anik C focuses four transmit beams to provide regional coverage to the more densely
populated southern portions of Canada. Each satellite can provide audio, video, and data
transmission services.
The cylindrical Anik C satellite, with a deployable antenna reflector and two
concentric, telescoping solar panels, sat upright in the shuttle's cargo bay. This
configuration conserved valuable cargo space on the shuttle and also reduced launch costs.
The spacecraft was contained in a special cradle that housed the ejection system and
was covered by a protective sunshield. The sunshield was opened, and Anik C was spun up
while in the cradle. Explosive bolt cutters fired, allowing four springs to eject the
satellite. After orbiting halfway around earth, the satellite fired its McDonnell Douglas
payload assist module (PAM) for insertion into an elliptic transfer orbit. The apogee
motor, a Thiokol Corporation Star-30B solid
propellant rocket, placed the satellite into a near-synchronous orbit. The satellite then
drifted to its final orbital location.
When the satellite neared its orbital slot, the electronics shelf was despun, the
antenna erected, and the telescoping solar panel deployed, exposing the inner solar array
to sunlight.
Anik C's solar array of K7 cells, which generates 19.7 milliwatts per square
centimeter, produced more than 900 watts of dc power at beginning of life. Three
nickel-cadmium batteries provide power during eclipse, when the spacecraft passes through
Earth's shadow. The communications repeater uses 15 watt, multicollector traveling wave
tube amplifiers in each of the 16 channels. A shared aperture grid antenna 6 feet (1.8
meters) wide creates the transmit and receive beams using two reflecting surfaces. One
surface is sensitive to vertical polarization and the other to horizontal. Separate
microwave feed networks are used for the different polarizations. With the high gain
developed by the antenna, the effective isotropic radiated power (EIRP), or signal
strength, is 46.5 dBW in the primary coverage zones.
Stowed for launch, with solar arrays telescoped together and the antenna reflector
folded down, Anik C measured only 2.82 meters high and 2.16 meters in diameter. When the satellite began operation, with antenna raised and
solar panels deployed, its height increased to 6.43 meters. The
on-station weight of the satellite is 562.5 kg, of which 99 kg
is propellant. Attitude control and stationkeeping is provided by four thrusters. The
design life of each satellite is 10 years. In geostationary orbit, 35,680 km above the equator, Anik C-3 is positioned at 114.9 degrees West longitude, Anik C-2 is
at 110 degrees West longitude, and Anik C-1 is at 107.5 degrees West longitude.
A significant portion of the design, manufacture, and testing of the Anik C spacecraft
was done in Canada. Spar Aerospace Ltd. of Toronto, Ottawa, and Montreal was the principal
subcontractor. Other Canadian participants included SED Systems Ltd. in Saskatoon,
Saskatchewan; COMDEV Ltd. in Montreal; and the Fleet Industries division of Ronyx
Corporation Ltd. in Fort Erie, Ontario.
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