CAPE CANAVERAL, Fla. A robotic NASA explorer is poised to set sail Monday, July 30 on a mission to catch the solar wind and then return to Earth with a representative sampling of the primordial stuff that seeded the solar system.
Some 4.6 billion years after an interstellar cloud of gas, dust and ice collapsed and spawned the Sun and its attendant planets, the spacecraft will blast off in late July for a distant space harbor where conditions remain much the same as those at hand when the solar system formed.
Pristine material tossed off the turbulent sun then will be snatched up before the spacecraft swings back by Earth, flinging a sample return capsule toward a daring helicopter recovery over the Utah desert in September 2004.
The scientific prize: A cache of interplanetary matter that could enable 21st century researchers to decipher the elemental and isotopic make-up of the original solar nebula.
"Were looking at the beginnings," said Richard Bennett, a mission systems engineer with NASAs Jet Propulsion Laboratory in Pasadena, Calif. "The focus here is to try to gather information about how the solar system formed."
Now set for launch July 30 aboard a Boeing Delta 2 rocket at Cape Canaveral, the aptly named Genesis spacecraft will embark on a three-month journey to L-1, an interplanetary libration point where the gravitational pulls of the Sun and the Earth are balanced.
Flying some 1 million miles (1.5 million kilometers) away from Earth, the spacecraft then will spend the following two years cruising outside the influence of the planets magnetic field, sweeping through pure solar wind with a set of sophisticated collectors.
The anticipated product: Samples of the same type of matter that combined eons ago to form the Sun, nine planets and their concomitant moons as well as comets and asteroids.
"Were getting out the influence of the magnetosphere and into an area where the solar wind will not be perturbed as its coming off the sun," Bennett said.
"Well just get the pristine wind as its coming in toward Earth, and thats what were after. We dont want to see something that in essence was manipulated or tainted by the Earth and its environment."
The Sun is thought to contain more than 99 percent of the various matter found throughout the solar system, and material blasted off its surface is constantly carried through interplanetary space by the solar wind.
Built by Lockheed Martin, the $90 million Genesis spacecraft is equipped with collector arrays that are designed to gather matter being blown toward Earth.
Housed in a conical sample return capsule that will swing open like a clamshell, the arrays contain wafers of ultra-pure silicon, sapphire and other materials that first will capture and then preserve solar wind particles.
"The particles are trapped really simply," said JPL project manager Chet Sasaki. "We expose the collectors. The solar wind comes zipping along, and the particles slam into the collector and embed within it."
After flying five halo orbits around L-1, the collectors will be stowed back within the sample capsule before its lid is tightly closed for a five-month trip back to Earth.
As simple as all that sounds, project managers faced a huge engineering challenge in designing and building the spacecraft: Preventing sample contamination.
"We had to make sure that the (collector) materials we put on the spacecraft were properly sealed and maintained as pristine as possible so that when they are exposed, what were really measuring is the matter within the solar winds," Bennett said.
"And after that, the solar wind particles have to be sealed back up in the return capsule and brought back to Earth safely without breaching those seals."
Next page: Counteracting contamination
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