The astronauts of the International Space Station (ISS) experienced an unusual day this Friday after NASA ordered them to take shelter in their respective spacecraft and remain prepared for a possible evacuation. The measure was taken as a precaution during a planned operation to review an air leak in the Russian segment of the orbital laboratory, a fault known for some time but which has worsened in recent days.
The alert was lifted about two hours later. Roscosmos suspended structural repair work on the Russian Zvezda module pending new measurements and data on the damage, allowing the crew to return to normal operations inside the station.
The leak is not new. According to NASA, the Zvezda module has had cracks and air leaks "for some time," although Roscosmos had managed to partially mitigate their effects with periodic interventions. The appearance of new leaks led the Russian space agency to prepare a broader repair this Friday, during which NASA raised the security level for its astronauts.
"Out of an abundance of caution, NASA has directed the agency's four SpaceX Crew-12 crew members and NASA astronaut Chris Williams to assume a heightened safety posture aboard the Dragon spacecraft while the repair is being performed," explained the US agency's spokesperson, Bethany Stevens.
Shelter in the Dragon spacecraft
The four members of the Crew-12 mission and astronaut Chris Williams moved to the SpaceX Dragon capsule, docked to the International Space Station, as part of the safety protocol. This spacecraft allows emergency return to Earth if necessary.
Currently on board the ISS are seven crew members: NASA astronaut Chris Williams; cosmonauts Sergey Kud-Sverchkov and Sergei Mikayev; and SpaceX Crew-12 members Jessica Meir, Jack Hathaway, Sophie Adenot, and Andrey Fedyaev.
The situation returned to normal after the suspension of work by Roscosmos. The Russian agency decided to gather more data before continuing with the repair of the Zvezda module's transfer tunnel, a particularly sensitive area because it connects the Russian segment with the docking ports used by Soyuz and Progress spacecraft.
An old problem in the Russian module
The cracks in the Zvezda module are a constant concern for NASA and Roscosmos. The module was put into orbit by Russia in 2000 and performs essential functions for the station: housing, life support, electrical power distribution, data processing, flight control, and propulsion.
It also serves as a docking port for Russian spacecraft, making its condition a key element for the safety and operability of the orbital laboratory.
Although this Friday's episode did not end in evacuation, NASA has warned on various occasions of the importance of finding a stable solution to these leaks. The International Space Station is an aging structure, with almost three decades of activity, and its systems are worn from years of continuous service in orbit.
A laboratory inhabited since 2000
The International Space Station began construction in 1998 with the orbital joining of the US module Unity and the Russian Zarya. Since then, new modules have been assembled to form an orbital complex 109 meters from end to end.
The first permanent expedition arrived in November 2000. Since then, the station has never been uninhabited. Nearly 300 astronauts from 26 countries have passed through its modules, in one of the greatest experiences of international scientific cooperation.
Inside, experiments are conducted in microgravity with applications in medicine, biology, physics, materials, and space exploration. Among other fields, research carried out on the ISS has contributed to the study of treatments for cancer, osteoporosis, solar radiation, and space weather.
Operational until 2030
NASA maintains the schedule to cease operations of the International Space Station at the end of 2030 and to deorbit it in a controlled manner in 2031. The plan involves pushing the station toward Earth so that it re-enters the atmosphere and falls into a remote, uninhabited ocean area.
The US agency wants to concentrate its resources on returning to the Moon and future human exploration of Mars. For low-orbit research, NASA plans to turn to commercial stations developed by private companies in the coming years.
Among the alternative projects are initiatives from Blue Origin, Voyager Space, and Airbus, as well as Axiom Space, which plans to launch commercial modules initially connected to the ISS. Meanwhile, China maintains its own space station, Tiangong, with a permanent crew of three astronauts.
