WASHINGTON — Proposals to develop commercial space stations in low Earth orbit that could serve as successors to the International Space Station face both an uncertain regulatory environment and questions about their economic viability, according to both those planning such stations and those who might regulate them.

At a panel discussion on commercial space stations held here Sept. 22 by the Secure World Foundation, government and industry officials noted that such facilities fall into a regulatory gray area, with no U.S. government agency having clear oversight of them as required by international treaty.

“I’m not a fan of regulation, but I do think this could create problems when you ask for a launch license or payload review,” said Mike Gold, director of Washington operations and business growth for Bigelow Aerospace, a North Las Vegas, Nevada-based company planning commercial stations.

Gold noted that Article 6 of the Outer Space Treaty of 1967 requires governments to perform “continuing supervision” of space activities of entities under its jurisdiction, like companies. That supervision is carried out for some other space activities, like licensing of commercial remote sensing satellites by the National Oceanic and Atmospheric Administration and of communications satellites by the Federal Communications Commission.

Some in industry have proposed that the Federal Aviation Administration, which licenses commercial launches and reentries, take on that oversight role for other commercial space activities. Gold said he envisioned a relatively simple system where companies registered their spacecraft with the FAA and informed them of any significant changes. “I think that would meet the Outer Space Treaty’s obligations and create the environment of certainty and predictability that industry and investors need,” he said.

The FAA is interested in taking on that responsibility. “We’re going to continue to work within government to put together the right oversight framework,” said Steph Earle of the FAA’s Office of Commercial Space Transportation (AST). That would, he noted, ultimately require congressional action to give the FAA that authority.

Earle added that he believed the FAA would be a better fit for regulating commercial space stations than other agencies, like the FCC and NOAA. “It doesn’t seem that the other agencies are well suited to this, and the FAA thinks that it is,” he said.

Not everyone in industry agrees, however. “I’m not convinced FAA/AST is the right long-term choice to be the orbital space regulating agency,” said Charles Miller, president of NexGen Space. “It’s more than transportation, and I’m not sure in the long term that transportation is the right place for all these functions.”

Miller said he thinks the Commerce Department might be a better fit for on-orbit regulation, since it is charged with broadly supporting commerce, not just transportation, and has some regulatory capability today with NOAA.

Regulatory uncertainty, though, may not be the biggest challenge facing commercial stations. “The barriers to the development of the low Earth orbit economy are economic barriers far more than they are regulatory barriers at the moment,” said Carissa Christensen, managing partner of the Tauri Group,an Alexandria, Virginia-based consultancy.

NASA, in its efforts to stimulate commercial use of the ISS, has played up the potential benefits of performing research in microgravity. However, panelists were skeptical that research could become a viable commercial market for the foreseeable future.

“You won’t find bigger believers in the revolutionary capabilities that microgravity R&D can bring,” Gold said. “However, that market is very immature right now, and it is going to take a long time to grow. I don’t think we’re going to see it in the next 10 years.”

Miller said microgravity research was one of four applications he identified for commercial stations. “To me, it’s kind of speculative,” he said, noting that more research on the ISS is needed to see what could be commercially viable. Markets he thought could be more feasible for commercial stations were serving as “transfer nodes” for spacecraft bound for other orbits, propellant depots, and on-orbit assembly of satellites.

“The immediate market is flying people,” Gold said, both for current ISS partners and other national space agencies. Miller added that tourism could also be a sizable market, particularly if training could be made less onerous than that currently required to fly to the ISS on Soyuz vehicles.

Both Gold and Miller suggested NASA should help support commercial space station development by agreeing to purchase capacity on such stations or supporting their development through a partnership similar to the one NASA used for commercial cargo and crew systems. “NASA needs to play some role as a catalyst,” Gold said.

That support, they said, could help avoid a hiatus in crewed missions when the ISS reaches the end of its life. “The number one issue is that we are at risk of another gap in human spaceflight,” Miller said. “We need a seamless, low-risk transition to private, commercial space stations.”