Susan Roberts was a member of the Ares One mission to Mars in the early 21st century. She piloted the Argosy to the planet's surface along with Commander Lee Forbes, Tanya Webster and Paul Webster. She and Forbes discovered an artificial structure and investigated, discovering the Fifth Doctor and Peri inside. Further exploration revealed that it contained the tomb which held Izdaal's body and his Ice Warrior guardians frozen in ice.
After the guardians became unfrozen, Forbes and the Doctor were held captive. Susan threatened to shoot the Ice Warriors if they did not release them, but was shot by Sstast and died of her injuries shortly afterwards. The Doctor angrily revealed to Lord Zzaal that her "weapon" was in fact a spectographer and that she was only bluffing. (AUDIO: Red Dawn)