WRAL WeatherCenter Blog

Trouble at 22,300 Miles Up

Posted December 6, 2007 7:15 a.m. EST
Updated December 6, 2007 12:39 p.m. EST

Anomaly -- It's such an innocent-looking word, but as anyone who follows the US space program knows, it might as well only have four letters.

As you may know, most of the satellite pictures we use on air and on WRAL.com come from a pair of geostationary satellites.  These multi-million-dollar satellites -- known as GOES-West and GOES-East -- orbit the earth at an altitude of 22,300 miles.  Each satellite orbits the earth such that it "hovers" above the same point on the earth's surface at all times.  To keep them that way, the folks in charge of the satellites have to occasionally move them a bit to correct for drift in position and other effects. (For a more detailed explanation, see the Wikipedia article associated with this blog entry.)

They were performing one of these "station keeping maneuvers" with GOES-East on Tuesday afternoon when one of those dreaded anomalies occurred.  Ever since then, the spacecraft is having trouble maintaining a proper attitude.  In other words, the satellite folks are having trouble keeping it pointed in the right direction.  As you might imagine, this is a problem.

What does that mean for us?  Well, fortunately, an older incarnation of GOES-East is still in orbit and in good working order.  Before Tuesday, it had been collecting images of South America and the southern Atlantic, but it's since been re-positioned in order to collect the same imagery we got from GOES-East before the anomaly occurred.  While some of the more advanced products are not available temporarily, most of the basic images we're used to seeing from GOES-East are available once again.

As for GOES-East, NESDIS -- the government agency in charge of the satellites -- says that it's "safe" and that it's been repositioned so that it will receive plenty of solar power.  Hopefully, with a full battery, they'll be able to correct this nasty anomaly.