WASHINGTON — Engineers at the U.S. National Oceanic and Atmospheric Administration (NOAA) are reactivating a key geostationary weather satellite knocked offline last week in hope of pinpointing exactly why it malfunctioned. 

Geostationary-orbiting Operational Environmental Satellite (GOES)-13 suffered an outage of its two main instruments May 22, prompting NOAA to activate a spare satellite in order to maintain East Coast coverage. The spare, GOES-14, was launched in 2009 and placed in a storage orbit at 105 degrees east, where it still resides despite being pressed into service last week as the temporary GOES-East.

NOAA said May 29 it has no immediate plans to drift GOES-14 eastward — a fuel-consuming manuever it would prefer to avoid if GOES-13 can be returned to service soon — but is prepared to do so if severe weather, including tropical activity brewing in the Atlantic and Gulf Coast, threatens the East Coast.

“As we’ve already seen this year, severe weather is a constant, potentially deadly, threat in the United States, which means NOAA’s satellites — including the back-ups — must be ready for action, so the flow of data and imagery can continue without interruption,” said Mary Kicza, assistant administrator for NOAA’s Satellite and Information Service.

NOAA maintains two operational GOES satellites, overlooking the East and West coasts of the U.S. mainland. Each satellite has an imager, which monitors storms and cloud coverage, and a sounder, which takes vertical profiles of atmospheric temperature and humidity.

GOES-13, the primary East Coast satellite, is located at 75 degrees west longitude, while GOES-15 provides West Coast coverage at 135 degrees west. 

GOES-13 was launched in May 2006 into a storage orbit and was activated in April 2010. GOES-15 was launched in March 2010 and activated in December 2011.

The GOES-13, -14 and -15 satellites were built by Boeing Space and Intelligence Systems of El Segundo, Calif., and are designed to operate for 10 years.

Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...