Marco Alain Sieber graduated from the European Astronaut Centre alongside his classmates on 22 April 2024. As a member of the 2022 European Space Agency Astronaut group, he represents Switzerland as its second astronaut, following Claude Nicollier. His career spans specialized medical practice, military service, and extensive training for upcoming missions into the space environment.
Early Development and Academic Background
Born in 1989 in Biel, Switzerland, Sieber spent his childhood in Kirchberg, located in the Canton of Bern. He completed his secondary education at the Gymnasium Burgdorf in 2007. His interest in physiology began early, leading him to assist with anatomy and physiology coursework at the University of Bern. In 2015, he earned his Doctor of Medicine degree from that institution, achieving top marks for a thesis centered on robot-assisted surgery.
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Sieber entered the Swiss Army in 2009, undergoing paratrooper training with the Special Forces Command and attaining the rank of Sergeant. Between the ages of 20 and 23, he held various manual labour positions, including factory assembly, construction site assistance, and the maintenance of portable sanitation units for Mobitoil. During this same period in 2009, he also functioned as a parachute instructor for pre-military students.
Medical Practice
His clinical career began between 2015 and 2017 with roles in general surgery and intensive care in Interlaken. He served as a chief medical officer for the NATO-led peacekeeping force KFOR in Kosovo. From 2019 to 2021, he held positions as an anesthesiology assistant and as a physician for helicopter emergency rescue services. In 2021, he joined the urology team at the Biel Hospital Center and earned a specialist diploma in pre-hospital emergency and rescue medicine.
Astronaut Training
Selected as one of five career astronauts for the European Astronaut Corps in 2022, Sieber completed the Basic Training curriculum at the European Astronaut Centre. In September 2025, he participated in the ESA CAVES course located in the Matese mountains of the Italian Apennines. He maintains fluency in German, Swiss German, French, and English, and holds a private pilot license. He plans to perform his first flight between 2027 and 2030.
Fast facts
- Born: 1989, Biel/Bienne, Switzerland
- Citizenship: Switzerland
- Medical degree: University of Bern, 2015
- Military rank: Sergeant, Swiss Army Special Forces
- ESA selection: 2022
- Training graduation: 22 April 2024
- Languages: French, German, English, Swiss German
- Professional specialties: Astronaut, Urologist
Questions readers ask
Will Marco Sieber continue to practice medicine?
He intends to perform occasional shifts in hospital emergency wards to maintain his medical proficiency while fulfilling his duties at the European Space Agency.
What is his official status within the European Astronaut Corps?
He is a career astronaut who graduated from the Basic Training curriculum in 2024 and is currently preparing for missions scheduled between 2027 and 2030.
Achievements
- Recorded as astronaut and urologist
