Morton (Secrets of Telos)
Morton was the engineer on Captain Hopper's rocket. During their expedition on Telos, in which they re-awakened Cybermen from their Cyber-tomb, Morton was busy making repairs to the rocket, (AUDIO: Secrets of Telos) because it was sabotaged, (TV: The Tomb of the Cybermen) and never met the Second Doctor.
She was a capable mechanic, though there were still repairs to be made when they departed. Unseen by the crew, a Cybermat had managed to stow away aboard the rocket. It quickly made repairs of its own, even augmenting the ship's travel capabilities, for faster travel. Morton was more trusting of the Fifth Doctor, when he arrived with Tegan Jovanka and Nyssa, than was Hopper. She still deferred to Hopper, as her captain, and locked down the TARDIS on his orders.
When a partially converted Cyberman became a threat on their rocket, she sent it out into the vacuum of outer space, opening the airlock by reversing the magnetic pulse field in the hold, and freed Tegan and Nyssa from their handcuffs. Later, on Telos Minor, she was practical about threats, but still echoed her earlier reasoning that Cybermen hadn't been seen for centuries, refusing to believe their factory might be in operation. She ignored their pleas to leave until the danger became more obvious. In fact, it was Professor Vansom who had restarted operation. (AUDIO: Secrets of Telos)