Crew Altitude Protection System

The crew altitude protection system is worn by the flight crew members during launch and entry. Oxygen from the orbiter's environmental control and life support system is supplied to the crew members through the CAPS. A skullcap is worn under the helmet. A microphone and headphones are worn over the skullcap for two-way communications and receiving caution and warning tones. The CAPS also incorporates an anti-exposure, anti-gravity suit to prevent pooling of body fluids and to aid in maintaining the circulation of blood during entry. Pooling of body fluids can occur when high ''g'' loads are imposed on the body, particularly after crew members have had more than 12 hours of zero-gravity activity. The anti-gravity portion of the CAPS is pressurized from the ECLSS oxygen system.