The last surviving astronaut from the first successful U.S. space mission, Apollo 7, Walt Cunningham died Tuesday morning at age 90 in Houston, according to NASA.

NASA administrator Bill Nelson released a statement about Cunningham's death.

“Walt Cunningham was a fighter pilot, physicist and an entrepreneur — but, above all, he was an explorer. On Apollo 7, the first launch of a crewed Apollo mission, Walt and his crewmates made history, paving the way for the Artemis Generation we see today. NASA will always remember his contributions to our nation’s space program and sends our condolences to the Cunningham family,” Nelson said.

Cunningham hailed from Iowa and served as a Navy fighter pilot in Korea during that conflict. He later served in the Marines and retired with the rank of colonel.

Chosen for Apollo missions

After leaving the military active duty, Cunningham attended UCLA and received a Bachelor of Arts with honors in physics in 1960 and a Master of Arts with distinction in physics in 1961. He worked at Rand Corporation for three years as a scientist and accumulated thousands of flying hours in 40 different aircraft.

He was chosen to be an astronaut in 1963 and slated for the Apollo 2 crew. That launch was later scrubbed when Apollo 1 failed.

Cunningham was the lunar module pilot for the Apollo 7 mission in 1968, which was the first human test of the Apollo space craft.

The successful mission saw humans in space for 11 days and paved the way for the Apollo 11 mission that landed humans on the moon for the first time in 1969.

"All I remember is just kind of keeping my nose to the grindstone and wanting to do the best I could as — I didn’t realize at the time, but that was because I always wanted to be better prepared for the next step," Cunningham said of the mission during a 1999 interview with NASA's Oral History Office. "I’ve always been looking to the future."

Cunningham retired from NASA in 1971. He went on to get a doctoral degree from Harvard and ran numerous businesses for the balance of his career. He also did speaking and was a national radio host.

Family statement and awards

His family released a statement following his death.

“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 world has lost another true hero, and we will miss him dearly,” the statement read.

Cunningham received the NASA Exceptional Service Medal and NASA Distinguished Service Medal for his service. He was inducted into the Astronaut Hall of Fame, International Space Hall of Fame, Iowa Aviation Hall of Fame, San Diego Air and Space Museum Hall of Fame, and Houston Hall of Fame.

Cunningham and the Apollo 7 crew won an Emmy in the form of the National Academy of Television Arts and Sciences Special Trustee Award, since their mission was partially televised.