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NASA Primes Spacecraft to Probe Solar System's Fringe

NASA Primes Spacecraft to Probe Solar System's Fringe
Artist's impression of NASA's IBEX spacecraft studying the edge of our solar system. (Image credit: NASA/GSFC)


NASA is gearing up to launch a new spacecraft to probe thefringe of the solar system this month where material from the sun hits the coldexpanse of space.

The InterstellarBoundary Explorer (IBEX) spacecraft is set to lift off atop an air-launchedPegasus XL rocket Oct. 19 from Kwajalein Atoll, a part of the Marshall Islandsin the Pacific Ocean.

While it won't actually travel beyond all the planets toinvestigate the solar system's far reaches, the coffee table-sized spacecraftmust escape the area where Earth'smagnetic field reigns, which could interfere with its measurements. The $169million observatory is due to climb 200,000 miles (322,000 kilometers) aboveEarth and settle into orbit there for a mission of at least two years. Forcomparison, the moon orbits about 240,000 miles (385,000 km) from Earth.

"One of [IBEX's] prime goals is to tell us the place ofthe solar system in the galaxy," said Eric Christian, IBEX programscientist at NASA headquarters in Washington, D.C., during a Monday briefing."How the solar system moves through the galaxy is scientificallyinteresting and may be interesting from an evolution-of-Earth standpoint."

The boundary at the solar system's final frontier was first exploredby the Voyager1 spacecraft in 2004, when it encountered an invisible shock created as thecharged particles streamingoff the sun hit the neutral gas from interstellar space. This so-calledtermination shock marks the beginning of the edge of the solar system.

The spacecraft will utilize a novel three-stage method toreach its distant orbit around Earth to scan the solar system?s edge. Unlikeprevious launches of the solid-fueled Pegasus rocket, IBEX will boost itselfbeyond its initial orbit using an additional solid rocket motor and a hydrazinefuel stage, mission managers said. ?

"IBEX will let us make the first global observations ofthe region beyond the termination shock at the very edges of our solarsystem," said David J. McComas, IBEX principal investigator from theSouthwest Research Institute (SwRI) in San Antonio, Texas. "This region iscritical because it shields out the vast majority of the deadly cosmic raysthat would otherwise permeate the space around the Earth and other planets."

IBEX plans to create an all-sky map of the interactionbetween particles from the solar wind, called the heliosphere, and the materialin the galaxy beyond our solar system. Sometimes, when a neutral atom frominterstellar space passes a positively-charged particle from the sun, anelectron hops from one to the other, making the charged atom neutral. IBEX isdesigned to detect these fast-moving neutral particles and trace theirdirection back to the solarsystem's edge, gradually building up a picture of this chaotic frontier.

"We know that the pictures that IBEX gives us are goingto surprise us, and that's one of the fun things about science," Christiansaid. "This is really exciting, it's really going to increase ourknowledge of the heliosphere."

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Clara Moskowitz is a science and space writer who joined the team in 2008 and served as Assistant Managing Editor from 2011 to 2013. Clara has a bachelor's degree in astronomy and physics from Wesleyan University, and a graduate certificate in science writing from the University of California, Santa Cruz. She covers everything from astronomy to human spaceflight and once aced a NASTAR suborbital spaceflight training program for space missions. Clara is currently Associate Editor of Scientific American. To see her latest project is, follow Clara on Twitter.