Yuri Kerenski

Yuri Kerenski, born in 2032, was a Russian nurse and part of the Bowie Base One Mars colony. He was a known joker, using a spare solar panel to make a "No Trespassers" sign outside the base. He had a brother, Mikhail, who lived with his husband in Dagestan.

He initially had a low-level research position in the Russian Federal Space Agency and trained as a nurse in order to progress. He would end up earning the favour of the Director General after treating him, and was given a higher nursing position. This would lead to him training at the Johnson Space Centre and befriending Tarak Ital; Yuri would stay in the US, and Ital recommended him for the Bowie Base mission.

Yuri looked after a quarantined Maggie Cain after she was infected by Andy Stone. He was destined to die in an explosion of Bowie Base One, however he escaped along with Mia Bennett and Adelaide Brooke when the Doctor interfered with the course of events and rescued them. In the timeline where he did die, he was posthumously awarded the Hero of Russia title. (DW: The Waters of Mars)