Buzz Aldrin's Roadmap To Mars:

"In 1961, NASA was mulling over two possible flight plans to put a man on the moon. While agency officials argued the merits of Earth Orbit Rendezvous versus Direct Ascent, John C. Houbolt, a little-known engineer at the Langley Research Center in Hampton, Va., came up with a daring and ingenious alternative: Lunar Orbit Rendezvous. LOR, which would require two spacecraft to link up a quarter-million miles from Earth, initially struck many people--me included--as dangerously complex, even bizarre. But Houbolt stubbornly kept pushing his plan, and the elegant logic of LOR eventually won over the skeptics. On July 20, 1969, thanks to Houbolt's persistence, Neil Armstrong and I walked on the moon.

More than three decades later, as NASA debates how to send humans to Mars, it's time once again to invoke the outside-the-box spirit of John Houbolt. NASA's latest thinking for a manned Mars mission is basically the Apollo program writ large: a massive disposable spacecraft that must be boosted from Earth to interplanetary velocity, and then slowed back down to alight on Mars. This flight plan has a huge energy requirement that translates directly into size, complexity and cost. Because each mission would be so extremely expensive, it's all too likely that such a program will lead to the kind of short-term "footprints and flagpoles" thinking that eventually killed Apollo.

We can do better this time. My blueprint for manned travel to Mars, based on reusable spacecraft that continuously cycle between Earth and Mars in permanent orbits, requires much less energy over the long term. Once in place, a system of cycling spacecraft, with its dependable schedule and low sustaining cost, would open the door for routine travel to Mars and a permanent human presence on the red planet. Its long-term economic advantages make it less susceptible to cancellation by congressional or presidential whim. In effect, this system would go a long way toward politician-proofing the Mars program."

Buzz Aldrin was one of the third group of astronauts named by NASA in October 1963.
On November 11, 1966, he and command pilot James Lovell were launched into space in the Gemini 12 spacecraft on a 4-day flight, which brought the Gemini program to a successful close. Aldrin established a new record for extravehicular activity (EVA), spending 5-1/2 hours outside the spacecraft.
He served as lunar module pilot for Apollo 11, July 16-24, 1969, the first manned lunar landing mission. Aldrin followed Neil Armstrong onto the lunar surface on July 20, 1969, completing a 2-hour and 15 minute lunar EVA.
In July 1971, Aldrin resigned from NASA. Aldrin has logged 289 hours and 53 minutes in space, of which, 7 hours and 52 minutes were spent in EVA