Mr Aldrin, 78, said: "To me it's abysmal that it has come to this: after 50 years of Nasa, and after putting about $100 billion into the space station, we can't get our own astronauts to our space station without relying on the Russians."
He said his message to the next president is this: "Retain the vision for space exploration. If we turn our backs on the vision again, we're going to have to live in a secondary position in human space flight for the rest of the century."
He added: "These are important issues for consideration by the potential leaders of our country. They're not welcome criticisms for the present heads of NASA."
(Thanks to Gene Steinberg.)