Washington

One small step: NASA's push to revisit the Moon's surface starts with a lunar reconnaissance orbiter. Credit: JPL

A key Senate committee, frustrated with what it claims are inflated cost estimates at NASA, is calling for the next lunar science mission to be handed to the private sector. But space-agency officials say that letting an outside group run the Lunar Reconnaissance Orbiter mission would be risky and may jeopardize a planned 2008 launch date.

The lunar orbiter is meant to be a first step towards a manned mission to the Moon by 2020, which should in turn pave the way for future trips to Mars. NASA wants the orbiter to create a high-resolution photographic map of the lunar surface, locate mineral deposits and possible water ice from orbit and characterize the threat from radiation to future astronauts.

Even though the Moon is not a new destination, the mission will be challenging, says James Garvin, who heads NASA's lunar science programme. The craft will have to enter into low orbits, carry sophisticated instruments and handle high rates of data flow.

Garvin reckons that the orbiter will cost about as much as a Discovery mission, some $400 million. NASA estimates that its entire lunar programme, including the orbiter and early work on subsequent lunar landers, will cost some $1.3 billion between 2005 and 2009. The agency wants the orbiter to be built and operated by its Goddard Space Flight Center in Greenbelt, Maryland, with many of the components contracted out.

Senator Sam Brownback (Republican, Kansas), who chairs the authorizing committee that sets policy guidelines for NASA, calls those price tags “way too high”. He says it should be possible to do the first lunar mission by 2007 for less than $200 million. The 1994 Clementine lunar mission run by the Pentagon, for example, cost about $80 million, although much of the technology it used had already been developed.

Brownback has introduced a bill — written in part by adviser Simon ‘Pete’ Worden, a former US Air Force space official who worked on Clementine — calling for NASA to come up with a new plan for the lunar mission that includes “the use of the private sector to accomplish the goals of the mission”.

This could include private companies or non-NASA research groups, such as the Johns Hopkins University Applied Physics Laboratory in Maryland, which has built NASA spacecraft in the past. Splitting the lunar mission into several cheaper spacecraft could be one way of bringing costs down.

Echoing a recent presidential-commission report (see Nature 429, 793; 200410.1038/429793a ), Brownback says “we're not going to get to the Moon and Mars” unless NASA changes its way of conducting space missions. Leaving it to outside engineers and scientists to work out how to accomplish NASA's broad goals should help to kickstart a more diversified space industry, he adds.

But Garvin says that given the tough requirements and tight schedule, the safest course is for Goddard to build this first lunar spacecraft itself. Three years is generally considered barely enough time to mount a space mission, he says.

The debate should be settled over the next few months as the House of Representatives writes its own authorizing bill and the appropriations committees that set NASA's 2005 budget weigh in.