NASA announced on Thursday that it had signed contracts with three American companies for help them develop private space stations “that people can visit, where they can live and work,” said the head of the space agency, Bill Nelson, in a statement.
But NASA also intends to hire the services of these companies for its needs and send astronauts to carry out experiments in their stations. For good reason: within a few years, the famous international space station (ISS), which has hosted astronauts for more than twenty years, should bow out. Explanations.
Repeated incidents that cause concern
Launched in 1998, the international space station is now aging. The machine, as large as a football field, has suffered regular damage for several years.
In August, Russian astronauts located cracks in the Zarya module, the first to be put into orbit 23 years ago. A problem far from isolated: other cracks, and even air leaks, were reported by ISS astronauts in early 2021 and in 2019. This year, the station also observed losses of altitude twice. Last May, a hole was also located in one of the ISS’s robotic arms after the passage of orbital debris.
The Russian segment of the station, where several technical incidents have occurred in recent months, is the one causing the most concern. In July, the Zvezda module experienced an unexpected pressure drop as the thrusters on the Nauka module ignited by surprise, deflecting the ISS which made a turn and a half on itself before rocking 180 ° C.
Admittedly, these incidents did not cause any injuries and the scientific experiments carried out on board the ISS are continuing as planned. But these recurring events in recent years bear witness to a gradual and relatively advanced degradation of the international space station.
Last April, senior space official Vladimir Soloviev, chief engineer of the company responsible for the maintenance of the Russian part of the station, warned of the aging of a large part of the ISS. He also mentioned a probable “avalanche” of deteriorated equipment, or even impossible to use, after 2025.
In the Russian segment, “about 80% of flight systems are at the end of their service life, which means that once all the systems have exhausted their service life, irreparable breakdowns could occur the very next day. .
Online, NASA offers to follow live the continuous journey of the ISS above the Earth.
Towards use until 2030?
Despite these damages, the future of the international space station is officially assured until 2024. The intergovernmental agreement to continue the use of the ISS until that date has in fact been renewed between the ESA for the Europe, NASA for the United States, Jaxa for Japan, ASC for Canada and Roscosmos for Russia.
Russia has officially declared that it will withdraw from the project as early as 2025. The Russian space agency has also announced that it next wants to launch a manned space complex in low Earth orbit, called the “Russian orbital service station. “. Russia is also expected to collaborate with China in the future Chinese station, which is currently under construction.
NASA for its part has confirmed that it can technically operate in the ISS until 2028. But the American space agency and the European space agency (ESA) would like to push the operation of the station until 2030. In an audit on the state of the station unveiled on November 30, NASA said it was confident on the question:
The station was built to have a 15-year lifespan, with a safety factor of two, which means it can last 30 years after the launch of its first modules in 1998. Boeing has certified that the portions American station could last until 2028 and NASA is optimistic about the extension of the life of the ISS until 2030.
To use the station until that date, NASA must first obtain the agreement of the US Congress.
An inevitable end
However, NASA ensures that it is realistic about the lifespan of the ISS. “The structure cannot cope with the long-term effects of spatial conditions,” she wrote in her audit. Radiation, extreme temperature changes, micro-meteorites, orbital debris … So many factors which “weigh on the structure of the station and which will one day lead to its inevitable deorbitation”.
In addition, the maintenance costs of this space juggernaut are colossal. Over the past decade, NASA has spent between $ 2 billion and $ 4 billion annually to operate and keep the ISS in good condition. The US agency estimates that the cost of maintaining the station will remain stable – at around $ 3.2 billion per year – during the last years of its life. A significant cost for a station which, since it was put into orbit, will have cost the space agencies which sent astronauts there 150 billion dollars.
Towards the rental of private stations
As the end of the ISS approaches, NASA intends in the future to be able to hire the services of private companies for its needs, without having to finance the operating costs of a station. Hence the announcement of the signing of contracts with Blue Origin, Nanoracks, and Northrop Grumman, to whom the American space agency will give respectively 130, 160 and 125.6 million dollars to develop their own space stations. These should be launched in the second half of our decade.
Renting places in private space stations would save NASA a billion dollars a year. She wants to be able to send two astronauts into orbit continuously, and perform some 200 experiments per year.
But the space agency absolutely does not want to face a “vacuum” in the American presence in space. It is for this reason in particular that it wishes to operate the ISS until 2030. The contracts with the private stations “will help to ensure in the United States a continuous human presence in low orbit,” said at a conference release Phil McAlister, director of commercial flights for NASA. “A hole (in this presence) would be damaging for future human missions beyond Earth, by putting research on hold,” he added.
What to do with an obsolete and unused ISS?
It took 42 module and spacecraft launches to put the International Space Station into orbit. A titanic job. But bringing this 420-ton juggernaut back down to Earth could prove to be even more complicated.
In its audit made Tuesday, Nasa explained that it was “probable to put out of service and to de-orbit the ISS during this decade (…) after the end of its life”. In this hypothesis, the American space agency would gradually reduce the altitude of the craft to allow it to enter the atmosphere. A technique already observed in 2001 with the Mir station.
In this video from March 2001, we see the molten debris of the Mir station coming back down to Earth before going to crash into the Pacific.
For a return to Earth in December 2030, the station’s altitude will begin to decrease between 2026 and 2028, depending on atmospheric conditions. About 16% of the ISS could not be destroyed when it entered the atmosphere, and debris could fall on our planet as a result. No worries according to NASA, which ensures that the place of fall will be “directed in an uninhabited area of the South Pacific”.
Deorbiting the station is expected to cost $ 1 billion. A cost that will be shared between the different countries that have used the station during its more than 30 years of good and loyal service.