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Lawmakers last week questioned the Trump administration’s proposal to end direct U.S. government support of the International Space Station in 2025, citing concerns about the economic viability of commercial outposts in low Earth orbit.

In a pair of hearings before Senate and House panels, NASA’s manager in charge of human spaceflight activities, the agency’s inspector general, and independent experts testified on the future of the International Space Station, and the White House’s plans to discontinue government funding of the orbiting research laboratory.

It has been NASA’s goal since the Obama administration to eventually turn over human spaceflight operations in low Earth orbit, a region a few hundred miles in altitude, to commercial companies, freeing up federal funding to pay for expeditions deeper into space.

The Trump administration in February proposed ending direct U.S. government support of the space station in 2025, prompting debate and discussion over whether commercial industry can make a business of building and operating orbiting research facilities staffed by astronauts.

There are numerous unanswered questions facing lawmakers, NASA officials and entrepreneurs studying the issue.

What is the commercial demand for an orbiting laboratory? Can a commercial operator maintain a space station in low Earth orbit without substantial financial support from the government?

What are NASA’s needs for research in low Earth orbit, as the space agency turns its sights toward the moon and Mars? Will China’s planned space station eat into the market for a commercial research complex in orbit? What do the International Space Station’s other partners think about the plan to privatize human space operations in low Earth orbit?

And there are other questions under consideration, such as how much it will cost to transport humans and cargo between Earth and an orbiting space station in the late 2020s.

Paul Martin, NASA’s inspector general, told the Senate’s Subcommittee on Space, Science, and Competitiveness on Wednesday that it is unlikely a commercial operator could wholly take over the space station’s annual budget by 2025.

“Based on our work, we question whether a sufficient business case exists under which private companies can create a self-sustaining and profit-making business using the ISS, independent of significant government funding, Martin said. “From our perspective, it is unlikely that a private entity or entities would assume the station’s annual operating costs, currently projected at $1.2 billion in 2024.

“Such a business case requires robust demand for commercial market activities,” Martin added. “Candidly, the scant commercial interest shown in the station over its nearly 20 years of operation give us pause about the agency’s current plans.”

Two senators expressed their opposition to the station’s privatization during Wednesday’s hearing.

Sen. Ted Cruz, R-Texas, called the Trump administration’s proposal to end federal funding for the space station in 2025 “deeply troubling.”

“Nowhere in federal statute is there a request from Congress seeking a hard deadline to end federal support for ISS, to cross our fingers and hope for the best,” said Cruz, chairman of the Senate subcommittee that oversees NASA. “We’ve seen that act play out too many times in our national space program, and it’s time we learn the lessons of history. Prematurely canceling a program for political reasons costs jobs and wastes billions of dollars.”

The subcommittee’s ranking member, Sen. Bill Nelson, D-Florida, agreed with Cruz.

“Abandoning this incredible orbiting laboratory where they are doing research, when we are on the cusp of a new era of space exploration, would be irresponsible at best, and probably disastrous,” Nelson said.

Nelson said the White House’s proposal to end federal funding of the space station in 2025 was a “random date.”

“So it was a political decision, and as far as this committee is concerned — and I can tell you as far as this senator is concerned — that proposal is dead on arrival,” Nelson said.

“It’s not fair to NASA or to industry to force a transition based on an arbitrary date,” Nelson said. “That decision should be based on factors like NASA’s research requirements and the readiness of industry to take the lead. We need to listen to our scientists and the experts at NASA.”

“We didn’t see the necessity of picking a specific date within the agency, but as part of the administration, we came to the conclusion that picking a date would prompt a serious discussion,” said Bill Gerstenmaier, NASA’s associate administrator for human exploration and operations.

Cruz and Nelson said they agreed on the importance of maintaining support for the space station.

“As long as I am chairman of this subcommittee, the ISS will continue to have strong support — strong bipartisan support — in the United States Congress,” Cruz said.

NASA and its partners have spent more than $100 billion designing, building and operating the space station over three decades. The research facility costs between $3 billion and $4 billion per year to operate, a budget that includes costs for cargo and crew transportation.

Following the privatization model used in cargo and crew transportation after the space shuttle’s retirement, NASA wants to commercialize human spaceflight operations in low Earth orbit in hopes of easing costs and freeing up government funding for deep space missions.

NASA plans to construct a mini-space station in orbit around the moon in the 2020s for use as a research platform to gain experience with long-duration crew stays farther away from Earth. The Lunar Orbital Platform-Gateway could also be a staging point for landers carrying experiments and astronauts to and from the moon’s surface.

Gerstenmaier said NASA does not intend to give up on human spaceflight in low Earth orbit, but that the agency aims to be one of multiple customers for a potential commercial space station — either a privatized ISS or a new privately-developed platform.

He identified the development of new pharmaceutical drugs and in-space manufacturing as two potential commercial applications for an orbiting space station.

“To be clear, NASA is not abandoning low Earth orbit,” Gerstenmaier said. “We must ensure the right pieces are in place to maintain an operational human presence in low Earth orbit, whether through a modified ISS program, commercial platforms, or some combination of both.”

A recent audit concluded that NASA will not be able to complete research aboard the International Space Station into the human health risks of long-duration spaceflight, or finish developing new technologies to enable lengthy crewed missions to the moon and Mars, by the end of 2024, according to Martin, the agency’s inspector general.

NASA released a solicitation Thursday asking U.S. companies and research institutions for studies examining the market for a commercial space station in low Earth orbit, detailed business plans, and concepts for orbiting human research outposts. Organizations selected by NASA later this summer will receive up to $1 million each for their studies.

NASA is also asking companies for concepts that may include the attachment of commercial habitats or labs to the forward end of the International Space Station’s Harmony module.

But Martin said the agency must find a way to reduce its expenditures on low Earth orbit human spaceflight programs if it hopes to pay for crewed missions to the moon’s vicinity, and eventually the lunar surface.

“Any assumption that ending direct federal funding (of the International Space Station) frees up $3 to $4 billion beginning in 2025 to use on other NASA exploration initiatives is wishful thinking,” Martin said. “That said, unless the agency receives a substantial increase in funding or can dramatically reduce costs, it will be hard-pressed to continue supporting ISS operations under its current model while attempting to fund other initiatives such as the lunar gateway … a moon landing, and a crewed Mars mission.”

Gerstenmaier said he believes a relatively flat budget, adjusted for inflation and economic growth, could simultaneously support a somewhat reduced low Earth orbit human spaceflight program and NASA’s deep space exploration initiatives.

He said the International Space Station, which has modules originally designed for a 15-year lifetime, could be operated safely through at least 2028, the 30-year anniversary of the launch of the facility’s first elements.

“I think we have a good operational life at least through 2028, and possibly a little bit further beyond that,” Gerstenmaier said. “We just need to continue to watch station, continue to maintain it.

“What we don’t want to have happen is where we’re spending more time doing maintenance than we are doing research,” he said. “At that point, then the utility of station starts to diminish. We have not seen that. Station is very viable at least through 2028.”

In a separate hearing Thursday before the House Science Committee, lawmakers heard testimony from Bhavya Lal, who led a study investigating the viability of a commercially-operated space station at the Institute for Defense Analyses’s Science and Technology Policy Institute.

“This transition (to a commercial space station) can occur in two primary ways,” she said. “The ISS could be privatized, as in all or parts of it could be taken over by a private entity and operated on behalf of the government, much like most DOE (Department of Energy) labs are today. Alternatively, a private sector entity could build, launch and operate a commercial low Earth Orbit based platform for profit.”

Lal’s team looked at two different space station configurations, and they assumed that launch prices in 2025 would be reduced by 50 to 75 percent from today’s prices, a prospective price cut she described as an “aggressive assumption.”

“In three of the four scenarios we postulated, revenues did not cover costs,” she said. “Venture capitalists we spoke to indicated that projected revneue streams are too far in the future and too uncertain to warrant making significant investments today. Overall, our analysis showed that it is unlikely the a commercial space station would be economically viable by 2025.”

Lal agreed with Gerstenmaier and Martin that an extension of the space station’s lifetime through 2028 — with operating costs similar to today’s — would take money away from deep space exploration and delay the return of astronauts to the moon.

“It may also take away opportunities from a rapidly burgeoning private sector that feels ready to lead activities in LEO,” Lal said.

“The ISS or modules within it could be privatized with a private sector entity operating the station, but paid for largely by the government,” she said. “Depending on how the deal is structured, this could, in principle, yield cost savings, although this cannot be assumed.

“NASA could select a private entity to operate a commercial platform and grant space or request services as a tenant,” Lal said. “While this option is best suited to help LEO commercialization, it will likely require some level of a government subsidy for the commercial operator. In our analysis, an annualized payment of about $2 billion could cover the cost of the platform, even in a case of zero revenues.”

Gerstenmaier said NASA will take the information from the commercial studies to be conducted later this year to help plan the future of the International Space Station.

“We need to see what comes from industry and see what’s reasonable, and then do the budget analysis.”

Once NASA decides to retire and decommission the space station, the complex will be de-orbited over the Pacific Ocean, and most it will burn up during re-entry.

One company that has long planned to develop a commercial space station is Bigelow Aerospace, founded by Robert Bigelow, a billionaire who made his fortune in real estate.

Bigelow announced in February the formation of a subsidiary named Bigelow Space Operations that will manage sales, operations and customer service for Bigelow Aerospace’s space stations. Bigelow has an experimental expandable module currently attached to the International Space Station, the company says it plans to launch two larger expandable modules in 2021.

In a statement accompanying the announcement, Bigelow said the new sales firm will spend “missions of dollars this year” to probe the market for a commercial space station.

“The time is now to quantify in detail the global, national and corporate commercial space market for orbiting stations,” the Bigelow statement said. “This subject has had ambiguity for many years.”

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