Starstruck

Spacecraft Launched to Watch Earth and Warn of Solar Storms

From a million miles away, an Earth-watching satellite will issue solar storm warnings.
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NOAA’s Deep Space Climate Observatory spacecraft nears completion. Known as DSCOVR—a partnership between NOAA, NASA, and the U.S. Air Force—the craft will warn of threatening solar geomagnetic storms before they reach Earth.


Update: The DSCOVR spacecraft launched Wednesday, February 11, at 6:03 p.m. EST. The 1,256-pound (570 kilogram) observatory will take about 110 days to reach its orbital position and begin operations.

A planned attempt to land the rocket's first stage on an ship was canceled because of weather.

Earth’s newest space sentinel, the Deep Space Climate Observatory, is scheduled to launch Sunday to provide a 24-hour view of the Earth’s face and 20- to 30-minute warnings of threatening solar geomagnetic storms before they reach Earth.

“These geomagnetic storms can be very dangerous to critical infrastructure on Earth-power grids, aviation communications systems, satellites in orbit,” said Tom Berger of NOAA’s Space Weather Prediction Center.

The $340 million National Oceanic and Atmospheric Administration spacecraft will observe both the sun and Earth from a stable point in space roughly one million miles (1.6 million kilometers) away from our planet. The craft is set for a February 8 launch at 6:10 p.m. EST from Cape Canaveral in Florida.

“The spacecraft will sit like a lighthouse off the shore, watching for solar storms before they strike our planet,” says solar physicist Thomas Bogdan, head of the University Corporation for Atmospheric Research in Boulder, Colorado. (For more on the threat of powerful solar storms, read “Sun Struck” from National Geographic magazine.)

Replacing a decades-old space weather satellite, the craft—nicknamed DSCOVR—is also meant to more accurately observe clouds, weather, vegetation, and pollution patterns with around-the-clock observations of the planet’s sunlit face.

Fast Movers

Fast-moving blasts of charged particles erupting off the sun, called coronal mass ejections, can trigger geomagnetic storms if they strike Earth. The most dangerous blasts have a magnetic field that points south, opposite Earth’s magnetic orientation, which allows them to penetrate to the planet’s surface.

These monster storms can induce power surges along pipelines and electrical wires, even triggering transformer blowouts like those that knocked out power across the province of Quebec on March 13, 1989. The famed 1859 “Carrington event” solar storm burned out telegraph wires across North America and sparked northern lights above Hawaii and Cuba. (Read about the devastating effect the Carrington event would have if it hit today.)

Until a solar blast reaches a satellite, Bogdan says, scientists can’t tell the direction of its magnetic field. That’s why DSCOVR will orbit at a gravitationally stable Lagrangian point closer to the sun. At this Lagrangian point, the Earth, the sun, and centrifugal force combine to hold the satellite steady.

“The power grids really need a heads-up if we are looking at another Carrington event,” Bogdan says. “The fastest moving ones can arrive at Earth only 20 hours after they erupt from the sun.”

Space Odyssey

Watching space weather was originally a secondary mission for DSCOVR when it was first suggested in 1998 by then U.S. Vice President Al Gore. Gore proposed having a satellite that would broadcast a continuous video of Earth from space, a view that might raise environmental awareness and measure how much sunlight is re-emitted back into space by the Earth’s surface, a crucial climate question.

Built and intended for launch on NASA’s space shuttle, the mission was mothballed by the Bush Administration in 2001.

However, in 2008, the mission’s fortunes changed with the retirement of NASA’s Advanced Composition Explorer (ACE), which since 1997 had provided solar storm warnings from the same Lagrangian point that DSCOVR will occupy.

“Absolutely this is a great thing for science and the planet, that it will finally reach space,” says Bogdan, who was part of the team that designed its solar storm monitoring instruments. “And I do wonder if it will change the way we look at our planet, to always have a view of its face, fragile and alone in the solar system.”

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