"It's remarkable to think that the samples Apollo 16 brought back more than half a century ago still have secrets to reveal about the moon's history." ...

John Young, Ken Mattingly and Charlie Duke of Apollo 16 and Gene Cernan, Ron Evans and Harrison Schmitt of Apollo 17 traveled ever farther and collected more moon rocks on their missions.

In Texas, we found Charlie Duke, lunar module pilot on Apollo 16, and Walt Cunningham, who served as command module pilot during Apollo 7, the inaugural test flight. In Chicago, we interviewed the ...