The Ganymede Laser Altimeter (GALA) for the Jupiter Icy Moons Explorer (JUICE): Mission, science, and instrumentation of its receiver modules

The Jupiter Icy Moons Explorer (JUICE) is a science mission led by the European Space Agency, being developed for launch in 2023. The Ganymede Laser Altimeter (GALA) is an instrument onboard JUICE, whose main scientific goals are to understand ice tectonics based on topographic data, the subsurface structure by measuring tidal response, and small-scale roughness and albedo of the surface. In addition, from the perspective of astrobiology, it is imperative to study the subsurface ocean scientifically. The development of GALA has proceeded through an international collaboration between Germany (the lead), Japan, Switzerland, and Spain. Within this framework, the Japanese team (GALA-J) is responsible for developing three receiver modules: the Backend Optics (BEO), the Focal Plane Assembly (FPA), and the Analog Electronics Module (AEM). Like the German team, GALA-J also developed software to simulate the performance of the entire GALA system (performance model). In July 2020, the Proto-Flight Models of BEO, FPA, and AEM were delivered from Japan to Germany. This paper presents an overview of JUICE/GALA and its scientific objectives and describes the instrumentation, mainly focusing on Japan’s contribution

Plasma Dynamics

Contains table of contents for Section 2 and reports on four research projects.National Science Foundation Grant ECS 89-02990U.S. Air Force - Office of Scientific Research Grant AFOSR 89-0082-BU.S. Army - Harry Diamond Laboratories Contract DAAL02-89-K-0084U.S. Department of Energy Contract DE-AC02-90ER40591U.S. Navy - Office of Naval Research Grant N00014-90-J-4130Lawrence Livermore National Laboratory Subcontract B-160456National Science Foundation Grant ECS 88-22475U.S. Department of Energy Contract DE-FG02-91-ER-54109National Aeronautics and Space Administration Grant NAGW-2048U.S.-Israel Binational Science Foundation Grant 87-0057U.S Department of Energy Contract DE-AC02-78-ET-5101

Extracellular inorganic phosphate regulates gibbon ape leukemia virus receptor-2/phosphate transporter mRNA expression in rat bone marrow stromal cells

In mammalian cells, several observations indicate not only that phosphate transport probably regulates local inorganic phosphate (Pi) concentration, but also that Pi affects normal cellular metabolism, which in turn regulates apoptosis and the process of mineralization. To elucidate how extracellular Pi regulates cellular functions of pre-osteoblastic cells, we investigated the expression of type III sodium (Na)-dependent Pi transporters in rat bone marrow stromal cells and ROB-C26 pre-osteoblastic cells. The mRNA expression level of gibbon ape leukemia virus receptor (Glvr)-2 was increased by the addition of Pi in rat bone marrow stromal cells, but not in ROB-C26 or normal rat kidney (NRK) cells. In contrast, the level of Glvr-1 mRNA was not altered by the addition of extracellular Pi in these cells. The induction of Glvr-2 mRNA by Pi was inhibited in the presence of cycloheximide (CHX). Moreover, mitogen-activated protein kinase (MEK) /extracellular-signal-regulated kinase (ERK) pathway inhibitors; U0126 (1.4-diamino-2, 3-dicyano-1, 4-bis [2-amino-phenylthio] butadiene) and PD98059 (2-Amino-3-methoxyflavone) inhibited inducible Glvr-2 mRNA expression, but p38 MEK inhibitor SB203580 [4-(4-fluorophenyl)-2-(4-methyl-sulfinylphenyl)-5-(4pyridyl) imidazole] did not inhibit the induction of Glvr-2 mRNA expression, suggesting that extracellular Pi regulates de novo protein synthesis and MEK/ERK activity in rat bone marrow stromal cells, and through these, induction of Glvr-2 mRNA. Although Pi also induced osteopontin mRNA expression in rat bone marrow stromal cells but not in ROB-C26 and NRK cells, changes in cell viability with the addition of Pi were similar in both cell types. These data indicate that extracellular Pi regulates Glvr-2 mRNA expression, provide insights into possible mechanisms whereby Pi may regulate protein phosphorylation, and suggest a potential role for the Pi transporter in rat bone marrow stromal cells

Miniature Space GPS Receiver by means of Automobile-Navigation Technology

Miniature space GPS receivers have been developed by means of automobile-navigation technology. The weight and power consumption of the GPS receiver are 35 g and 1 W, respectively. We expanded the frequency sweep range in order to cover large Doppler shift in orbit. We tested the performance in low earth orbits by means of a GPS simulator. The GPS receiver succeeded in cold start acquisition in less than 60 minutes. The GPS receiver for automobile- navigation generates position data with time tag which is not accurate enough to space application. The GPS receiver was modified to output pseudorange data with accurate time tag. The range error caused by the receiver is measured to be 1 meter. The position accuracy is estimated to be less than 20 meters in the low earth orbits. The GPS receiver can be operated with 20 krad (Co60) radiation and is SEL-free for 200MeV proton radiation. SEU may occur in low earth orbits once a several days. This GPS receiver will be on-boarded on INDEX satellite, which will be launched in 2005

Miniature Space GPS Receiver by means of Automobile-Navigation Technology

Miniature space GPS receivers have been developed by means of automobile-navigation technology. The weight and power consumption of the GPS receiver are 35 g and 1 W, respectively. We expanded the frequency sweep range in order to cover large Doppler shift in orbit. We tested the performance in low earth orbits by means of a GPS simulator. The GPS receiver succeeded in cold start acquisition in less than 60 minutes. The GPS receiver for automobile- navigation generates position data with time tag which is not accurate enough to space application. The GPS receiver was modified to output pseudorange data with accurate time tag. The range error caused by the receiver is measured to be 1 meter. The position accuracy is estimated to be less than 20 meters in the low earth orbits. The GPS receiver can be operated with 20 krad (Co60) radiation and is SEL-free for 200MeV proton radiation. SEU may occur in low earth orbits once a several days. This GPS receiver will be on-boarded on INDEX satellite, which will be launched in 2005