WASHINGTON —  One of two primary satellites used by the U.S. National Oceanic and Atmospheric Administration (NOAA) to track severe weather in the United States has been knocked out of service, prompting the agency to activate a spare satellite to maintain East Coast coverage.

According to status updates posted on NOAA’s website, service from the Geostationary-orbiting Operational Environmental Satellite (GOES)-13 suffered an outage of its two main instruments May 22. The Boeing-built spacecraft was launched in May 2006 into a storage orbit and was activated in April 2010.

With GOES-13 out of commission, East Coast coverage is now being provided by the newly activated GOES-14 satellite, which was launched into a storage orbit in June 2009, the latest status update, issued May 23, said.

NOAA normally 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-15 was launched in March 2010 and activated in December 2011.

Despite being activated, GOES-14 remains in its storage location at 105 degrees west, the status report said. NOAA currently has no plans to drift that satellite, which launched in 2009, eastward, the latest status report said.

“GOES-13 will remain in storage mode while the anomaly is being investigated,” the status report said. “No estimate on return to operations at this time.”

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

NOAA also maintains the aging GOES-12 satellite at 60 degrees west to provide coverage of South America. That spacecraft, launched in 2001, was built by Space Systems/Loral of Palo Alto, Calif.

NOAA spokesman Tom Renkevens said the outage occurred late May 21 East Coast time, and that the agency initially switched GOES-15 to so-called full disk imaging mode to maintain coverage of the entire continental United States. GOES-14 is operating well and providing the full range of data products while engineers continue to troubleshoot the GOES-13 issue, he said.

Warren Ferster is the Editor-in-Chief of SpaceNews and is responsible for all the news and editorial coverage in the weekly newspaper, the spacenews.com Web site and variety of specialty publications such as show dailies. He manages a staff of seven reporters...