Destructive anti-satellite missile tests generate huge amounts of space debris that can endanger other satellites and manned spacecraft. Photo: Atalayar

The US has announced that it will not conduct further destructive anti-satellite (ASAT) missile tests, in a move that seeks to shape norms for the responsible use of outer space and curtail further militarization of the increasingly contested domain.

In an April 18 speech at Vandenberg Space Force Base, US Vice President Kamala Harris stated that the US has committed not to conduct destructive direct-ascent anti-satellite missile testing in the future.

“Simply put, these tests are dangerous, and we will not conduct them,” Harris said. She also expressed hope that other nations will follow the US’ lead in stopping ASAT tests.

In a separate statement, the White House said that “this commitment addresses one of the most pressing threats to the security and sustainability of space.”

The White House also singled out Russia and China for their destructive ASAT weapons tests, which have generated large amounts of fast-moving space debris that potentially endangers other satellites and spacecraft.

Last November, Russia conducted a destructive ASAT missile test which destroyed one of its satellites that had been defunct since 1982 and generated at least 1,500 trackable pieces of space debris.

The test occurred at an altitude of 500 kilometers, and 80 kilometers above the International Space Station’s (ISS) orbit. The test forced the ISS’ multinational crew to take shelter multiple times and seal off modules within the station, as its orbit intersected with incoming space debris.

US Secretary of State Antony Blinken sharply criticized Russia’s ASAT test, saying that “the long-lived debris created by this dangerous and irresponsible test will now threaten satellites and other space objects that are vital to all nations’ security, economic and scientific interests for decades to come.”

China conducted a destructive ASAT test in 2007, destroying a defunct FY-1 weather satellite at an altitude of 863 kilometers with a modified DF-21 ballistic missile. The test resulted in an estimated 3,000 pieces of space debris, which at the time was the largest debris cloud ever created by a single event in orbit.

At the time, US National Security Council Spokesman Gordon Johndroe stated that “The US believes China’s development and testing of such weapons is inconsistent with the spirit of cooperation that both countries aspire to in the civil space area,” and that the US and “other countries have expressed our concern regarding this action to the Chinese.”

Military satellites are an increasingly critical capability. Photo: Wikimedia Commons

However, the US has conducted its own destructive ASAT tests. In February 2008, the US shot down a crippled top-secret National Reconnaissance Office satellite at an altitude of 241 kilometers using an SM-3 missile from the USS Lake Erie cruiser.

In comparison to the Russian and Chinese tests, most of the debris from the US test re-entered the atmosphere and self-incinerated after 48 hours, and all remaining debris from the US test re-entered within 40 days, with no piece large enough to survive re-entry.

Vice President Harris’s announcement comes amid concerns that Russia may directly attack US intelligence, surveillance and reconnaissance (ISR) satellites, which are widely believed to be key enablers for Ukraine to resist Russia’s onslaught.

While a direct Russian attack against US satellites still seems unlikely, as it would draw the US even closer in the ongoing conflict in Ukraine, Moscow has locally deployed several non-destructive ASAT capabilities such as jamming and cyberattacks.

The US announcement is not the first effort to create norms regulating the use of ASAT weapons. In 2008, China and Russia presented a Draft Treaty on the Prevention of the Placement of Weapons in Outer Space. The draft places important limits on the use of ASAT weapons but mentions little to limit their development or deployment.

In 2010, the EU presented a draft Code of Conduct for Outer Space Activities, which prohibits the deployment of ASAT weapons but likewise did not place any restriction on their deployment and development.

While the EU draft set the reasonable expectation that space assets should not be a target of aggression, in January 2012 the US announced that instead of signing the EU Code it would work with the EU to develop an International Code of Conduct for Outer Space Activities.

However, despite this self-imposed ban on destructive ASAT weapons testing and efforts to create international norms curtailing the further militarization of space, it is believed that the US is developing more advanced satellite-killing technologies, such as ground-based mobile lasers, radiofrequency jammers, microwave weapons and even hunter-killer satellites.