The ISS Is in the ‘Riskiest Period of Its Existence,’ NASA Safety Panel Warns

The International Space Station (ISS) has been orbiting Earth since 1998, housing groups of astronauts in the microgravity environment around 250 miles above the surface of the planet. All of that time in space has taken a toll on its aging hardware, and the space station is due to retire within the next few years. Until then, however, safety experts are warning of long-running issues that threaten the safety of the ISS, and the crew on board.

During a meeting of the Aerospace Safety Advisory Panel (ASAP) held on Thursday, members of a NASA safety panel stated that there are growing risks threatening the space station as it nears the end of its use, SpaceNews reported. “The ISS has entered the riskiest period of its existence,” Rich Williams, a member of the panel, said during the meeting.

At the top of the list of growing risks is a leak where air has been escaping at an increasing rate from a tunnel that connects a docking port to a Russian module. In 2019, Russia’s space agency Roscosmos reported the detection of an air leak found in the vestibule (named PrK) that connects a docking port to the Russian Zvezda module, which the space agency had launched to low Earth orbit in July 2000. The rate of air that has been leaking from Russia’s Zvezda module had doubled from one pound of air per day in 2019 to a little over two pounds around a week before the launch of the Progress MS-26 cargo spacecraft in February 2024.

Both NASA and Roscosmos have been monitoring the air leak since then, and officials from the two space agencies are scheduled to meet later this month to update mitigation efforts for the growing safety concern, according to Williams. A report issued in late 2024 elevated the air leak to the highest level of risk based on its likelihood and severity. In the meantime, the source of the leak remains unknown. The astronauts on board the ISS are prepared to close the hatch to the service module when access is not required in order to minimize the amount of air lost, as well as to isolate the leak itself from the rest of the space station.

Another safety issue addressed during the meeting is the lack of a deorbit plan for the ISS in case of an emergency. NASA is in the process of solidifying a plan to ditch the nearly one-million pound space station in 2030, sending it flying through Earth’s atmosphere to mostly burn up from the heat, with its remaining bits ending up at the bottom of the Pacific Ocean in a controlled reentry. But as of now, NASA has no emergency plan in place to deorbit the ISS, and that’s a big problem. If NASA is forced to destroy the space station ahead of its retirement, then it increases the risk of ISS debris falling on inhabited areas.

“If there is a deorbit of the ISS before the [U.S. Deorbit Vehicle] is delivered, the risk to the public from ISS breakup debris will increase by orders of magnitude,” Williams said, according to SpaceNews. The panel highlighted other issues with the ISS, including having enough spare parts for life support systems on board and delays with cargo deliveries. Williams blamed these issues on “ISS budget shortfall.”

“As programs near final phases, it is tempting to assume less resources will need to be available,” Williams said. “For the ISS, it is critical to maintain adequate budget and resources until the vehicle is safely reentered.”