WASHINGTON — The founder of Bigelow Aerospace says his company decided not to pursue a NASA competition for a commercial International Space Station module because of funding concerns, but remains interested in a separate effort for supporting a free-flying facility in low Earth orbit.

In a Jan. 28 interview, Robert Bigelow said his company decided not to bid on a NASA competition for access to an ISS docking port for a commercial module because the funding NASA offered for doing so was too low. NASA announced Jan. 27 it selected Axiom Space to use the port through its Next Space Technologies for Exploration Partnerships (NextSTEP) program.

When NASA issued the request for proposal in June for the docking port, NASA said it projected making $561 million available for both the docking port solicitation and a separate one to support development of a free-flying commercial facility. “That was asking just too much” of the company, Bigelow said. “So we told NASA we had to bow out.”

Bigelow said that NASA later indicated to him the agency might have erred with that funding estimate. “They shouldn’t have made the statements that they did regarding that particular number, let’s put it that way,” he said.

In questions and answers released by NASA for the draft NextSTEP request for proposals for a free flyer, NASA has said the $561 million figure is not a “hard constraint” on the program’s budget. “Offerors should propose what they feel is required to close their business case,” the agency said.

NASA has yet to release a final version of that request for proposals for free flyers, even though the agency said it would do so by December. Bigelow says his company remains interested in that program, depending on funding. In the meantime, it is continuing work on a habitation module concept for NASA’s lunar Gateway through a separate NextSTEP effort.

Bigelow said either a commercial ISS module or a free flyer would need significant NASA support to be viable since the commercial market isn’t big enough yet to support such facilities.

“Commercialization isn’t robust at all,” he said, noting the challenges the ISS has had attracting commercial users. “No single industry is mature enough. There’s not enough there to maintain a large structure and have frequent traffic.”

“The mantra is that NASA will be a customer, but not the only customer, and at some point that will work well,” he said. “It’s just that the pump-priming needs to happen at the inception of that, and there has to be substantial government subsidies for a period of time until industries can stand on their own feet.”

Bigelow added another issue was the perception that NASA’s resources were being increasingly diverted to lunar exploration efforts, like a lunar lander. While supportive in general of a human return to the moon, he said he was worried the program might not be sustainable.

“If the lunar lander is all that there is come 2024 — if it can be executed by that time, and I have my doubts — my concern is that it’s a repeat of what was done a half-century ago,” he said, with just “flags and footprints” missions that don’t establish a long-term presence there.

“I don’t see a base that you can keep occupied, and rotate people in and out of,” he said. “That’s a concern that I have about the lunar program as a whole.” Language in a House authorization bill for NASA, introduced Jan. 24, would deemphasize any work on a permanent outpost in order to keep the agency focused on sending humans to Mars. Bigelow said he was aware of the bill but had not yet had time to review it in detail.

Bigelow has, in the past, talked about the importance of establishing a lunar base, and the company has created models of such a base that make use of versions of its expandable habitat technology. He said he would not rule out working with other companies on a commercial lunar base of some kind.

“If Elon [Musk] or Jeff [Bezos] actually want to pursue lunar bases, I would love to join a partnership in putting something together as a team and try to make something like that happen,” he said, citing the company’s expertise in habitation modules. “I think we could provide a lunar base successfully.”