The nose landing gear is steerable. The landing gear are retracted and deployed by hydraulic mechanism, and are locked in position within a wheel well and protected by landing gear doors when not in use. The Caution and Warning System , which is designed to warn the crew of any conditions that may adversely affect the performance of the Orbiter. The Caution and Warning System primarily consists of a set of visual and aural alarms that alert the crew when any system has exceeded or strayed from its operational limits. The Orbiter Lighting System , which provides both interior and exterior lighting for the Orbiter.
Interior lighting is used primarily to support crew operations.
Exterior lighting is used primarily to illuminate the payload bay area in order to aid visibility during payload operations and spacewalks. The Smoke Detection and Fire Suppression System , which is designed to warn the crew of any fires, as well as protect the Orbiter from any fires that might develop. The system is made up of smoke detectors, portable fire extinguishers and automatic fire extinguishers. The Payload Deployment and Retrieval System , which includes an electromechanical arm that maneuvers a payload from the payload bay and back again, plus all of its related hardware. The RMS can remove payloads from the payload bay for deployment.