Maybe you think NASA should send a probe to Pluto, pronto. Or perhaps you think the space agency should invest more in asteroid research to save our planet. Whatever your pet space project, you've got until the end of the month to speak your mind.

That's the deadline to provide input to the Solar System Exploration Survey, being conducted by the National Academy of Science's National Research Council at NASA's request.

The SSE Survey, as it is called, will give NASA a roadmap for spending on everything from Mercury to Pluto -- and all the planets and rocks between and beyond -- through 2013.

"This is one of the most direct chances the public has to provide input to NASA", said Bruce Betts of the Planetary Society, a group whose members advocate exploration of the solar system. "I'd say it's very rare."

Betts, a working astronomer and former employee at NASA headquarters, said in an interview that many things influence NASA decisions on what missions will fly. Considerations include cost, of course, as well as the expected scientific return.

But the Federally funded agency has long known that public opinion is important, too. The NRC will ultimately decide what to do with the input collected in the public survey, but Betts is optimistic that it will hold some sway with NASA officials.

"I think it will have impact," he said, "but one has to realize it is one piece of the process."

The online survey asks participants to rate the importance, on a scale of 1-10, of eight objectives, including:

• Looking for life on other planets
• Determining the suitability of other planets for human colonization
• Searching for any potential danger to Earth from space

Another question asks which of 15 destinations, from planets to asteroids and comets, is the most important to pursue. In addition, educators are asked to provide input on how NASA can help in the classroom.

Your views, along with those from the scientific community, will be funneled to a steering committee at the NRC, which will deliver the final SSE Survey report to NASA this summer.

Inside the planetary science community, the SSE is seen as a way to make a direct challenge to criticisms from the White House Office of Management and Budget, which has called the researchers fractious in its dealings with Washington.

Mark V. Sykes, past chairman of the American Astronomical Society's Division for Planetary Sciences, heads up the effort to gather input from researchers whose interests range widely, from the atmosphere of specific planets to the overall characteristics of, say, the asteroid belt.

In all, Sykes and his colleagues have received 23 so-called white papers representing more than 370 scientists. Many more researchers are aware of the individual papers and thus know that their views are represented, Sykes said.

He could not discuss what is in the papers, beyond the fact that they include topical discussions regarding the value of radio astronomy or the study of planetary atmospheres, as well as pleas for specific missions to Venus, Mars and elsewhere.

Sykes said no effort was made to squelch or homogenize views. "Everybody is saying what they think," he said. Scientists have had ample opportunity to make their cases, he added, a fact he expects will give the document wide support in the science community.

Regardless of how much sway the SSE holds in Washington, Sykes expects the document to be a valuable planning resource for future grant and mission proposals. "It's an incredibly useful exercise," he said.

Now, however, the NRC steering committee -- also staffed by scientists, who Sykes said have been very cooperative and helpful -- must prioritize all the input.

To that end, two simple questions were crafted: What are the three most significant discoveries of the past decade? What are the three most important investigations for the coming decade? A separate online survey seeks input from scientists on these questions, and the NRC will collate the results.

We asked Sykes whether the planetary science community, as a whole, is confident that NASA will in fact pay attention to the report.

"NASA has a track record for paying attention," Sykes said. He referred to roughly 40 years of similar reports prepared by the astrophysics community, folks who study objects and phenomena generally beyond the solar system. Among the missions that resulted from those decadal surveys was the Hubble Space Telescope.

Sykes also points out the Weiler, the NASA official who requested the survey from the NRC, is an astrophysicist and knows the value of such long-range planning rooted in input from the scientists in the trenches.

Assuming NASA buys into the survey's recommendations, the remaining question is to what extent Congress and the White House will grant the wishes that emerge from the report.