NASA's Genesis spacecraft, on a mission to collect particles of the solar wind, successfully conducted its first flight path maneuver Wednesday after completing its first loop around a gravitational point between the Sun and Earth.

Genesis mission trajectory illustration. Photo: NASA/JPL

Genesis is orbiting a Lagrange point, designated L1, about 1.5 million kilometers (just under 1 million miles) away from Earth toward the Sun, where gravitational and centrifugal forces acting on the spacecraft are balanced. The L1 point is a convenient place to position spacecraft because it allows an uninterrupted view of the Sun, is outside the Earth's magnetosphere and requires few spacecraft maneuvers to stay in orbit.

"Genesis crossed the finish line of its first loop and moved smoothly into its second loop (May 22)," said Genesis mission manager Don Sweetnam, of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Last month, a strong solar storm passed over Genesis. High-energy protons several times more abundant than usual bombarded the spacecraft. Proton storms can cause outages in the delicate electronics of a spacecraft or satellite. But Genesis' onboard software helped the spacecraft weather the proton storm well.

During the solar storm, the star tracker, which orients the spacecraft by centering on stars, was briefly blinded. The attitude control software handled the situation as intended, so that overall spacecraft performance was unaffected and all daily tasks were completed as scheduled.

Genesis is collecting samples of the solar wind, invisible charged particles that flow outward from the Sun. This treasured smidgen of the Sun will be returned to Earth in 2004 and preserved in a special laboratory for study by scientists in search of answers to fundamental questions about the composition and development of our solar system.

Genesis occupies what scientists call a "halo" orbit around L1, meaning that its orbit, when viewed from Earth, would look like a large oval around the Sun. Genesis went into the halo orbit on November 16, 2001.

JPL, a division of the California Institute of Technology in Pasadena, manages the Genesis mission for NASA's Office of Space Science, Washington, D.C. Lockheed Martin Astronautics, Denver, Colo., designed and built the spacecraft and operates it jointly with JPL. Major portions of the payload design and fabrication were carried out at JPL, the Los Alamos National Laboratory in New Mexico and at NASA's Johnson Space Center, Houston, Texas.