Claude Nicollier is the first astronaut from Switzerland. He has flown on four Space Shuttle missions. His first spaceflight was in 1992, and his final spaceflight was in 1999. He took part in two servicing missions to the Hubble Space Telescope. During his final spaceflight he participated in a spacewalk, becoming the first European Space Agency astronaut to do so during a Space Shuttle mission. In 2000 he was assigned to the Astronaut Office Extravehicular Activity Branch, while maintaining a position as Lead ESA Astronaut in Houston. Nicollier retired from ESA in April 2007.