With its post-launch engineering checkouts complete, NASA’s TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics) spacecraft is now globally studying one of Earth’s final atmospheric frontiers.

Since its launch December 7, 2001, TIMED principal investigators and mission operations personnel at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., and the spacecraft instrument teams located in Colorado, Michigan, Virginia and Maryland, have been conducting routine engineering checkouts of the spacecraft and its four instruments and preparing TIMED for data collection.

TIMED will be studying the basic structure of the MLTI (Mesosphere and Lower Thermosphere/Ionosphere) – a mysterious region of space located about 40-110 miles above the Earth. During its two-year science mission, TIMED will examine the MLTI’s chemistry and flow of energy to and from this layer of the atmosphere. Scientists will analyze how the region affects, and is affected by, the lower atmosphere, how it influences the space near Earth occupied by low-Earth orbiting satellites, and how events on the Sun affect the MLTI.

“We’re very excited that our science mission is underway,” says Dr. Sam Yee, TIMED project scientist and the mission’s science team leader at The Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “TIMED’s observations will provide us with the first-ever global picture of this critical region of our atmosphere, which will allow scientists to form a baseline for future studies of this area.

“During its mission, TIMED will characterize the physical properties of this region, enabling the scientific community to make future ‘space weather’ predictions and how it affects things like communications, satellite tracking, spacecraft lifetimes and spacecraft reentering Earth’s atmosphere.”

Orbiting from a unique vantage point above the MLTI, TIMED will use its remote sensing instruments, together with a network of ground-based observation sites to obtain an unprecedented set of comprehensive global measurements of the region.

TIMED is the first of six Solar Terrestrial Probes (STP) to launch. STP missions focus mainly on responses to two goals of the Sun-Earth Connection theme: (1) How and why does the Sun vary; and (2) How do the Earth and planets respond?

The STP Program Office at Goddard manages the TIMED mission for the Office of Space Science in Washington, D.C. APL designed, built and operates TIMED, and manages the mission’s Science Data Center for NASA.

Detailed mission information, images and animation, are available on the Internet at:

http://stp.gsfc.nasa.gov/missions/timed/timed.htm

http://www.timed.jhuapl.edu