Genesis Mission Status
May 23, 2002
NASA’s Genesis spacecraft, on a mission to collect
particles of the solar wind, successfully conducted its first flight
path maneuver yesterday after completing its first loop around a
gravitational point between the Sun and Earth.
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 yesterday,” said Genesis mission
manager Don Sweetnam, of NASA’s Jet Propulsion Laboratory, Pasadena,
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.
Genesis leaving Earth's orbit
this transition from solar nebula to planets took place has both
fascinated and mystified scientists. Why did some planets, like Venus,
develop thick, poisonous atmospheres, while others, like Earth, become
hospitable to life? Partial answers are available from the study of the
elemental and isotopic compositions of the solar system bodies which
suggests that moons, planets, and even asteroids, are significantly
different in composition. These objects are "fossil residues" and
differences in basic elements and isotopic compositions provide invaluable
insight into how the solar nebula evolved. Using these differences
scientists can model various evolutionary processes, but we are hampered
by one major issue -- we do not know what the original solar nebula was
sun, which contains well over 99 percent of all the material in the solar
system, may help us find the answer. While its interior has been modified
by nuclear reactions, the outer layers of the sun are composed of very
nearly the same material as the original solar nebula. Some of the sun's
composition can be determined by the characteristics of the light it emits,
but the abundances of many elements and nearly all isotopes are as yet
we could collect a piece of the sun? The sun's hot, turbulent surface,
over 3,000 degrees Fahrenheit, prevents collecting a sample in the same
way we would for a planet, but we can collect material flung from
the sun, material we call the solar wind. By stationing a
spacecraft outside Earth's magnetic field, this material can be captured
and returned to Earth where high precision analyses can be carried out
with some of the most sophisticated laboratory instruments in the world.
Comparing the sun's isotopic composition and abundances against known
planetary composition data sets may provide another piece of the puzzle in
our continuing search for origins.
What Is Genesis All About?
believe the solar system was formed 4.6 billion years ago by
the gravitational collapse of the solar nebula, a cloud
of interstellar gas, dust and ice created from previous generations of
stars. As time went on most of the gas and dust were pulled together
by gravity to form the sun while other grains of ice and dust stuck to
one another, eventually forming the planets, moons, comets, and
asteroids as we know them today.
spacecraft will be placed into orbit around
L1, a point between Earth and the sun where the gravity of
both bodies is balanced. Once in orbit, Genesis will unfurl its
collector arrays and begin collecting
particles of the solar wind that will imbed themselves in
specially designed high purity wafers. After two years, the sample
collectors will be re-stowed and returned to Earth for an exciting
mid-air recovery of the sample return capsule. The samples will be
stored and cataloged under ultra-pure cleanroom conditions and
made available to the world scientific community for study.
GENESIS PLANNED TRAJECTORY