One of NOAA's most important weather satellites returned to normal service last week, nearly a month after a micrometeroid struck the satellite and knocked it slightly off its path in orbit around the Earth.
Tests showed the GOES-13 satellite likely took a hit in the arm of its solar array panel on May 22, which shifted the satellite off its "delicate, geostationary balance" over the eastern United States, NOAA reported in a press release June 6.
The impact forced the satellite to shut down immediately, which alerted NOAA engineers to put the GOES-13 into safe mode while they studied what went wrong. The collision was determined not to have damaged the satellite's instruments or the satellite itself.
During normal operations, the GOES-13 satellite remains parked over the eastern U.S., where it monitors the East Coast and the tropical Atlantic. The data it collects is used in models for hurricanes and tropical storms, as well as models for day-to-day weather forecasting, explained Mark Elliot, a meteorologist for The Weather Channel.
GOES-13 Satellite artist's rendering.
"Many of the images shown on TV are images from GOES-13 and we rely on this to tell the weather story," he added. "So real time views and forecasts both come from this satellite data."
As NOAA explains on its website, the GOES satellite system is designed with backups for situations like this. "At all times, NOAA operates two GOES spacecraft -one in the East and the other in the West- both hovering 22,300 miles above the equator," its press release notes. "NOAA always keeps an additional GOES in orbital storage mode ready to step in if one of the active satellites experiences trouble."
While GOES-13 was shut down, NOAA configured two of its other GOES satellites (GOES-14 and GOES-15, which is parked over the western U.S.) to provide backup coverage for the eastern U.S. and part of the Atlantic Ocean.
The micrometeroid impact was a first for a NOAA weather satellite but hardly a first for U.S. space operations, Elliott said. The Mars Orbiter Mirrored Surface has been pelted by micrometeors in the past, and the International Space Station is protected by micrometeor shields, even for its astronauts on spacewalks.
"So these are known issues," he added. "That said, there is no clear answer for how many micrometeors may be out there, or if/when this may happen again."
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