Steffi Ehrlich

Steffi Ehrlich was a German astronaut born on September 3rd 2021 in Iserlohn, Germany. She was a member of Bowie Base One until she was infected with the virus known as The Flood. She died on November 21st 2059 when Adelaide Brook activated the nuclear bomb in the heart of Bowie Base One.

Early life and career
After attending secondary school in Iserlohn, Ehrlich spent two years in the Bundeswehr. She then went on to study physics at RWTH Aachen University, taking a doctorate in solid state physics (2046). After that, she worked at Argonne National Laboratory (in Chicago) and the University of California. In 2048, she was selected to join the German astronaut team in the European Space Agency. She completed basic training at the German Aerospace Centre between 2048 and 2050.

She was part of the crew for the tenth German moon mission in the spacecraft AWARQ. In 2051, she was married and had two children Ulrika and Lisette. Shortly after her second child was born, she was selected for the Mars mission. She initially refused to leave her family but changed her mind after an unspecified event that devastated many parts of Germany.

On Mars
During the Flood invasion on 21 November 2059, she witnessed three of the crew become zombie-like water monsters before becoming one herself. In 2059, the Flood invaded the base, planning to take over the population of Earth. She was separated from the rest of the crew by falling water and trapped, with the Flood attempting to break into the room. She hid in Section 9 of the main hub and was unable to get out. Captain Adelaide Brooke said to her that she will let her out through the back of the section. Steffi watched a video of her two children just moments before the water came into the section. Steffi cried as the water gushed into the section, and Mia and Adelaide watched in horror as she was infected. Adelaide escaped with Mia Bennett after the infected Steffi came out of the section. The infected physical form of Steffi was killed in the nuclear explosion set off by Captain Adelaide Brook.

Behind the scenes

 * The obituary article was cut off, only stating that she said, "I don't want to live here any longer".
 * Like the other female member of the Flood, Margaret Cain, she kept her eye colour. It seems the males had milky, blue eyes while females kept their colour. The Doctor noted this during the episode and suggested that it meant she was closer to human than the others.