Walter Cunningham, a retired NASA astronaut and pilot of the first crewed flight in the space agency's famed Apollo program, died early Tuesday morning at the age of 90, NASA said

Cunningham was one of the earliest members of NASA's human spaceflight program as a member of its third astronaut class, joining the space agency in 1963.

He was selected to pilot Apollo 7, the first crewed mission of the NASA program that went on to land humans on the moon for the first time.

"We would like to express our immense pride in the life that he lived, and our deep gratitude for the man that he was — a patriot, an explorer, pilot, astronaut, husband, brother, and father," the Cunningham family noted in a statement shared by NASA.

"The world has lost another true hero, and we will miss him dearly."