TIMED

The TIMED (Thermosphere, Ionosphere, Mesosphere Energetics & Dynamics) mission was designed to study the physical and chemical processes acting within and upon the coupled mesosphere, lower-thermosphere/ ionosphere system between about 60 and 180 km. TIMED investigates a region that is difficult to study because it is too high for even the largest research balloons and still dense enough to quickly cause a satellite to decay from orbit. Because of the lack of measurements this atmospheric region is often referred to as the "ignorosphere". Absorping a considerable amount of solar ultraviolet radiation from the sun and intercepting high energy atomic particles, this region is the "skin" between the life-sustaining lower layers and outer space. Originally proposed as a two-spacecraft mission, the TIMED project was rescoped to a one-satellite mission due to budgetary pressure. TIMED was downsized to a core mission of four experiments and six interdisciplinary investigations and mission management was moved to JHU-APL in an effort to reduce the cost to the $100M level. The instruments include:

• the Solar EUV Experiment (SEE) provided by the University of Colorado,
• the TIMED Doppler Interferometer (TIDI) provided by the University of Michigan,
• the Global Ultraviolet Imager (GUVI) provided by the Aerospace Corp., and
• the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) provided by NASA's Langley Research Center.