Space tracking passive radar in a box offered by Silentium Defence of Australia. (Silentium Defence)
SYDNEY — An Australian company, Silentium Defence, has built what it calls a space observatory in a box, designed to operate almost anywhere in the world and track objects in Low Earth Orbit with an easily and quickly deployable system that does not emit any radio waves to make it a target.
Silentium, based in Adelaide, has found multiple uses for its low-power passive radars, pursuing contracts with Australia’s navy, army and air force, as well as as working with several large primes as subcontractors, including American behemoths Lockheed Martin and Northrop Grumman.
The company plans to unveil its new system on Tuesday, at Adelaide’s Australian Space Forum. The passive radar works by tracking reflections of objects from FM radio waves. Multiples of the relatively low-cost system can be deployed around the world to track a wide array of LEO objects as they are networked.
“We’re talking about a shipping container that includes everything: the power supply (which is a generator with batteries) all of the computers, all of the antennas that will fit inside,” CEO James Palmer said in an interview. “You can put it into an area where you wish to get some coverage, deploy the aperture out, and within half-a-day you’re up and running and observing stuff in Low Earth Orbit completely covertly.”
For perspective, there are much more advanced systems out there, such as Lockheed Martin’s Space Fence on Kwajalein Atoll in the Marshall Islands. Although it can track objects as small as a marble, while the Silentium system is designed to track objects larger than 10 centimeters, the Space Fence uses a 10-megawatt power station, is fixed in place and provides emissions that adversaries can use to track and target it, Palmer noted. “Now that capability is exquisite. It’s a fantastic capability. But it comes with an exquisite price tag,” he said.
The Space Fence uses Gallium Nitride (GaN) powered S-band radars. The transistors operate at higher temperatures, frequencies and voltages. That 10-megawatt station could power 1,640 American homes.
The Silentium system uses a relatively small portable generator for its power.
Secure World Foundation’s Brian Weeden told Breaking Defense he could “see a role for those systems to play in expanding” space situational awareness (SSA).
“I could see it being used to deploy in support of specific tracking campaigns, such as objects headed to unusual orbital inclinations that aren’t well covered by the existing sensors,” Weeden said. “It also could be very useful for those countries who don’t have advanced systems of their own yet but are keen to develop better indigenous SSA.”
However, he added, “the downside is that the system is reliant on external sources of FM radio signals, say from terrestrial radio stations, which bounce off satellites in LEO. That means it might be difficult to use in very remote areas where those signals are few and far between, and it’s not going to be tracking small objects. But for the cost, I could see it being very useful.”
After its unveiling in Australia, Silentium Defence system will be showcased the first week of November at Colorado Springs, where it is being developed with the assistance of the US Air Force Research Lab as part of an initiative called the Catalyst Accelerator Program. Palmer spoke from Colorado, where he is getting ready for the demo.
Silentium was one of eight companies picked for the catalyst program’s International Space Domain Awareness Cohort. They started working with AFRL, US Space Force and others in August.
“I think, based on the sort of early conversations that I’ve been having with different parties over here, there’s absolutely a role for this system to play,” Palmer said.
Tracking the increasingly dense region of space known as LEO has grown vastly more important as commercial, civil and military satellites deploy there in large numbers.
“It’s a case of you need to understand everything up there, particularly in Low Earth Orbit where you’re seeing such a huge increase in traffic. So I think the rule of thumb 30 years ago was that 90 percent of the objects resided in low Earth orbit, whereas 90 percent of the value was in geosynchronous orbit,” Palmer said. “I think in recent times we’ve kind of seen the second part of that equation flip.” The ability of smaller satellites to maneuver in that lower orbital band has increased the need for monitoring it even more.
The US Space Force has repeatedly stressed the importance of resilience in its operations. Having a lightweight space tracking system that can be deployed almost anywhere in the world in a relatively short period of time would seem to provide greater resilience.
One intriguing fact: The Australian system is, Palmer said, ITAR free as it’s been developed entirely in Australia. That means it can be directly exported to any country Australia approves, without first getting permission from the United States. If the system proves itself, that could lead to a substantial export market.
