Solar storm's impacts to spacecraft should be limited
BY STEPHEN CLARK
Posted: September 12, 2014
Skywatchers with clear skies as far south as the northern United States and Europe could glimpse spectacular auroral displays this weekend, but officials say the solar storm spawning the light show is not expected to affect satellite operations or the International Space Station.
The coronal mass ejections came from a sunspot on the face of the sun pointed toward Earth, blasting clouds of radiation into space at 2.5 million mph.
When the energy starts interacting with Earth's magnetic field, the solar storm should produce auroras across mid-latitude regions. With clear skies, observers in northern Europe, Canada and the United States could get a rare treat Friday and Saturday nights.
NOAA experts rate the event as a G3, or strong, storm.
With strong geomagnetic storms, "typically we will see the Aurora right along northern tier states, so essentially New England, across the Central Great Lakes, through the Dakotas to Washington and Oregon. If it's a little stronger, we'll see it even a little farther south," said William Murtagh, program coordinator at NOAA's Space Weather Prediction Center.
NASA ground controllers were keeping watch on the storm Friday, but officials did not expect to take any special precautions on the International Space Station, according to Rob Navias, a spokesperson at NASA's Johnson Space Center in Houston.
The space station and satellites, along with airplanes flying over the poles, face additional risks from solar storms.
NOAA's website says strong G3 geomagnetic storms may cause surface charging on satellite components, increased drag on satellites in low Earth orbit, and could require corrections for spacecraft orientation problems.
A spokesperson for Intelsat, the largest operator of large commercial communications satellites in geostationary orbit, said its spacecraft have been designed to sustain space weather.
"In addition, we have various processes and alarms on the ground that will alert us to any satellite issue," said Michele Loguidice, an Intelsat spokesperson.
Such minor solar radiation storms pose no risk to astronauts in space or sensitive spacecraft electronics, according to NOAA's website.
"The satellites are engineered to survive the increased radiation dosage expected," said Martin Halliwell, chief technology officer for SES of Luxembourg, operator of more than 50 communications satellites in geostationary orbit.
"It's got everybody watching, but no serious actions need to be taken," Murtagh said.
"If we get into the higher levels, mission control will direct the astronauts into more hardened parts of the station," Murtagh told reporters Thursday. "And they've got vulnerabilities to the equipment up there as well -- some of the electronics. They will take actions fo protect those electronics during big radiation storms. The key here is we did not have a big radiation storm."
The storm's terrestrial impacts may include radio communications problems and degradation in GPS navigation signals caused by irregularities in Earth's ionosphere, according to Thomas Berger, director of the Space Weather Prediction Center.
"These storm levels also may cause some voltage irregularities in the electrial power grids in the northern latitudes of the U.S.," Berger said. "These effects are expected to be manageable and not cause any major disruptions to power transmission."
Berger said Thursday the sunspot that produced the solar flares appears to be diminishing in intensity.
"It's packed a pretty big bunch and has produced a few big flares," Berger said. "It may be a swan song. We can't say for sure, but the sunspot is now in the process of breaking up. The region is looking like it's spreading out, becoming less complex, and therefore less dangerous in terms of producing large flares, but these things can surprise you, so we are keeping a close eye on it."
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