Second to None: Here's the Buzz on Buzz Aldrin

Not to be deterred, Aldrin figured out another way to become an astronaut. He knew that one of the biggest engineering unknowns of spaceflight was how to dock with another vehicle in orbit, so Buzz decided to become an expert in it. He earned a Ph.D. from the Massachusetts Institute of Technology (MIT) in astronautics with a thesis titled, "Line-of-sight guidance techniques for manned orbital rendezvous."

When he applied to NASA a second time in 1963, Aldrin won a spot and became the first astronaut with a doctoral degree. His fellow astronauts called him "Dr. Rendezvous."

At NASA, Aldrin lived up to his nickname, taking command of the rendezvous and docking preparations for the Gemini missions. Buzz's first spaceflight was Gemini 12, the very last Gemini mission before the launch of the Apollo program. He and James Lovell rocketed into orbit on Nov. 11, 1966, with two critical missions: dock with the Agena spacecraft and conduct the longest spacewalk to date.

The first task was almost a failure if not for Aldrin's speedy math skills. The astronauts were approaching the Agena when their computerized tracking system went down.

"We seem to have lost our radar lock-on at about 74 miles [119 kilometers]," Aldrin told mission control. "We don't seem to be able to get anything through the computer."

Lucky for NASA, one of the men on the Gemini 12 crew had spent the last six years calculating orbital trajectories.

"For a lot of people, that would have been a mission ender," says Pyle. "But Buzz pulled out a sextant, a pencil, a pad of paper and a slide rule, and calculated the trajectory by hand. They rendezvoused and docked with the Agena using less fuel than anybody had previously using computers."

Then came the spacewalk, known in NASA parlance as "extra-vehicular activity" or EVA. Pyle says that previous spacewalks hadn't gone as planned. Astronaut Gene Cernan almost didn't make it back from his Gemini 9 EVA, suffering from poor visibility through a fogged up visor, no handholds on the ship's exterior and dangerous levels of exhaustion.

Gemini 12 was NASA's last chance before Apollo to prove that its astronauts could make critical repairs in orbit, but Aldrin didn't think the top brass was taking it seriously enough. To prepare for his EVA, Aldrin was one of the first astronauts to use underwater training extensively. Pyle says that NASA didn't have its own neutral buoyancy pool yet, so they sunk pieces of the Gemini trainer in the deep end of a private boy's school in Maryland.

"Buzz was a scuba enthusiast, so he just poured himself into the training and was there all the time," says Pyle. "He was really aggressive about it."

All that preparation paid off. Aldrin spent more than five hours conducting space walks on the Gemini 12 mission. He moved around the ship effortlessly thanks to special handholds and foot restraints that Aldrin himself designed. He performed test maneuvers with tools and even cleaned the windows for fun.

Buzz was so relaxed outside the capsule that he even snapped the very first space selfie. He brought his clunky camera out during the first EVA and pointed it at Earth, joking to mission control, "Okay, tell everybody down there to smile." Then he balanced the camera on the edge of his hatch and aimed it at himself.

"Now let me raise my visor and I'll smile," said Aldrin, posing for the slightly awkward selfie that would later sell at auction in 2015 for nearly $10,000.

After Gemini 12, Aldrin was slotted for Apollo 11 along with Neil Armstrong and Michael Collins. Pyle says that Deke Slayton, who was in charge of scheduling astronauts for NASA at the time, swore that it was simply the "luck of the draw" that Aldrin and Armstrong were picked for Apollo 11 and that Armstrong was the first to step foot on the lunar soil.

"Those guys were both uniquely qualified," says Pyle. "Buzz was the orbital dynamics guy who figured out the EVA. Neil was this incredible X-15 pilot who was known for extreme flying skills. If you read between the lines, though, Neil is the guy with almost no ego and best-suited to be the first on the moon. There was pushing and pulling up until the last few months about who was going to be out first."

Aldrin's father really wanted his son to be the first human on the moon, and Buzz lobbied hard for the honor, arguing that his position in the Lunar Module offered easier access to the hatch. But once NASA chose Neil, Pyle says, Buzz swallowed his pride and dutifully executed the mission.

While Armstrong's "one small step for man" quote has been immortalized, fewer remember Aldrin's poetic description as he took his own first steps on the moon: "Beautiful, beautiful. Magnificent desolation."

Returning home, Aldrin and the Apollo 11 crew were celebrated as global heroes. Pyle says that of the three, while Buzz eventually "leveraged" his fame the most, he wasn't prepared for the rebound effect after such an intense emotional high. How do you follow mankind's greatest single achievement?

"He descended into a deep depression," says Pyle. "Buzz talks openly about this in his memoir 'Return to Earth.' His first marriage failed, he had a drinking problem, money was tight. At one point, he was actually selling used cars to make ends meet."

After hitting rock bottom, Aldrin found sobriety and his post-NASA calling. He's spent every day of the past four decades promoting the future of manned spaceflight. Who better than Buzz Aldrin, Apollo 11 hero, to make the case for mankind's return to the moon and beyond?

Aldrin isn't just a rocket "booster"; he's very much still an engineer and adventurer at heart. In the 1990s, Buzz developed an ingenious scheme for transporting astronauts to Mars called the Aldrin Mars Cycler. The Cycler is a cross between a space station and a spacecraft that continuously orbits the sun in a path that periodically intersects both the Earth and Mars. Astronauts could shuttle to and from the cycler without burning lots of fuel.

"Buzz has a plan for everything," says Pyle, who describes a recent three-hour phone conversation with Aldrin as the equivalent of sitting in on graduate-level course in aerospace engineering. "You do get the sense that there's three or four brilliant minds in there all competing for the same mouth, and that's just how smart he is and how driven he is."

The Aldrin Family Foundation, which Buzz launched with his son, Andrew, focuses on inspiring and preparing the next generation of astronauts through STEAM (science, technology, engineering, arts and mathematics) education. And the Aldrin Space Institute at Florida Tech is dedicated toward "the goal of establishing and sustaining a permanent human presence on Mars" using Aldrin's cycling model.