Deeva Jansen was the new captain of the Vanguard in 2503 who was secretly an Orion android. She worked for human security forces as part of their plan to recruit the Cybermen to help them in the Orion War. In reality, she was a double agent working to learn about cyber-conversion to help her android comrades in the war.
She ultimately sacrificed herself by giving her helmet to Charley Pollard to save her life, as Charley's helmet was damaged. Jansen was left damaged and floating in space, though the Eighth Doctor noted that it was possible that someone would be able to find and reactivate her at some point in the future. (AUDIO: Sword of Orion)