However, there's lots of distance to cover within the solar system and limited dollars to spend. Trying to satisfy everyone's wish list is an effort likely to fall short. Ask any one of the 1,100 scientists gathered here this week for the 33rd Lunar and Planetary Science Conference, sponsored by NASA and the Lunar and Planetary Institute.

On request

Michael Belton, an astronomer at the National Optical Astronomy Observatories in Tucson, Arizona is chair of the survey, a year's worth of work kick-started by a request from NASA Headquarters to the prestigious National Research Council (NRC).

The effort is patterned after astronomy and astrophysics surveys done over numbers of years to help guide and prioritize research in those areas.

"The survey is complete," Belton told conference goers that sat in what was billed as the last public meeting of the survey team. "I can't tell you what the results of the survey are yetI have to communicate those to NASA first. And before I do that, it has to undergo extensive reviews within the NRC," he said.

Now in the last stages of being written, the final report should hit desks at NASA by late March or early April, Belton said.

In large part, the survey is based on eight town hall meetings of space scientists held across the country. Six survey panels have been busy at work: Inner planets, giant planets, primitive bodies, and large satellites. Two other NRC groups provided inputs to the survey on Mars exploration and astrobiology research.

Mars: the welfare planet

One hoped for result of the decadal plan is to broaden what some scientists characterize as too narrowly focused NASA attention on one location: Mars.

"It has turned into the welfare planet. NASA keeps saying 'follow the water". What's really happening is 'follow the money', with Mars just sucking up time, talent and funds at the expense of other important places to study," said one space scientist.

Those working on the decadal plan were charged with providing the following:

-- A "big picture" of solar system exploration, what it is, how it fits into other scientific endeavors, and why it is a compelling goal today;

-- A broad survey of the current state of knowledge of the solar system today;
 
-- An inventory of the top-level scientific questions that should provide a focus for solar system exploration today; and lastly,

-- A prioritized list of the most promising avenues for flight investigations and supporting ground-based activities.

Land of apples and oranges

There was a catalyst for conducting the survey in the first place.

It was perceived by power brokers in Washington, D.C. that the planetary space science community was far too fragmented "and not terribly coherent," Belton explained.

"Once you get the final results, some of you will be very happy with the resultsand some of you may not be quite so happy, for various reasons," Belton said. "We think it very important that we prepare ourselves as a community for the results of the survey. There are many difficult choices being made by my group," he said.

"We have a wonderful opportunity here to build a program through the survey," Belton added. He asked the audience of scientists to move forward by working together on the priorities identified in the report and "make these things happen".

Belton said that the survey has had to deal with apples and oranges figures of scientific merit.

"To compare things in the outer solar system to things in the inner solar systemsometimes in terms of scientific meritdoes not make sense. So we're wrestling with all of those things. We have to tread very carefully," Belton said.

Slice of time

David Black, president of Universities Space Research Association (USRA), said, in some sense, the decadal study is a historic effort.

"It's a first time having this wide assemblage of people involved in solar system research to truly have an opportunity to try and work togetherand define a set of priorities," Black said. "You can't talk about a planetary community. There is no such thing," he told SPACE.com.

"It almost certainly will not achieve the lofty goals that everybody hopes. It would be a pleasant surprise if it did. But not achieving that, I don't think we should be overly critical. I think it will have value. But I think we shouldn't expect out of this something will magically appear that everybody agrees with wholly," he said.

Black said its worth debating whether studies done in 10-year slices of time are too long a time scale, given the pace of development. "That's particularly true with astrophysics. Is it true with planetary exploration? Maybe not," he said.

Tight schedule

Colleen Hartman, NASA director of solar system exploration, said the decadal plan is key in helping the agency select future missions.

In particular, destinations for NASA's New Frontiers program - which replaced the agency's outer planets program - will be determined according to the new decadal survey, Hartman said. A New Frontiers spacecraft will be flown on the order of every three years, and the program is not solely dedicated to outer planet exploration, she stressed.

A casualty of NASA's new budget is loss of a proposed Europa Orbiter mission and the Pluto Kuiper-Belt spacecraft. While cancelled as a project, the Europa Orbiter avionics package - the smarts of the craft - will be retained and put on the shelf for the New Frontiers program, Hartman said.

As for the Pluto Kuiper-Belt (PKB) mission, $30 million is now being used to keep work going on that effort this year. However, the $122 million that's needed to move PKB to the next development step is not available "without external intervention," Hartman said.

Hartman said the Pluto Kuiper-Belt mission is on a very tight schedule and is a very ambitious mission. Those issues are spurred by the fact that the Atlas 5 or Delta 4 Heavy boosters have yet to make their respective maiden flights.

Which one of those rockets could hurl the PKB into space has yet to be determined. 

"So we continue to work hard to make sure it stays on track without knowing the future," Hartman said.

Change the paradigm

Hartman said NASA's Nuclear Systems Initiative promises to become a critical element in shaping future exploration plans. "It changes the paradigm of science that we might be doing," she said, like enabling a spacecraft to "go all over the planet, when you want and where you want."

NASA is teaming with the nuclear Navy, the Department of Energy, and others, Hartman said, to tap into cross-governmental expertise. "Nuclear power is so astronomically larger than anything else we can do," she said.

To help Hartman gauge the impact on space exploration by using nuclear power and propulsion, she is putting together a science and technology definition team.

"The last thing we want to do," Hartman said, "is spend nearly a billion dollars and end up with something that isn't optimized for solar system exploration."