- For other uses, see Thorsson.
Thorsen was a Human male who served aboard the Federation starship USS Endeavour as a Lieutenant in the 23rd century.
By 2266, Lt. Thorsen was serving as the Endeavour's Chief of Security. (VAN novel: Reap the Whirlwind)
In 2268, Lt. Thorsen was on the bridge at the navigator's console during an altercation with the Tholians in the Eremar system. At Captain Atish Khatami's command, Thorsen served as the tactical officer, operating and reporting on shields, phasers and photon torpedoes. (VAN novel: Storming Heaven)