Thermal Technology Advancements for Extended-Duration Lunar Operation



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2023 International Conference on Environmental Systems


The desire for extended-duration robotic exploration of the moon without radioisotopes has highlighted a need for improved thermal capabilities. Described in this paper are ten innovations to enable multi-day/night operability/survivability of lunar instruments/systems. Extended-duration lunar operation is highly challenging due to the 50-100 K temperatures during the (15 Earth-day) lunar night and the 350-400 K temperatures (at low-to-mid latitudes) during the (15 Earth-day) lunar day. The innovations and the reasons why they’re needed are as follows: (1) thermally-switched enclosure (TSE), which houses the instrument/system and (using innovations 2-5, 8-9 below) passively transitions from daytime thermal coupling to nighttime thermal isolation; (2) parabolic reflector radiator (PRR), which provides a low sink temperature during lunar day at low-to-mid latitude sites; (3) spacerless MLI (SMLI), which is a low e* MLI concept involving nested double-aluminized Mylar layers hung from tension cable supports without spacers; (4) low conductance thermal isolator (LCTI), which conductively isolates systems from carriers and subsystems from each other; (5) reverse-operation DTE thermal switch (ROD-TSW), which is a high ON/OFF ratio, fully passive thermal switch used within the TSE; (6) extended duration ROD-TSW (ES-ROD-TSW), which is an extended-stroke version of the ROD-TSW for non-vacuum (or vacuum) environments; (7) miniaturized ROD-TSW (mini-ROD-TSW), which is needed for highly compact thermal-switching applications; (8) miniaturized loop heat pipe (mini-LHP), which transports heat from the TSE internal housing to the radiator with high conductance and minimal cross-sectional area; (9) Vectran tension cables (VTC), which provide conductive isolation and structural support; and (10) lunar magnetometer thermal enclosure (LMTE), which is the TSE for a future JPL lunar magnetometer. These ten advancements were developed at JPL under the PALETTE, ARTEMIS-T, and ROD-TSW projects. PALETTE is funded by NASA GCD, while ARTEMIS-T/ROD-TSW were funded by JPL. Also introduced in the paper are a few related future advancements.


David Bugby, Jet Propulsion Laboratory, California Institute of Technology, USA
Jose Rivera, Jet Propulsion Laboratory, California Institute of Technology, USA
ICES104: Advances in Thermal Control Technology
The 52nd International Conference on Environmental Systems was held in Calgary, Canada, on 16 July 2023 through 20 July 2023.


extended duration lunar exploration, thermally switched enclosure, parabolic reflector radiator, spacerless MLI, thermal isolator, reverse-operation DTE thermal switch (ROD-TSW), extended stroke ROD-TSW, miniaturized ROD-TSW, miniaturized loop heat pipe (mini-LHP), Vectran tension cables