Kaguya, also known as SELENE, is a Japanese lunar orbiter spacecraft currently in integration. SELENE stands for Selenological and Engineering Explorer, and it is produced by Institute of Space and Astronautical Science for NASDA (now both organizations are part of the Japan Aerospace Exploration Agency). The proposed launch period is sometime between July and August 2007.
There are three separate units comprising the spacecraft. The main orbiter is a rectangular box measuring about 2.1 m by 4.2 m, with a mass of about 1600 kg. A small relay satellite and a VLBI satellite are both octagonal prisms. The relay satellite transmits communications from the orbiter to Earth, and the VLBI satellite will be used to measure the position and precession of the moon precisely.
Kaguya carries 13 science instruments, including imagers, a radar sounder, a laser altimeter, an X-ray fluorescence spectrometer and a gamma-ray spectrometer. The goal is to study the origin, evolution and tectonics of the Moon from orbit.
The total launch mass will be 2000 kg, and it will be launched from the Tanegashima Space Center by an H-2A rocket. Five days later, it will reach the moon and enter an initial 120 by 13,000 km polar orbit. The relay satellite will move to a 100 by 2400 km orbit, and the VLBI satellite will move to a 100 by 800 km orbit. Finally, the orbiter will move to a 100 km circular orbit. The expected life of the mission is one year.