three questions about the possible “fall” of the International Space Station, raised by Russia

A threat of 420 tons overhead? The director-general of the Russian space agency Roscosmos, Dmitry Rogozin, said on Saturday that the International Space Station (ISS) could crash on Earth because of Western sanctions against Russia after the invasion of Ukraine.

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At the center is the delivery of an essential module, which, according to Roscosmos, could very soon be disrupted by the measures taken against Vladimir Putin’s regime. Until now relatively protected from land conflicts, the ISS remains at the heart of American and European interests and is now the subject of unprecedented tensions since its launch in the late 1990s. Franceinfo takes stock of this unfolding geopolitical crisis 400 kilometers above sea level.

1What is this warning based on?

In messages to the American (Nasa) and European (ESA) space agencies, the boss of Roscosmos draws a disastrous chain reaction that he believes is linked to the sanctions against Russia. For Dmitri Rogozin, these measures threaten to disrupt the operation of the Russian ships that supply the ISS. Problem: The Russian module Zvezda, which allows the station to maintain altitude, would then no longer be able to play its vital role.

In this diagram of the International Space Station, the Russian segment is in the lower part of the image.  Most of the structure has been put into orbit by NASA.  (CNES)

“The Russian segment ensures that the station’s orbit is corrected (an average of 11 times a year), also to avoid space debris”, said Dmitry Rogozin, who posted on his Twitter account on Saturday a map of the world showing the area flown by the ISS — and where the station could potentially crash. A broad band that includes the United States, the countries of the European Union and only a small part of the Russian territory. This area where the ISS could crash could not be verified by franceinfo.

“People in other countries, especially those ruled by the ‘war dogs’should think about the price of sanctions against Roscosmos”threatened Dmitry Rogozin, who regularly posts slogans and photomontages on social networks mocking Ukraine and its president.

Since the first ISS module was put into orbit in 1998, Roscosmos has played a key role in its expansion and maintenance. Three to four times a year, Soyuz rockets lift off from the Baikonur cosmodrome (Kazakhstan) to propel the station’s supply ships. The last launch took place on February 15, nine days before Russia invaded Ukraine.

2Can the ISS continue to operate without Russia?

This is currently not possible, but this scenario is being actively explored, particularly by NASA. On March 1, the US space agency stated that companies had offered their services to ensure strategic supplies to the ISS rather than Russia.

“Our friends at SpaceX are looking at how we can improve our capabilities (in question)also said NASA manned spaceflight manager Kathy Lueders in reference to billionaire Elon Musk’s company already well involved in US space programs. On February 21, a Cygnus freighter designed by US conglomerate Northrop Grumman and France’s Thales delivered 3,800 kilograms of material to the ISS. According to the designers, this type of ship is quite capable of supplying the fuel needed to propel the station.

For its part, the European Space Agency is more discreet, even if it assured, in a press release dated 28 February*, “fully apply the sanctions” decided by the Member States. The space cooperation with Roscosmos was partially halted after the withdrawal of Russian personnel from the French base in Kourou (Guyana) on February 26. As for the launch of the joint ExoMars program, heading for the red planet, it is: “very insecure” that it can take place this year, the ESA says.

3Can the station do damage by falling back to Earth?

In the worst case scenario, there would indeed be a fear of falling debris on Earth. Two parameters must be taken into account. First, the disintegration of the structure raises questions. With its many modules and solar panels measuring 108 by 73 meters in total, the ISS would partially withstand reentry into Earth’s atmosphere, about 50 miles (80 km) above the ground. Many smaller spacecraft, such as a Russian freighter in 2015 and the Chinese space station Tiangong-1 in 2018, have already led to small debris showers in the Pacific without causing any damage.

The other unknown in this equation would be the fall point of this possible debris. Since the earth is 70% covered with water, there is a good chance that the remains of the station will end up at the bottom of a sea or an ocean. This is also NASA’s plan*, which envisions a “deorbiting” and then a fully controlled crash of the ISS in 2031, at “point Nemo” in the South Pacific. a remote area used as a burial site for spacecraft. In the case of uncontrolled deorbitation, the duration of the descent of the ISS and the point of fall are the subject of intense speculation in the scientific community.

If we don’t know for sure the damage that the station’s fall to Earth would cause, the ISS compromising would be a strong symbol. Since launch, more than 250 astronauts from 19 countries have followed each other* to conduct thousands of unprecedented science experiments. – an example of international cooperation, started after 40 years of the Cold War.

*All links followed by an asterisk lead to content in English.