Rescue Operational Security Module G723 (ROSM) was an artificial intelligence built into a spacecraft working around the Cimmerian System. It was designed by Professor Astrov to protect company interests and property, including rescue of company employees from danger.
ROSM consisted of an interstellar rescue ship with an AI core and twenty roving assault units. All were outfitted with weapons and scanners. The ship included a teleportation system and force field generators.
The AI itself was designed to be a bit heavy-handed in protecting company interests. In the case of danger to company personnel, ROSM had no hesitations in destroying whatever threat existed. Unknown elements (such as the Doctor and Charley) were subject to a detailed cellular scan and interrogation looking for any possible threat.
ROSM picked up a distress signal coming from the nearby Cimmeria IV base and moved in to assist. It found the TARDIS hovering in space nearby and retrieved it, suspecting that it was involved with the distress call. ROSM examined the Eighth Doctor and Charlotte Pollard for potential dangers, declaring Charley a biohazard due to the carcinogenic potentials in her body. Its solution was to execute her until the Doctor convinced ROSM that there were larger problems at hand.
ROSM landed on the planet and was attacked by the Cimmerians, who blanketed the base in particles that disrupted electronics. These disabled all of ROSM's roving units and caused serious malfunctions in its central core. With its sensors off-line and its logic circuits compromised, ROSM began to doubt the validity of all outside data and refused advice from others.
The Doctor recognised that the Cimmerian particles were interfering and activated a system of mini-suns in orbit around Cimmeria IV to clear them out. He also made contact with the Cimmerians and determined that they were using the particles to hide from their ancient persecutors, the Solarians. With the particles purged ROSM was able to recover full functionality.
ROSM lifted back to orbit over the planet, where it was attacked by the Solarians. Rescued base commander Orllensa ordered ROSM to destroy the sun system to stop the Solarians, but ROSM considered this destroying company property and refused any further orders. The Solarians soon disabled and captured the rescue craft. Luckily the conflict was resolved as a centuries-old misunderstanding between the Solarians and Cimmerians and the rescued humans were released.