America’s leadership in space, established 50 years ago with President John F. Kennedy’s bold vision of landing a man on the Moon, is slipping away under the guidance of President Barack Obama, according to lunar pioneers Neil Armstrong, Jim Lovell and Gene Cernan.

In a May 24 column in USA Today, the Apollo astronauts say the Obama administration’s decision to cancel the Moon-bound Constellation program “ignored NASA’s operational mandate and strayed widely from President Kennedy’s vision and the will of the American people.”

Recalling Kennedy’s declaration that space would be “the new ocean,” they say: “For 50 years we explored the waters to become the leader in space exploration. Today, under the announced objectives, the voyage is over.”