To shed new light on the sun's magnetic field and how it impacts life on Earth, NASA is preparing major instrument components for launch this September on the Japan Aerospace Exploration Agency's (JAXA) Solar-B spacecraft.

"Solar-B will record how energy stored in the solar magnetic field is released as that field rises into the sun's outer atmosphere," said Larry Hill, Solar-B project manager at NASA's Marshall Space Flight Center, Huntsville, Ala.

Solar-B's three instruments -- the Solar Optical Telescope, the X-Ray Telescope and the Extreme Ultraviolet Imaging Spectrometer -- will perform coordinated measurements of the different layers of the solar atmosphere. Continuous, simultaneous observations of specific solar features by all three instruments will enable Solar-B to observe how changes in the magnetic field at the sun's surface spread through the layers of the solar atmosphere.

JAXA is the overall lead for the Solar-B mission, the spacecraft, the launch vehicle and management of space operations. NASA provided the Focal Plane Package for the Solar Optical Telescope, and components for the Solar X-ray Telescope and the Extreme Ultraviolet Imaging Spectrometer, as well as engineering support for integration of the instruments.

The Solar Optical Telescope will be the first space-borne instrument to measure the strength and direction of the sun's magnetic field in the sun's low atmosphere, also called the photosphere.

The sun's outer atmosphere, the corona, will be captured by the X-ray Telescope. The corona is the spawning ground for solar flares and coronal mass ejections. Powered by the sun's magnetic field, this explosive solar activity produces significant effects in the space between the sun and Earth. By combining observations from Solar-B's optical and X-ray telescopes, scientists will be able to study how changes in the sun's magnetic field trigger these powerful events.

The Extreme Ultraviolet Imaging Spectrometer will measure the speed of solar particles. The spectrometer provides a crucial link between the other two instruments, measuring the layers that separate the photosphere from the corona - an area known as the chromosphere and the chromosphere-corona transition region. The spectrometer will also be able to measure the temperature and density of solar plasma - the hot, ionized gas surrounding the sun.

"The information that Solar-B will provide is significant for understanding and forecasting of solar disturbances, which can interfere with satellite communications, electric power transmission grids, and threaten the safety of astronauts traveling beyond the safety of the Earth's magnetic field," said John M. Davis, Solar-B project scientist at NASA Marshall.

After its launch from Uchinoura Space Center in Kagoshima, Japan, the Solar-B spacecraft will circle Earth in an orbit that places the instruments in continuous sunlight for nine months each year. Following launch, NASA and the science teams will support instrument operations and data collection from the spacecraft operations center at JAXA's Institute of Space and Astronautical Science facility.

NASA; Lockheed Martin, Palo Alto, Calif.; the High-Altitude Observatory, Boulder, Colo.; JAXA's Institute of Space and Astronautical Science (JAXA/ISAS), Sagamihara, Japan; and the National Astronomical Observatory of Japan (NAOJ), Tokyo, participated in the development of the instrumentation for the Solar Optical Telescope. The X-ray Telescope was built by the Smithsonian Astrophysical Observatory, Cambridge, Mass.; JAXA/ISAS; and NAOJ. The spectrometer was developed by the Mullard Space Science Laboratory of the University College London, United Kingdom; the Naval Research Laboratory, Washington; and NAOJ.

Solar-B is a collaboration among the space agencies of Japan, U.S., the United Kingdom and Europe. The mission is part of the Solar Terrestrial Probes Program within the Heliophysics Division of NASA's Science Mission Directorate in Washington.

For more information about Solar-B, visit:

http://www.nasa.gov/solar-b