SELENE: The largest lunar mission since the Apollo program

The SELenological and ENgineering Explorer "KAGUYA" (SELENE), Japan’s first large lunar explorer, was launched by the H-IIA rocket on September 14, 2007 (JST). The mission, which is the largest lunar mission since the Apollo program, is being keenly anticipated by many countries.
The major objectives of the mission are to understand the Moon’s origin and evolution, and to observe the moon in various ways in order to utilize it in the future. The lunar missions that have been conducted so far have gathered a large amount of information on the Moon, but the mysteries of its origin and evolution have been left unsolved.
KAGUYA will investigate the entire moon in order to obtain information on its elemental and mineralogical composition, its geography, its surface and sub-surface structure, the remnant of its magnetic field, and its gravity field. The results are expected to lead to a better overall understanding of the Moon’s evolution. At the same time, the observation equipment installed on the orbiting satellite will observe plasma, the electromagnetic field and high-energy particles. The data obtained in this way will be of great scientific importance for exploring the possibility of using the moon for human endeavors.

KAGUYA’s configuration and mission

The KAGUYA consisted of the Main Orbiter and two small satellites ("OKINA" (Relay Satellite) and "OUNA" (VRAD Satellite). The Main Orbiter was injected into a peripolar orbit of the Moon at an altitude of 100 km. The Relay Satellite was placed in an elliptic orbit at an apolune altitude of 2400 km to relay communications between the Main Orbiter and the ground station for measuring the gravity field of the backside of the Moon. The VRAD Satellite, which was in an elliptic orbit at an apolune altitude of 800 km, played a role of measuring the gravity field around the Moon by sending radio waves.
The KAGUYA was maneuvered to be dropped around 80.5 degrees east longitude and 65.5 degrees south latitude onto the Moon on June 11, 2009.

Major Characteristics