To the moon?
Japan's LUNAR-A spacecraft looks like it won't get off the ground.


LUNAR-A Gets an F

A Japanese space mission once expected to reveal the secrets of the moon's origin and evolution has crashed even before launch, the victim of a too-ambitious technological hurdle.

Planned by the Institute of Space and Astronautical Science (ISAS) in Sagamihara, near Tokyo, the $150 million LUNAR-A mission called for an orbiting spacecraft to drop two torpedo-shaped probes onto the moon's surface--one on the near side and one on the far side. The probes were to burrow 2 meters below the ground, while seismometers picked up vibrations from moonquakes and sensors measured heat flow across the moon. The data from these "penetrators" was then to be transmitted to the orbiter and relayed to Earth. Scientists hoped to deduce details on the structure and composition of the lunar interior, which would provide clues about how the moon formed.

LUNAR-A was originally scheduled to launch in 1995. The orbiter was ready to go; the penetrators were not. Over the past 10 years, the launch was rescheduled and postponed again and again. (The ISAS Web page still says LUNAR-A will be launched in 2004.) "It was very, very difficult technology," says Hitoshi Mizutani, a planetary scientist who headed the project until retirement 2 years ago. "In the early stages, the penetrators consistently failed when tested," he admits. "But I think another round of testing might have done it," he adds.

Unfortunately, ISAS's parent organization, the Japan Aerospace Exploration Agency (JAXA) thought otherwise. Yesterday, the agency announced it was scrapping the mission on 15 January. A spokesperson for the agency says the decision stemmed from the fact that the orbiter is gathering dust and the penetrators are still not ready for prime time. A committee will study what to do with the orbiter and the penetrator technology.

Mizutani is, of course, "very disappointed." He adds that Japan's planetary scientists still think it is research worth doing. They're hoping to add the penetrators to some other country's moon mission or somehow resurrect a LUNAR-A successor in the future. Meanwhile, a second Japanese moon mission, the $300 million Selenological and Engineering Explorer (SELENE), which will train a bevy of instruments on the moon to collect the most detailed information yet on its topography and the elemental and mineral content of its surface, is scheduled for launch this summer.

For more on LUNAR-A's demise, stay tuned for the 19 January issue of Science.

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