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THE NATION

New NASA 'Time Machine' Craft to Take in Some Sun

July 12, 2001|STEPHANI SUTHERLAND | TIMES STAFF WRITER

Hoping to catch a cosmic breeze, NASA is preparing to launch a new spacecraft to seek evidence of the earliest days of our solar system 4 1/2 billion years ago.

The satellite, to be known as Genesis, is scheduled to launch July 30. Its mission is scheduled to end in 2004 with a dramatic helicopter recovery over the Utah desert.

If all goes according to plan, NASA officials said Wednesday, Hollywood's top stunt pilots will fly in formation with the capsule as it floats to Earth on a parafoil, a highly maneuverable parachute. They will have 12 chances to lasso the craft in midair, preventing the damage of a ground landing. The trial runs have been a success, and the recovery is expected to go smoothly, said the National Aeronautics and Space Administration officials.

Mission spokesman Gilbert Yanow likens the spacecraft to a time machine. Its mission is to gather evidence about the composition of the solar system in its earliest form by collecting particles of the sun's surface.

Scientists believe the solar system began with a dense cloud of gas and dust that collapsed in on itself. Most of this "solar nebula" condensed to form the sun, while outlying particles coalesced into the planets, moons and comets.

But, although scientists have a general understanding of the formation of the solar system, they are missing a key piece of information: What was the initial nebula composed of? That question can be answered because, as unlikely as it seems, the nebula "is now stored for us in the outer layers of the surface of the sun," said Don Burnett, of Pasadena's Jet Propulsion Laboratory, who is the mission's chief scientist.

The outer layer of the sun constantly spews particles into the solar system, the so-called solar wind. Genesis is designed to collect those solar wind particles and return them to Earth for study.

Once at its destination--an orbital station known as L1, a place where the gravitational forces of the Earth and sun are balanced and little energy is required for orbit--Genesis will collect the solar wind on wafers made of sapphire, gold and diamond. Looking like a giant secret decoder watch, the lid of the craft will flip open and the collector arrays will unfurl.

Solar particles should stick in the hexagonal wafers much like bullets shot into a wall. To maximize the amount of material it can bring back for study, Genesis will bask in the sun's rays for 29 months. Apollo missions to the moon in the 1970s brought back a smattering of solar wind but used aluminum foil for collection over only a few days. The high-tech, clean wafers will provide a much more accurate sample of the sun's surface.

Back on Earth, scientists will perform sophisticated analysis to determine exactly what the nebula contained. Unlike large samples of moon rocks, the particles from the sun will add up to only 20 micrograms, the weight of a few grains of salt.

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