May 10, 2002

Colloquium Speaker: Jeng-Hwa Yee and David Kusnierkiewicz

Dr. Jeng-Hwa Yee received his M.S. (1977) and Ph.D. (1980) degrees from the College of Engineering at the University of Michigan majoring in Atmospheric and Space Sciences and joined the Space Department of the Applied Physics Laboratory in 1992. Dr. Yee has been the Section Supervisor of the Atmospheric Sensing Techniques Section (SRA) since 1995 and a member of the Principal Professional Staff since 1996. He is currently the Project Scientist for the TIMED mission. Mr. David Kusnierkiewicz received his B.S. (1976) and M.S. (1982) degrees from the University of Michigan in Electrical Engineering and joined the Space Department of the Applied Physics Laboratory in 1983 as a Power System Electronics designer. He has been a Section Supervisor of the System Engineering Section (SEA) since 1992, and Assistant Group Supervisor since 2000. Mr. Kusnierkiewicz has been a member of the Principal Professional Staff since 1996. Currently he is the Mission and Spacecraft System Engineer for the TIMED mission, and the Mission System Engineer for the New Horizons mission to Pluto and the Kuiper Belt.

Colloquium Topic: TIMED Spacecraft: Science & Technology

Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) is the first mission in NASA's Solar Terrestrial Probes Program, part of NASA's initiative to lower mission costs and provide more frequent access to space for systematically studying the Sun-Earth system. The 2-year TIMED mission will study the influences of the Sun and humans on the least explored and understood region of the Earth's atmosphere, the Mesosphere and Lower Thermosphere (MLT), a region located approximately 40-110 miles (60-180 kilometers) above the surface. The spacecraft was successfully launched into its 388 miles (625 km) circular orbit on December 7, 2001. It has four instruments onboard that provide measurements of the global pressure, temperature, and winds in the MLT region, along with solar EUV and X-Ray spectral irradiances, high latitude auroral energy inputs and atmospheric infrared cooling rates. The observational data provided by these four advanced sensors will enable us to define the basic structure of the MLT region and its thermal balance on a global basis. Several technological innovations, including autonomous operations, GPS navigation, and integrated electronic modules, are incorporated to lower the mission operations costs while enhancing science returns by enabling instruments to operate at their full capacity around the clock. The mission is managed by NASA GSFC and designed, built, and implemented by APL. APL is responsible for the operations of the spacecraft and leads science research activities