A report from NASA’s Office of Inspector General (OIG) today expresses skepticism about NASA’s timetable for transitioning to an era of commercial space stations. The Trump Administration wants to end government support of the International Space Station (ISS) in 2025 and rely on the commercial sector instead.

The general conclusions of the OIG report were presented by NASA Inspector General Paul Martin at a May 16 hearing before the Space, Science, and Competitiveness Subcommittee of the Senate Commerce, Science, and Transportation Committee. Today’s report provides the complete analysis and recommendations.

The first ISS module was launched in 1998 and astronauts have permanently occupied ISS on 4-6 month tours of duty since 2000. The ISS is a partnership among NASA and its counterparts in Russia, Japan, Canada and Europe.

NASA spends $3-4 billion a year operating ISS and paying for transportation for crews and cargo. Until 2011, NASA used its space shuttle to get back and forth, but the shuttle was terminated in part because NASA wanted to use the money needed to operate the shuttle, also about $3-4 billion a year, to send astronauts back to the Moon and on to Mars.

The same choice is facing NASA today with ISS. Despite comparatively generous funding from Congress, NASA still is not a position to fund both ISS and human exploration of the Moon and Mars in a timely manner. Either significantly more resources must be made available or priorities will have to be set.

The Trump Administration’s choice is to end government support of ISS in 2025. It concedes that NASA will still need access to facilities in low Earth orbit (LEO) like ISS to conduct research and train crews after that. It hopes that the commercial sector will build private space stations, perhaps using parts of ISS, and NASA will be just one of many customers paying to use them.

Two key Senators are strongly opposed to that plan. Sen. Ted Cruz (R-TX) represents NASA’s Johnson Space Center, home to the astronauts and Mission Control. Sen. Bill Nelson (D-FL) represents NASA’s Kennedy Space Center and the Air Force’s Cape Canaveral Air Force Station where crews and cargo are launched to the ISS. He flew into space himself on the space shuttle in 1986 when he was a Congressman. Today they both serve on the Senate Commerce, Science, and Transportation Committee that authorizes NASA activities.

Their counterparts in the House also question whether the private sector will be ready by 2025.

Cruz, Nelson and Sen. Ed Markey, the top Democrat on the Commerce Committee’s space subcommittee, have introduced the Space Frontier Act that would require ISS to be operated until 2030. The bill will be marked up by the Senate Commerce Committee on Wednesday, August 1.

NASA’s OIG joins in the skepticism about when the private sector will be ready.

Based on our audit work, we question the viability of NASA’s current plans, particularly with regard to the feasibility of fostering increased commercial activity in low Earth orbit on the timetable proposed. Specifically, we question whether a sufficient business case exists under which private companies will be able to develop a self-sustaining and profit-making business independent of significant Federal funding within the next 6 years. — NASA Office of Inspector General

One focus of the research conducted aboard ISS is to ensure that humans can survive exploring deep space. NASA estimates that “6 of 20 human health risks that require the ISS for testing and 4 of 40 technology gaps will not be completed by the end of FY2024 when funding for the Station’s operation is scheduled to end,” the OIG report asserts.

The report also questions NASA’s plan to decommission the ISS at the end of its lifetime, whenever that occurs. The 400 metric ton space facility is composed of many modules and other equipment. It is the largest human-made object in space. Most space objects disintegrate due to heat during reentry through Earth’s atmosphere, but the OIG report says that NASA estimates 16 percent of the ISS could survive.

“NASA estimates a controlled reentry or nominal deorbit will take up to 2 years to execute and cost approximately $950 million.” That is assuming the end of life is planned. In the event of an emergency (“contingency”) deborbit due to impact by space debris, fire, or other catastrophic situation, “NASA does not have the ability to ensure a targeted reentry” over an unpopulated area of the planet such as an ocean.

NASA’s first space station, Skylab, made an uncontrolled reentry in 1979, raining debris over western Australia and the Indian Ocean. No one was injured, but the United States does not want a repeat.

The OIG report made five recommendations.

“To the extent practicable, establish plans for additional one-year missions to the ISS.” That refers to astronauts remaining aboard the space station for one year rather than typical 4-6 month missions. NASA has conducted only one year-long (actually 340 days) mission so far to study the long term effects of the space environment on human health.

“Ensure there is a contingency plan for each human health risk not scheduled to be mitigated prior to 2024.”

“Ensure there is a contingency plan for each exploration-enabling technology demonstration not scheduled to be fully tested by 2024.”

“Complete all end-of-mission critical systems and open work related to nominal and contingency deorbit operations.”

“Develop options for obtaining supplemental emergency deorbit propellant support from U.S.commercial vehicles.”

NASA concurred in all the recommendations. Its response to the report is published as an appendix. Estimated completion dates range from November 30, 2018 to December 31, 2020 depending on the recommendation.