While it may seem like the International Space Station is just now fully hitting its stride as far as scientific output and the ability for crew rotations from several different spacecraft, the ISS has been operating with astronauts on board for over 21 years. Knowing the modules and entire physical structure cannot endure the long-term effects of the harsh space environment forever, NASA’s Office of the Inspector General has issued a new report outlining the agency’s plans to keep the space station in orbit until 2030, and to replace it with one or more commercial space stations.
“Anticipating its retirement, NASA has committed to replacing the ISS with one or more commercially owned and operated space destinations,” the report says, emphasizing that they hope at least one commercial station could be operational by 2028. This would provide a period of two years of overlap and handover to avoid a “substantial gap” in on-orbit science investigations. Such a gap would result in the delay of deep space human exploration missions, the report says.
Even though the retirement of the ISS is currently scheduled for 2024, NASA and the international partners have indicated that the ISS’s operational life could be extended to 2030.
“The Station was designed with a life expectancy of 15 years with a safety factor of two, meaning it could last 30 years after the 1998 launch of its first segments,” the report says, adding that “NASA is optimistic that the Station’s life can be extended to 2030.”
But structural wear and tear is becoming evident. NASA and Roscosmos are investigating the cause and long-term impacts of cracks and leaks that were recently discovered in the Station’s Service Module Transfer Tunnel, which connects the Service Module to one of eight docking ports on the Station. Causes being explored include structural fatigue, internal damage, external damage, and material defects.
Notably, the report says an updated analysis of the structural longevity of other segments as well should be done because the leaks were caused by cracks that models suggest should not exist. This would suggest the possibility of an earlier-than-projected obsolescence for at least one element of the Station.
The ISS costs about $3 billion a year, roughly a third of NASA’s annual human space flight budget. Commercial companies say they can provide brand new facilities for a better price, making for a better investment for NASA.
NASA says the Artemis program, aimed at returning humans to the Moon and ultimately landing astronauts on Mars, is not feasible without continued human health research and technology demonstrations being conducted on the ISS and its eventual replacement.
Therefore, in looking ahead, NASA announced today they have signed agreements with three U.S. companies to develop designs of space stations and other commercial destinations in space. They agency said they want to “enable a robust, American-led commercial economy in low-Earth orbit.”
The companies are Blue Origin for their Orbital Reef space station design, receiving $130 million, Nanoracks LLC, for $160 million, Northrop Grumman Systems Corporation for $125.6 million.
“NASA seeks to maintain an uninterrupted U.S. presence in low-Earth orbit by transitioning from the International Space Station to other platforms,” NASA said in a press release. “These awards will stimulate U.S. private sector development of commercial, independent space stations that will be available to both government and private-sector customers.”
In early 2020, NASA announced a Plan for Commercial LEO Development, which they hope will foster economic development in LEO and to drive innovation. At that time, they announced the selection of Axiom Space of Houston to provide a commercial habitation module for the ISS.
It’s great that NASA and the other international partners are planning ahead to keep an operational space station in orbit for the long term. But ultimately, whether in response to an emergency or at the end of its useful service life, NASA acknowledged in the report that there needs to be a plan decommission and deorbit the ISS. This will be technically complex, as well as costly, requiring international participation and a critical decision on timing.