Sara Mitich reveals why she left Airiam’s prosthetics behind to play Nilsson, how the switch unfolded on set, and what followed after Discovery
Sara Mitich says the switch from cyborg lieutenant Airiam to bridge officer Nilsson on Star trek: Discovery wasn’t drama behind the scenes — it was practical. On the Star Trek and Chill podcast, Mitich described how long prosthetic sessions and gruelling makeup calls made the heavy-appliance role hard to sustain, and how production found a way to keep her on the show without the same physical toll.
Mitich first appeared as Airiam in Discovery’s early episodes, a character that required extensive facial prosthetics. Those sessions could take up to five hours before a shoot, and some days stretched into 20‑plus hour workdays once removal and pickups were added. Between seasons, producers offered her a new part — Nilsson, an engineer who appears on the bridge as Mitich herself. She accepted, and the change let her perform without masks that muted facial expression and limited spontaneity.
When Airiam briefly returned later, Hannah Cheesman was credited in the role. The makeup meant the character could be recast without breaking audience immersion, and the production presented the switch as a creative and logistical decision rather than the result of any on‑set incident. Mitich says she was told about Airiam’s narrative fate only a few episodes before it aired, a reminder of how fluid television production schedules can be.
On screen the handover was smooth: prosthetics and costume design preserved continuity, and most viewers didn’t spot the swap until Mitich talked about it publicly. She also recalls a memorable moment walking onto the bridge in her own face and watching the live reactions from fellow cast members — a small but meaningful payoff for stepping out from behind the appliances.
Nilsson remained part of Discovery’s bridge crew through season 4; per production notes the character was later written as transferred to the USS Voyager‑J and did not return in season 5. Mitich has framed that absence as part of broader life choices and shifting priorities, not as a single plot-driven dismissal.
Since leaving Discovery as a regular presence, Mitich has shifted some of her energy toward wellbeing work. She founded the Gratitude and Growth platform and podcast, mixing public speaking with selective acting and using her genre‑show visibility to reach audiences interested in emotional regulation and sustainable mental health practices.
In short: this wasn’t a mystery scandal but a practical reshuffle — prosthetics and production logistics reshaped a performer’s path, and Mitich turned the change into an opportunity to do different kinds of work on and off camera. Her full account is available on the Star Trek and Chill podcast, which remains the primary source for the details she shared.