WASHINGTON — A major solar storm early this month appears to have caused one or more momentary satellite computer failures, but the Air Force’s top space official said Thursday the Pentagon’s fleet of orbiters is tough enough to withstand an increasingly energetic sun.
The recent solar storm that hurled billions of tons of charged solar particles into space — some of which reached Earth — is the latest in series of eruptions as the 11-year sunspot cycle moves toward a period of maximum activity next year.
The storms can impede radio communications and if they’re strong enough, cause electrical surges that destroy ground-based power grids and electronics. They also affect satellite operations.
“We’re very concerned about solar activity,” said Gen. William Shelton, commander of Air Force Space Command. “What it really does is provide this increase of highly charged particles that our satellites fly through.”
Earth’s magnetic field shields the planet’s surface from solar particles, but it provides little protection to satellites orbiting hundreds or thousands of miles above Earth.
Although it’s hard to prove cause and effect, Shelton said, recent solar storms have lined up with brief computer problems onboard Air Force spacecraft. Speaking to reporters Thursday, Shelton did not specify which satellites’ computers had been effected.
“Something that should have been a zero went to a one or vice versa, and that causes the computer to say, ‘I don’t understand what’s going on,’ so it reboots, and that’s precisely what happened,” he said.
These “single-event upsets,” in Air Force terminology, have had no operational effects, Shelton said.
“The computer just resets and it starts working again, and it works fine,” he said.
The Air Force continually works to harden its satellite parts against radiation from solar particles, Shelton said, and it would take an extremely rare and vicious solar storm to permanently disable an Air Force satellite.
In the case of a truly devastating storm, the failure of electrical systems across wide regions of the Earth might render the fate of satellites a minor concern.
“Short of something truly catastrophic, which would be catastrophic to people on Earth as well, I don’t believe there’s a scenario where we would just wholesale lose spacecraft,” he said.