MISSION_DESCRIPTION |
The Japanese lunar orbiter Kaguya (SELENE) was successfully
launched on September 14, 2007 and entered its nominal 100 km
circular orbit on October 19, 2007. Acquisition of scientific
data was carried out for 10 months of nominal mission that began
in mid-December 2007 and included an 8-month extended mission.
The Kaguya spacecraft impacted the Moon on June 10, 2009. Data
are archived at
http://l2db.selene.darts.isas.jaxa.jp. The mission is described
in KATOETAL2010. The following information is taken from that source.
SPACECRAFT AND SCIENCE PAYLOAD
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The mission included a large orbiter and two subsatellites
(KATOETAL2010). There were 15 science instruments carried by
the three spacecraft, with 11 carried by the main orbiter.
1. Gamma Ray Spectrometer (GRS) and
2. X-ray Spectrometer (XRS) for measurement of surface elemental
abundances;
3. Multiband Imager (MI), a multispectral imaging system;
4. Spectral Profiler (SP), a spectrometer that collected spectra
along the groundtrack of the spacecraft;
5. Terrain Camera (TC), a stereo mapping camera;
6. Lunar Radar Sounder (LRS) and
7. Laser Altimeter (LALT) for altimetric measurements;
8. Relay Satellite Transponder (RSAT), and
9. Very Long Baseline Interferometry Radio Source (VRAD) to measure
the gravity field of the lunar farside and nearside;
10. Charged Particle Spectrometer (CPS),
11. Lunar Magnetometer (LMAG),
12. Plasma Energy, Angle, Composition Experiment (PACE),
13. Radio Science, and
14. Upper Atmosphere Plasma Imager (UPI) to determine the impact of
cosmic radiation and/or solar wind on the Moon and Earth; and
15. High Definition Television (HDTV) used for public outreach.
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MISSION_OBJECTIVES_SUMMARY |
The primary science objectives of the Kaguya mission were:
- To determine the chemical constituents of the Moon,
- To determine the interior structure of the Moon,
- To explore the dichotomy of the nearside and farside of the Moon,
- To explore differentiation in the magma ocean,
- To determine the origin of the lunar magnetic field, and
- To look for evidence of lunar tectonics.
Major scientific achievements as of the publication of KATOETAL2010
include:
- Identification of ubiquitous pure anorthosite in outcrops of
central peaks of large craters by MI and SP.
- Discovery of multiple reflectors of radio waves under large mares
in the nearside by LRS.
- Use of RSAT for confirmation of free-air gravity anomaly in the
whole Moon and identification of farside anomalies that are different
from nearside mass concentration anomalies.
- Confirmation of lunar global topography by LALT.
- Re-estimation of crustal thickness by Kaguya data of gravity and
topography.
- Re-estimation of the formation ages of farside mares by crater
countings using high resolution images of TC.
- Confirmation of magnetic anomalies and mini-magnetosphere by LMAG and
PACE.
- Reconfirmation of global distribution of radio-active elements K, U
and Th by GRS.
- Discovery of SW proton reflection from the lunar surface, SW entry
into lunar wake, and interaction with the Moon by PACE.
- Confirmation of the polar illumination rate by LALT topographic data.
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