000007680 001__ 7680
000007680 005__ 20260102144345.0
000007680 0247_ $$2DOI$$a10.1007/s11214-025-01149-7
000007680 037__ $$aSCART-2026-0001
000007680 100__ $$aHussmann, Hauke
000007680 245__ $$aThe Ganymede Laser Altimeter (GALA) on the Jupiter Icy moons Explorer (JUICE) Mission
000007680 260__ $$c2025
000007680 520__ $$aThe Ganymede Laser Altimeter (GALA) on the Jupiter Icy Moons Explorer (JUICE) mission, is in charge of a comprehensive geodetic mapping of Europa, Ganymede, and Callisto on the basis of Laser range measurements. While multiple topographic profiles will be obtained for Europa and Callisto during flybys, GALA will provide a high-resolution global shape model of Ganymede while in orbit around this moon based on at least 600 million range measurements from altitudes of 500 km and 200 km above the surface. By measuring the diurnal tidal deformation of Ganymede, which crucially depends on the decoupling of the outer ice shell from the deeper interior by a liquid water ocean, GALA will obtain evidence for (or against) a subsurface ocean on Ganymede and will provide constraints on the ice shell thickness above the ocean. In combination with other instruments, it will characterize the morphology of surface units on Ganymede, Europa, and Callisto providing not only topography but also measurements of surface roughness on the scale of the laser footprint, i.e. at a scale of about 50 m from 500 km altitude, and albedo values at the laser wavelength of 1064 nm. GALA is a single-beam laser altimeter, operating at a nominal frequency of 30 Hz, with a capability of reaching up to 48 Hz. It uses a Nd:YAG laser to generate pulses with pulse lengths of 5.5 ± 2.5 ns. The return pulse is detected by an Avalanche Photo Diode (APD) with 100 MHz bandwidth and the signal is digitized at a sampling rate of 200 MHz providing range measurements with a sub-sample resolution of 0.1 m. Research institutes and industrial partners from Germany, Japan, Switzerland and Spain collaborated to build the instrument. JUICE, conducted under responsibility of the European Space Agency (ESA), was successfully launched in April 2023 and is scheduled for arrival at the Jupiter system in July 2031. The nominal science mission including multiple close flybys at Europa, Ganymede, and Callisto, as well as the final Ganymede orbit phase will last from 2031 to 2035. In May 2023 GALA has completed its Near-Earth Commissioning, showing full functionality of all units. Here we summarize the scientific objectives, instrument design and implementation, performance, and operational aspects of GALA.
000007680 594__ $$aNO
000007680 700__ $$aLingenauber, Kay
000007680 700__ $$aStark, Alexander
000007680 700__ $$aEnya, Keigo
000007680 700__ $$aThomas, Nicolas
000007680 700__ $$aLara, Luisa M.
000007680 700__ $$aAlthaus, Christian
000007680 700__ $$aAraki, Hiroshi
000007680 700__ $$aBehnke, Thomas
000007680 700__ $$aBinger, Jan
000007680 700__ $$aBreuer, Doris
000007680 700__ $$aCasotto, Stefano
000007680 700__ $$aCastro, Jose M.
000007680 700__ $$aChoblet, Gaël
000007680 700__ $$aChristensen, Ulrich
000007680 700__ $$aCoppoolse, Willem
000007680 700__ $$aEisenmenger, Henri
000007680 700__ $$aFerraz-Mello, Sylvio
000007680 700__ $$aFujii, Masayuki
000007680 700__ $$aFujishiro, Naofumi
000007680 700__ $$aGallina, Giovanni
000007680 700__ $$aGwinner, Klaus
000007680 700__ $$aHauber, Ernst
000007680 700__ $$aHeer, Ulrich
000007680 700__ $$aHenkelmann, Reiner
000007680 700__ $$aHerranz, Miguel
000007680 700__ $$aHüttig, Christian
000007680 700__ $$aIwamura, Satoru
000007680 700__ $$aJiménez, Jaime
000007680 700__ $$aKimura, Jun
000007680 700__ $$aKirino, Okiharu
000007680 700__ $$aKobayashi, Masanori
000007680 700__ $$aKurita, Kei
000007680 700__ $$aLainey, Valéry
000007680 700__ $$aLeikert, Thomas
000007680 700__ $$aLichopoj, Alexander
000007680 700__ $$aLötzke, Horst-Georg
000007680 700__ $$aLüdicke, Fabian
000007680 700__ $$aMartínez-Navajas, Ignacio
000007680 700__ $$aMichaelis, Harald
000007680 700__ $$aNakagawa, Hiroyuki
000007680 700__ $$aNamiki, Noriyuki
000007680 700__ $$aNishiyama, Gaku
000007680 700__ $$aNoda, Hirotomo
000007680 700__ $$aOberst, Jürgen
000007680 700__ $$aOshigami, Shoko
000007680 700__ $$aPommerol, Antoine search by orcid
000007680 700__ $$aRech, Markus
000007680 700__ $$aRoatsch, Thomas
000007680 700__ $$aRodrigo, Rafael
000007680 700__ $$aRodríguez, Adrián
000007680 700__ $$aRösner, Kerstin
000007680 700__ $$aTouhara, Kazuyuki
000007680 700__ $$aSaito, Yoshifumi
000007680 700__ $$aSasaki, Sho
000007680 700__ $$aSato, Yuki
000007680 700__ $$aSchmidt, Frédéric
000007680 700__ $$aSchreiber, Ulrich
000007680 700__ $$aSchulze-Walewski, Stefan
000007680 700__ $$aSohl, Frank
000007680 700__ $$aSpohn, Tilman
000007680 700__ $$aSteinbrügge, Gregor
000007680 700__ $$aStephan, Katrin
000007680 700__ $$aTanimoto, Kazuo
000007680 700__ $$aThabaut, Pascal
000007680 700__ $$adel Togno, Simone
000007680 700__ $$aVermeersen, Bert
000007680 700__ $$aWegert, Henry
000007680 700__ $$aWeidlich, Kai
000007680 700__ $$aWendler, Belinda
000007680 700__ $$aWickhusen, Kai
000007680 700__ $$aWieczorek, Mark
000007680 700__ $$aWillner, Konrad
000007680 700__ $$aWolff, Friederike
000007680 700__ $$aYokozawa, Takeshi
000007680 700__ $$aYseboodt, Marie
000007680 773__ $$pSpace Science Reviews$$v221$$y2025
000007680 8560_ $$fmarie.yseboodt@ksb-orb.be
000007680 905__ $$apublished in
000007680 980__ $$aREFERD