Research the Relationship Between Surface Roughness and Drag at Trans/Super-sonic Speeds

[Joedang]

This paper provides some info on the subject. I also have a scan of an AIAA paper from the PSU library. Unfortunately, it's not open-access, so I can't link to a PDF. (I'll try to remember to post the journal/volume/title and a Google Scholar link here.)

This is far into "it's probably fine" territory, but it would be interesting to know how much altitude we stand to gain by improving surface finish.