Out
to Launch
New Satellite sends Defence into space age
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An
Ariane Launch vehicle.
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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.
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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 Australias
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 Defences 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 earths 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.
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Satellite
coverage areas
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X-band
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Ka-band
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UHF-band
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