Comment by pjscott
6 hours ago
If you're familiar with the technical specs, I'd be interested in hearing what size of objects the star trackers can sense and at what range. In theory the fancier star trackers can see objects around 10 cm diameter hundreds of kilometers away, without needing to worry about a pesky atmosphere [1], but I don't know how sensitive the sensors on Starlink's current generation satellites are, and this web site isn't saying.
They're mostly touting the improvement in latency over existing tracking, from delays measured in hours to ones measured in minutes. Which is very nice, of course, but the lack of other technical detail is mildly frustrating.
[1] https://www.mit.edu/~hamsa/pubs/ShtofenmakherBalakrishnan-IA...
Note from analysis in the paper: (CST = Commercial Star Tracker, for which they model several common ones flown on satellites)
>From Fig. 1, it is clear that many typical CSTs can be used to detect debris with characteristic length less than 10 cm at distances as far as roughly 50 km. These same sensors have the potential to detect debris as small as 1 cm in diameter as far as 5 km away. Even space-limited CubeSats using nanosatellite-class CSTs can detect 10-cm-class debris at roughly 25 km away or 1-cm-class debris at a distance of 2.5 km. Higher-performing imagers like the MOST telescope can further characterize orbital debris of 10 cm diameter as far as 400 km away or be used to characterize orbital debris smaller than 1 cm at ranges not exceeding 40 km.
NASA tracks debris 10cm or larger. They also detect and statistically estimate debris as small as 3mm in LEO.
This is my source, from 2021 fwiw: https://oig.nasa.gov/office-of-inspector-general-oig/ig-21-0...
10cm is huge, that could even be a functioning 1U cubesat.
So it looks to be just the latency improvement that's noteworthy, then. Thank you!
Yes. Sorry for the brief answer. Too bad I got downvoted. There's no size improvement.