US astronaut John Young. Pic/AFP

John Young, America's "most experienced astronaut" who walked on the Moon during the Apollo programme and commanded the first space shuttle mission, has passed away, NASA said on Saturday. Young died on Friday night following complications from pneumonia, Xinhua quoted the US space agency as saying. He was 87 years old. "Today, NASA and the world have lost a pioneer," acting NASA Administrator Robert Lightfoot was quoted as saying.