NASA’s Management of the International Space Station and Efforts to Commercialize Low Earth Orbit
WHY WE PERFORMED THIS AUDIT
Astronauts have lived and worked onboard the International Space Station (ISS or Station) orbiting roughly 250 miles above the Earth’s surface for more than 20 years. The ISS costs about $3 billion a year, roughly a third of NASA’s annual human space flight budget, and while current plans call for the Station’s retirement in 2024, an extension to 2030 is likely.
Anticipating its retirement, NASA has committed to replacing the ISS with one or more commercially owned and operated space destinations. In the fiscal year (FY) that ended September 30, 2021, Congress authorized $17 million to that end—a fraction of the $150 million the Agency said it needed. NASA’s plans for long-term, deep space human exploration missions depend on continuous access to a research laboratory in low Earth orbit. In fact, the Artemis mission, 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. As long as humans intend to travel in space, NASA expects research and testing will be needed in the microgravity environment of low Earth orbit.
In this audit, we examined the costs associated with the Station’s continued use and maintenance, risks to its structure, NASA’s utilization of the ISS, and the Agency’s plans for commercialization of low Earth orbit. Most of our work focused on the ISS Program office at NASA Headquarters and Johnson Space Center. We interviewed officials from the Program Office, the Commercial Low Earth Orbit Development Program, the ISS National Laboratory, and private industry space firms. In addition, we reviewed ISS analyses, assessments, hazard reports, risk assessments, and structural health and life extension reports among other documents.
WHAT WE FOUND
While overall ISS operations and maintenance costs remained steady at about $1.1 billion a year from FY 2016 through 2020, systems maintenance and upgrade costs trended upward 35 percent in the same 5-year period, rising to approximately $169 million in FY 2020 due primarily to upgrades. Meanwhile, 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, based on the models NASA used to assess the structure, the cracks should not have occurred, suggesting the possibility of an earlier-than-projected obsolescence for at least one element of the Station. Ultimately, whether in response to an emergency or at the end of its useful service life, NASA and its partners will need to decommission and deorbit the ISS—a technically complex and costly operation requiring international participation and a critical decision on timing.
In reviewing NASA’s planned research onboard the ISS, we found that research needed for long-duration missions to the Moon and Mars will not be complete by 2030. NASA uses the ISS microgravity and harsh space environment to study the human health risks of deep space travel and to demonstrate key technologies for crewed missions to the Moon and Mars. Under the Agency’s current plans, both health risk mitigation and technology demonstrations will not be complete by 2030—the expected retirement date of the ISS. Consequently, a substantial gap between the Station’s retirement and the introduction of a new, commercial destination in low Earth orbit would force NASA to accept a higher level of health risk or delay start dates for long-duration, deep space human exploration missions.
Given the Station’s inevitable retirement and NASA’s continuing need for low Earth orbit research, the success of the Agency’s Plan for Commercial Low Earth Orbit Development is crucial to avoid a gap in low Earth orbit access. NASA’s plan to close that gap is for one or more commercial low Earth orbit destinations to be operational by 2028, which would allow a two-year overlap with the ISS before its anticipated retirement in 2030. The Agency’s Plan for Commercial Low Earth Orbit Development, published in 2019, identifies five steps in the near-term and also outlines mid- and long-term objectives. We found that the Agency’s near-term actions show promise, with NASA’s recent efforts resulting in market interest and growth, especially for private astronaut missions. However, NASA faces significant challenges with fully executing the plan in time to meet its 2028 goal and avoid a gap in availability of a low Earth orbit destination. Challenges of commercialization include limited market demand, inadequate funding, unreliable cost estimates, and still-evolving requirements. The risk of deep space human exploration missions will increase significantly if NASA is not able to conduct the required microgravity health research and technology demonstrations on a habitable space destination in low Earth orbit. Furthermore, without a destination the nascent low Earth orbit commercial space economy would likely collapse, causing cascading impacts to commercial space transportation capabilities, in-space manufacturing, and microgravity research.
WHAT WE RECOMMENDED
In order to mitigate risks to the Station’s structural integrity, we recommended that the Associate Administrator for the Space Operations Mission Directorate ensure the risks associated with cracks and leaks in the Service Module Transfer Tunnel are identified and mitigated prior to agreeing to an ISS life extension.
We provided a draft of this report to NASA management, who partially concurred with our recommendation. In its response, the Agency agreed that it is essential to complete ongoing work to assess the risks with the cracks and leaks along with Roscosmos’ plans to locate and repair leak locations in the Service Module Transfer Tunnel. However, NASA does not agree that this work must be completed prior to agreeing to an ISS life extension. We acknowledge that ongoing work to assess, repair, and monitor the leaks is needed, and in our judgment the Agency’s ongoing and planned efforts are responsive to the intent of our recommendation. The recommendation will be closed upon completion and verification of the proposed corrective actions. That said, we will continue to monitor NASA’s efforts to manage the issues associated with the Service Module Transfer Tunnel and any impacts these issues may have on the integrity of the ISS.
