Wernher von Kerman
Wernher von Kerman is a famous rocket scientist at the Kerbal Space Center who tutors you in assembling a spaceship during the first tutorial "Construction Basics". Wernher can also be found in-game in Career Mode manning the Science Archives in the Research and Development Facility.
Wernher's personality seems casually self-congratulatory with regular mentions of his fame and the player reminding him of "a younger, less experienced, considerably less famous version" of von Kerman himself. He is known to roll his eyes at your "interesting" design choices.
His Steam Trading Card says, "Well, in theory it should have worked."
His name most likely alludes to Wernher von Braun, the "Father of Rocket Science" who was a Nazi scientist picked up by American Intelligence in Operation Paperclip after WW2, and led much of the USA's efforts during its space race with the USSR.
His name may also be referencing to Theodore von Kármán, a Hungarian-American mathematician, aerospace engineer and physicist who was active primarily in the fields of aeronautics and astronautics.
Wernher von Kerman appears to be the lead scientist at KSP, like von Braun at NASA; but the similarities seem to end there. The real Wernher von Braun was not known for bragging, in contrast with von Kerman. Also, von Kerman sports a moustache and glasses while von Braun was clean-shaven and didn't wear glasses.
The fanwork Kerbal Comics call him Wernher von Grün, as grün is German for green (like Kerbals' skin color).