I also prefer thematic instances, but try to find appropriate communities within those instances. Just because it’s coming from NASA, doesn’t make it astronomy.
Depending on which aspects of the project you think are important and want to discuss there are a few communities here that might be relevant.
Earth Science includes environment, and environmental impact seems to be the most popular talking point so far.
Noise and other forms of pollution are public health issues and there is a local community for that, although I’m not sure it’s really a great fit there.
Physics might be another choice due to the fact that a lot of physics is going into the engineering of something that reduces sonic booms.
Or maybe you just need to find the right thematic instance. For example, I’m registered on slrpnk for my climate, energy efficiency, and anarchism fixes.