MINNEAPOLIS - Since the late 1980's NASA has been monitoring Earth's level of ozone and watching the ozone hole change size in the southern hemisphere. Ozone in the upper atmosphere helps to block Ultraviolet light which can cause sunburn, cataracts and even crop damage. SAGE III, the latest instrument was just installed on the International Space station in the past few days and for it to work, it needs to look at the sun through our atmosphere.

"You are looking at that really strong source that's back lighting the atmosphere and you are scanning through the atmosphere back and forth, back and forth and it allows you to look at Ozone, which has been a product of sage going all the way back to the beginning." said Joe Gasbarre, SAGE III Chief Engineer.

SAGE III was installed completely by a robotic arm on the ISS and will measure Earth's level of ozone for several years to come. Scientists predict that by the year 2040, the ozone hole will shrink to a size smaller than 8 million square miles, which is 20 percent smaller than it is now.

To learn more about the SAGE III mission, visit NASA.: Stratospheric Aerosol Gas Experiment III