Media Contacts:
Kristi Marren (The Johns Hopkins University Applied Physics Laboratory)
phone: (240) 228-6268

Susan Hendrix (NASA Goddard Space Flight Center)
phone: (301) 286-7745

Applied Physics Lab Ships Atmospheric Spacecraft
TIMED Transported to Vandenberg for Upcoming Launch

A spacecraft that will explore one of the last frontiers in Earth’s
atmosphere is nearing launch. NASA’s TIMED (Thermosphere, Ionosphere,
Mesosphere, Energetics and Dynamics) spacecraft was shipped today from The
Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md.,
where it was designed and built, to Vandenberg Air Force Base, Calif. The
spacecraft is currently scheduled to launch from Vandenberg’s Western Range
on Aug. 10, 2001.

The 2-year TIMED mission will study the effects of the sun and human-induced
activities on the least explored and understood portion of Earth’s
atmosphere known as 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 Earth’s surface, studying its basic structure and
how energy is transferred into and out of this area.

“Compared to other layers of our atmosphere, we know very little about this
region, which is located just a few miles above our heads,” says Sam Yee,
TIMED project scientist from APL, who is leading the science team’s efforts
throughout the mission. “A comprehensive global study of the MLTI as an
integrated system has never before been accomplished.” The region is too
high for balloons and rockets can only provide a brief snapshot of the
area’s activity near the rocket, according to Yee. Ground-based instruments
can only observe a small portion of the upper atmosphere located over an
observation site.

Employing advances in remote-sensing technology, the TIMED spacecraft will
be the first to conduct a global study of the MLTI and will establish a
baseline against which future studies of changes within this area can be
compared and analyzed. “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 and chemical composition, along with its energy inputs and outputs,”
says Yee.

“This mission will help scientists gain a better understanding of the MLTI
region’s structure and how it varies,” continues Yee, “which will help the
space science community predict its effects on communications, satellite
tracking, spacecraft lifetimes and on spacecraft reentering Earth’s

TIMED is the initial mission in NASA’s Solar Terrestrial Probes Program,
part of NASA’s initiative to lower mission costs and provide more frequent
access to space to systematically study the sun-Earth system.

The TIMED mission is sponsored by NASA’s Office of Space Science in
Washington, D.C., and managed by NASA’s Goddard Space Flight Center,
Greenbelt, Md. APL designed, built and will operate the spacecraft and lead
the project’s science effort during the mission.

For more information about TIMED, visit the mission Web site at Images of the spacecraft and its journey to Vandenberg
Air Force Base, Calif., will be made available online.

The Applied Physics Laboratory (APL) is a not-for-profit laboratory and
division of The Johns Hopkins University. APL conducts research and
development primarily for national security and for nondefense projects of
national and global significance. APL is located midway between Baltimore
and Washington, D.C., in Laurel, Md.