this thread just made my day as last week I just finished my study work for the Academy ("Is Oberth Class the missing design evolution link between USS Enterprise
and USS Reliant
When I became aware that NCC-640 has been used for USS Tsiolkovsky (model) I thought "wow"!
Of the three fathers of rocket science we'd then have the Russian Konstantin Tsiolkovsky (640) in the same company as the German Hermann Oberth (602).
Of course, someone is missing: America's father of rocket science, i.e. Robert Goddard.
According to the (Matt) 'Jefferies Rule' this class of ships would be the 6th Federation design and the first serial number / ship would become the name for the class, thus there has to be an NCC-601 which I strongly believe would have been USS Goddard
Yes, I'm aware of the problem that Goddard Class is somewhat not compatible with the Oberth Class designation seen on screens. Unfortunately! Maybe they can still CGI fix this for the upcoming Blu-rays?