WASHINGTON — NASA’s proposal to spend $3 billion less than previously promised for science missions and research between now and 2010 is drawing criticism from some U.S. lawmakers and scientists.

Although NASA’s 2007 budget request would increase science spending by 1.5 percent next year and 1 percent annually thereafter, the U.S. space agency had said just last year that it expected science spending to grow by 8-9 percent annually through the end of the decade.

Because NASA science spending would not keep pace with inflation under the new plan, the agency’s Science Mission Directorate is postponing several major missions, canceling several smaller missions, and reducing grant funding for research scientists.

NASA’s funding priorities have come in for the strongest criticism from the Planetary Society. The Pasadena, Calif.-based space-interest group has blasted NASA for “eviscerating” robotic exploration of the solar system and has been exhorting its members to “join the fight for science and exploration” by urging Congress to save a number of imperiled projects including several deferred missions to Mars, a Europa orbiter mission and planet-hunting space telescopes.

Even the normally more reserved Planetary Science Institute has issued a “Call to Action” this year to protest cuts to NASA’s research and analysis budgets. The Tucson, Ariz.-based institute employs over 40 scientists who are funded largely by NASA research grants. Mark Sykes, the institute’s director, said NASA’s plan to reduce grant money by 25 percent over the next two years would severely damage U.S. leadership in space science.

“In the large scheme of things it’s not very much money we’re talking about, but the impact is enormous,” Sykes said of the roughly $100 million NASA plans to cut from its solar system research account over the next two years. “Without these research programs, tax payers would get little more than a press release and a pretty picture for their half a billion dollar investment” in the typical NASA science probe.

NASA Administrator Mike Griffin, facing a House Science Committee largely displeased with the science and aeronautics portion of NASA’s budget request, said the agency could continue to do great science with the $5.3 billion-plus a year it is seeking.

“We’re not slashing science to the bone here,” Griffin said during the Feb. 17 budget hearing. “It’s a pretty strong proposal for science.”

In response to concerns expressed by Rep. Mark Udall (D-Colo.) about cuts to the research and analysis budget, Griffin said the funding levels would be reconsidered in light of the outcry the cuts provoked.

“Working scientists are concerned about the balance of [research and analysis] versus missions,” Griffin said. “The balance within the science portfolio is something we thought we had right, but if we don’t quite have what the community would most like to see, we’re willing to consider changes.”

Griffin said slowing the rate of growth in NASA science spending was necessary in order to clear a “speed bump” standing in the way of a reinvigorated human spaceflight program.

“In order to get from where we have been for the past 30 years to where we need to be, we have a speed bump in the road for the next three or four years,” Griffin said. “We have to get out of what we have been doing and onto this new path while creating as little collateral damage as possible. And that is not to say that there is no collateral damage, because there is some.”

Griffin said the “sum and substance” of the science impacts is that NASA would be delaying the start of several major missions deemed high priorities by the science community. These include the Solar Dynamic Observatory, a sun-studying spacecraft that would see its launch slip three months to August 2008; the Global Precipitation Measurement mission, an Earth-observing satellite that would launch in late 2012 instead of mid-2010; the Space Interferometry Mission, a space-based observatory that would launch in 2015 or 2016 instead of 2012; and the Terrestrial Planet Finder mission, a series of planet-hunting telescopes that has been deferred indefinitely.

Griffin did not mention during the hearing several smaller missions that have been canceled or are up for termination this year. While the dollar amounts involved are not as large, for the scientists and institutions that have been working on the projects, the disappointment is just as great.

Scientists and lawmakers in the United States and abroad are waiting to see what NASA decides about SOFIA, a modified 747 jetliner being outfitted with an infrared telescope supplied by Germany. As expected, NASA requested no money for the Stratospheric Observatory for Infrared Astronomy for 2007 even though the project has not been canceled. NASA is conducting a detailed review this spring to determine whether to terminate the over-budget and behind-schedule program.

Rep. Mike Honda (D-Calif.) whose Silicon Valley district is home to some of the NASA Ames Research Center employees who would operate SOFIA, said he did not understand why NASA would consider canceling a project seemingly so close to completion.

Griffin said it is not clear just how much further SOFIA has to go to make its first flight. “We’re cutting a big hole in the side of an airplane and we have to be able to put a telescope inside it and have laminar flow over that hole and the telescope or we won’t get good science,” Griffin said. “That task has proven to be much harder than people thought. The question before the House is: Are those folks at the end of their technical problems as they would claim or are they still in the middle of them, and [do] we face just an unending stream of more money and more time spent to get the program to where we can do the science?”

Scientist at the California Institute of Technology in Pasadena, meanwhile, learned earlier this month that the budget ax had fallen on the Nuclear Spectroscopic Telescope Array (NuSTAR), a $140-million Small Explorer-class mission competitively selected in late 2003.

NuSTAR’s principal investigator, Fiona Harrison, said she was at the Jet Propulsion Laboratory (JPL) preparing for the mission’s upcoming confirmation review when a colleague told her that Mary Cleave, NASA associate administrator for science, had announced during the agency’s budget briefing earlier that day that NuStar was not going forward. A letter from Cleave the next day made it official.

Former JPL Director Edward Stone, now one of Harrison’s Caltech colleagues, said the abrupt cancellation of a competitively selected mission encountering neither budgetary nor technical setbacks was unusual, to say the least. “To my knowledge, the termination of NuSTAR, a peer-selected [Small Explorer mission] that was within weeks of successfully completing Phase A is unprecedented for the Explorer program,” Stone told Space News. “When there have been budget limitations in the past, new missions have continued with a slow start to Phase B until the future funding wedge was large enough to start Phase C/D.”

Stone said NuStar’s cancellation risks setting a new precedent “detrimental to the strong partnership between NASA and university researchers.”

Paul Hertz, the NASA Science Mission Directorate’s chief scientist, said that while technical issues and cost overruns are reasons for canceling a project still in its early stages, so are shifting science priorities and a change in the overall budget climate.

“I doubt that it’s unprecedented that a mission was canceled sometime during the Phase A formulation phase even when it hadn’t run into problems,” said Hertz, although he said he did not have any ready examples that he was sure of. “The reason we do Phase A is to support a decision whether to continue into the later phase of the project.”

Still, Hertz said NASA takes seriously concerns expressed by Stone.

“The success of the Explorer program certainly rests on the success we have had with the university and laboratory community and any decisions we make that might effect that partnership is of great concern to NASA because it could affect the success of future Explorers and other competed missions,” Hertz said. “Those concerns are very serious and we have to make sure we work with the community to ensure we don’t damage our partnerships.”

Another mission that appears to have reached the end of the road is Hydros. Picked in 2002 as a back-up to two other Earth Systems Science Pathfinder projects selected the same year, the soil-moisture monitoring mission got the ax in December.

Dara Entakhabi, the Massachusetts Institute of Technology-based Hydros principal investigator, said that while NASA treated the project as an alternate during its first year or so, a December 2003 letter approving Hydros to go forward into formulation made no mention of any probationary status.

Entakhabi said there were rumors late last year that Hydros’ funding was in jeopardy, but that nothing official was heard from NASA until Cleave announced at the American Geophysical Union’s annual meeting in December that the mission would not be going forward. “This is a cancellation without review,” he said, “This is a great disappointment to the community.”

According to Hertz, “Hydros was always an alternate. If there was some ambiguity in the [principle investigator’s] mind, then we should have discussed that because the status had not changed.”

Comments: bberger@space.com

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...