Scientists have successfully tested a key instrument for a next-generation
gamma-ray telescope that will ultimately stare down the barrel of massive
black hole particle jets.

The innovative gamma-ray detector, a prototype of a much larger detector
which will be integrated into the Gamma-ray Large Area Space Telescope
(GLAST) for a 2006 satellite launch, was tested on a 29 million-cubic-foot
NASA scientific balloon that flew for three hours from Palestine, Texas,
on August 4 at 127,000 feet, above 99.5 percent of the atmosphere.

This was a joint effort by researchers at NASA Goddard Space Flight Center,
the Stanford Linear Accelerator Center (SLAC), Stanford University, the
University of California Santa Cruz, the Naval Research Laboratory, and
Hiroshima University in Japan.

“The detector worked essentially flawlessly throughout the flight,” said
Dave Thompson, the Goddard scientist who led the project. “The flight gave
us an extra level of confidence in the instrument design, and the data we
collected will support the data analysis system now being constructed for
GLAST.”

GLAST will study celestial gamma rays, particles of light millions to
billions of times more energetic than visible light, which our eyes can
detect, ultraviolet light and X rays. Gamma rays are created by the most
violent phenomena in the Universe, such as black holes, neutron stars and
star explosions.

GLAST will also study gamma-ray bursts, the most powerful explosions in the
Universe, second only to the theoretical Big Bang. These mysterious bursts
are detected by satellites almost daily, last only for a few seconds, and
come to us from origins unknown.

The GLAST Balloon Flight Engineering Model, tested on the balloon flight,
was a working prototype of one of the 16 modules that will comprise the
GLAST Large Area Telescope. The model had the same types of detectors
that will be used on the satellite a plastic scintillator anticoincidence
detector built by Goddard; a silicon strip tracker built by the University
of California at Santa Cruz; a CsI calorimeter provided by the Naval
Research Laboratory; and a data acquisition system built by SLAC and
Stanford University.

“The success of the high-altitude balloon flight of the Large Area Telescope
prototype achieves a critical milestone for the GLAST mission,” said Peter
Michelson of Stanford University, Principal Investigator for the GLAST Large
Area Telescope. “It is a validation of the instrument design we will fly on
GLAST. This design incorporates state-of-the-art technology that allows an
extraordinary leap forward in capability.”

GLAST is an international collaboration of astrophysicists and particle
physicists, with funding from NASA, the U.S. Department of Energy and
agencies in France, Germany, Italy, Japan and Sweden. The National
Scientific Balloon Facility, operated for NASA by New Mexico State
University, managed the balloon launch.

For more information about GLAST, refer to:

http//www-glast.sonoma.edu/

For images of the balloon flight, refer to:

http//www.slac.stanford.edu/~mizuno/Photos/BFEM/thumbnail.html