Space is hard which is why the challenge is so valuable
It’s a pretty big deal. The Australian Space Agency is about to launch its first mission – a space telescope – into orbit. And SpIRIT is ready to fly.
The Space Industry Responsive Intelligent Thermal (SpIRIT) satellite is one of Australia’s flagship space projects. It may not have the same profile as participating in NASA’s Artemis return to the Moon mission, but its significance is no less.
Project insiders gathered at the Discover Space forum at Melbourne University in August to report on the SpIRIT satellite’s progress as a technology demonstrator.
Its primary payload – a gamma and X-ray detector built by the Italian Space Agency – was delivered last month. Other components, such as Australia’s Neumann Space metal-fuelled ion thruster, are also in place.
“We’ve tested our components. We made sure we are able to command it, and it’s performing really, really well,” Professor Michele Trenti of the University of Melbourne School of Physics and Chief Investigator of the SpIRIT program announced to the audience.
“With the Hermes instrument, we’ll be able to watch stars die – massive stars becoming black holes and emitting gamma-ray flashes so powerful that they outshine the host galaxy a thousand times.
“We can see them out to the edge of the observable universe – neutron stars smashing into each other and creating collisions so powerful they create ripples in space time.”
SpIRIT’s mission will be to help capture the afterglow of such a flare across the entire electromagnetic spectrum.
It’s doing so on a shoestring. And a tiny one at that.
”This is part of the idea of miniaturising satellites to have a lower price point, but still enable the same kind of precision instrumentation that we desire from a lot of our space-based observations,” says SpIRIT’s chief investigator of mechatronics, Dr Airlie Chapman.
SpIRIT demonstrates both the challenges and solutions of doing this.
“Initiatives that are now coming out of projects like SpIRIT are so exciting … We can do really innovative things on a budget.”Professor Rachel Webster, University of Melbourne head of astrophysics
Immensely sensitive instruments such as the Hermes telescope must be kept at a very specific temperature at all times.
“So we’re talking about plus or minus one degree Celsius,” says Dr Chapman. “How do you do this when you’re on orbits where you suddenly go from the sun-facing side of the planet to the dark side – or you’re rotating and get heat bouncing off the Earth’s atmosphere?”
The solution normally involves bulky, energy-intensive systems.
“So a cryocooler is something that’s really essential,” she adds. “Putting a cryocooler thermal regulation system on a small satellite is really, really hard. And it’s one of the technology deliverables we are demonstrating on this mission. It’s going to be one of the first of its kind – and we’re really excited to see how it performs (early) next year on launch.”
The other big problem is communication.
The Hermes telescope will generate immense amounts of data. Getting it down to Earth involves a unique set of physics.
Satellites move at very high speeds relative to each other. So simply bouncing a signal off another when the ground station is out of sight isn’t as easy as it sounds.
“There are existing communication networks around the planet,” Professor Chapman says. “But they usually aren’t designed to work with other satellites.”
“So you have to be smarter about what you communicate and when. This is where the idea of “edge computing” comes in. We need more autonomy, more AI, on-board the satellite itself that is capable of computing the value of the information before disseminating it”.
The SpIRIT satellite delivers big bang for your buck
University of Melbourne head of astrophysics Professor Rachel Webster says the project “revolutionises” the type of science that can be achieved in space on a very tight budget.
“We have a bit of a science budget in Australia, but not the sort the Americans, Russians – and more recently the Chinese and Europeans – have been able to put into space,” she says.
The James Webb Space Telescope (JWST) is many times more powerful, but it also cost US$9 billion and took decades to construct.
The 12 kilogram, shoebox-sized SpIRIT will be contributing valuable science for a complete design, build and launch cost of about AU$6 million – after just a few years.
“This is why the sort of initiatives that are now coming out of projects like SpIRIT are so exciting,” Webster explains. “We can do really innovative things on a budget that we can afford.”
And a return on this investment is virtually guaranteed, adds Professor Trenti.
“It is well established from studies by NASA, the European Space Agency and other foreign space agencies, that if you invest $1 in a space project, the nation gets back about $4; $2 in direct economic return, and $2 into indirect return through innovation and promotion of STEM.”
Eventually, though, SpIRIT will come crashing back down to Earth.
And that’s also a matter of national pride.
“In order to get a launch permit, you have to demonstrate sustainability,” Professor Trenti explains. “We have to demonstrate, for example, for SpIRIT, that we will re-enter the atmosphere and be completely burned up in the process, within a given number of years.”
The requirement is within less than 25 years. “We are going to be good citizens, and do it in seven to eight years.”
Space is hard which is why it’s so valuable, says Webster.
“If you have a difficult problem and you’ve got to solve it, that’s where the ingenuity and innovation come in.”
For space, things need to be light. They need to be small. They need to be resilient and accurate.
“There are an infinite number of challenges in terms of what we want to do. And these are exactly the problems that will be solved and then the solutions can be applied elsewhere.”
President of Melbourne University’s Aerospace and Rocketry Engineering Society (ARES), Harrison Dean, says that the down-to-earth benefits of Australia’s space program aren’t just about technology.
It’s also about data. Big data.
That’s what observation satellites such as SpIRIT produce. But data is meaningless on its own. And that’s why a lot of businesses are going to realise the potential of turning such raw information into insight, Dean says.
“Let’s say a farmer wants to know ‘how is this bit of land doing’. And if we can get some imaging on it, we need people to ask, ‘what’s the insight that tells me what I need to do to maximise the output of this land’?”
“Data processing science – that’s going to be the type of area that could do quite well out of this. It’s about generating insights for someone who can benefit from it.”
Jamie Seidel is a freelance journalist based in Adelaide.