Nancy Neal
Headquarters, Washington
(Phone: 202/358-2369)
A swarm of spacecraft, designed to fly through the space
storms that cause aurora, has been chosen as the next mission
in NASA’s Medium-class Explorer (MIDEX) program.
“The Explorer program allows the science community to identify
the most compelling science questions and then design the most
effective mission to answer those questions,” said Edward
Weiler, Associate Administrator for Space Science, NASA
Headquarters, Washington. “The mission we’ve selected will
directly address the science goals of the NASA strategic plan
within a focused, moderate sized project,” he said.
The mission, to be launched in 2007, is the Time History of
Events and Macroscale Interactions during Substorms (THEMIS).
THEMIS is a five-satellite mission with the job of determining
the causes of the global reconfigurations of the Earth’s
magnetosphere that are evidenced in auroral activity. THEMIS
consists of 5 small satellites, carrying identical suites of
electric, magnetic, and particle detectors, that will be put
in carefully coordinated orbits. Every four days the
satellites will line up along the Earth’s magnetic tail,
allowing them to track disturbances. The satellite data will
be combined with observations of the aurora from a network of
observatories across the Arctic Circle. Dr. Vassilis
Angelopoulos of the University of California, Berkeley,
Calif., will lead THEMIS at a total mission cost to NASA of
$173 million.
NASA also selected, as a mission-of-opportunity, an instrument
for the Extreme Universe Space Observatory (EUSO) mission of
the European Space Agency (ESA). EUSO will study the most
energetic particles in the universe. Little is known about the
explosive events that create these particles throughout the
universe.
From its location on the International Space Station, EUSO
will look down on the Earth’s atmosphere to observe the
characteristic blue light that high-energy cosmic rays
generate after hitting the Earth’s atmosphere. NASA will
provide the largest Fresnel lens ever built for the EUSO
telescope. Dr. James Adams Jr. of NASA’s Marshall Space Flight
Center, Huntsville, Ala., will lead the agency’s contribution
to EUSO at a total project cost to NASA of $36 million.
NASA has decided to continue studying the Widefield Infrared
Survey Explorer (WISE), a four-channel, super-cooled infrared
telescope designed to survey the entire sky with 1,000 times
more sensitivity than previous infrared missions. A decision
on proceeding to flight development with WISE will be made in
2004. Dr. Edward Wright of the University of California, Los
Angeles, is the Principal Investigator for WISE.
The Explorer Program is designed to provide frequent, low-cost
access to space for physics and astronomy missions with small
to mid-sized spacecraft. The first two MIDEX missions are the
Imager for Magnetopause-to-Aurora Global Exploration (
(IMAGE), launched in 2000, and the Wilkinson Microwave
Anisotropy Probe (WMAP), launched in 2001. The third MIDEX
mission, the Swift Gamma Ray Burst Explorer is scheduled for
launch in December 2003. Swift will study the origins of black
holes in gamma ray bursts, the most energetic explosions in
the universe.
The selected proposals were among 31 MIDEX and 11 mission-of-
opportunity proposals originally submitted to NASA in October
2001 in response to an Explorer Program Announcement of
Opportunity issued in July 2001. NASA selected five proposals
in April 2002 for detailed feasibility studies. Funded by NASA
at $450,000 each, these studies focused on cost, management,
and technical plans, including small business involvement and
educational outreach. NASA’s Goddard Space Flight Center,
Greenbelt, Md., manages the Explorer Program for the Office of
Space Science, Washington.
For more information about NASA and the Explorers Program on
the Internet, visit:
http://www.nasa.gov and
http://explorers.gsfc.nasa.gov
Information and artist’s concepts of these missions are
available on the Internet at:
THEMIS: http://sprg.ssl.berkeley.edu/themis/
