A European Space Agency (ESA) astronaut is a professional spaceflight crew member selected, trained and managed by the European Space Agency to fly on international human spaceflight missions, conduct scientific research, operate spacecraft systems and represent European participation in crewed space programmes. ESA astronauts come from ESA member states and typically have backgrounds as test pilots, scientists, medical doctors or engineers; they complete core training at the European Astronaut Centre in Cologne and additional mission-specific training with partner agencies such as NASA or Roscosmos[5][1]. Notable roles for ESA astronauts include long‑duration expedition crewmembers aboard the International Space Station (ISS), mission specialists on multinational missions, and leaders of European activities in microgravity research and technology demonstrations; several have commanded the ISS or performed spacewalks while carrying out experiments in biology, physics, human physiology and radiation research[3][1]. Key achievements by ESA astronauts include early Spacelab flights and contributions to shuttle servicing missions, participation in ISS assembly and science (including operation of the Columbus laboratory), and pioneering roles in international collaborations such as Hubble servicing and long‑duration ISS expeditions[5][1]. ESA astronauts remain currently relevant as Europe’s human-spaceflight workforce for ISS expeditions, commercial crew missions and preparatory activities for lunar and deep‑space exploration; recent years have seen multiple European long‑duration missions (for example Alexander Gerst, Luca Parmitano, Thomas Pesquet and Matthias Maurer) and ESA assignments on NASA commercial crew flights[1][3][1]. ESA maintains an active astronaut corps and continues to assign new astronauts to upcoming ISS and exploration missions, reflecting Europe’s ongoing partnership in international human spaceflight[1]. For agency biographies and up‑to‑date mission assignments, ESA’s official astronaut pages provide current details on individual crew members and their flight histories[1][3].