HAMPTON, Va., Feb. 11, 2011 /PRNewswire-USNewswire/ -- News media are invited to observe testing of an Earth-observing satellite instrument being prepared for flight on the International Space Station (ISS).
The SAGE III instrument will measure ozone, water vapor and aerosols in the atmosphere after it is launched into orbit in 2014. SAGE III-ISS will be attached to the space station via robotics. SAGE stands for Stratospheric Aerosol and Gas Experiment.
During testing, the instrument will be commanded to point to and lock onto the sun as if the satellite was engaging a sunrise event over the horizon.
Once locked onto the sun, the instrument's scan mirror will scan the full disk of the sun every two seconds. The event will last two to six minutes. At the conclusion of the event, the scan head will be returned to its park position until the next scheduled event.
When testing at night, the moon is used as the radiant source and the procedure is the same.
SAGE III is the newest incarnation of two previous SAGE instrument designs. SAGE I was launched in 1979, followed by SAGE II in 1984. SAGE II gathered data for more than 20 years, and the information it collected was part of the effort that led to a global ban on chlorofluorocarbons in 1987.
Chlorofluorocarbons were used in air-conditioning units and aerosol spray propellants that contributed to the Earth's shrinking layer of protective ozone, which has begun to recover due to these actions.
A third SAGE instrument, SAGE III Meteor-3M, was launched in 2001 on a Russian satellite. It went out of service five years later when the satellite's power supply failed.
SAGE III-ISS is set to launch in 2014. SAGE III-ISS has been stored in a clean room at Langley since 2002. It was called back into service in 2010 and has been undergoing testing at Langley.
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