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STS-121 Payload Carries Breath of Fresh Air
The Oxygen Generation System is uncrated after delivery to Kennedy Space CenterA device roughly the size of a refrigerator could allow larger crews than ever to live on the International Space Station, increasing research that benefits life on Earth and supports future exploration.

The new Oxygen Generation System (OGS) can provide 12 pounds of oxygen during a normal day aboard the station, enough to support six crew members -- double the size of the largest crews in the past. Space Shuttle Discovery will carry the system to the station during the STS-121 mission, set to launch in July from NASA's Kennedy Space Center, Fla.

Image to left: At NASA's Kennedy Space Center, the new Oxygen Generation System is moved into the Space Station Processing Facility after being removed from its shipping container in January 2006. Image credit: NASA/KSC

When circumstances call for more oxygen -- for example, if additional people are aboard during a space shuttle mission or crew exchange, or if oxygen is lost through experiments or airlock depressurization -- the system could provide an extra eight pounds of oxygen per day, bringing the total maximum output to 20 pounds.

Like the Elektron system currently used on the station, the OGS relies on a process called electrolysis, in which water is split into oxygen and hydrogen. The oxygen is released into the station atmosphere, and the hydrogen then is discarded into space. The OGS offers a higher oxygen production capacity than Elektron and will provide important backup capability for supplying oxygen to the station crews.

Initially, the OGS will use water carried up to the station from Earth. Ultimately, the device will draw water from the Water Recovery System which will be launched and operational before the first six-person crew arrives in 2009. Together, they will form a "closed-loop" regenerative life-support system in which wastewater generated on the station will be recycled and used as a source of additional drinking water and to supply water to the OGS.

NASA astronaut Peggy Whitson examines a plant experiment on the International Space StationImage to right: NASA astronaut Peggy A. Whitson, Expedition Five flight engineer, works with the Advanced Astroculture soybean plant growth experiment in the Destiny laboratory on the International Space Station in July 2002. The new Oxygen Generation System to be delivered during the STS-121 mission can help make up oxygen lost through such experiments. Image credit: NASA/JSC

"Once complete, the regenerative life-support system will sustain additional crew members onboard that can conduct more scientific research," explained Mike Suffredini, station program manager. "It also will give us experience operating and sustaining a closed-loop life support system similar to that necessary for future human spaceflight missions farther from Earth."

During the STS-121 mission, astronauts will move the OGS from the multi-purpose logistics module Leonardo into the U.S. laboratory module, Destiny. The new system could be up and running as early as spring 2007, supplying a new breath of fresh air to explorers living and working in orbit.
Anna Heiney
NASA's John F. Kennedy Space Center