BioEd Online

Japan's space agency JAXA has recommended scrapping its planned impact mission to the Moon, after more than a decade of delay.

The unmanned Lunar-A mission, originally scheduled for launch in 1995 and then pushed to 2004 and beyond, was planned to be Japan's first foray to the Moon's surface. The craft consists of an orbiter and two surface-penetrating probes, which would smash into the ground to take seismic and heat-flow measurements on the near and far sides of the Moon. But development of the probes is far behind schedule, and the orbiter has fallen so much into disrepair that it would be uneconomical to fix up, said a JAXA spokesperson on 15 January.

The proposed cancellation doesn't come as a big surprise. Lunar-A had been classified as "postponed" since a 2004 JAXA review, which called for further technology testing until the end of 2007. Tests of how the probes would stand up to the impact of slamming into the Moon showed that both the casing and the instruments themselves would be damaged, says Peter Bond, communications officer for the Royal Astronomical Society, UK. "They had to go back to square one and redesign them. The whole mission has had the guillotine hanging over it for quite a while now."

A final decision on the fate of the mission is expected later this month. One possibility is that the probes could be finished, but for use on another project.

Many more missions

The fate of Lunar-A won't necessarily affect Japan's lunar ambitions. The project has been leapfrogged by at least one other: an orbiter known as SELENE is due for launch this summer. "SELENE is a much bigger, much more ambitious mission," says Bond. Next in the queue is a robotic explorer, slated for 2010.

Japan has been increasingly ambitious in its plans for space exploration. In spring 2005 they began to consider such far-flung ideas as building a base on the Moon. Researchers reaffirmed these (as yet unfunded) ambitions in 2006, declaring a deadline of 2020 for sending astronauts to the Moon, and 2030 for constructing the base. Such plans would require international collaboration.

The United States has firm plans to return to the Moon, as a stepping-stone to Mars. And China, India, Russia, Europe and even some private companies have also announced missions to visit the rock. It is largely expected that humans should be treading the Moon's surface again, after a long hiatus since 1972, within a dozen years.

Problematic impacts

As for the scientific goals of Lunar-A, other missions may have to fill in the gaps.

The United Kingdom has completed a feasibility study for a proposed mission called MoonLITE that would, like Lunar-A, carry missile-shaped 'penetrators' to the Moon to study its seismology. The mission also aims to demonstrate high-data-rate telecommunications abilities on the Moon. But so far it is only a proposal.

NASA's Lunar Reconnaissance Orbiter, due for launch in 2008, will also carry two 'impactors' - but these will be designed to look for water ice.

"It's funny that there have been several penetrator missions designed and launched but none have been successful so far," says Bond.

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