LOWDOWN - Australia's History in Satellite Technology

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Australia's Satellites & Programs > FedSat-1

FedSat-1 - the Federation Satellite was intended for launch in the Centenary of Federation Year 2001.

On the 20 August 1996, in the 1996 Budget Statement, the Minister for Science and Technology, the Hon. Peter McGauran announced the start of a small demonstration project; i.e. Federation Satellite 1 (FedSat).

In early 1996, the Minister had considered a draft proposal for a new national space agency. The proposal was poorly recieved, so another approach was tried. Given that funding was scarce, the initiative was linked to the Centenary of Federation in 2001 program. The prevailing administrative arrangements for space were also changed and the Cooperative Research Centre for Satellite Systems was established specifically for the FedSat project.

The FedSat project has suffered from a number of vexing issues including the closure of, Space Innovations Limited (SIL), the British company contracted to build the FedSat platform. Further delays were due to the failure of the Japanese H-IIA rocket which had been booked to carry FedSat into orbit with several other satellites.

It is interesting to note that Australia's first satellite WRESAT took less than a year from concept to launch while FedSat took six and a half years.

FedSat

FedSat flight model

FedSat is an Australian scientific microsatellite mission, a 58cm cube weighing approximately 50 kg. It was launched on the 3rd of December 2002 when a Japanese H-IIA rocket carried the research pod FedSat into ordit. The Japanese National Space Development Agency had offered to put Australia's satellite into space as a gift for the centennial anniversary of Australia's commonwealth government and in exchange for data gathered from the project.

FedSat departed Canberra on the 30th of October 2002 and arrived in Tokyo on 31 October. It arrived at Tanegashima Space Centre on 5 November afer a journey by truck and ferries. FedSat was then prepared for launch and on 21 November was mated with the payload support structure of the H-IIA rocket.

FedSat was the first international payload for the Japanese H-IIA rocket. A launch system that had suffered multiple failures.

Its purposes are: to establish Australian capability in microsatellite technologies; to develop expertise necessary for sustaining those industries and profiting from them; to test and develop Australian-developed intellectual property; and to provide a research platform for Australian space-science, communication and GPS studies.

FedSat is being developed by the Cooperative Research Centre for Satellite Systems, which combines the resources and skills of 12 Australian organisations. Contributions from each of the partner organisations are doubled by the Commonwealth Government, under its Commonwealth Government's Cooperative Research Centre's Program. The total budget of the Centre is approximately $60 million over 7 years, with $20 million of that allocated for the FedSat mission.

CRCs are a means for encouraging Australian industry by targeting research into fields attractive to industry. This should encourage commercial development of Australian domestic research.

Like all CRCs, the CRCSS includes government research agencies,universities, and private companies. The universities provide industry-specific training for graduate students in cooperation with industry partners.

In the CRCSS case, that means the universities provide PhD and Masters students with experience in working in a satellite-systems environment: working on the FedSat design or payload design teams, or research work involving the FedSat payloads.

Much of FedSat is being developed in Australia by the CRCSS. Three of the 6 main payloads have been fully developed by the CRCSS, and the other three have been supplied by overseas organisations in consultation with the CRCSS.

The satellite platform, the structure that houses and maintains the payloads, is being provided by overseas organisations. The CRCSS has stated that CRCSS engineers could have developed an Australian platform, but given the time available from project-start to launch, that was not practical. So CRCSS opted to contract an overseas platform supplier, avoiding the need to reinvent established technologies. As FedSat took six and a half years to develop and launch this claim seems somewhat curious.

Payloads

GPS Receiver

The GPS, Global Positioning System, is an American network of satellites which transmit radio signals containing time and orbit-position codes. GPSreceivers decode the signals, and by comparing signals of up to 4 satellites with known positions, they can derive their own locations by triangulation.The system was designed for mainly military use, but now GPS provides many scientific and civilian applications.

NASA provided FedSat's dual-frequency GPS receiver. It has 4 uses on FedSat.

On-board satellite GPS receivers allow accurate measurement of the satellite's position. This information will support the CRCSS study into methods of precisely determining satellite orbits. This includes metre-level accuracy for satellite operations control; centimetre-level accuracy for mission-data processing; and position determination using multiple antennas.

The Precise Orbit Determination study includes a section on GPS multipath errors. On the ground, reflections of the GPS signal from the landscape give conflicting information to the GPS receiver, causing errors in position-calculation. Investigating the multipath errors on FedSat's simple shape will help establish principles for studying the more complex reflections on the ground. Thiswill help eliminate multipath as a source of GPS position errors.

The FedSat GPS receiver will also support space-science studies of the ionoshere, an electrically-charged layer of the atmosphere. GPS satellites are much higher than FedSat's orbit, so FedSat can detect GPS signals that have travelled through the ionosphere. Interpretation of the GPS signals can illustrate the dynamics of that region. By taking GPS slices of the ionosphere, it's possible to build up a 3D moving picture of the ionosphere. The CRCSS is the only organisation studying the little-known southern region of the ionosphere in this way.

Finally, the GPS receiver will provide timing data for other FedSat payloads.

NewMag

The NewMag magnetometer is a very sensitive and rapid-sampling device for measuring the strength of the Earth's magnetic field. Earth is like a big bar magnet, with magnetic field lines emerging from the poles and far out into space. FedSat's polar orbit crosses all these lines, so NewMag can effectively gain a window into the whole magnetosphere region. NewMag can also measure vibrations simultaneously with ground- based magnetometers, so investigating the dynamics of the magnetosphere (changes in it shape due to variations in the Sun), and study magnetospheric wave-propagation.

Earlier research has shown this is a complex region, with variations in the solar wind having a huge effect on the magnetosphere and space weather. This can also affect ground infrastructure. The CRCSS study will help provide early warning systems against solar- magnetic events and space weather events, which damage satellites.

NewMag will be mounted away from the main satellite on a 2.5 m extendable boom. This is to avoid magnetic interference from the satellite itself.

The National Space Development Agency of Japan offered the CRCSS a free launch in exchange for the NewMag data.

The CRCSS and University of California, Los Angeles, built NewMag to the CRCSS design.

High performance computing

The FedSat high performance computing payload is the world's first use of reconfigurable computing technology in space. Reconfigurable computers permit change of their physical circuits via software control; new physical circuits can be installed into a reconfigurable computer module by remote command. For spacecraft, this technology means that satellites can be rewired without having to retrieve them.

The FedSat payload will establish the basics of working with these devices in space, including their susceptibility to radiation. This study is of great interest to the international community, including NASA and Johns Hopkins University who supplied the module.

If these devices work in space, it could mean a new species of reconfigurable and adaptable spacecraft, which could eventually fix and modify their own circuits. Reconfigurable computing could open up new realms of spacecraft adaptability, including re-use of old spacecraft.

Ka-band transponder

The FedSat Ka-band transponder is designed to handle the new experimental high- frequency and high-capacity Ka part of the radio spectrum. The transponder processes signals to and from the ground in the frequency band. The transponder incorporates CRCSS-designed Gallium Arsenide monolithic microwave circuits; FedSat will space qualify these for the first time.

The FedSat Ka-band transponder will interface with the CRCSS-designed Ka-band ground station. Together they will lead to new Australian-developed remote area communications applications. The CRCSS will use FedSat and its ground station to study a range of Ka-related issues.

The Ka-band system has been built entirely by the CRCSS.

Baseband processor

The baseband processor provides on-board computer processing of the Ka- and UHF- band payloads. It has been designed and built by the CRCSS, to operate as a low power single modem with flexible operation. It will also provide the channel for satellite operations commands.

Students will use the FedSat baseband processor to study and develop a variety of telecommunications protocols, including ground-satellite links and inter-satellite links.

UHF communications payload

The Ultra High Frequency band payload will introduce a new type of packet data service for Low Earth Orbiting satellites to obtain environmental data. For example, ocean buoys may transmit their data using this means to orbiting satellites, which are retransmitted back to the lab for analysis.

This payload will facilitate high speed transmission via a special multiple access scheme and error-control techniques.

The payload has been designed and built by the CRCSS and should also fly on Korean and other Asian satellites over the next few years.

CD ROM

FedSat also carries a compact disc mounted on the side, containing the audio messages members of the Australian public recorded to go into space from March to August 2000. The disc also contains a copy of the song From Little Things, Big Things Grow, by Paul Kelly, with kind permission of the writers (Kev Carmody/Paul Kelly) and publishers (Larrikin Music, Mushroon Records).

The CD will orbit Earth as long as FedSat does, about a century, so the recorded messages are a time capsule about life in Australia in 2000.

In case future historians cannot retrieve or play the FedSat CD, a duplicate is held in the National Museum of Australia with a CD player.

Launching

FedSat will be launched from the Tanegashima Space Centre, Japan, early in 2002, aboard a Japanese HII-A rocket.

Satellite engineers must design the satellite for certain purposes. Depending on the mission purpose, satellites may require special orbits.For instance, remote sensing satellites need to see as much of the Earth'ssurface as possible and with a quick revisit time, therefore they need polar sun-synchronous orbits (about 800 km). Conversely, telecommunications satellites need to appear fixed in the sky so ground antennas can point at them, and that requires a very high geostationary orbit (about 36,000 km).

Specialist satellites may also need very eliptical orbits taking them far into space and back again. So usually the purpose of the satellite defines the orbit required, since different orbits have a different set of problems and advantages.

Decisions about the orbit type form part of the design process,including such basic things as size and weight. High orbit satellites need more transmission power for their signals to usefully reach Earth, so they must be bigger to accomodate the extra power generation capacity; they also need more radiation shielding since high orbits are a much less benign environment than Low Earth Orbit. Consequently, high orbit satellites are often large and heavy, requiring a dedicated launch from a large rocket, which is extremely expensive.

While it would be desirable to design microsatellites the same way, the strict budget requirements of those missions usually make obtaining a dedicated launch impractical. Therefore microsatellites are often designed for piggyback launch, where several small satellites may be launched together with one large one, sharing costs. However, this often means microsatellite designers work to a given orbit which may not always be ideal for the purpose.

This is the case with FedSat. FedSat will be launched piggyback with the large Japanese remote sensing satellite ADEOS-II.

But this introduces another problem for designers. The launch environment is very demanding on equipment, it involves very destructive vibrational and acceleration forces, so satellites must be designed to cope with those stresses. They must also be shown to cope with them, to satisfy the launchagency that the small satellite will survive launch without threat to the large satellite or rocket. So launches, either piggyback or dedicated, require a strict testing regime to certify the satellites' safety.

The testing is also to certify that satellites are reliable before launch, since it's usually not possible to fix them afterwards (however, see above about reconfigurable computing modules).

Each piece is tested separately, and together after each addition to ensure there are no conflicts. Piece by piece, and then as a whole, the test-satellite is turned on and off, to simulate use. Any problems that arise may require redesign.

The mission budget determines the extent of testing. For large complex satellites, a complete duplicate of the flight hardware may be built just for testing. But this is not possible in FedSat's case, for budget and time reasons.

FedSat will adopt the minimum qualification standard. This involves:

structural model vibration testing
payload thermal vacuum testing
system assembly, integration & testing
flight model vibration testing
flight model thermal vacuum testing

Vibration testing basically involves shaking the equipment on a special shaker, a more precise and larger version of the paint-tin shaker in hardware stores, in each of the three planes in simulation of the launch environment. If the equipment breaks, or sustains microfractures, it must be redesigned and re-tested. If it survives the vibration testing, it is certified for launch.

Satellites usually work in extremes of temperatures, from cryogenic to extremely hot, plus certain components may generate heat. But in space there is no air, so air-convection as a form of heat dissipation is not an option. Ifsatellites can't dissipate the heat, they may burn out. So satellites need special means for dissipating heat, and must be tested to show they survive the temperature extremes in a vacuum.

Some complex satellites have an array of active control systems, but FedSat is small enough to only need passive systems. The thermal vacuum test involves subjecting the satellite to a simulated vacuum in addition to the likely extremes of temperature. If it passes, it's certified for launch.

Normally the testing would be done on an engineering model, but time and money do not permit that for FedSat. FedSat testing will done onthe flight model.

More FedSat pictures can be found here

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