NASA Mission Receives More "TIMED"

	Artist concept of TIMED spacecraft

NASA has extended the TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics) mission for another three years of operations and data analysis beginning in January 2004 with an additional year of data analysis to be conducted after orbital operations are completed.

For nearly two years, NASAs TIMED spacecraft has made great strides in its exploration of one of Earths last atmospheric frontiers during a time when the Suns activity has been near the peak of its 11-year cycle. As its initial2-year orbital mission draws to a close this winter, the team is preparing to embark on the extended mission to study how declining solar activity affects a portion of the upper atmosphere that serves as the gateway between Earths environment and space, where the Suns energy is first deposited into our environment.

In a society increasingly dependent on satellite technology and communications, its vital to understand the variability within a critical region of our upper atmosphere, known as the MLTI (Mesosphere, Lower Thermosphere/Ionosphere). This will help scientists predict this regions effects on communications, satellite tracking, spacecraft lifetimes, degradation of spacecraft materials and on the reentry of piloted vehicles.

Solar cycle variations strongly affect our upper atmosphere, says Sam Yee, TIMED Project Scientist from The Johns Hopkins University Applied Physics Laboratory in Laurel, Md. As solar activity levels transition from maximum to minimum, we see dramatic changes in solar ultraviolet radiation, in the frequency and intensity of magnetic storms and substorms, and in the nature of high-energy particles entering the upper atmosphere. TIMEDs extended mission is critical to exploring these variations and improving our understanding of the final link in the energy chains connecting the Sun and Earth.

The Laboratory for Extraterrestrial Physics at NASA's Goddard Space Flight Center, Greenbelt, Md., oversees the TIMED mission for the Office of Space Science in Washington, D.C. TIMED is the first mission in NASAs Solar Terrestrial Probes Program.

For more on extension of the TIMED mission, go to: http://www.gsfc.nasa.gov/news-release/releases/2003/03-91.htm