WASHINGTON — NASA expects that retiring the International Space Station in favor of leasing capacity on commercial space stations will ultimately save the agency up to $1.8 billion a year.

This estimate comes from an updated report on the ISS transition released by NASA last week. The report was submitted to Congress as an update to a 2018 report, required by a provision of a 2017 NASA authorization bill requesting information about the use of the ISS by the agency and how it will transition to future commercial stations.

NASA currently spends about $3.1 billion a year on the space station program, including more than $1.3 billion for station operations and research conducted there, and nearly $1.8 billion. billion dollars for the transportation of crew and cargo. A chart included in the transition report predicted spending would remain flat through fiscal 2027.

Spending would then temporarily increase in fiscal year 2028 as NASA begins efforts to decommission the station. This decommissioning would include de-orbiting the station in 2031 through the use of three Progress cargo spacecraft, or possibly Cygnus cargo spacecraft, to drop the station over an uninhabited region of the South Pacific Ocean. regularly used to deorbit spacecraft.

Spending on ISS operations and research, as well as transportation to the station, would be phased out from 2028 to 2031 as spending increases on purchases of commercial destination services in low Earth orbit, in using commercial stations whose development is currently supported by NASA. LEO Destination Program (CLD). The report estimates that NASA will spend about $1 billion a year on CLD services by 2033.

A few hundred million dollars of costs currently borne by the ISS program will be transferred to other parts of the agency, the report said. These are mainly mission control and related operations as well as the work of civil servants.

The rest will be savings: $1.3 billion in 2031, rising to $1.8 billion in 2033. “This amount can be applied to NASA’s deep space exploration initiatives, allowing the Agency to explore farther and faster in deep space. This amount may also be applied to other NASA programs,” the report states.

Phil McAlister, director of commercial spaceflight at NASA Headquarters, offered a similar estimate at a meeting of the NASA Advisory Council’s Human Exploration and Operations Committee on January 19. “We anticipate, once we retire, we’re going to save the agency about $1.5 billion” a year, he said. ‘to come up.”

Committee members raised questions about this estimate, noting the high costs of space transportation. “It will mainly depend on the prices, and we don’t know what the prices are yet. I don’t think even the suppliers really know that, ”acknowledged McAlister. Part of the work that the three teams, led by Blue Origin, Nanoracks and Northrop Grumman, selected by NASA in December for CLD awards will be to improve the fidelity of their estimated awards.

He added that NASA’s Office of the Chief Financial Officer had made an independent estimate of the cost savings resulting from the transition to commercial space stations and had come up with a similar figure.

Part of the estimated cost savings comes from the expectation that NASA will be one of many commercial space station customers. “If we’re just one of many customers, suppliers will be able to amortize their fixed costs on a broader basis,” he said. “We’ll see cost savings just from that.”

McAlister added, however, that even if NASA is the biggest or only customer of a commercial station, the agency should still realize cost savings compared to the ISS. “At first they will be much smaller than the ISS,” he said of commercial stations, and therefore cheaper to operate. Additionally, NASA’s requirements for these stations – housing at least two astronauts and performing 200 surveys per year – will be less demanding than the ISS, and with less demand for crew and cargo transport.

“For these reasons, you are going to see a significant decrease” in costs, he concluded.