Last updated December 13, 2017 at 2:52 pm
WRESAT may have been Australia’s first satellite in space, but it was not the first Australian satellite to be built. In the 1960s, a group of students from Melbourne nearly beat WRESAT off the launch pad with their self-built Australis-OSCAR 5 satellite.
In the mid-1960s, at the height of the space race, a group of students at the University of Melbourne set up the Melbourne University Astronautical Society (MUAS) to build equipment to track and receive signals from a variety of American and Soviet satellites. The students’ abilities quickly became increasingly sophisticated, and ambitious, and included receiving and decoding images from American TIROS and Nimbus weather satellites, which they supplied to the Bureau of Meteorology until the Bureau set up its own receiving facilities. The group also tracked the Orbiting Satellite Carrying Amateur Radio (OSCAR) 3 and 4 satellites that had been built by American amateur radio enthusiasts and launched by piggy-backing on major satellite launches, just as cubesats do today.
The success of the OSCAR amateur radio satellites inspired the Melbourne students to build their own, and they joined forces with the Melbourne University Radio Club to pull it off.
As well as being the first amateur satellite built outside of North America, it would also be the first satellite built in Australia. No one in Australia had yet built or launched a satellite of any sort, WRESAT hadn’t even been though of yet, and the students’ ambition was ridiculed. They contacted the OSCAR organization to ask for help, who told them that if they built it, OSCAR would try to get it launched.
But now they needed to build it. They named their venture Project Australis, and started building the Australis satellite in March 1966.
Building the satellite was a labour of love that tested the students’ ingenuity and innovation. They worked in their spare time with a minimal budget, and many of the electronic components were donated. Those that needed to be bought were purchased with the students own money. They weren’t completely on their own however, as it went on Project Australis received assistance from the Wireless Institute of Australia, the Post Master General’s Department, the Department of Supply, and even NASA representatives in Australia.
As no one locally had built a satellite before, the Project Australis group opted to keep it relatively simple and build a beacon satellite that would transmit telemetry data to the ground on fixed frequencies. The rectangular aluminium box contained two battery powered transmitters, one working on a frequency of 29.450MHz, and the other on 144.050MHz. On both channels the same telemetry signal was broadcast – “hi” in Morse code before transmitting data including battery voltage and current, spacecraft temperature, and rate of rotation. The satellite also contained a receiver that could be commanded to switch the 29.450MHz transmitter on or off, enough to make Australis the first amateur satellite from anywhere in the world that could be controlled from the ground.
The innovative sophistication of the telemetry system contrasted with the ingenious simplicity of many of the spacecraft’s other systems. To deploy the satellite once in space, a Melbourne mattress company supplied two springs that were carefully matched in strength to prevent the satellite from rotating as the springs pushed it out of its launch housing — a system still used to deploy cubesats today. The antennae for the radio systems were cut from metal tape measures. Wrapped around the body of the satellite while it was stowed in the rocket, these antennae would spring into position as soon as it was set free, avoiding the need for any complicated deployment mechanisms. Finally, two bar magnets were installed to align the satellite with the Earth’s magnetic field, a primitive stabilisation system to reduce the rate of rotation of the craft and maintain a better orientation for the antennae.
Like all spacecraft, Australis had to go through a comprehensive set of tests to make sure it was suitable for spaceflight. Important electronic components, including the transmitters and command systems, were flown on high-altitude weather balloons to check they were working correctly and were robust enough to survive the extreme environment in space. Some of the other tests of the radio systems were carried out in one of the students backyard (however, as they could not go near the equipment while the tests were underway they had to read the meters looking through the scope of a rifle). Cold testing, to ensure the satellite could withstand the freezing temperatures it would encounter as it passed through Earth’s shadow, took place in the University of Melbourne Glaciology Department’s freezer. For the high temperature tests, the components were placed in an oven back at the home of one of the students.
Weighing in at 17.7 kilograms, Australis went from idea to complete satellite in a little over a year, and was ready to fly before construction of WRESAT had even commenced.
In June of 1967, Australis was triumphantly delivered to the Project OSCAR headquarters in San Francisco ready for launch. There, it was given an experimental black and white stripe paint scheme in an effort to control and stabilize the satellite’s internal temperature as it swung in and out of the full glare of the sun. But then, things stalled.
The US Air Force, which had launched the previous OSCAR satellites, refused to launch Australis. While Australis languished in a garage, WRESAT leapfrogged the amateurs, becoming the first Australian satellite launched into space in November of 1967, much to the disappointment of the students who had poured their time and effort into Australis.
Australis was grounded for over a year before the newly formed Radio Amateur Satellite Corporation (AMSAT), which took over from Project OSCAR, managed to get NASA support behind the satellite. NASA required that Australis have some sort of scientific or technological merit, so AMSAT convinced NASA to launch it by explaining that Australis would provide training for amateur satellite users, and that the dual frequency telemetry would allow for investigations of unusual transmissions through the upper atmosphere. AMSAT refurbished Australis’s batteries and spent several months preparing the craft to a state that NASA would approve for launch.
Now known as Australis-OSCAR 5, or AO 5, the satellite was launched from Vandenberg Airforce Base at 9:31pm on 23rd January 1970, piggy-backing on the launch of a TIROS-M weather satellite. The Delta rocket placed AO 5 into a high orbit that varied in altitude from 1416 km to 1464 km, circling the Earth every 115 minutes.
Amateur radio operators on the ground eagerly tracked the satellite, with the first report coming from an operator in Madagascar 66 minutes after launch. A few minutes later, another amateur in Darwin reported receiving a signal from the craft. As the satellite came within range of Melbourne, the Melbourne University Radio Club was able to pick up the signal of their own satellite in orbit, to the great excitement of all of the students involved.
Radio amateurs from North America and Western Europe also reported receiving signals from the satellite. In AO 5’s first day of operation over 100 reports from around the world were collated at AMSAT headquarters. AMSAT eventually received reports from hundreds of stations across 27 countries.
The 144.050 MHz transmitter operated for 23 days until its batteries ran out on 14th February. The 29.450 MHz transmitter, which could be commanded to switch off and on from the ground to conserve power, was switched on only at weekends, and lasted for 46 days into the flight. When these batteries ran out on 9th March 1970, AO 5 went silent. Although it had missed out on being the first Australian satellite in orbit, its mission was a success.
Following this success, the Project Australis students aimed higher, and considered building a solar-powered repeater satellite that could re-transmit signals it received from the ground. But studies, family life, and lack of funding got in the way, and this even more ambitious goal was never realized. The group did, however, contribute components to other AMSAT projects.
The legacy of AO 5 lives on, with it paving the way for a bright future of amateur, and professionally built cubesats. The successful demonstration of the ability to command the satellite from the ground made it easier for future amateur satellites to receive licences from the US Federal Communications Commission. AO 5 was also the first time a 29.450MHz band transmission had been used from an amateur spacecraft, and led to its use in the following OSCARs 6, 7 and 8, while its simple tape measure antennae can be found on many modern cubesats. The bed spring ejection system is also still being used, albeit in a slightly more refined form, to eject cubesats today. And amateur satellites are still being built, launched, and tracked around the world.
Meanwhile, Australis-OSCAR 5 is still up there, looking down at the future it helped create. While WRESAT burned up in the atmosphere less than two months after its launch, AO 5’s higher altitude means that it will continue to orbit for around another 100,000 years, silent, but not forgotten.
For more about the history of WRESAT, read WRESAT: When Australia beat the world to space and watch Fifty years since Australia beat the world to space
Why doesn’t Australia celebrate WRESAT and OSCAR-5? Find out in Alice Gorman’s article From the outback to orbit: Why doesn’t Australia celebrate our achievements in space?
Main image courtesy of Alice Gorman
Australis-Oscar 5 image courtesy of australiaspace.info