For Release: May 10, 1996

Steve Roy
Office of Media Services
(205) 544-0034
steve.roy@msfc.nasa.gov

RELEASE: 96-37

INTERNATIONAL SPACE STATION AIR PURIFICATION SYSTEM COMPLETES MAJOR TEST

The system that will purify the air aboard the International Space Station recently passed a major test at NASA's Marshall Space Flight Center in Huntsville, Ala. The month-long test evaluated the system’s ability to control carbon dioxide, oxygen and air pressure inside the Station’s living and laboratory quarters.

Simulating the breathing activity of a crew of four, engineers injected carbon dioxide and water vapor, and removed oxygen from the school bus-size, six thousand two-hundred cubic foot test module throughout the 30-day test to evaluate an air purification system.

"The test provided an excellent demonstration of the Atmosphere Revitalization Subsystem's capability for maintaining the cabin air composition using control procedures to be used onboard the International Space Station," said Jay Perry, life support engineer of Marshall Center’s Thermal and Life Support Division and test principal investigator. "Throughout the test, the systems operated in a fully-automated fashion and its components responded very well to the simulated human breathing activity," explained Perry. The test was the fifth in a series of the Atmosphere Revitalization Subsystem begun in 1987.

The test also featured operation of the carbon dioxide removal system at reduced levels to save power. The test system operated at full power levels during the fifty-three minute daytime portion of the orbit and at lower levels during the thirty-seven minute nighttime orbit, just as planned for Space Station. The nitrogen and oxygen composition of the atmosphere was controlled by signals from an air composition monitor and special computer software was developed for automated control very similar to that planned for use on the Space Station.

The Atmosphere Revitalization Subsystem demonstrated the capability of providing a healthy working environment for the crew and achieved a power savings of up to 200 Watts over previous operating modes. These savings are significant and represent additional electrical power available for science experiments onboard the Space Station.

Additional testing of the Atmosphere Revitalization Subsystem is planned to determine the capability of the various subsystems to remove other trace contaminants. The air purification hardware is scheduled to be launched in the U.S. Laboratory Module in 1998.

Marshall Center is conducting a variety of air purification tests in support of the Space Station Program Office.