You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.

Category: THE HISTORY OF APRIL 9th 
Clue: 1959: NASA publicly introduces Messrs. Glenn, Shepard & the rest of this program's 7 astronauts
mercury

Category: RED ROVER, RED ROVER 
Clue: This NASA "Lab" based in Pasadena designed the rovers used on Mars
jpl

Category: "F" I DO SAY SO 
Clue: It's the German equivalent of the English word "miss"

fraulein