Washington ? An unmanned mission to the only planet in the solar system that has yet to be explored should be one of NASA’s top priorities, a panel of scientists said Thursday.

The recommendation for a mission to Pluto comes at a crucial time, as NASA Administrator Sean O’Keefe begins setting long-term goals for the agency.

There’s just one problem: Money.

NASA has nothing budgeted for such a flight for at least the next year.

The space agency last year asked the committee of researchers, part of the National Academies of Science, to look at where it should be headed with planetary exploration.

The answer that the United States should be pushing for a trip to Pluto and the icy Kuiper Belt that surrounds it adds fuel to a debate that has raged in the scientific community for a couple of years as NASA has waffled about whether to pay it.

The debate does not center on the value of such a research mission, but instead on NASA’s decision against funding it. The scientific panel makes it clear that the agency should move forward immediately.