Alexander Gerst

Alexander Gerst was born on 3 May 1976 in Künzelsau, Germany, and is one of the rare astronauts to reach orbit from a career in Earth science rather than aviation. He studied geophysics at the University of Karlsruhe and earned a master's in earth sciences in New Zealand before completing a doctorate in natural sciences at the University of Hamburg in 2010, with research on volcano dynamics that took him to active volcanoes on several continents. That background — comfortable in extreme, remote and hazardous environments — served him well when he was selected to the European Astronaut Corps in 2009 and certified as an astronaut in November 2010. An enthusiastic paraglider, climber and diver, he brought a scientist's eye to human spaceflight.

Gerst has flown two long-duration missions to the International Space Station. His first, the Blue Dot mission, began on 28 May 2014 with his launch to join Expedition 40/41, a roughly five-and-a-half-month stay devoted to a heavy program of experiments and to the striking orbital photography that became a hallmark of his time in space. His second flight, the Horizons mission, launched on 6 June 2018 for Expedition 56/57. During Horizons he became the second ESA astronaut ever to command the ISS, taking charge of Expedition 57 in October 2018, and he hosted CIMON — an artificial-intelligence-powered, free-flying robot assistant tested aboard the station. Across his two missions he accumulated some 362 days in space — roughly 8,700 hours.

Gerst emerged as one of ESA's most influential and visible astronauts, celebrated both for his command of a scientifically demanding mission and for images and messages from orbit that consistently returned to themes of climate and the fragility of Earth. Recognized in Germany with the Grand Cross of Merit and honored with the gold Humboldt Medal and other awards for his scientific and public contributions, he remains an active member of the corps. Since 2023 he has led astronaut operations at the European Astronaut Centre in Cologne, shaping the training and flight assignments of the next generation of European crews while remaining eligible for future missions of his own.