The instrument is approaching four years of operation in space, with its over- all thermal performance as predicted and no changes to cryocooler performance. To date, all three cryocoolers have accumulated over 32,000 operating hours. On the 210th day after the initial power-on, a fault condition was detected, and the instrument put itself into standby mode with the coolers off. [1] On the 258th day, the instrument went through a planned power cycle for firmware updates that left the coolers off for 45 days. [1] The coolers have since undergone eleven additional short duration power cycles to date. The heat rejection system, including the custom cryocooler heat exchangers, has performed as expected by maintaining all components within their allowable flight temperatures while meeting the fluid loop requirements for pressure drop and outlet fluid temperature.
The research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). ©2022. California Institute of Technology. Government sponsor- ship acknowledged.
References
[1] Cha, J., et al. (2020). Thermal Design and On- orbit Performance of the ECOSTRESS Instrument. IOP Conference Series: Materials Science and Engineering. Vol. 755. No. 1. IOP Publishing.
[2] https://ecostress.jpl.nasa.gov/
[3] Arts, R., et al. (2016). LPT9310 COTS cooler for ECOSTRESS. International Cryocooler Conference.
[4] Cha, Jeff, Brian Carroll, and Memo Romero. (2017) Heat Rejection System for Thermal Management in Space Using Non-planar Liquid Cooled Cold Plates. 47th International Conference on Environmental Systems.
Image: ECOSTRESS attaching to the ISS. Credit: NASA
[Originally published in Cold Facts Vol. 38, Num. 3, Space Cryogenics Column]
