The 257 days he has spent in space over the past few years have reaffirmed his conviction that it is vital to pursue one’s dreams, whatever the cost. Michael López-Alegría is NASA’s most experienced astronaut. He participated in four space missions between 1992 and 2012 and holds three records: the longest space flight (with a duration of seven months), the highest number of extra-vehicular activities (10 spacewalks), and the longest accumulated duration of these activities (67 hours and 40 minutes). He played a fundamental role in the construction of the International Space Station (ISS), which he led as Commander. He has made three space shuttle missions and has been NASA’s Director of Operations in the Yuri Gagarin Cosmonaut Training Centre in Star City (Russia), where he trained US astronauts for flights to the International Space Station. Currently, López-Alegría is the President of the Commercial Spaceflight Federation, an association that brings together leading companies in the aerospace sector to promote technological innovation and encourage young people to study for science and engineering degrees.