alt Hacker NewsI don't have a good intuitive feel for that.
At 25km altitude, with 1% of normal atmosphere, maybe you're close enough to vacuum that it can get really quiet?
I don't have a good intuitive feel for that.
At 25km altitude, with 1% of normal atmosphere, maybe you're close enough to vacuum that it can get really quiet?
The engine noise can still be conducted through the body of the plane. With the kind of ramjet being talked about, I think that's still likely to be significant even at very high altitude.