What is a star tracker, and how does it work on satellites?

A star tracker is a device utilized on spacecraft and satellites to establish their spatial orientation and location. It functions by recognizing and gauging the positions of celestial bodies, leveraging this data to determine the satellite’s orientation and posture.

What is a star tracker?

Our star trackers are essential components for satellite navigation and exploration, comprising a sophisticated combination of cameras and electronics/software that enable spacecraft to determine their orientation. Serving as “guides” for satellites in Earth’s orbit or those venturing through the solar system, our star trackers provide precise orientation information, allowing these space-based assets to fulfill their intended missions with accuracy and confidence.

Satellites often use star trackers to determine their orientation in space. These trackers typically consist of a telescope that gazes up at the sky, a detector array to capture images of the stars, and an onboard computer to process the data. The telescope captures images of the stars, which are then compared to a catalog of known star positions to determine the satellite’s orientation in space.

The detector array commonly used is a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) sensor. These sensors are responsive to light and able to take high-resolution and precise images. The onboard computer analyzes the data from the detector array by matching the stars’ positions in the image with the pre-determined positions in a star catalog to determine the satellite’s orientation and location.

Star trackers play a vital role in various satellite-based applications, including remote sensing, earth observation, and communication. By maintaining a consistent orientation in space, star trackers enable satellites to gather precise data and facilitate effective communication. Moreover, they can be utilized to calibrate other satellite instruments, such as cameras and spectrometers, thus ensuring the accuracy and reliability of the collected data.