WASHINGTON — A month after NASA rolled out a strategy to increase commercial use of the International Space Station, some in Congress are skeptical of the effort.

At a July 10 hearing of the House Science Committee’s space subcommittee, some members suggested that allowing commercial activities on the station, including visits by private astronauts, wasn’t an appropriate use for the facility as NASA prepares to return humans to the moon and go on to Mars.

“We need to ensure that those resources are focused on those tasks that can only be done by the ISS and that are a high priority,” said Rep. Eddie Bernice Johnson (D-Texas), chair of the full committee, in opening remarks at the hearing. “We will be taking a close look at NASA’s proposed commercialization initiative to see whether it meets that standard. At this point, I’m not convinced that it does.”

She cited as one example hosting private astronauts, like space tourists, on the station. “I’m skeptical that sending wealthy space tourists to ISS is the best or even a good use of a taxpayer-funded facility,” she said, contrasting it with NASA’s desire to perform research to reduce human health risks of long-duration spaceflight. “Our focus should be on sending additional crewmembers or researchers to the station, not well-heeled individuals seeking an exotic vacation.”

Bill Gerstenmaier, in his final public appearance as NASA’s associate administrator for human exploration and operations before being reassigned to a special advisor position later the same day, noted that the new commercialization strategy allocates only five percent of ISS resources to commercial activities.

“We are very focused on reducing the risk associated with Mars, both technically and also from a human physiology standpoint,” he said. “We’re spending a lot of research time on both of those activities.”

He described allocating that small fraction of ISS resources to commercial activities as a step towards fully commercial space stations in low Earth orbit, of which NASA would be a customer. “At some point, this station will wear out,” he said of the ISS. “We would like to be able to use a private facility.”

Another issue raised at the hearing is how much funding, if any, NASA will save by encouraging commercial activities on the station. NASA’s plans “call into question whether this plan will save NASA money that it can apply to the moon program, or if it will end up costing us more,” said Rep. Kendra Horn (D-Okla.), chair of the space subcommittee.

The prices NASA is charging for commercial use of the station is “substantially subsidized,” noted Paul Martin, NASA’s inspector general. He wondered whether commercial activity can be sustained on the station without such subsidies.

“We continue to 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 in the short or mid-term,” he said.

Companies take a different view of the prospects of low Earth orbit commercialization. “I don’t see a trend of companies coming up to the Hill to ask for more and more money for the station,” said Eric Stallmer, president of the Commercial Spaceflight Federation. “I think what we’re looking for is stable policies.” Such stability, he argued, applied to NASA’s pricing policies for ISS commercial use: he said any changes to those prices should be infrequent and made with advance notice to limit disruption to business plans.

There was support for extending NASA’s authorization to operate the ISS, which currently runs through 2024, to at least 2028. “It’s hard to do a business plan for something that may not exist” in a few years, said Stallmer. “If we can do 2028 or beyond, it makes for a better case for investment.”

Any extension, though, comes with funding tradeoffs. “We are spending money in low Earth orbit that we could be spending in deep space,” said Gerstenmaier. “We need to make sure we have that right balance.”

“It seems like the white elephant in the room is whether this plan will actually work with commercialization and whether it will work in the timeline,” said Rep. Michael Waltz (R-Fla.) late in the hearing. He noted that Martin appeared to be particularly skeptical of the plan.

“Skepticism is in an inspector general’s job description,” Martin responded.