6:06pm

Thu April 18, 2013
Space

Tracking 'Killer Electrons' Help Predict Risks To Satellites

Originally published on Thu April 18, 2013 10:26 pm

Transcript

MELISSA BLOCK, HOST:

We're accustomed to hearing about local weather conditions like high pressure zones or the jet stream. But just outside of the atmosphere, the conditions are a little stranger.

(SOUNDBITE OF ELECTROMAGNETIC WAVES)

BLOCK: That's a recording made by two new NASA satellites launched to study space weather.

As Lauren Sommer reports from member station KQED, the satellites could be in for some extreme conditions this year.

LAUREN SOMMER, BYLINE: There are more than a thousand satellites orbiting our planet; satellites that we depend on every day for GPS navigation, weather forecasts and TV.

JEAN-LUC FROELIGER: Certainly every Olympic Games, the Super Bowl, as well as the Academy Awards.

SOMMER: Jean-Luc Froeliger is responsible for satellites that carry those events. He's a vice president at Intelsat, a global satellite operations company. One thing he knows - space is not a boring place.

FROELIGER: In April 2010, we had an event on our Galaxy 15 satellite. We were sending commands to the satellite but the satellite was not accepting any command.

SOMMER: Galaxy 15 had become a zombie - a $100 million zombie.

FROELIGER: The satellite started to slowly drift.

SOMMER: Right into the path of another satellite. Froeliger says it took months to reboot Galaxy 15 - just about all you can do for a satellite that's 22,000 miles away. He says it's a risk you take in the harsh environment outside our planet's atmosphere.

FROELIGER: Satellites are constantly bombarded by high energy particles that flow from the sun.

SOMMER: Our sun sends out a stream of charged particles, which gets more intense when the sun is active, like this year.

(SOUNDBITE OF FOOTSTEPS)

SOMMER: David Smith is a physicist who studies these particles. He's taking me up to the roof of a four-story building at the University of California Santa Cruz, where there are about a dozen antennas.

DAVID SMITH: So this is it from the outside. This is our mission operation center.

SOMMER: Smith says protons and electrons from the sun get trapped in the Earth's magnetic field and create basically a giant, invisible donut around the planet, known as the radiation belt.

SMITH: What we're studying is electrons that come slamming down onto the atmosphere from Earth's radiation belts.

SOMMER: Should I be concerned standing on the roof here right now?

SMITH: No. So, none of this makes it to us.

SOMMER: Some electrons in the radiation belts travel at almost the speed of light.

SMITH: They can penetrate several millimeters of aluminum or steel.

SOMMER: They can pass through a satellite's casing and hit a computer chip, corrupting its data. That's why they have the nickname killer electrons. Smith and his team have sent large research balloons to the top of the Earth's atmosphere to detect how many killer electrons are in the radiation belt.

SMITH: The balloons are over Antarctica. I think we have about six up as of today.

SOMMER: Smith says forecasting the danger from high-energy particles is tricky because when they leave the sun's surface, they're low-energy.

SMITH: It's after the Earth captures them that something ramps them up to these really high energies.

SOMMER: To find out what that something is, Smith and his team are working with a new NASA mission.

UNIDENTIFIED MAN #1: Rock report range status.

UNIDENTIFIED MAN #2: This is the rock range is green.

SOMMER: Last August, NASA launched the Van Allen Probes.

(SOUNDBITE OF A ROCKET LAUNCH)

SOMMER: The probes are two satellites that fly right through the Earth's radiation belt. In December, they made this recording of a mysterious phenomenon - electromagnetic waves.

(SOUNDBITE OF ELECTROMAGNETIC WAVES)

DR. CRAIG KLETZING: We've known about these waves for quite a long time. But we've never had the kind of measurements that we needed to really understand them.

(SOUNDBITE OF ELECTROMAGNETIC WAVES)

SOMMER: Craig Kletzing, of the Van Allen Probes mission, says one theory is that these waves could be responsible for Killer Electrons.

KLETZING: Actually the waves give energy to particles much like a surfer does.

(SOUNDBITE OF ELECTROMAGNETIC WAVES)

SOMMER: Think of these waves as the ocean and the electrons as little surfers. These results and others could give scientists a better understanding of the Earth's radiation belt. That could lead to better forecasts about the risks; something that's key for NASA and for the satellites we depend on for live sporting events and tomorrow's weather report.

For NPR News, I'm Lauren Sommer in San Francisco.

(SOUNDBITE OF MUSIC)

ROBERT SIEGEL, HOST:

This is NPR News. Transcript provided by NPR, Copyright NPR.