From: Alliant Techsystems
Posted: Friday, July 25, 2008
THEMIS Performance Demonstrates Capability of Satellite Constellations
ATK Innovative Technology Provides Answers to Dancing Northern Lights
Alliant Techsystems (NYSE: ATK - News) reported today that the constellation of five micro satellites it built for NASA's THEMIS (Time History of Events and Macroscale Interactions during Substorms) mission has successfully demonstrated how satellites can work together to collect data, which in this case, advances the scientific understanding of the Earth's atmosphere. The THEMIS mission determined the cause of the shimmering effect of the Aurora Borealis, commonly referred to as the Northern Lights. Importantly, the mission advances the understanding and capabilities of small, affordable satellite constellations that can be used for future scientific, military, and commercial missions.
On February 28, 2008 the constellation of five satellites were lined up along the Sun-Earth line which was designed to occur once every 4 days. During this line-up scientists observed an isolated substorm onset. In conjunction with part of the THEMIS ground base observatory system located in the North America, the satellites recorded intense auroral brightening and space currents. With the combination of space measurements from the THEMIS satellite constellation and ground base systems scientists were able to determine the process by which the northern lights suddenly brighten and break into spectacular formations moving towards the poles. The science data appeared online July 24 in Science Express and will be in print on August 14 in the Journal of Science.
The THEMIS mission launched from Cape Canaveral Air Force Station on February 17, 2007 on a Delta-II 7925 launch vehicle. ATK provided nine strap-on GEM 40 boosters to provide augmented thrust during the launch. The company's STAR(TM) 48B Third-stage rocket motor completed the separation and properly positioned the constellation of satellites for its eventual orbit that ensured mission success. The five spacecraft buses, built by ATK were integrated with a suite of magnetospheric physics instruments by the University of California at Berkeley (UCB) Space Sciences Laboratory (SSL) in collaboration with Germany, France and Austria.
"We are extremely proud to be part of such an extraordinary science accomplishment. The mission highlights the effectiveness of small, affordable satellite constellations to perform a variety of scientific, military, and commercial missions," said Frank Koester, Vice President and General Manager of ATK Spacecraft Systems. "ATK's THEMIS constellation has enabled Scientists to understand the physics behind the onset and progression of substorms in the magnetosphere. These findings will also assist in a better understanding of space weather, which is crucial to designing more reliable space platforms."
ATK is a premier aerospace and defense company with more than 17,000 employees in 21 states and $4.5 billion in revenue. News and information can be found on the Internet at http://www.atk.com.
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