Why Do Small Satellites Need Star Trackers?

Small satellites are limited in terms of mass, volume, power consumption, and cost. However, mission requirements may be similar to those of large spacecraft. Both need to accurately determine the spacecraft's attitude.

Key Requirements for Star Trackers on Small Satellites

Miniaturization

The internal space of small satellites is limited, so star trackers need to adopt a compact structural design. A smaller size can reduce the space occupied by the device on the satellite platform and facilitate integration with other attitude control components.

Low Power Consumption

The power capacity of small satellites is usually limited by the solar panel area, battery capacity, and satellite size. Star trackers need to reduce power consumption while maintaining attitude measurement performance, thereby reducing the burden on the satellite's power system.

Low Mass

Star trackers are an important part of a satellite's attitude determination system. Lower device mass helps control the overall satellite mass and reduce launch costs.

High Attitude Measurement Accuracy

For missions such as Earth observation, communications, and scientific exploration, small satellites typically require stable and reliable attitude information. Star trackers should provide high attitude measurement accuracy.

Good Interference Resistance

Stray light from the Sun, Earth, and the satellite's own components may affect the star tracker's observation of stars. Star trackers for small satellites need good stray-light suppression capabilities and must be able to operate reliably in complex space lighting environments.

High Reliability

On-orbit maintenance of small satellites is difficult. Once an attitude sensor fails, it may directly affect the entire satellite mission. Therefore, star trackers need to undergo sufficient environmental testing and reliability verification to meet the requirements for long-term on-orbit operation.

Easy System Integration

Small satellites typically use standardized and modular designs. Star trackers need to provide standard mechanical, electrical, and communication interfaces and be able to work together with devices such as OBCs, gyroscopes, magnetorquers, and reaction wheels.