First Year of Solar Wind Satellite “Genesis” a Success

Los Alamos National Laboratory: As scientists at Los Alamos National
Laboratory begin analysis of first-year data from the solar wind probe
GENESIS they have determined the spacecraft is working so well that they
are considering possibilities for research beyond the planned 2004 mission
completion date. Three of GENESIS’ instruments were designed and built
at Los Alamos.

Along with colleagues from NASA’s Jet Propulsion Laboratory and the
California Institute of Technology, Los Alamos scientists have been
analyzing data from GENESIS to study solar wind in more detail than ever
before and will eventually return solar wind particle samples to earth in
September 2004. Lead researcher Roger Wiens of the Laboratory?s space
and atmospherics sciences group will present the findings today at the
American Geophysical Union meeting, held at San Francisco’s Moscone
Convention Center.

“The two solar wind monitors aboard GENESIS, designed and built at Los
Alamos, were turned on in August 2001, and have been working flawlessly
ever since,” said Wiens. The monitors instantaneously determine the speed,
density, temperature and approximate composition of the solar wind and
translate that knowledge into actions for the solar wind collector arrays –
five meter-sized panels containing 55 coaster-sized tiles made of a variety
of materials selected to trap specific elements in the solar wind.

The solar wind concentrator, also built at Los Alamos, is designed to
collect high concentrations of oxygen and return the samples back to Earth
for analysis. The concentrator takes solar wind and passes it through a
series of electrically charged grids into a bowl-shaped mirror. The mirror
reflects a filtered stream of elements heavier than hydrogen upward into a
centrally poised collector tile, where oxygen and other elements embed
themselves.

GENESIS will collect just 10 to 20 micrograms of the solar wind elements of
interest – or the equivalent of a few grains of salt. The extraterrestrial
material will return to Earth in the spacecraft?s specially designed
sample-return capsule for study over the next century by scientists around
the world in search of answers to fundamental questions about the exact
composition of the sun and solar system. The only other time solar wind
particles were returned to Earth was during the Apollo lunar exploration
missions of the 1970s. Those samples consisted of particles from only a few
minutes of solar wind exposure, while the GENESIS mission will collect
samples over two years of its three-year mission.

Working with Wiens on the early GENESIS data analysis program are Los
Alamos’ Bruce Barraclough, John Steinberg, Randy Bremmer, John Gosling and
Daniel Reisenfeld together with JPL’s Marcia Neugebauer and Caltech’s
Donald Burnett.

GENESIS began its solar observation orbit in November 2001, around the
Lagrange 1, or L1 point, nearly one million miles from the Earth and 92
million miles from the sun, where the gravities of the Earth and sun are
balanced. GENESIS will eventually complete five “halo” loops around L1
traveling a distance of about a million miles in each loop. GENESIS’
instruments will collect samples of the solar wind to reveal the makeup of
the cloud that formed the solar system nearly five billion years ago, and
it will help scientists understand the origin of the solar system.

Wiens and his collaborators plan to propose to NASA that the mission be
extended beyond the originally designed three years. The researchers have
determined that the spacecraft is working so well, and that it entered its
L1 orbit so perfectly, that there is enough fuel on board to propel the
ship even closer to the sun following its return trip to Earth and the
delivery of the solar wind sample container. “We believe that after the
sample container is returned to Earth, the spacecraft will be in good
enough shape to enter a new solar observation orbit, a distant
retrograde orbit, some four to six million miles from Earth, where it can
continue to provide us with valuable solar wind data,” said Wiens.
“There’s a lot of fuel left, the possibilities are really endless.”

At the AGU meeting Wiens will report on early data analysis that has
yielded a surprise finding of sunward traveling electrons in high-speed
“coronal hole” solar wind that mimics solar wind electrons from Coronal
Mass Ejections (CMEs) that are sometimes responsible for communications
blackouts and power interruptions on Earth. With CMEs, both ends of the
magnetic field lines are connected back to the sun, forming a large loop
along which electrons can travel in both directions. Coronal holes do not
have such loops, leading to the question of why the electrons travel in
both directions in this type of wind.

Wiens and his colleagues have determined that the sunward electrons have
leaked from plasma heated at more distant shock waves. The shock waves are
associated with the long spiraling arms of solar magnetic fields drawn out
into space by the fast coronal hole solar wind. This phenomenon has been
observed in the solar wind much further from the sun by another Los Alamos
instrument on the Ulysses spacecraft. The new GENESIS observation is the
first time that bi-directional flow in coronal holes has been observed near
the Earth. The discovery now allows scientists to better differentiate
between two very similar types of solar wind signals originating from two
very dissimilar solar phenomena – potentially resulting in more accurate
early warning of large solar events that could disrupt power and
communications on Earth.

Los Alamos National Laboratory is operated by the University of California
for the National Nuclear Security Administration (NNSA) of the U.S.
Department of Energy and works in partnership with NNSA’s Sandia and
Lawrence Livermore national laboratories to support NNSA in its mission.

Los Alamos enhances global security by ensuring the safety and reliability
of the U.S. nuclear stockpile, developing technologies to reduce threats
from weapons of mass destruction, and solving problems related to energy,
environment, infrastructure, health and national security concerns.

Images Available On-line:

http://www.lanl.gov/worldview/news/photos/space_5.jpg

and

http://www.lanl.gov/worldview/news/photos/MagFields.jpg.

Contact: Kevin Roark, knroark@lanl.gov, (505) 665-0582 (02-130)