Coming from a multi-national background (her father is an Englishman of Hungarian descent and her mother is Burmese), Sandra encountered many different languages as her family moved from place to place during her youth. Perhaps this is where her interest in communication was born, but her interest in electronics stems from the years she spent as a child working in the lab of her father, Professor Lawrence Benes. Professor Benes developed the Interstellar Transmitter, a powerful broadcasting device vital for deep space communications. Knowing more about the unit than anyone besides her father, Sandra was a natural choice for the Data Section of Moonbase Alpha. Her expertise and skills allowed her to rise quickly to the position of Data Section Coordinator.
Titled "data analyst" in Matter of Life and Death and Black Sun. She is renamed "Sahn" in Year 2 (the name first appears in the script of Journey to Where, but she first appears with the name in Catacombs of the Moon onwards; the name Sahn also appears on her ID badge, with no surname).
Sandra is usually at her Main Mission/Command Centre desk, working on communications or scanners and sensors. Sometimes assigned to missions: Matter of Life and Death, Black Sun, The Full Circle, Missing Link, The Last Sunset. She is part of the command team, and attends command conferences. In addition to operating communications and sensors, Sandra also has practical training as an electrician and advises Fraser on setting up an electrical barrier in The Beta Cloud.
Her fiancee was pilot Peter Rockwell, seen in The Bringers of Wonder - Part 1 (their marriage was to be when her duty tour on Alpha ended). In Black Sun she was attached to pilot Mike Ryan. By the end of Black Sun a relationship was evolving with Paul Morrow; the alternative Paul and Sandra in Another Time, Another Place were married with children. Their closeness is also seen in Matter of Life and Death, Alpha Child, The Last Sunset, The Full Circle: "Give my love to Sandra" he tells Alan. "Not if I can help it" Alan replies. She is often placed under great emotional stress, but recovers her wits and composure quickly (she is blinded in Matter of Life and Death, she faints at the death of her boyfriend in Black Sun, she is captured and tortured by cavemen in The Full Circle).
Prominent roles in Matter of Life and Death, Black Sun, Missing Link, The Full Circle, The Beta Cloud and The Bringers of Wonder - Part 1. She also appeared in Message From Moonbase Alpha as the last Alphan to leave the base before the Exodus to Terra Alpha.