Sodern, a space instrumentation company based in Paris, France, is celebrating their 60th anniversary this year. At Small Sat they displayed their newest star tracker, the Auriga-CP. A 200g instrument that attaches to small satellites. Among other vendor booths at the USU fieldhouse, business communication officer, Axelle, explained the function of star trackers on small satellites.
“It’s like a GPS, like in your car. You're driving and you need to go to a direction, so you need your GPS, if you don't know the road," Axelle said.
According to Axelle, most satellites contain internal mechanisms that allow them to be remotely oriented in space. However, to properly orient a satellite towards, for example, the earth, or towards a distant star of interest, scientists on the ground must first know the orientation of the satellite in its current position.
“Star trackers enable satellites to orient themselves in space just by looking at the stars. Just like ancient travelers did before,” said Axelle.
Product manager Jerome Reecht said Auriga-CP is designed to identify unique clusters of stars.
“Basically we take a picture of the sky, identify your pattern of stars, and then compare it to a library,” Reecht said.
According to Reecht the star tracker pattern recognizes not just the spatial pattern of stars, but also their varying light intensities to decide what part of the sky the satellite is viewing in that moment.
Satellites are often spinning, a technical term called tumbling. Reecht says that their tracker can pattern recognize the stars even when tumbling at high speeds. Additionally, the Auriga-CP can regain tracking within 4 seconds of being subjected to bright intensity light, like the Sun.