WASHINGTON
— For the second time this year NASA is asking scientists to ponder how they could advance humanity’s understanding of the heavens and the Earth by flying experiments aboard one of the reusable suborbital spaceships now in development by Virgin Galactic and others.

NASA put out its first call for ideas earlier this year, but did not get much of a response. This time around the
U.S.
space agency has sweetened the deal by offering to pay a total of $400,000 for as many as eight one-year studies. The call for proposals was made July 10 as an amendment to NASA’s annual Research Opportunities in Space and Earth Sciences omnibus solicitation. Notices of intent to propose are due Aug. 6. Proposals are due Oct. 8.

Ed Weiler, NASA associate administrator for science, said he knows the NASA-funded science community well enough to understand that a lackluster response to an unfunded request for information does not necessarily mean an opportunity lacks merit.

“I’m trying to keep an open mind,” Weiler said in a recent interview. “If I ask them for ideas and there is no money involved, I will get a certain level of response. If I put money on the table, I will get a different level of response. I’m trying to give it a chance.”

If Weiler sounds skeptical about the research potential of sending scientists and their payloads to the edge of space for the view and the few minutes of weightlessness such trips afford, it probably is because he is. “I still have a hard time understanding why the scientists have to go along,” Weiler said. “If there’s an opportunity to put something on the outside of the [vehicle] then it gets more interesting.”

The seeds for a human-tended suborbital science program were sown by Weiler’s predecessor, Alan Stern, who sought during his short tenure to revitalize a NASA suborbital science program that had been allowed to whither due to the rising cost of sounding rockets. Stern said offering scientists more opportunities to send payloads up on sounding rockets, high-altitude balloons, and even reusable suborbital spaceships would help train a new cadre of principal investigators by giving them a chance to cut their teeth on million-dollar projects.

Weiler
, an astrophysicist who rose through the ranks to hold top management jobs at NASA, is no stranger to suborbital science. In his first interview after being recalled to NASA headquarters in late March to replace Stern, Weiler praised Stern as “absolutely on target” in the actions he took to reinvigorate the suborbital flight program. But Weiler pled ignorance when asked in that same interview whether the initiative to fly researchers and their payloads aboard piloted suborbital craft would continue under him. “I know nothing about this,” he said at the time.

Now that Weiler has had a chance to get up to speed on the proposed program, he said the burden is on scientists to show why flying their payloads on the likes of Virgin Galactic’sSpaceShipTwo or one of the other vehicles in development promises the best science bang for the buck.

“We’re talking about science money,” Weiler said. “The only way I can justify committing research money is by having the community show through peer review that this is a credible opportunity.”

Kelly Snook, the NASA discipline scientist for the human-tended suborbital science program, acknowledged that Weiler does not share Stern’s enthusiasm about the research potential of suborbital vehicles currently being marketed to wealthy would-be space tourists. “He doesn’t have the passion for it that Alan did,” Snook said, adding that Stern’s “idea was to immediately institute a flight program” backed by “a good size budget.” Stern confirmed Snook’s characterization of his intentions, but otherwise declined comment.

As it stands now, NASA intends to fund up to two concept studies for each one of the Science Mission Directorate’s four divisions: astrophysics, heliophysics, planetary science and Earth science. Classic microgravity research of the sort performed aboard the international space station is not part of the call for concept studies.

The yearlong studies would get under way in December or January, according to Snook, who said she understands her new boss’ skepticism about the potential of human-tended suborbital science.

“I think there is a healthy skepticism about this platform and its usefulness to the four Science Mission Directorate divisions,” she said. “But I don’t think it’s outside the realm of possibility that something new and innovative could come out of it. That’s why we are putting some money into it.”

Would-be suborbital operators and their advocates praised NASA for moving forward on the human-tended program, even if the agency’s Science Mission Directorate is not moving out as quickly on a new flight program under Weiler as it might have under Stern.

“[Weiler] is clearly putting his money where his mouth is. He is clearly saying let’s go find out what this can do for science,” said James Muncy, an Alexandria, Va.-based aerospace consultant who specializes in commercial space.

NASA, meanwhile, has been hearing from lawmakers from
California
,
Florida
and
New Mexico
urging the agency to start a suborbital flight program sooner rather than later, according to NASA and industry sources who declined to identify the interested lawmakers by name.

New Mexico
is the base of operations for Virgin Galactic, while
California
is home to several suborbital concerns, including XCOR Aerospace and Scaled Composites, both in Mojave. Some Florida officials, meanwhile, would like to entice suborbital operators to conduct science flights from Kennedy Space Center, reasoning that the additional activity will help blunt the economic impact of the space shuttle’s looming retirement.

Snook acknowledged that NASA has heard from lawmakers concerned that spending a year studying the merits of human-tended suborbital science will only delay the formal establishment of a funded flight program. “There is some concern in Congress that this would delay a flight program, but the way the Science Mission Directorate looks at it is we want to make sure there’s compelling science to be done before we initiate a program.”

If suborbital operators are working Congress behind the scenes to pressure NASA to move forward with a bona fide human-tended suborbital science flight program, publicly they are expressing only gratitude for NASA’s willingness to spend $400,000 to find out more about what piloted suborbital flights can do for science.

George Whitesides, a senior advisor to Virgin Galactic, praised the concept studies as a “step in the right direction.”

“What is exciting about NASA’s suborbital efforts is that they will enable new research programs to be done, and done at a lower cost, while getting students and researchers fired up about space and science in a transformative way,” Whitesides said. “The next generation vehicles are designed to operate at flight rates that will enable studies of high frequency – potentially multiple times per day, over long periods. And of course having a human in the loop can be very useful for many experiments.”

XCOR Aerospace President Jeff Greason also emphasized the cost advantage of doing suborbital science aboard reusable vehicles such as the two-seater Lynx spacecraft it hopes to have ready to fly in 2010.

“This announcement may seem like a small step in NASA’s overall research program but it is a giant leap for science,” Greason said in a July 21 statement. “This new approach should cut the cost of conducting research in space and the result will be more science for last money.”