The government agency took to Twitter to remember retired astronaut Gene Cernan on Monday.

NASA said that Cernan logged more than 566 hours in space, 73 of which were on the moon.

Cernan served in Gemini 9A, Apollo 10 and Apollo 17 missions in the 1960s and 1970s. Cernan served as spacecraft commander of Apollo 17, the last scheduled manned mission to the moon for the United States, in December 1972. 

He since received a number of awards and decorations for his work.

Read more at NASA.