i would say Neil Armstrong because he was the first person to take a step on the moon with 2 other astronauts.
From Encyclopedia we can get a list of famous & not famous astronomers & astronauts of the past & present.
neil armstrong is the most famous one
NASA
Neil Armstrong
neil armstrong, and other famous astronauts
Walter Cunningham
Elena Ochoa is famous because she is the first astronaut women
haise
it's Christine Mae suarez
Jim lovelle
neal Armstrong and john glenn
Elena Ochoa is famous because she is the first astronaut women