Updated 6:45 p.m. Eastern.

WASHINGTON — NASA Administrator Jim Bridenstine told Senate appropriators May 1 that while the administration is not yet ready to release a revised budget that accommodates an accelerated human lunar landing program, the costs will not be as high as some rumors.

During a hearing of the commerce, justice and science subcommittee of the Senate Appropriations Committee, members sought details about how much it will cost to achieve the goal announced by Vice President Mike Pence March 26 of landing humans on the south pole of the moon in the next five years.

“Someone in the administration is going to be requesting additional dollars,” said Sen. Jerry Moran (R-Kan.), chairman of the subcommittee. “Do we know what the amount of those additional dollars will be?”

Bridenstine declined to offer a dollar figure, saying that the agency submitted a “pretty good” proposal to the Office of Management and Budget, which is performing its own review along with the staff of the National Space Council. The goal, he said, is to “come up with a unified administration position” on how much additional funding NASA will request.

He downplayed reports, though, that claimed NASA would seek an additional $8 billion a year for five years. “I will tell you that is not accurate,” he said. “It is nowhere close to that amount. But I don’t want to throw out a number until we have gone through the process with OMB and the National Space Council.”

Speculation has focused on a smaller, but still significant, increase of about $3 billion to $5 billion a year. That revised budget proposal is expected to be delivered to Congress in the near future, but Bridenstine didn’t give a specific date he thought it would be ready.

Bridenstine emphasized in his testimony that NASA could land humans on the moon in 2024 with existing technology. “We are very capable of achieving that end state,” he said of the lunar landing goal. “Technologically, everything we need to accomplish that is there.”

Moving up the landing from 2028, the deadline NASA had set prior to Pence’s speech, to 2024 primarily involves accelerating programs and their funding, in particular lunar landers, which he said will receive most of the additional funding. “The only thing we need to do is take those elements that were going to be funded in those other years and move them forward,” he said. “Think of this, in essence, as a surge of funding for the purpose of getting to the moon in the next five years.”

He argued that a sprint to the moon is more likely to be successful that a longer program. “The longer the program goes, the more difficult it becomes to achieve the end states because of the political risks,” he said, citing examples like the Space Exploration Initiative and the Vision for Space Exploration. “The faster we go, the more likely it is that we can realize the end state.”

Bridenstine, though, faced skepticism about that 2024 deadline from one committee member. “Our policy decisions here need to be driven by the science and not by political calendars,” said Sen. Chris Van Hollen (D-Md.)

Commercial crew investigation

During the brief hearing, truncated because of votes on the Senate floor, Bridenstine also faced questions from the chairman of the full committee, Sen. Richard Shelby (R-Ala.), about the April 20 mishap involving a SpaceX Crew Dragon vehicle that was performing a static-fire test of its SuperDraco abort thrusters at Cape Canaveral.

“The most recent SpaceX anomaly caused the complete loss of the crew capsule,” Shelby said, among the first public statements about the extent of the damage the capsule suffered in that test. Neither SpaceX nor NASA have released many details about the incident since it took place.

Shelby questioned the propriety of SpaceX leading the investigation without a parallel, independent NASA investigation. “It seems more than appropriate for NASA, of all agencies, to conduct its own independent investigation to ensure, of course, crew safety,” Shelby said.

Bridenstine defended the current approach, which he said involved NASA “side by side” with SpaceX. “Can you be independent and reach independent conclusions if you’re doing something jointly with somebody?” asked Shelby.

“The engineers that we have at NASA are extremely sensitive to what we are trying to achieve,” Bridenstine said. “I have every confidence they will, as SpaceX conducts the investigation with our engineers, that we will get very accurate information.”

“That’s not the norm, I don’t believe,” Shelby insisted of the structure of the investigation. “We’ll check that out.”