US Pledges to End Anti-Satellite Missile Tests, Asks the World To Follow Suit

So far, only four countries have this ability – the United States, Russia, China, and India.

At Vandenberg Space Force Base in California on 18 April, Vice President Kamala Harris announced that the United States will no longer conduct destructive, direct-ascent anti-satellite (ASAT) missile testing.

"Simply put, these tests are dangerous, and we will not conduct them," she said, calling on other nations to follow suit and establish this as an international norm, since it would benefit all nations.

This announcement is part of a larger initiative of US agencies to develop proposals for norms that advance the nation's interests and preserve the security and sustainability of space.

Notably, the US hasn't conducted an ASAT test in fourteen years. So why has it made such a commitment at this stage?

This has something to do with the tests conducted by Russia and India in the last few years, the rapid commercialisation of space, and the massive threat ASATs pose to the future of global spaceflight.

The Big Four

ASATs, which were first developed during the cold war era, have never actually been used in warfare.

So far, only four countries have managed to successfully demonstrate this technology in tests – the United States, Russia, China, and India.

In 2007, China destroyed its defunct Fengyun-1C weather satellite with an anti satellite missile. It was the first such test since the cold war era.

A year later, presumably in response to China's test, the United States fired a RIM-161 Standard Missile 3 to destroy a new American reconnaissance satellite that had failed to function properly.

The US maintained that this was to safely destroy toxic hydrazine fuel which would have otherwise posed health risks to people near the crash site, CNN reported.

Over a decade later, in 2019, India conducted an ASAT test called Mission Shakti, and succeeded in destroying one of its own satellites in the Low Earth Orbit (LEO).

Russia, which had been testing its Nudol missile system for years, successfully destroyed a Soviet era satellite with it in November 2021.

The Problem with ASATs

Blowing up a satellite in space creates space debris. Some of it burns up in the atmosphere, but some remains in orbit for years.

"This debris presents a risk to the safety of our astronauts, our satellites and our growing commercial presence," Kamala Harris said in her speech.

"A piece of space debris the size of a basketball, which travels at thousands of miles per hour, would destroy a satellite. Even a piece of debris as small as a grain of sand could cause serious damage," she added.

When China destroyed its weather satellite in 2007, it created thousands of fragments, some of which are still in orbit today. In fact, the International Space Station had to maneuver to avoid one of these fragments last year.

The Indian government said that its 2019 ASAT test was conducted at low altitude so that the resulting debris would decay and fall back onto the Earth within weeks.

The US Defense Secretary Patrick Shanahan initially raised concerns, but later said that he expected the debris to eventually burn up, avoiding a China-type scenario, according to Reuters.

Others weren't as optimistic.

“We already have 15-16 objects with apogees about 1,000km, and that alone is really bad. It also shows that the Indian government’s claim that the debris is not a problem is nonsense,” Jonathan McDowell, an astrophysicist at Harvard Smithsonian Center for Astrophysics told Breaking Defense in April that year.

Commercialisation of Space

Thanks to more cost effective technology and low launch prices, private companies and governments are launching more satellites than ever before.

There were 146 orbital launch attempts in 2021 – the most since 1967, according to CosmoQuest.

While China was responsible for most of these launches, Elon Musk-run SpaceX accounted for 31, through which it launched a staggering 989 satellites. India accounted for two launches.

In all, there were 4,852 satellites in orbit at the start of 2022, according to the Union of Concerned Scientists. This number is expected to increase exponentially in the next few years, mainly due to commercial satellites.

SpaceX alone hopes to have as many as 42,000 satellites in its Starlink constellation, which aims to provide low-cost internet to remote locations. It already has roughly 1,500 Starlink satellites in orbit.

As the space around Earth becomes increasingly crowded with spacecraft, the chances of one colliding with space debris increases significantly. Even small debris can destroy satellites since they move at over 11,000 kph.

This could theoretically cause a phenomenon called Kessler syndrome, in which one collision could cause a satellite to explode, creating more space debris which would collide with other satellites creating even more debris.

A cascading effect like that could ruin the space infrastructure that humankind has built so far.

(With inputs from CNN, Reuters, and Breaking Defense)