NASA safety panel warns of increasing risks to ISS operations

WASHINGTON — Members of a NASA safety panel said they were “deeply concerned” about the safety of the aging International Space Station, citing long-running issues and funding shortfalls.

During a public meeting of the Aerospace Safety Advisory Panel (ASAP) April 17, members expressed concerns about growing risks as the station nears its projected end in 2030.

“The ISS has entered the riskiest period of its existence,” said Rich Williams, a member of the panel, arguing there were “increasing risks” to the station.

Some of those risks are problems the station has been facing for years, such as leaks in a vestibule of the station’s Zvezda module called PrK. Russian and American experts have been investigating small cracks seen in PrK for several years, with no resolution on their cause or how to best address them.

Williams said officials from NASA and Roscosmos are scheduled to meet later this month in Moscow to update efforts to mitigate risks on the cracking. In the meantime, he said ISS managers have implemented procedures such as limiting repressurization of the vestibule, which links a docking port to the rest of the station. “The panel has considered this one of our highest concerns,” he said.

Another concern is developing deorbit plans for the ISS, particularly in an emergency before its scheduled retirement at the end of the decade before the arrival of the U.S. Deorbit Vehicle (USDV) that NASA has contracted SpaceX to build. “If there is a deorbit of the ISS before the USDV is delivered, the risk to the public from ISS breakup debris will increase by orders of magnitude,” Williams said.

The station is dealing with several other issues, such as keeping sufficient spare parts for life support systems and delays with cargo resupply vehicles. That latter concern involves both the delays in the first flight of Sierra Space’s Dream Chaser vehicle, now expected no earlier than late summer. and Northrop Grumman scrapping its NG-22 Cygnus mission to the ISS, which was scheduled to launch in June, because of damage to the spacecraft incurred during shipping.

“Overarching all of these risks is a large ISS budget shortfall,” Williams said. “All of these risks are actually a derivative of this budget shortfall and collectively contribute to potential compromise of the low Earth orbit transition plan.”

He did not elaborate on the nature of the budget shortfall ASAP perceives in ISS operations. In the agency’s fiscal year 2024 operating plan, NASA allocated $993 million to ISS operations and maintenance, with more than $1.63 billion to crew and cargo transportation. In 2023, NASA spent $1.03 billion on ISS operations and maintenance and $1.64 billion on crew and cargo transportation.

ASAP, in its 2024 annual report, warned that ISS operations could face budget pressures from the costs of building the USDV and funding needed for supporting commercial space stations. “The Panel has grave concerns, however, that if the necessary funds for both the USDV and the supporting launch infrastructure (over $1B in total) comes solely from the existing ISS budget, this will unduly strain NASA’s ability to safely perform normal and contingency ISS on-orbit operations,” it stated.

“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.”

“The panel appreciates the demonstrated operational excellence of the ISS program, but remains deeply concerned about the increasing and cascading risk attending the program over the next several years,” he concluded.

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