The Boston Marathon is 26.2 miles, whether you finish it with thousands in Copley Square or, like astronaut Sunita Williams, by yourself in outer space.

Williams, a NASA astronaut, discussed her out-of-this world performance in the historic race and shared stories from her time aboard the International Space Station at the John F. Kennedy Presidential Library Monday night.

Williams, who set a world record for longest amount of time in space by a woman after living at the International Space Station for 6 months, also set two other records, including the most space walks and most time spent outside the space station by a female.

Through it all, she said becoming the first astronaut to complete the Marathon on a treadmill in space is her greatest accomplishment.

“[Running the Marathon] is the one I am most proud of, the crazy one,” Williams said.

Williams grew up in Needham, where she graduated from Needham High School in 1983 before attending the U.S. Naval Academy. Following years of Naval Aviation she said she decided to join NASA as an astronaut.

“I couldn’t think of a better place to work or a better job to have,” she said.

She said the goal of her mission while aboard the station was to replace the entire electrical system and solar panels for more permanent use, adding the astronauts also worked on the oxygen, computer and heating systems.

She also conducted scientific research while performing tests on the growth of plants, human physical reaction time and blood samples — one of which was put together by the Massachusetts Institute of Technology.

After the speech, audience members launched questions, ranging from asking Williams’ aeronautical inspiration to common criticisms of NASA.

When asked about the weight of her experiences, Williams said, “There are moments when you start reflecting on this ball we live on, and you start to wonder what it’s all about.”

Many questions focused on recent allegations that astronauts have been operating space shuttles drunk in previous expeditions and also questioned the necessity of prolonging the space program.

According to an Aug. 29 New York Times article, NASA investigated 20 missions into space for evidence of drunkenness before launch, but found no conclusive proof that it had ever happened.

“I am confident that there are reasonable safeguards in place to prevent an impaired crew member from boarding a spacecraft,” said former astronaut and NASA Safety Chief Brian D. O’Connor in the article.

Williams also dismissed the claims.

“It would be difficult to do that in the period of time before the launch,” she said. “I can’t even imagine that being a realistic concern.”

Williams also promoted the continuation of the Shuttle Program — sche -uled to end in 2010 — which critics say is not worth the cost to taxpayers.

“[The Shuttle Program provides] all sorts of benefits from the political, to the scientific, to the way we understand each other,” she said.