[2] From 1998 to 2003 Gerst participated in several international scientific collaborations and field experiments, including some in remote locations such as Antarctica.

[2] From 2001 to 2003, Gerst studied for a master's degree in earth sciences at Victoria University of Wellington in New Zealand.

[3] While researching his master's thesis, he developed volcano monitoring techniques that might improve forecasts of volcanic eruptions.

[7] In September 2019, he participated[8][9] in the ESA CAVES[10] mission of the European Space Agency alongside Janette Epps, Takuya Onishi, Joshua Kutryk, Joe Acaba and Nikolay Chub.

The astronauts moved a failed cooling pump from temporary to long-term storage on the station's truss.

They also installed a new relay system that will provide backup power options to the mobile transporter, which moves the large robotic arm around the out outside of the space station.

[18] On 10 November 2014, he landed on Earth in the same Soyuz TMA-13M spacecraft that flew him to the International Space Station on 28 May along with Russian commander Maxim Suraev and NASA astronaut Reid Wiseman.

[28] Some of Gerst's background and appearance is incorporated into the character of Alex Vogel, a German astronaut and part of the crew of the Hermes vessel in the 2015 science-fiction film The Martian.