Australia to Ban Direct Ascent Anti-Satellite Tests

As the space around Earth becomes increasingly congested with satellites and space junk, it is becoming increasingly important for states to consider how they are impacting the sustainability of human activities outside of our atmosphere. For Australia, part of being a responsible space-faring nation is to ensure a safer, more stable, and more peaceful space domain, and so the government has recently committed to a ban on direct ascent anti-satellite missile testing.

Direct-ascent anti-satellite missile testing can generate large amounts of space debris that remain in space for years and poses a direct threat to the satellites and spacecraft of other nations. Australia is just the eighth nation (after the United States, United Kingdom, Canada, New Zealand, Japan, Germany, and the Republic of Korea) to commit to banning tests on anti-satellite weapons.

Incredibly, there exist few enforceable rules for restricting military action in space. The Outer Space Treaty, which entered into force in 1967, merely restricts nuclear weapons and weapons of mass destruction from being deployed in space. But the use of anti-satellite weapons and other conventional weapons in space is not covered by any treaty or law.

Anti-satellite weapons (ASATs) may be either co-orbital or direct ascent. While direct ascent missiles are launched directly to destroy a satellite target, co-orbital weapons are placed into orbit and then manoeuvre close to the target where they can attack it by collision, explosion, or even using robotic arms.

“Some countries have developed or are developing new capabilities to target satellites to destroy space systems or degrade their capabilities, threatening our networks," recently said Defence Space Commander Air Vice-Marshal Cath Roberts, at the 2023 Australian International Air Show in Avalon.

“We respond to threats in space using the full spectrum of response options, from designing resilient mission systems that mitigate the risks of attack right through to contributing to combined space operations with our allies and partners."

“A space electronic warfare capability seeks to detect and deter attempts to interfere with our use of the space domain without creating debris or damage the space environment. We are exploring options for non-kinetic capabilities for consideration by government," she said.

Our activities in space support so much of our modern lives, from providing high-speed communications networks to enabling a global banking system and helping us to monitor our planet and environment. The most significant threat to this is the growing problem of space junk, and while irresponsible military testing of destructive ASAT weapons does contribute significantly to this, it is avoidable if all space-faring nations can work together.

There is a long history of research and development into ASATs, stretching right back to 1957 and the launch of Earth’s first artificial satellite, Sputnik. Fearful that the Soviet Union’s technological superiority could allow them to establish a global network of nuclear-armed satellites, the US set up a project called Bold Orion to develop and test air-launched ballistic missiles capable of destroying satellites.

In 1959 a B-47 Stratojet bomber carried a Bold Orion ASAT to an altitude of 35,000 and targeted a US Explorer 6 satellite, and pressed the launch button. The missile passed its target at a range of around 6 km, and would have destroyed it had it been armed with a nuclear warhead. The feasibility of ASATs had been proved.

In 1985 a US Air Force F-15 fighter aircraft launched an ASAT from an altitude of 38,100’, destroying the Solwind P78-1 solar observatory. Nearly 300 pieces of orbital debris were created by the impact, with the last piece deorbiting in 2004. Solwind remains the only satellite to have been destroyed by an air-launched ASAT; it was also the last ASAT test carried out by the US until 2008.

Research and spending on ASATs decreased in the 1990s, but when the US changed its own policy on the weaponisation of space in the early 2000s, China joined the race and developed its own ASAT missiles. They conducted their first tests in 2005 and 2006, but in 2007 they destroyed a weather satellite and created the largest cloud of space debris in history. Many of the original 150,000 pieces of debris remain in orbit today.

The following year the US used an ASAT against one of its satellites for the second time when the Navy destroyed a failed reconnaissance satellite in Operation Burnt Frost. Only weeks before, Russia had drafted a new treaty to ban space weapons which was backed by China at a UN-sponsored forum. The US had rejected the proposal on the grounds that there was no way to ensure compliance with the treaty, and in doing so left the space arms race to continue on unabated.

In 2019, India became the third nation to launch its own ASAT and destroy a satellite, but it was Russia’s destruction of an inactive satellite in low-Earth orbit in 2021 that caused perhaps the biggest outcry. The debris cloud threatened the orbiting International Space Station and its crew of seven (including 2 Russian cosmonauts), and it had to carry out evasive manoeuvres just a few months ago to avoid debris.

According to a fact sheet published by The White House in April, this event provided at least some of the impetus needed for the US government to announce that it was committing to ban further direct-ascent ASAT missile testing. While that does not include other types of ASATs (such as co-orbital ASATs), it is a step in the right direction.

Thankfully, the Australian government agrees. Let’s now hope that it is not too little, too late, to curb the militarisation of space.