Japan Geoscience Union Meeting 2016

Presentation information


Symbol P (Space and Planetary Sciences) » P-PS Planetary Sciences

[P-PS11] Planetary Sciences

Thu. May 26, 2016 1:45 PM - 3:15 PM 104 (1F)

Convener:*Keiko Hamano(Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo), Shunichi Kamata(Creative Research Institution, Hokkaido University), Chair:Hirotomo Noda(National Astronomical Observatory of Japan), Shunichi Kamata(Creative Research Institution, Hokkaido University)

2:00 PM - 2:15 PM

[PPS11-26] JUICE/GALA-J (1) : The Ganymede Laser Altimeter (GALA) for the JUICE mission
- Introduction, current status, and role of the Japan team

*Keigo Enya1, Noriyuki Namiki2, Masanori Kobayashi3, Jun Kimura4, Hiroshi Araki2, Hirotomo Noda2, Shoko Oshigami2, Shingo Kashima2, Ko Ishibashi3, Shingo Kobayashi5, Masanobu Ozaki1, Takahide Mizuno1, Shin Utsunomiya1, Yoshifumi Saito1, Kazuyuki Touhara1, Shunichi Kamata5, Koji Matsumoto2, Kiyoshi Kuramoto5, Sho Sasaki6, Satoru Iwamura7, Teruhito Iida8, Yoshiaki Matsumoto8, Masanori Fujii9, Naofumi Fujishiro10, Tomoyasu Yamamuro11, Kay Lingenauber12, Thomas Behnke12, Juergen Oberst12, Judit Jaenchen12, Horst-Georg Loetzke12, Harald Michaelis12, Hauke Hussmann12 (1.JAXA/ISAS, 2.NAOJ, 3.CIT, 4.Earth-Life Science Institute, Tokyo Institute of Technology, 5.Hokkaido University, 6.Osaka University, 7.MRJ, 8.PLANET, 9.FAM Science, 10.Astro-Opt, 11.OptCraft, 12.DLR)

Keywords:JUICE, GALA, Jupiter, Icy moon, Ganymede, Laser altimeter

We present an introduction, current status, and especially role of the Japan team for the Ganymede Laser Altimeter (GALA) for the Jupiter Icy Moon Explorer (JUICE) mission. JUICE is a mission of ESA to be launched in 2022, and GALA is one of the payloads of JUICE.
Major objectives of GALA are to provide topographic data of Ganymede, the largest satellite of Jupiter, and to measure its tidal amplitudes. The latter is crucially important to detect and to characterize an underground ocean on Ganymede. Furthermore, GALA support geological studies, e.g., identification of characterization of tectonic and cryo-volcanic regions, impact basins, and craters. GALA also provides information on surface roughness and the albedo.
For the laser altimetry, GALA emits and receives laser pulses at about 500 km altitude above Ganymede. Wavelength, energy, and nominal repetition frequency of the laser pulse are 1064 nm, 17 mJ, and 30 Hz, respectively. Reflected beam from the Ganymede surface is received by the receiver telescope with 25 cm diameter aperture, re-focused by the BEO including a narrow band-pass filter, and then detected by the APD detector.
Development of GALA is carried out in international collaboration from Germany, Japan, Switzerland, and Spain. GALA-Japan will develop the Backend Optics (BEO), the Focal Plane assembly (FPA) including an avalanche photo-diode (APD) detector, and the Analog Electronics module (AEM) in the receiver chain. It should be noted that responsibility of development of the receiver telescope has been moved from Japan to Germany. Based on the heritage of studies for the telescope, GALA-Japan will contribute to the receiver telescope development through the German team.