Listen to this article:
New Delhi: The thousands of pieces of trackable debris generated by Russia’s anti-satellite (ASAT) missile test will pose a threat to future space missions and it will be decades before they are fully gone, scientists have said.
On November 15, Russia destroyed a defunct Soviet-era satellite called Tselina-D – a.k.a. Cosmos-1408. The test generated more than 1,500 trackable pieces of debris in low-Earth orbit (LEO). Ground instruments can continuously track only objects that are the size of a softball or larger.
They can’t keep track of smaller pieces, and the potential population of such pieces could mean the total number of debris pieces from the test could be much higher.
After Russia conducted the test, the seven-member crew of the International Space Station (ISS) – four US astronauts, a German astronaut and two Russian cosmonauts – was directed to take shelter for two hours as a precaution.
An ASAT weapon is a missile that is launched from the ground and can target and destroy assets orbiting the planet at various altitudes.
US secretary of state Antony Blinken condemned the missile test as “reckless and irresponsible”.
Data to date suggests that there are around 20,000 objects trackable pieces of debris in orbit around Earth – with Russia’s test expected to increase that figure by as much as 10%.
Ed Lu, the founder of LeoLabs, a startup that has said it can track debris as small as half a golf ball, told National Geographic “We are counting many, many objects – we’re not even sure how many there are yet, but it’s a lot.”
Further processing of recent LeoLabs data on #Cosmos1408 breakup shows 216 unique objects identified so far. This number will grow significantly as we gather more data and the objects begin to further separate from one another in their new orbits. pic.twitter.com/B7J3g2WS2U
— LeoLabs, Inc. (@LeoLabs_Space) November 16, 2021
In a tweet, LeoLabs also said it has thus far identified 216 unique objects created by the test, adding that the number is expected to grow significantly as more data become available.
Astronomical telescopes on the ground have captured images of some shattered pieces as well. According Numerica Corp, a company that tracks space debris, the pieces are spreading in many directions.
In addition to these images, Slingshot Aerospace’s partner @numerica_corp has also provided a video from shortly after impact. The circled areas show the newly created debris in LEO from the Russian anti-satellite test (#ASAT) against #Cosmos1408. pic.twitter.com/E1FZbjVZEy
— Slingshot Aerospace (@sling_shot_aero) November 15, 2021
Scientist Hugh Lewis said that the debris is expected to pose a long-term threat. Based on a simulation of the test he conducted, Lewis said it would take “several years before most of the fragments … re-entered [Earth’s atmosphere] and decades before they were all gone”.
Also from the #Kosmos1408 simulation: re-entry predictions or, if you read the graph another way, prediction of the longevity of the debris cloud. Looks like several years before most of the fragments in the simulation re-entered & decades before they were all gone. pic.twitter.com/6zZtojkgJs
— Hugh Lewis (@ProfHughLewis) November 15, 2021
After India conducted its own ASAT test in March 2019, the space community had expressed similar apprehensions – that the debris would take years to disintegrate. National Geographic noted, however, that only three trackable pieces from India’s ASAT test currently remain in orbit. This is still contrary to the Indian government’s own claims that the pieces would all reenter Earth’s atmosphere in three months. Untrackable pieces are likely to still be in orbit.
This is still a big problem: satellites orbit Earth at high speeds, so even small fragments can cause noticeable damage upon impact because the relative velocity would be very high.
In May this year, for example, the ISS was hit by a metal fragment “no bigger than the width of an eyelash”, punching a hole in one of its robotic arms.
It took some 2 years for the debris from the 2019 Indian #ASAT test to clear (one tracked debris piece from that test is currently still in orbit). And that test was at a clearly lower altitude (285 km) than this Russian test (~480 km).
So this does create a long-term problem.
— Dr Marco Langbroek 💉x2 #Vaccinate (@Marco_Langbroek) November 16, 2021
— Megs H. (@megsylhydrazine) April 18, 2020
An object in orbit can reenter the atmosphere when atmospheric drag slows it down to such an extent that it no longer has the momentum to maintain the shape of its orbit, and begins to descend towards Earth.
Russia acknowledges test
On November 16, the Russian defence ministry confirmed – and thus also acknowledged – that it had “successfully conducted a test”. According to The Guardian, defence minister Sergei Shoigu, however, denied that the test posed any threat to space activity.
It also appears to be the case that Roscosmos, Russia’s space agency, did not know about the test in advance, according to National Geographic. NASA Administrator Bill Nelson also said he had reason to believe that Roscosmos hadn’t been informed, saying, “They’re probably just as appalled as we are.”
The European Space Agency has also criticised Russia for the test. “Our models show an increase in probability of a collision in low Earth orbit of five percent,” Philippe Baptiste, head of the French space agency CNES, told Space News.
Thierry Breton, the EU commissioner in charge of EU space policy, tweeted on Tuesday to “join the strongest condemnations expressed against the test conducted by Russia on Monday.”
“The launch poses a major risk to our astronauts currently on the International Space Station and has triggered emergency procedures to protect them,” he added.
Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, said that for the next few years, “there’s going to be an enhanced risk of collision” in LEO as a result of the test.
“Making unnecessary debris in LEO is bad. Making unnecessary debris in LEO when we’re vastly increasing the number of active LEO satellites is super-bad,” McDowell said, referring to the fact that over 90,000 new satellites are expected to enter orbit in the next few years.
According to National Geographic, since Cosmos-1408 was orbiting 480 km above ground, it could pose a risk to SpaceX’s constellation of Starlink satellites, which provide wireless broadband internet services. These satellites orbit at an altitude of 547 km.
“You’ve got thousands of targets in the form of the Starlink satellites, and if you manage to hit a few, now you’ve got dead Starlink satellites passing through this crowded region,” McDowell said.
In a statement, the Secure World Foundation condemned Russia’s test, saying deliberately creating “orbital debris of this magnitude is extremely irresponsible”.
“Orbital debris poses an indiscriminate risk to everyone’s satellites in orbit, endangering critical space-based services we all rely on, as well as the human lives on the International Space Station and China’s Tiangong Space Station,” the foundation said.
It also called upon the US, Russia, China and India – the four countries that have tested ASAT weapons so far – to declare “unilateral moratoriums on further testing of their antisatellite weapons” and work with other countries towards solidifying an international ban on destructive ASAT testing.
Of these four countries, India has conducted one ASAT test and China at least two. Both the US and Russia have conducted multiple tests – from as far back as the 1950s (in Russia’s case as the Soviet Union).
The Outer Space Treaty of 1967 forbade the installation of nuclear weapons in Earth orbit, in the context of the Cold War between the US and the Soviet Union. But weapons have since become much more sophisticated in the way they use the space environment.
For example, Financial Times reported in October this year that China may have tested an advanced hypersonic fractional orbital bombardment system in August.
This is a missile system with a nuclear warhead that is launched from the ground, enters orbit and stays there. When it is required at a later time, it fires special motors to de-orbit right away into the atmosphere and bear down on its target, giving the target little response time.