Collaboration puts a firm focus on space domain awareness

At the end of World War 2, Australia possessed a pool of supremely-talented radar engineers who, with scientists from the CSIRO, turned their skills to the emerging field of radio astronomy.

That gave Australia an early lead in exploration and understanding of the cosmos through its radio emissions, an expertise which endures by way of the Parkes Observatory and many other radio telescopes around Australia and which will be further enhanced with the new Square Kilometre Array.

Now radio astronomy antennas are emerging as a useful capability for an activity much closer to planet Earth – the tracking of the vast amount of orbiting space debris.

That’s happening through a collaboration between defence and technology company HENSOLDT Australia, the University of Tasmania (UTas), and the Tasmanian State Government.

Though every state and territory is keen to grow its space capabilities, Tasmania is especially well-located geographically to observe objects in polar orbits, as distinct from the more common equatorial orbits. The benefit of this is that Australia gets to view objects sooner than anyone else, and before their angular dispersion spreads them across the sky.

As such, Space Domain Awareness (SDA) – once termed Space Situational Awareness (SSA) – has become Tasmania’s headline space activity. 

Through the collaboration, University of Tasmania is providing its assets and expertise, the Tasmanian Government support and some funding, and HENSOLDT Australia – the local subsidiary of its German multinational parent – is providing its skills in data-fusion and network management.

“We are taking the company technology, the existing understanding of the problem, marrying that with the assets that are in place through UTas, to actually bring that capability forward for defence use but also commercial use in a rapid timeframe,” Scott Reeman, HENSOLDT’s Vice-President Tasmania, Strategy, and Government Relations told ADBR.

Australia is on an SDA journey. It’s of growing importance to a nation with aspirations to be a significant player in space.

Australia will soon launch its own satellites and the Australian Defence Force (ADF) sees space as a warfighting domain akin to air, sea, land and cyber. In May RAAF chief AIRMSHL Mel Hupfeld announced a new ADF Space Division would be formed within Air Force in 2022, under the command of AVM Cath Roberts.

SDA will be front and centre. “SDA underpins all other space missions, providing the ability to identify, characterise and understand factors that affect the space domain,” a Defence spokesperson told ADBR. “Effective SDA will enable Australia to make considered decisions as to what objects constitute a threat and how to counter that threat.” 

But SDA isn’t a matter just for the ADF. It’s also of crucial interest to civil operators who, if given sufficient warning of a potential collision, can adjust the orbit of expensive satellites.

Australia already possesses substantial SDA capabilities. These include a ground-based telescope and radar system – both sourced from the US – located at Naval Communications Station Harold E Holt at Exmouth in Western Australia. 

Additionally, Canberra company Electro Optic Systems (EOS) has developed advanced capabilities for laser and optical tracking, operating SDA facilities at Mount Stromlo in Canberra and Learmonth in WA.

Emerging technology offers interesting possibilities including the use of passive radar which detects and tracks objects through reflected radio signals originating from FM radio broadcast stations. There are also space-based systems, including sensors on dedicated SDA satellites or existing Earth-observation satellites.

Then there’s the proposal from the HENSOLDT/ UTas/Tasmanian Government collaboration to use existing radio astronomy infrastructure.

It seems you just can’t have enough SDA and, last year, Defence launched Joint Project 9360 (JP9360) to develop a sovereign SDA capability through a suite of multi-technology sensors to detect, track, identify, and characterise space objects.

To assess the art of the possible and a potential direction, Defence sought industry input by way of a Request for Proposal (RFP), and is expected to respond to industry around mid-year.

In its JP9360 submission, HENSOLDT outlined the potential of the UTas SDA network, and proposed the addition to the UTas network of an ASTRA (Australian Space Surveillance and Tracking Radar) based on the German GESTRA.

This is a multi-mode AESA radar able to detect very small radar cross-section objects, either as a stand-alone system or as part of a multi-static network. Importantly the ASTRA system would be relocatable, meaning the complete system layout can be optimised for evolving SDA capabilities.

HENSOLDT Australia Managing Director Jon Wachman said Defence really opened up more questions than it probably resolved through the JP9360 RFP. “There was a focus on what people knew and the way you would do it, not realising there were other capabilities being developed that would enhance the picture,” he told ADBR.

Defence acknowledged that a variety of sensors was required for complete and resilient detection of objects of interest from LEO out to geosynchronous orbit and that credible capability could only be achieved through diversity.

Wachman said this didn’t mean it has to be a ‘big bang solution’. “Rather than waiting 10 years for the most expensive solution, we actually have a capability to start working on that now,” he said. “It can be stepped out with small sensible steps forward that allow both an economic and a capability solution to roll out.”

He said that rather than simply waiting for the release of the Defence program, HENSOLDT had created a collaboration and was already moving. 

“Otherwise you are left behind,” he explained. “We have actually taken the steps to get the team moving to actually start answering the key questions from a technical point of view, not theoretical. We forget to realise how clever we are as a nation. We think it has to come from offshore, and we just miss the fact that we are as good as anyone, if not – in a lot of cases – better.”

Australia’s space renaissance is well under way. Though we once launched rockets and have long been a major user of space services with significant domestic space capabilities, the formation of the Australian Space Agency (ASA) in July 2018 signalled a new impetus.

In September 2019, Tasmania signed a MOU with the ASA, and the Commonwealth committed $1.2 million from the Space Infrastructure Fund to upgrade UTas’s tracking facilities, “to allow for precision tracking of satellites and spacecraft”.

Tasmanian Defence Advocate, retired RADM Steve Gilmore, said the MOU recognised the state’s impressive space capabilities. “This is one of those great opportunities: the recognition of what the University of Tasmania has and the recognition of the great capabilities and well proven capacity of HENSOLDT to fuse an enormous amount of information to be used, in this case in SDA,” he told us.

To that end, the Tasmanian Government has committed $330,000 for the project, as well as $150,000 of the $580,000 cost of upgrading the high-speed fibre-optic link to the UTas Greenhill Observatory outside Hobart.

UTas possesses a number of radio astronomy assets, and they’re not all in Tasmania. These include a 26-metre ex-NASA dish near Hobart, a 30-metre dish at Ceduna in South Australia, a 12-metre antenna at Yarragadee near Geraldton in WA, and a 12-metre antenna on the Charles Darwin University campus near Katherine in the Northern Territory. 

It also operates an optical telescope at the Greenhill Observatory outside Hobart, where a new 7.3-metre satellite tracking antenna with transmit capability will also be located.

“Those antennas have been used to support a whole range of missions. We have done commercial tracking for various people,” UTas’s Professor of Physics and Dean of School for the School of Natural Sciences, Simon Ellingsen told ADBR. “We have also been involved in scientific missions with NASA, JAXA and the like.

“We have done things in lunar orbit and we have actually detected spacecraft around Mars and the Jovian (Jupiter’s) systems,” he added. “There are things you can do with big antennas you can’t do with anything else. You can get exquisite sensitivity, and we have been doing a range of work in the last year or so testing the capabilities for SDA.

“Most recently we have done some work with the (NASA) Deep Space Network (DSN) antennas at Tidbinbilla. They have been doing some transmissions.”

Those efforts directly relate to SDA, with returns from transmissions from the DSN antenna outside Canberra detected simultaneously at the Hobart and Katherine antennas.

“We recently detected an Atlas 5 Centaur rocket body at about 30,000 kilometres, and we were able to measure differences between the predicted and actual velocity of the rocket body of the order of a few centimetres per second,” Professor Ellingsen said.

He added that these sorts of very accurate measurements would be needed for space traffic management, specifically for determining the potential for collisions.

“It is going to be important for the future for Australia to have more of those sort of capability to work with our allies in determining where there’s something weird and wonderful happening (or) where it’s going to come down,” he said.

This work demonstrates the potential for bistatic and multistatic radar systems – transmitting from one antenna and receiving at one or more remote antennas. To further the work, HENSOLDT has funded a PhD student at UTas who is working on the data from the DSN trials, as well as on broader SDA capabilities.

UTas itself doesn’t yet have a transmit capability of its own, although one is on the way courtesy of the ASA grant which is being used to build the new 7.3 metre antenna at Greenhill. Scott Reeman said data from their recent trials involving the DSN antenna indicated potential detection of objects smaller than 10 centimetres.

“Once we go to our own transmit system, again it will depend on the power of the transmitter and the objects we are looking at,” Reeman said. “We expect that to be competitive with the best that the world can do at the moment. 

“Obviously, we have some plans and thoughts about what we are likely to be able to achieve but we have to demonstrate it properly,” he added. “It is going to take six to 12 months to achieve that.”

Detecting objects in space is a challenge which itself generates huge amounts of data. Fusing data from diverse and distant SDA sensors, classifying objects, and then getting that information where it needs to be is the next essential step.

As the Defence Science and Technology group (DST) says on its Science, Technology, and Research (STaR) Shots website, “Acquiring reliable data in real time is one challenge, processing it and getting it where it needs to be is another.”

Reeman said the architecture of the solution was important as not one size would fit all. “What we have doesn’t answer everything inside the SDA problem, so the architecture needs to be able to support the addition of other capabilities,” he said. “Whether that’s to the far left of field like the passive radar capability, or to the far right of field which is probably more aligned with our eventual ASTRA solution.

“That will then allow us to use a single transmitter, in this case with multiple receive sites, really accelerating that multi-static radar array. That’s where we are going.”

With the formation of the Space Division within RAAF, Defence’s own space practice appears to be evolving. As the Defence Space Domain lead, AIRMSHL Hupfeld is conducting a Space Domain Review to improve how space capabilities are managed, acquired, and operated.

“It’s to allow us to establish an organisation to sustain, force-generate, operate space capabilities and assign them to a joint operation command if needed,” he told the ABC in a recent interview. 

One of Defence’s most ambitious projects is to create an integrated air and missile defence system, creating a network of sensors and effectors through the highly ambitious Project AIR 6500. Reeman observed that while AIR 6500 doesn’t cover space, the envisioned SDA network was really an extension of AIR 6500 without atmosphere.

“All the techniques and what you have to achieve are not particularly different between the air and space environment,” he said. “You look at the same problems. 

“We have been talking a lot about space debris, but clearly a number of military satellites are also being launched every year, filled with all sorts of capabilities that you need to understand. You need to be able to monitor and, indeed, decide what you want to do.

“That may well be nothing, or it may be ‘something’,” he added. “What is that ‘something’ and how do you achieve that ‘something’, so all of these systems will need to be layered so that that can actually be achieved.”

This isn’t just an issue for Australia. Although designated a national system, the Australian SDA capability proposed through JP9360 will be linked with the US and other coalition space operations partners, with the sharing of all relevant data.

SDA is an activity where not even the US can go it alone, and the best result for everyone comes from a partnership. To this end, in 2014 Australia signed the Space Situational Awareness data-sharing agreement with US Strategic Command.

Currently, Australian SDA is run from the Australian Space Operations Centre (AUSSpOC) at Headquarters Joint Operational Command (HQJOC) near Canberra. That was formed in 2012 and, importantly, AUSSpOC liaises with the US through the Combined Space Operations Centre (CSpOC) at Vandenberg US Air Force Base in California.

CSpOC is a US-led multinational strategic partnership between the US, Australia, Canada, and UK, working in collaboration with France, Germany, and New Zealand. This is the peak international defence body for SDA information.

Significantly the US Department of Defense also maintains the Space Objects Catalogue, an ever-growing database of operational and defunct satellites and debris. 

So how much is up there? The latest European Space Agency (ESA) report on the space environment –released in May 2021 – gives a total of 28,218 objects larger than 10 centimetres in orbit, more than half of which
are in LEO.

Fortunately, the ESA acknowledges that the global ability to track what’s out there is improving. 

This article appeared in the May/June 2021 issue of ADBR.