http://www.space.com/businesstechnology/070912_techwed_kaguyamoon.html This is three tons and carries every kind of instrument to suit a Lunar geologist's fondest dreams. Highlights:
The 6,000-pound (2,271-kilogram) Kaguya spacecraft is a nearly seven-foot (2.1-meter) wide box that stands almost 16 feet (4.8 meters) tall. The probe's X-ray and Gamma-ray spectrometers will track the distribution of elements on the lunar surface such as hydrogen, which researchers hope will help aid in the search for water ice on the moon, Sobue said.
Other instrument suites will study mineral distribution on the moon's surface; use cameras, radar and lasers to catalogue lunar terrain and subsurface structure; and probe the moon's ionosphere and magnetic field. A high-definition camera is also launching aboard Kaguya, but is destined for a more aesthetic purpose.
and
Atop the orbiter sit the relay (RSAT) and VRAD microsatellites, two solar-powered probes about three feet (one meter) in diameter. Kaguya will jettison the 110-pound (50-kilogram) probes as it enters lunar orbit. The two satellites are designed to then work together with their mothership to generate a complete global map of the moon's gravitational field. VRAD will also probe the moon's thin ionosphere, JAXA officials said.
With this beauty, the Japanese vault into the lead of current unmanned Lunar exploration, and are positioning themselves to locate Lunar resources. Sure, they'll share data, but does anyone doubt that they'll keep a few really juicy discoveries to themselves?
Now, all the Japs need is a manned Lunar program, and we'll have real competition in the 2020's. :)