Part two of Jamie Seidel’s look at the nascent local industry putting satellites into space. You can read part one here.
Space is hard. And that means expensive. But all things are relative, Professor Craig Smith told a recent SmartSat CRC presentation in Adelaide.
“Space has never been more accessible. The cost of launch is going down dramatically. The tools and technology have improved. You can actually go out and buy satellites – or at least their vital components. So the capability is there and the barrier to entry has never been lower,” the SmartSatCRC Professorial Chair in Telecommunications told the gathering of defence, business and academic figures.
“So I think it’s time to embrace space rather than use it as an excuse not to do things – because you actually can.”
But, aside from cost, many practical hurdles remain.
Hurdle 1: Launch
Satellites aren’t as fragile as they may seem.
They are, after all, built to cope with the acceleration, vibration, and temperature extremes of being strapped on a rocket and blasted into space.
That doesn’t mean you want to drop your customer’s cubesat on the workshop floor.
“It’s a big chunk of electronics, and nothing likes being thrown around too roughly,” says CEO and founder of satellite builder INOVOR Technologies, Dr Matthew Tetlow.
But, before it’s allowed to be put inside a launch container on top of a rocket, it must be certified as sufficiently resilient.
“You’re going to have this huge rocket engine running below it, and it’s not like it’s wrapped in bubble wrap. It’s metal on metal. The vibrations feed straight into your satellite. It’s certainly no cushy business class trip!”
He adds that the risk of losing a satellite in launch is very low.
“Obviously, a rocket can always blow up. But mostly, it’s one of the younger or more experimental ones.”
The standardisation of cubesat deployment containers also offers a low-risk deployment. These have been through hundreds of launch cycles, and the bugs have been removed.
“You’ve done all the shake-table testing. But it’s just been through the ultimate test – the rocket ride. The chance of something disconnecting is always there,” he adds.
Hurdle 2: Phone home
Once it’s been spat out of its deployment slot, the cubesat’s on its own.
“Those first three or four orbits are critical to be able to talk to your satellite,” Tetlow notes.
Only then can the satellite’s health be determined.
“There are two of three points of failure that we can do nothing about other than test, test, and test again to ensure it works,” he says.
“If the antenna doesn’t deploy, it has no way to talk to us. If something in the power system fails, it won’t wake up. And the one thing you’ve never been able to properly test is the communications link between Earth and space. That’s always risky.”
You also need to find it.
“They deploy a whole lot of them at the same time. Exactly which one’s yours, you don’t know. So everybody’s trying to talk to all these satellites at the same time. And that’s challenging.”
Every satellite behaves differently. Some send out electronic handshakes. Others await trigger signals. And once the link is established, it has to be sustained and strong.
While Australia’s not looking to compete with space-based broadband communications providers like Elon Musk’s Starlink constellations, it does have an edge in narrowband technology.
That’s ultra-low power systems supporting data links for emergency services and IoT (internet of things) ground stations.
But a handshake doesn’t mean a cubesat’s entirely happy.
Hurdle 3: Activation
Solar panels must be deployed. It has to be stopped from tumbling. Then, each of its internal sensors and systems have to be activated.
“Each of those steps has a risk associated with it,” says Tetlow. “And, invariably, you’ll have some unexpected niggle where something is not doing what it should. You’ve got to problem-solve that from the telemetry coming down.”
The best guarantee for success in space, says Tetlow, is testing.
A cube sat’s tumble can be arrested by onboard electromagnets pulling the craft into alignment with the Earth’s magnetic field. Small heaters and heat sinks balance the temperature of the motherboards, batteries and sensors. And replacement charge must flow from the solar panels.
“Once you’ve got communications, you can ask the satellite what’s going on. It can tell you what’s wrong. Then you can try one fix, see what happens, then try another …” he explains.
And, as a recent scare with Voyager 2 proves, it’s not always the spacecraft’s fault.
Earlier this year, engineers accidentally sent an old version of a command intended to re-orient Voyager 2 as it cruises beyond the edge of our Solar System.
As a result, it turned its antenna away from Earth.
They had to send an electronic “shout” from the Deep Space Communication Complex in Canberra to regain its attention.
Modern satellites, however, have been coded to protect themselves. If something goes wrong, they shut down and dial the orbital equivalent of “000.”
“Human error is always a problem,” says Tetlow. “And that’s also why we have a flat-set. We tell it what we’re going to tell the satellite. We watch to make sure it doesn’t make it do something stupid or send it to sleep. And once the real satellite goes over on the next pass, you’ll know it’s probably safe to transmit that piece of code.”
Vaccinating against failure
The best guarantee for success in space, says Tetlow, is testing.
So, how much is enough?
“The more I practice, the luckier I get – or so the saying goes,” he says. “I think it’s the same for testing. There is always an element of luck. There’s no question you can just be unlucky in this game. But you improve your chances of being lucky if you do the testing with these things.”
And when your luck runs out, you must learn.
“About one-third of all satellite failures cannot be attributed to a particular cause,” Barton adds.
That’s not because there’s some mysterious satellite-killing force in the upper reaches of our atmosphere.
“It’s because many universities and startups don’t have the resources to investigate every potential failure or put the diagnostic systems that you’d need aboard in the first place,” he says.
More serious commercial and government ventures, however, do.
“They can follow the data chain to see where things went wrong,” adds Dr Andrew Barton, Research Program Manager of Smartsat CRC. “They can investigate the whole project from start to finish to see what was missed. Good records mean good traceability.”
When the Hubble Space Telescope first opened its eye in 1990, it was unexpectedly blurry. An urgent review discovered that the simple miscalibration of a single lens-grinding machine had jeopardised the multi-billion-dollar project. Likewise, a failure to convert imperial to metric measurements was identified as the cause behind the Mars Climate Orbiter arriving 150km off course in 1999, leading it to burn up in the Red Planet’s atmosphere.
Modern technology makes identifying such errors before they happen much more feasible.
“I see Digital Twin mainly as a marketing term for what I would call detailed systems modelling, covering the full product life cycle,” says Barton. “These high fidelity models capture more data during a project’s development, but also during their operation.”
Every detail is visible in computer models.
“That means you can find the cause of a failure or improve the efficiency of a process. Unfortunately, we don’t have a lot of people in Australia who have experience in space systems engineering,” he adds.
Without such skills, Barton warns, Australian advanced manufacturing – whether for space, air, land or sea systems – won’t get the opportunity to drive down risks and grow their industries.
“Technology is getting more and more advanced in all areas,” he says. “As a nation, we must choose which areas we will pursue, stick with them, and give them the best chance to succeed.”