5:15 PM - 6:30 PM
[PPS11-P09] JUICE/GALA-J (6): Optical/thermal/structural design for the receiver part of the Ganymede Laser Altimeter (GALA) for the JUICE mission
Keywords:JUICE, GALA, optical/thermal/structural design
Thermal environment of GALA is unique: The Receiver telescope and some parts are cooled to intermediately cryogenic temperature by radiation to the cold surface of Ganymede and deep space while the APD detector has to be kept at 25 degree in its operation time. Many parts of GALA are warmed by self-heating. Furthermore, GALA repeats observation time of 16 hours and data downlink time of 8 (power of observation part is off) hours. So the thermal environment is dynamic.
On the other hand, GALA have to keep stability of optical performance, especially absolute agreement of the optical axis of the emitter and the receiver and to the spacecraft coordinate system. Radiation shield also has to be mandatory. Considering these conditions, we are carrying out design of optics, structure and thermal design for the BEO, FPA, and AEM. The current baseline design, the BEO is simply consisting of a collimator lens, a narrow band-pass filter, a focusing lens supported without adhesive. The material used for the structural material of both BEO and FPA must have small thermal expansion and good radiation shielding. Iterative studies of thermal analysis of whole GALA and the optical/thermal/structural design is ongoing.