Lockheed Martin
Instrument to Monitor Solar Eruptions on Latest NASA Sun Mission
(19 October 2006) The Extreme
Ultraviolet Imager (EUVI) instrument - designed and built at the Solar and
Astrophysics Laboratory of the Lockheed Martin Advanced Technology Center (ATC)
in Palo Alto - will soon begin returning stereo images of the Sun's corona as
part of NASA's Solar Terrestrial Relations Observatory
(STEREO).
STEREO will utilise two nearly identical spacecraft on
different trajectories to study the most energetic events on the surface and in
the lower atmosphere of the Sun, and their travel through interplanetary
space.
Data from spacecraft instruments will allow scientists to
construct the first ever three-dimensional views of the Sun, providing a new
perspective on Coronal Mass Ejections (CMEs). CMEs are violent explosions on
the surface of the Sun that can propel up to 10 billion tons of the Sun's
atmosphere - at a million miles an hour - out through the corona and into
space.
The two STEREO spacecraft will be launched together on a Delta-II
on Oct.25, 2006 from Cape Canaveral Air Force Station, Fla. Both spacecraft
will fly by the Moon taking advantage of a gravity assist that will propel one
of the observatories into an orbit "ahead" of the Earth in its journey around
the Sun, and the other "behind" our planet as it makes its yearly
revolution.
EUVI is one element of an instrument suite on each STEREO
spacecraft called SECCHI - the Sun-Earth Connection Coronal and Heliospheric
Investigation - under the direction of Principal Investigator Dr. Russell
Howard of the Naval Research Laboratory of Washington, D.C. SECCHI comprises a
suite of telescopes, including three white light coronographs and
EUVI.
"We've been studying CMEs for a long time, but SECCHI will offer
us new insight into the structure and evolution of the solar corona in three
dimensions, while EUVI focuses specifically on the initiation and early
evolution of CMEs," said Dr. James Lemen, Lockheed Martin co-investigator on
SECCHI. "EUVI and the other instruments on SECCHI will follow the propagation
of these events through the corona, out into interplanetary space and all the
way to Earth, giving us a comprehensive view of these enormous
phenomena."
Coronal mass ejections, which are often associated with
solar flares, can take several days to reach the Earth. Fast, powerful
ejections give rise to geomagnetic storms, which can disrupt radio
transmissions and induce large currents in power transmission lines and oil
pipelines. They have resulted in large-scale failures of the North American
power grid and greatly increased pipeline erosion. CMEs also can generate
spectacular auroras in Earth's polar skies, but can disrupt spacecraft and be
extremely hazardous to astronauts.
NASA Goddard Space Flight Center in
Greenbelt, Md. manages the STEREO mission. The Johns Hopkins University Applied
Physics Laboratory in Laurel, Md. designed and built the spacecraft. The
laboratory will maintain command and control of the observatories throughout
the mission, while NASA tracks and receives the data, determines the orbit of
the satellites, and co-ordinates the science results.
The Solar and
Astrophysics Laboratory at the ATC has a long heritage of spaceborne solar
instruments including the Soft X-ray Telescope on the Japanese Yohkoh
satellite, the Michelson Doppler Imager on the ESA/NASA Solar and Heliospheric
Observatory, the solar telescope on NASA's Transition Region and Coronal
Explorer and the Solar X-ray Imager on the GOES-N environmental satellite. The
laboratory also conducts basic research into understanding and predicting space
weather and the behaviour of our Sun including its impacts on Earth and
climate.
The ATC is the research and development organisation of
Lockheed Martin Space Systems Company (LMSSC). LMSSC, a major operating unit of
Lockheed Martin Corporation, designs, develops, tests, manufactures and
operates a variety of advanced-technology systems for national security, civil
and commercial customers. Chief products include human space flight systems; a
full range of remote sensing, navigation, meteorological and communications
satellites and instruments; space observatories and interplanetary spacecraft;
launch vehicles, fleet ballistic missiles; and missile defence
systems.
Headquartered in Bethesda, Md., Lockheed Martin employs about
140,000 people world-wide and is principally engaged in the research, design,
development, manufacture, integration and sustainment of advanced technology
systems, products and services. The corporation reported 2005 sales of US$ 37.2
billion.
(source: Lockheed Martin)