Cubesat Design to Test Passive Thermal Coatings in Space

Riccardo Bevilacqua, a distinguished member of Miami Scientific Italian Community, is the principal investigator of the PATCOOL (Passive Thermal Coating Observatory Operating in Low-Earth Orbit)


The PATCOOL is a NASA sponsored, University of Florida developed 3U Cu-beSat meant to investigate the feasibility of using a cryogenic selective surface coating as a new, more efficient way of passively cooling components in space. Initial tests on the ground demonstrate that this coating should provide a much higher reflectance of the Sun’s irradiant power than any existing coating, while still providing far-infrared power emission. The ultimate validation of this tech-nology requires on-orbit testing.

PATCOOL hosts a 4-sample housing, with the samples shaped as thin cylinders (coin-like). Two samples are coated with state-of-the-art material, while the other pair uses the new coating to be evaluated. The temperatures of all samples during the mission (minimum 72 hours of data col-lection) are measured via thermistors. The samples are connected via thin Kevlar strings to the housing, to minimize heat transfer. The housing is designed to shield the samples from Earth’s thermal radiation, and the CubeSat is attitude stabilized and controlled via a gravity gradient, magnetorquers and a reaction wheel set. Thermal Desktop simulations show PATCOOL’s ability to thermally isolate the samples from heat exchanges other than with Sun and deep space, thanks to its thermal design and the chosen attitude profile.


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To accurately portray the Sun’s effects on the samples, the vehicle is kept pointing away from Earth using a off-the-shelve ADCS.

The satellite was launched onboard the Dragon CRS-24 cargo spacecraft to the ISS.


Patcool live deployment from ISS will begin on January 26th at 5:00 a.m. ET on