SELenological and ENgineering Explorer "KAGUYA"(SELENE)

Operation Completed

Project Topics


July 5, 2010 Updated

Global distribution of olivine from the lunar interior and its origin revealed by KAGUYA

Spectral Profiler onboard on Japanese lunar explorer SELENE/Kaguya revealed the global distribution of olivine on the lunar surface and its origin. This new finding provides us important insight into the Moon’s origin and evolution. This result was published in the British scientific journal "Nature Geosciences" on July 4, 2010.

Overview


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SELENE: The largest lunar mission since the Apollo program

SELENE

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

International Designation Code 2007-039A (Main Orbiter)
Launch Date 10:31, September 14, 2007 (JST)
Launch Vehicle H-IIA Launch Vehicle No.13
Location Tanegashima Space Center
Main OrbiterShape Upper module: 2.1m x 2.1m x 2.8m
Lower module: 2.1m x 2.1m x 1.4m
Adaptor truss: φ2.2m octagonal column x 0.6m (temporary)
Orbiter Circular orbit
Altitude Approx. 100km
Inclination 90 degree
Attitude Control Three-axis stabilization
OKINA
(Relay Satellite)
Shape Octagonal column shape (1m x 1m x 0.65m) with about 50kg in mass
Orbiter Elliptical orbit
Altitude Approx. 100km x 2400km
Inclination 90 degrees
Attitude Control Spin-stabilization
OUNA
(VRAD Satellite)
Shape Octagonal column shape (1m x 1m x 0.65m) with about 50kg in mass
Orbiter Elliptical orbit
Altitude Approx. 100km x 800km
Inclination 90 degrees
Attitude Control Spin-stabilization