  In the wake of the rapid deployment of large-scale low-Earth orbit satellite
constellations, exploiting the full computing potential of Commercial
Off-The-Shelf (COTS) devices in these environments has become a pressing issue.
However, understanding this problem is far from straightforward due to the
inherent differences between the terrestrial infrastructure and the satellite
platform in space. In this paper, we take an important step towards closing
this knowledge gap by presenting the first measurement study on the thermal
control, power management, and performance of COTS computing devices on
satellites. Our measurements reveal that the satellite platform and COTS
computing devices significantly interplay in terms of the temperature and
energy, forming the main constraints on satellite computing. Further, we
analyze the critical factors that shape the characteristics of onboard COTS
computing devices. We provide guidelines for future research on optimizing the
use of such devices for computing purposes. Finally, we have released the
datasets to facilitate further study in satellite computing.
