On June 4, 2002, NASA’s 2001 Mars Odyssey successfully deployed the Gamma
Ray Spectrometer boom. Odyssey is carrying the Gamma Ray Spectrometer (GRS),
built and operated by the Lunar and Planetary Laboratory at the University
of Arizona in Tucson.

The GRS is a suite of three instruments: a Gamma Sensor Head, Neutron
Spectrometer (built by Los Alamos National Laboratory) and a High Energy
Neutron Detector (built by the Space Research Institute, Moscow).
During the initial mapping phase of the mission, the UA’s Gamma Sensor Head
has been in a stowed open-door configuration. The UA team has been
collecting data in the stowed open-door configuration since Feb. 18, 2002.

Over the past few months the GRS instrument suite has provided significant
information about the hydrogen abundance on Mars, allowing scientists to
conclude there are large quantities of frozen water just below the surface.
“Deploying the boom, which extends approximately 6.2 meters (20 Feet) from
the spacecraft, enhances the sensitivity and accuracy of the GRS
instrument,” said William Boynton, principal investigator for Odyssey’s
gamma ray spectrometer suite at the University of Arizona. This enhanced
sensitivity will enable scientists to improve the accuracy of the hydrogen
measurements as well as begin the measurements of many other important
elements such as iron, potassium, chlorine, thorium, uranium, aluminum and
many others.

“The 2001 Mars Odyssey GRS instruments have already provided a great deal of
information that will answer many questions. The mission is just beginning;
we are optimistic the remainder of the science mission will provide
significant information that will help us understand ‘where the water went,’
as well as significantly increasing our understanding of the origin, geology
and climate history of Mars,” Boynton said.

In order to prepare the GRS instrument for boom deployment, the instrument
was placed in a closed-door configuration. The GRS team plans to open the
door tomorrow to begin their official data collection.

Animation and video that demonstrate the door-open and boom deployment are
available.