Stevenson (Revenge of the Cybermen)

Commander Stevenson was the head officer of the Nerva Beacon crew.

The Voga account
Stevenson, Lester and Kellman were the last survivors of a plague affecting the station. When he was captured by the Cybermen, they forced him to carry Cyber-bombs deep inside Voga along with the Fourth Doctor and Lester. The Doctor managed to deactivate the bombs and they met up with the Vogans. Stevenson used the controls there to redirect Skystriker into the cyber-ship, destroying it. (TV: Revenge of the Cybermen)

The asteroid account
According to another account, he was the commander of the Nerva Beacon and was still under a plague situation. (AUDIO: Return of the Cybermen)