How Are Remote Sensing Satellites Powered?

This week, IAM News discussed the components of a remote sensing satellite and touched on their potential sources of power: solar, batteries, or a combination of both. So, how is a remote sensing satellite powered, and how is this power distributed around the satellite?

In reality, the specific power systems employed in remote sensing satellites depend on the satellite’s size, mission requirements, and considerations of its operations. That said, the primary source of power for most remote sensing satellites is solar power. Some satellites are covered in solar panels and arrays that capture sunlight and convert it into electrical energy. Solar power is abundant in space, and the satellite's orientation can be adjusted to maximize exposure to the Sun. The generated electricity is stored in onboard batteries for use during eclipse periods (when the satellite is in Earth's shadow) or when higher power demand exceeds the immediate solar input.

Alongside solar panels, earth observation satellites are equipped with batteries to store excess solar energy for use during periods of eclipse or reduced solar illumination. Satellites in low Earth orbit (LEO) experience periodic eclipse periods when they pass through Earth's shadow, temporarily interrupting solar power generation. Batteries ensure a consistent power supply during such periods.

Moreover, earth observation satellites have sophisticated energy regulation systems known as Power Management and Distribution Units (PMDUs). Once the solar panels or RTGs generate electricity, it is fed through the PMDUs which regulate and distribute power throughout the satellite. These units ensure that the different subsystems and instruments within the satellite receive the appropriate voltage and current. Power distribution is closely intertwined with thermal management within satellites. Excess heat generated by power-consuming components is managed through radiators, heat pipes, and other cooling mechanisms to maintain optimal operating temperatures. Efficient thermal control is crucial to prevent overheating and ensure the longevity of satellite systems.