Mankind’s efforts in space are becoming critical for modern societies as communication systems and services such as Earth sensing through to precision location and timing, support both military and civilian operations.
Recent developments are also expanding the use of micro-gravity for the development of pharmaceuticals and materials that cannot be produced on Earth, unlocking tailored products for specific situations.
All these space-based capabilities require protection from accidents and intentional acts, with many civilian operated satellites becoming targets as they also provide services for military purposes.
While we can consider that there is plenty of room in space, specific areas such as Low Earth Orbit (LEO) are becoming more congested with an increased chance of collision, as evidenced by the 200m close approach between a Starlink satellite and a recently launched Chinese satellite in early December 2025.
CAS Space were the launch services provider who claimed their launch window was selected using a ground-based space awareness system to avoid collisions with known satellites or debris.
“We don’t yet have quite the right tools, whether it be sensors or software, to provide a good analysis of where everything is at a single point in time,” former Executive Chair of the Space Industry Association of Australia, Jeremy Hallett, told ADM.
“If we don't know what's there, how do we mitigate any potential impacts?”
Hallett also noted that orbits are regulated by the International Telecommunications Union (ITU) based on a satellite’s use of the electromagnetic spectrum as opposed to their physical orbits.
“If a satellite is in a particular orbit using a certain frequency and another goes near that orbit with the same frequency, they interfere with each other. The ITU has an incredible engineering team that does all the frequency analysis to keep those deconflictions in place, so it's not so much about getting the geography of space locked down, but companies do robustly prosecute their access to spectrum rights, which is a proxy for trying to secure more opportunities in space,” he said.
Terrestrial use of frequencies can also impact on satellites with cases including Ligado Networks being allocated frequencies adjacent to those used by GPS signal, raising concerns of potential interference.
This has also resulted in some regulators considering opening part of the X-Band (8.025-8.4GHz) for use by 5G and 6G mobile networks.
The X-Band is heavily used by Earth observation satellites to download high-resolution imagery for terrain mapping, crop surveillance, ice sheet tracking and troop movement observations, raising concerns from government and industry regarding potential interference with delivery of information from orbit.
With both physical space and frequency congestion becoming issues in orbit, improved Space Domain Awareness (SDA) capabilities are required to prevent spectrum and physical collisions in space.
Fortunately, Australian organisations have been progressing innovative solutions including Quasar Satellite Technologies’ work on radio frequency sensing, Electro Optical Systems’ (EOS) suite of sensors, and Space Machines Company’s (SMC) collaborative project as part of a Defence Trailblazer Accelerating Sovereign Industrial Capabilities (ASIC) program.
Intentional or accidental destruction of a satellite can create a cloud of debris which could, in turn, lead to a cascading series of collisions referred to as a Kessler syndrome, rendering entire orbits unusable.
While satellites are improving their ability to manoeuvre to avoid collisions, their changes can subsequently increase the risk of collisions. Many consider this to be a reactive solution but not actually preventing the issue in the first place.
“The real risk these days is not so much the bits of random junk, but rather the fact that, potentially by the end of this decade, there will be 100,000 satellites in LEO, which is a deliberately man-made problem, but we can deliberately develop a man-made fix for that as well,” Hallett said.