Space debris is a real risk to orbital navigation, but there are ways to reduce it, says a Swiss report to concerned parties. Will this be enough to stop the military from making it their playground?

This content is December 15, 2021 – 10:40 . was published on
December 15, 2021 – 10:40 am

Marc-Andre Miserez

November 15, 2021. 480 kilometers above the vast Russian steppe, the Kosmos-1408 satellite explodes in silence, in a shower of debris of all sizes. Retired for nearly 40 years, the machine has been hit by an A-235 anti-ballistic missile fired from the Plesetsk Cosmodrome.

480 km is dangerously close to the orbit of the International Space Station (ISS). The seven crew members are immediately asked to put on their suits and take refuge in the emergency capsule that will allow them to return to Earth in the event of a collision.

At the Pentagon, which condemns the act as “unconscious and dangerous”, Moscow replies that everything was done in compliance with safety regulations. Especially since there are two Russian cosmonauts on board the ISS – one of whom is the commander.

all kinds of conflicts

This achievement is not the first. China in 2007, the United States in 2008, then India in 2019 were already engaged in displays of such force – each time on their own satellites.

Accidental collisions also happen. On March 22, 2021, the Chinese military satellite Yunhai 1-02 struck a fragment of a stage of a Russian Zenit-2 rocket launched in the 1990s. It was the worst confirmed orbital collision since February 2009, when the Russian satellite (also military) Kosmos-2251 attacked Iridium 33, a US communications satellite.

Each of these events, voluntary or not, increases the number of debris in orbit (up to an altitude of 2000 km) to less than a few hundred. However, there are already 34,000, counting only those capable of detecting ground radar. There are also about 130 million small debris, which spin at 20 times the speed of a rifle bullet, and are also capable of doing a lot of damage.

alarm bell

Today, space agencies, private satellite launchers and academia are all too familiar with this problem. At the Federal Polytechnic of Lausanne (EPFL), we have been working on this since at least 2012, the date of birth of the Clearspace project, which should be the first garbage collection satellite.

But decision-makers are not yet fully convinced about the value of investing in waste-cleaning solutions. At EPFL, Marie-Valentin Florin, Director of the International Risk Governance Center (IRGC.)External Link), pointing to ClearSparse co-founder Muriel Richard-Noka, points out that there is no comparative study of the different solutions and their costs. The task of carrying out this study will be entrusted to a young physicist, Romain Buchs, who has just completed his master’s thesis on space debris management. first reportExternal Link Spring arrives in 2021, complete with options for politicians and producers at the end of November.

“We targeted it at space agencies and about 400 people in the private sector,” the authors say, acknowledging that “the Chinese and Russians are difficult to reach” and that the heads of state are not on the list.

“Normally, continues Romain Buch, should satellites enter the atmosphere [et donc y brûler] At a maximum of 25 years after the end of their operational life. But the rule is not binding, and therefore not adequately enforced. About 60% of satellites are inclined towards it, while we should reach at least 90%”.

Featherweight Vs. mastodons

However, there are more and more satellites. In recent years, access to space is no longer a monopoly of the states. The tendency is for constellations in low orbit. This 20. started at the end of^I Century with Iridium and Globalstar for satellite telephones. But these devices were barely more than a hundred.

With OneWeb, then Starlink (SpaceX) and Kuiper (Amazon), we go to thousands of satellites that are going to bring fast internet across the Earth. Their operators ensured that they took all necessary precautions, either by flying low enough for deorbitation to occur automatically after a few years, or by removing their machines from equipment with the aim of facilitating their capture by future space tugs. By equipping.

So for Romain Buch, these clouds of small satellites aren’t really a problem. “Basically, it was the states that created the problem. Rather new constellations are the victims. They are small satellites, weighing a little over 150 kg. The real problems come from the entire stages of the rocket – Russian in particular – which can weigh up to nine tons and which were issued between 1980 and 2005”, specifies the expert.

manage the chaos

However, Romain Buchs does not believe in doomsdays, such as Kessler syndrome.External LinkDue to which the surrounding area will look so congested that any flight there will be impossible.

“We’ll never be able to get smaller pieces of debris, we’ll focus on the bigger ones, which run the risk of colliding and creating thousands of smaller additional pieces. They’re about 2000 in low orbit. To significantly reduce the risk already.” It would be enough to seek three or four per year for this, ”the physicist explains.

This is the object of the Clearspace project that originated at EPFL and which now bears the colors of the European Space Agency (ESA).External Link) The Japanese also have a similar project (AstroscaleExternal Link) and others.

As for those who claim that this is enough to prevent a launch into orbit, they forget how dependent our world is on satellites. “To take just one example, only 26 of the 55 parameters used to measure climate change can be measured from space,” recalls Romain Buch.