Heaven Sent
Defence set for first satellite launch

An Ariane Launch vehicle.

The Defence satellite team at the X- and Ka-band anchor station from left; Satellite Engineer Mark Thompson, Resident Project Engineer Allan Jeffs, ILS manager Paul Jones, Project Director Martin Weir, Satellite Engineer FLTLT Shane Cooper, Assistant Project Manager Cliff Meyer, Ground Segment Engineer Mike Dower, Commercial Manager Steve Pitson and Data Manager David Delgado. Photo by LACW Simone Liebolt.

In June this year the shared Optus and Defence C1 communications satellite will be launched from Centre Spatial Guyanais — the European space centre in French Guiana, heralding the start of a new era in satellite communications for the Department of Defence.

Joint Project 2008 Phase 3D was established in 1997 following an invitation from Optus for Defence to share Australia’s next generation commercial communications satellite. The project provides for supply and support of a Defence owned payload operating on the shared C1 communications satellite, together with Defence owned fixed terrestrial infrastructure for control and management of the Defence payload and the new communications network.

The network, otherwise known as the Australian Defence Satellite Communications Capability, will provide Defence with satellite communications across Australia and throughout the Asia Pacific region in the X, Ka and UHF radio frequency bands. Contracts with Optus were signed in October 1999.

Defence and Optus are sharing the costs, benefits and risks of acquiring, launching and operating the C1 communications satellite.

The benefits for Defence are substantial — a very significant satellite communications capability delivered years ahead and at a fraction of the cost than could have otherwise been achieved, access to Optus’ considerable experience in acquiring and operating communications satellites and an accelerated development of Defence’s satellite communications expertise.
Project Director Martin Weir said the lessons learnt in this program by Defence will assist greatly in the acquisition of future Defence satellite communications capabilities. Optus too is gaining considerable benefits from Defence involvement the C1 satellite program.

“With four separate payload sub-systems and 16 antennas, C1 is a very large and technically complex communications satellite. It will have a mass of about five tonnes at launch and with antennas and solar panels deployed, it will span 25 metres across and eight metres in height,” he said

“The satellite will operate at 156 degrees east longitude from a geo-stationary orbit (a fixed position about 36,000 km above the earth’s surface).”

The Defence payload will feature three payload sub-systems, crossbanding between the X and Ka-band payload sub-systems (that is, communications up in one band and down in another) and a combination of earth, fixed Australian/regional and steerable spot coverage beams.

Mr Weir said Optus’ commercial Ku-band payload sub-system will enable it to provide broadcast services into Australia, New Zealand and parts of Asia.

“During launch, the satellite will be subjected to very high levels of vibration and stress and it will then be required to operate for 15 plus years in the harsh and forbidding environment — one characterised by high levels of radiation, extremes of hot and cold and an absence of atmosphere.

“As it will not be possible to undertake on-site repairs, the design, construction and testing of the satellite have been tasks of fundamental importance. The satellite design incorporates built-in redundancy where possible, and a comprehensive test program has demonstrated that the satellite meets and in many respects exceeds all functionality and performance design specifications.

“The test program, at satellite system level, has included thermal/vacuum, vibration, accoustics, passive intermodulation, compact antenna range and deployment mechanism testing.”

The success of the C1 satellite program is a testament to the design and manufacturing skills of Mitsubishi Electric Corporation (Japan), Space Systems/Loral (USA) and Raytheon Systems Company (USA), as well as the dedicated efforts of Optus and Defence project personnel. Construction of the satellite was completed in January 2003 and it is now at the launch site in French Guiana awaiting launch.

Arianespace, an experienced European launch service provider, will launch the C1 satellite using an Ariane 5-G launch vehicle. Another satellite, currently the Japanese owned and US manufactured BSAT-2C, will co-share the launch with C1.
“In recognising the inherent risks associated with satellite programs, Optus and Defence have implemented responsible risk management regimes, including the use of insurance to address the potential for the satellite to be lost or damaged during launch and the first five years of in-orbit operations.”

Mr Weir said fixed terrestrial infrastructure, including 11.2m diameter X-band and 9.0m diameter Ka-band anchor station antennas, together with primary and secondary Defence payload and operations control facilities, has been installed at Defence facilities in Canberra.

“Information Systems Division will be responsible for control and management of the new communications network. Optus has been contracted by Defence to supply payload operators, to maintain and support the fixed terrestrial infrastructure and to undertake telemetry, tracking and command of the satellite.

“A satellite management agreement has also been established to guide Defence and Optus in the management and operation of the shared satellite asset.

“The Australian Defence Satellite Communications Capability provides Defence with a very substantial increase in communications capability. This capability will be utilised immediately by the ADF through the availability of a range of new, upgraded and existing user terminals.”

Defence has UHF infrastructure and is currently acquiring X and Ka band user terminals for land and maritime applications.
A DEFGRAM will be issued in due course advising the launch date for the C1 communications satellite and arrangements for Defence personnel, where practicable, to access a live telecast of the launch.

Ka-band Payload Sub-System

Uplink
frequency: 30.0 - 31.0 GHz
Downlink
frequency: 20.2 - 21.2 GHz
Transponders: 4 x 33 MHz active, 1 x 33 MHz spare
Coverage
Beam: Earth, Australian Littoral, and 1800 km Steerable Spot
Usage: Medium to high data rate theatre broadcast and duplex video, voice and data communications. Ka-band communications is a new capability for Defence.

X-band Payload Sub-System

Uplink
frequency: 7.9 - 8.4 GHz
Downlink
frequency: 7.25 - 7.75 GHz
Transponders: 4 x 60MHz active, 1 x 60 MHz spare
Coverage
Beam: Earth, Regional and 2000 km Steerable Spot
Usage: Medium to high data rate one and two way video, voice and data communications. X-band communications is a new capability for Defence.
Crossbanding Sub-System
Capability: X to Ka-band crossbanding Ka to X-band crossbanding
Usage: Crossbanding will provide an increased level of payload flexibility.

UHF Payload Sub-System

Uplink
frequency: 290 - 320 MHz
Downlink
frequency: 240 - 270 MHz
Channels: 5 x 5kHz and 1 x 25 kHz channels (includes extensive tuneability)
Coverage
Beam: Earth
Usage: Low data rate two way voice and data communications. UHF is an existing capability within Defence.

Satellite coverage areas
X-band	Ka-band	UHF-band

 

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