This paper addresses the challenges of utilizing Commercial Off-The-Shelf (COTS) devices in low-Earth orbit (LEO) satellite constellations, focusing on thermal control and power management. The authors present the first measurement study on the performance of COTS computing devices in satellite environments, revealing significant interactions between the satellite platform and these devices in terms of temperature and energy. Key findings include: 1. **Thermal Control**: The vacuum of space and the alternation between daylight and eclipse zones significantly impact the temperature of COTS devices. Overheating can lead to frequency throttling, reducing computational performance by up to 10%. 2. **Power Management**: COTS devices consume a significant portion of the satellite's power, affecting the battery's Depth of Discharge (DoD) and overall operational longevity. Short-term intensive computing tasks can cause the DoD to exceed 30%, reducing battery life by approximately 25%. 3. **Energy Efficiency**: The satellite's energy collection shows cyclical patterns, with 6% of converted solar energy remaining unused. Computing tasks consume 30% to 40% of the energy, highlighting the need for efficient scheduling to maximize energy utilization. The study provides insights into the constraints and challenges of using COTS devices in satellite computing, offering guidelines for future research and task scheduling to optimize performance and reliability. The authors also release detailed datasets to facilitate further study in satellite computing.This paper addresses the challenges of utilizing Commercial Off-The-Shelf (COTS) devices in low-Earth orbit (LEO) satellite constellations, focusing on thermal control and power management. The authors present the first measurement study on the performance of COTS computing devices in satellite environments, revealing significant interactions between the satellite platform and these devices in terms of temperature and energy. Key findings include: 1. **Thermal Control**: The vacuum of space and the alternation between daylight and eclipse zones significantly impact the temperature of COTS devices. Overheating can lead to frequency throttling, reducing computational performance by up to 10%. 2. **Power Management**: COTS devices consume a significant portion of the satellite's power, affecting the battery's Depth of Discharge (DoD) and overall operational longevity. Short-term intensive computing tasks can cause the DoD to exceed 30%, reducing battery life by approximately 25%. 3. **Energy Efficiency**: The satellite's energy collection shows cyclical patterns, with 6% of converted solar energy remaining unused. Computing tasks consume 30% to 40% of the energy, highlighting the need for efficient scheduling to maximize energy utilization. The study provides insights into the constraints and challenges of using COTS devices in satellite computing, offering guidelines for future research and task scheduling to optimize performance and reliability. The authors also release detailed datasets to facilitate further study in satellite computing.