TIMED Atmospheric Spacecraft Successfully Launched

Press Release From: Johns Hopkins University
Posted: Friday, December 7, 2001

Watch video of the Launch at

NASA's TIMED (Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics) spacecraft ? en route to explore one of the last frontiers in Earth's atmosphere ? successfully launched today at 7:07 a.m. PST, aboard a Delta II rocket from Vandenberg Air Force Base, Calif.

Designed and built for NASA by The Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Md., the 1,294-pound (587-kilogram) spacecraft was placed into its 388-mile (625-kilometer) circular orbit, inclined 74.1 degrees from the equator, 2 hours and 5 minutes after launch. TIMED, which shared the launch vehicle with the Jason-1 spacecraft, was the second of the two spacecraft to be jettisoned from the Delta II rocket. After making initial contact with the ground station in Kiruna, Sweden, 3 hours and 2 minutes after liftoff, TIMED's APL-based Mission Operations Center reported the solar arrays deployed and began providing power to the spacecraft.

TIMED is the first mission in NASA's Solar Terrestrial Probes Program, part of the agency's initiative to lower mission costs and provide more frequent systematic studies of the sun-Earth system. "This is a terrific beginning for the Solar Terrestrial Probes Program," says Dr. Stamatios (Tom) Krimigis, head of APL's Space Department. "We're very excited about working with the broader science community and our colleagues at NASA's Goddard Space Flight Center as we begin to explore this uncharted region of our atmosphere."

Globally Studying a New Frontier

The 2-year TIMED mission will study the influences of the sun and humans on the least explored and understood portion of Earth's atmosphere ? the Mesosphere and Lower Thermosphere/Ionosphere (MLTI), a gateway between Earth's environment and space. TIMED will focus on a portion of this atmospheric region located approximately 40-110 miles (60-180 kilometers) above the surface, studying its basic structure and how energy is transferred into and out of this area.

Through advances in remote-sensing technology, this mission will be the first global study of the MLTI and will establish a baseline for future studies of this area. "TIMED's instrument suite will work with a worldwide network of ground-based observation sites to obtain an unprecedented set of comprehensive global measurements of the region's temperature, pressure, wind, chemical composition and energy inputs and outputs," says Dr. Sam Yee, TIMED project scientist at The Johns Hopkins University Applied Physics Laboratory.

"With society becoming increasingly dependent on satellite technology and communications, through devices such as cell phones and pagers, it's vital to understand the ever-changing nature of this region," continues Yee. "TIMED's comprehensive study of the MLTI as an integrated system will help the space community predict its effects on communications, satellite tracking, spacecraft lifetimes and on spacecraft reentering Earth's atmosphere."

TIMED's science payload consists of four instruments, each controlled independently from four Payload Operations Centers located across the country. TIMED's instrument package includes a spatial scanning, far-ultraviolet spectrograph that will globally measure the composition and temperature profiles of the MLTI region and auroral energy inputs; a multi-channel infrared radiometer designed to measure heat emitted by the atmosphere, and the temperature and composition of the MLTI region over a broad altitude and spectral range; a spectrometer and a suite of photometers designed to measure solar ultraviolet radiation ? the primary energy deposited into the MLTI; and an interferometer that will globally measure the wind and temperature profiles of the MLTI.

The TIMED mission is sponsored by NASA's Office of Space Science in Washington, D.C., and managed by the NASA Goddard Space Flight Center's Solar Terrestrial Probes Program Office, Greenbelt, Md. The Johns Hopkins University Applied Physics Laboratory operates the spacecraft, leads the project's science effort and manages the mission's Science Data Center for NASA.

For more information about the TIMED mission, or to view images from today's launch,visit

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