How working for NASA actually works, according to a former NASA astronaut

Mike Massimino is a former NASA astronaut and veteran of two Space Shuttle missions.

Massimino began his career as an engineer working at IBM and McDonnell Douglas Aerospace after earning degrees from Columbia University and the Massachusetts Institute of Technology. He applied to NASA three times before being selected as an astronaut in 1996. He went on to fly two Space Shuttle missions, in 2002 and 2009, both focused on servicing the Hubble Space Telescope. During these missions, he performed multiple space walks and was part of a team that set a record for total spacewalking time on a single shuttle mission.

He talks to Business Insider about astronaut training and recruitment, as well as daily life in space, including how astronauts eat, drink, and sleep. He also discusses becoming the first person to tweet from space and shares his perspective on the future of human spaceflight, including the Artemis II mission.

After leaving NASA, Massimino became a professor of mechanical engineering at Columbia University and works as a senior advisor for space programs at the Intrepid Museum. He has made numerous television appearances, including a recurring role as himself on "The Big Bang Theory."