WA space radar to spot orbiting objects as small as 2cm

You can see it unfolding above your head at night – streams of new bright new satellites taking their place in our skies. But this burgeoning new industry is already facing a tipping point.

Which is why a new radar facility is being built in Western Australia. LeoLabs Australia director Terry van Haren says work on the West Australian Space Radar (WASR) will begin in December. The two S-band phased-array radars will scan the Indian Ocean and southwestern Australia to pinpoint as many orbiting objects as possible.

There are already 18,000 items being tracked in low-Earth orbit. Not all of them are benign, and their numbers are exploding.

Former RAAF commander and fighter pilot van Haren says the world’s embryonic commercial exploitation of space is in peril and in danger of succumbing to the Kessler Syndrome.

The Kessler syndrome was a concept first suggested by NASA’s Donald Kessler, that once a critical amount of space junk is reached, space becomes unusable due to bouncing-billiard-ball-style collision risks.

“The sustainability of low-Earth orbit is at a tipping point,” he says. “And we may already be in a position where we can’t stop it.”

The problem is not just space junk. There’s also competition for prime orbital space.

“Right now, in low-Earth orbit, there are nearly 3500 active satellites – with 70 or 80 per cent of them being commercial,” van Haren says.

“We think that, by the end of the decade based just on current registrations of intent by commercial satellite companies, there will be 50,000 satellites in low-Earth orbit. Some people talk of 100,000.”

Collisions are already a disturbingly common occurrence. And in space, size doesn’t matter. A coin-sized piece of debris is capable of creating catastrophic harm.

A small hole was punched in the robotic arm of the International Space Station earlier this year. And, in May, a Chinese satellite was struck by a Russian satellite, sending another cloud of deadly debris cannoning through space.

“And these are just the collisions we know about. Debris-on-debris impacts, which generate more smaller debris, could be occurring quite regularly,” says van Haren. “The Kessler Syndrome is actually occurring very, very slowly, in terms of what we see now.”

LeoLabs says it is currently tracking about 18,000 objects in low-Earth orbit. These are mainly in the range of 10cm in size and above. A real-time visualisation of these objects can be seen on the LeoLabs website.

“We are building a global radar grid because we want to expand our object catalogue down to the limitations of the wavelength of our S-band radar, which is about 2cm across,” says van Haren.

That’s why the WA Bunbury facility is being built.

It improves radar coverage of the world’s skies. And that allows greater fidelity in the tracking of low-orbit objects.

“From our estimates, there are about 250,000 objects in that 2cm to 10cm range,” he says. “And, if you do the math, that represents about 95 per cent of the debris capable of causing a catastrophic collision in low orbit. That’s stuff no one has a track on.”

The Bunbury radar facility will be fully automated, with no staff on site. The data it collects will be injected directly into the “cloud”.

It will be the sixth LeoLabs site in LeoLab’s global radar network. Its specific position in WA is to complement the coverage of another already operating in New Zealand. Other LeoLabs radars are in Costa Rica, the Azores Islands and the United States.

Space junk is a problem that won’t go away any time soon.

Objects up to 650km in altitude will generally take about 20 years to burn up in the Earth’s atmosphere. Higher than that and the lifespan increases exponentially.

“We need to manage that debris problem and stop the slow degradation of space,” van Haren says.