Edition: U.S. / Global

NASA Urged To Give Pluto A Priority In Exploration

Published: July 12, 2002

A mission to Pluto, which has been on and off NASA's docket for years, should be a top priority in exploring the solar system over the next decade, a federal advisory committee said today.

Exploring Pluto and some of the thousands of similar frozen objects that also lie beyond the orbit of Neptune would open a new chapter in learning about the solar system and its origins, said the advisory panel, the Space Studies Board of the National Research Council.

Pluto is the solar system's most distant planet and the only one never visited by a spacecraft. Last fall, at the urging of Congress and space exploration advocates, NASA chose a team led by the Southwest Research Institute and the Johns Hopkins Applied Physics Laboratory to continue research on building a spacecraft, called New Horizons, to explore Pluto and the Kuiper Belt, a ring of debris beyond Neptune.

The Bush administration did not include money for the mission in NASA's budget for the current fiscal year, however, and the project survived only because Congress provided $30 million to keep it alive. For New Horizons to go forward on schedule, it will need at least $120 million that is not now in NASA's budget for next year. Congressional proponents of the project say they will push to provide the money.

The federal advisory committee, asked by NASA to help set a space exploration agenda for 2003 to 2013, called today for a mix of small, medium and large missions using robotic spacecraft to help explain the nature and history of the solar system.

The 15-member group of science and space experts, supported by the work of six panels that looked at what was needed next to learn about planets, comets, space biology and other elements of the neighborhood around the Sun, not only chose missions of scientific merit but also, for the first time, ranked them.

The committee called for three classes of missions: small-scale projects costing under $325 million each, which, it said, should be launched every 18 months; midsize missions costing up to $650 million, to be sent off every two to three years; and a large, ''flagship'' project once a decade, similar to the current Cassini mission to Saturn, typically costing more than $1 billion.

The top choice for a flagship mission was the Europa Geophysical Explorer, which would orbit Europa, a moon of Jupiter, to see if there is an ocean under its icy shell.

For midsize missions, the Kuiper Belt-Pluto Explorer got top priority, followed by a mission to gather samples from the south pole of the Moon, a project to orbit Jupiter's poles to see if the gaseous planet has a solid core, a mission that would dip down to Venus's hot surface and bring up a surface sample that would be analyzed when the craft returned to the cooler upper altitudes, and a mission that would visit a comet and send a sample back to Earth.

The committee said it gave such a priority to exploring the Kuiper Belt because little was known about that region of frozen objects, which might contain some of the original material from which the solar system was formed and could be a source of water and organic material that eventually ended up on Earth.

Dr. Colleen Hartman of NASA said that even if money could be found for the mission, it would be hard to have the launching by 2006, the latest the craft could take off in order to get a gravity boost from Jupiter to speed it to Pluto. Since the spacecraft would have to be powered by an atomic battery to work so far from the Sun, it would need expedited environmental studies and special presidential approval, Dr. Hartman said.