Inside an office complex along the Dutch coast lies a synthetic star.
It’s not an actual star. The complex is the European Space Agency‘s (ESA) European Space Research and Technology Centre (ESTEC), and its artificial star consists of a rotating table before some extent of sunshine that simulates the colour and brightness of a given star. Engineers use this room to check star trackers.
Staring out into the cosmos, it is simple for each humans and hardware to lose their bearings. The celebs can come to their aid. Just as humans have long used the celebrities to navigate themselves, satellites and other spacecraft often judge their position with star trackers.
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There are numerous models of star trackers. But a typical star tracker captures the sky with a camera or one other light-catching device. Then, the star tracker might reference its sight against a list of known, vibrant stars to reconstruct position. Electronic star trackers have existed because the Nineteen Fifties, and all varieties of gadgets from guided missiles to ground telescope Goto mounts use them.
But star trackers’ most outstanding users are satellites. Satellite star trackers range from low-cost open-source star trackers intended for cubesats to cutting-edge devices like ASTRO XP, which might autonomously keep satellites aligned to inside 0.1 arcsecond of sky and will likely be used on future ESA missions just like the ATHENA X-ray telescope and LISA gravitational wave observatory.
In fact, the builders of star trackers need to really test their tools before launching them aboard satellites. And that is where star simulators — just like the one featured within the photo above, in ESTEC’s GNC, AOC and Pointing Laboratory — turn out to be useful.