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Twin NASA probes will investigate space weather around Earth

Paul Sutherland, Feature writer
Aug 15, 2012, 7:00 UTC

Sen—While events on Mars are making most of the space headlines, NASA is getting ready to launch an upcoming mission to explore the environment of our own planet Earth.

Twin Radiation Belt Storm Probes (RBSP) are due to lift off aboard a United Launch Alliance Atlas V rocket on August 23 from Cape Canaveral, Florida. They were placed, in their nose cone, atop the rocket on August 10. 

The two satellites will travel in orbits that take them through two extreme and dynamic regions of space surrounding the Earth called the Van Allen Radiation Belts. They will probe space weather, the direct effects of activity on the Sun, which can in extreme cases damage satellite electronics, GPS services and cause power grids to fail.

Barry Mauk, RBSP project scientist at the Johns Hopkins University, in Maryland, said: "The dramatic dynamics of Earth's radiation belts caused by space weather are highly unpredictable.

"One of the fundamental objectives of the RBSP mission is to use Earth's magnetosphere as a natural laboratory to understand generally how radiation is created and evolves throughout the universe. There are many mysteries that need to be resolved."

The radiation belts, named after their discoverer, James Van Allen, are two concentric, donut-shaped rings filled with high-energy particles that dance about, bounce and drift through the region. Sometimes these particles shoot down to Earth's atmosphere, sometimes they escape into space. The radiation belts swell and shrink over time, a change that is part of a much larger space weather system that is driven by solar activity as material from the Sun spreads through space.

NASA says that the RBSP probes, the second mission in NASA's Living With a Star program, will help scientists to understand this radiation zone better and to design spacecraft that can survive such environments better. The spacecraft carrying out such research may eventually help scientists predict space weather before it hits the Earth's neighbourhood.

RBSP probes in orbit

An impression shows the probes' path through the invisible radiation belts. Credit: NASA

RBSP is the first to use a pair of spacecraft working together. Using two probes, speeding through the belts at around 2,000 mph, will help to tell whether changing conditions observed are genuine external disturbances rather than another effect on a single spacecraft.

The two RBSP spacecraft will have to operate in harsh conditions because of the nature of their task. Instead of switching off to protect themselves when there is a bout of bad space weather bombarding them with solar particles and radiation, they will need to "ride the storm" to continue collecting vital data during a mission designed to last two years.

The RBSP spacecraft was launched successfully on August 30, 2012 atop a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station.