Mission proposals that would discover the brightest
galaxy in the universe, measure the chemical building blocks
of life, track magnetic storms in the Earth’s magnetosphere
and study massive explosions on the Sun were recently
selected by NASA as candidates for the next missions in the
agency’s Explorer Program of lower cost, highly focused,
rapid-development scientific spacecraft.

NASA has also decided to fund as a “Mission of Opportunity”
U.S. participation in a European Space Agency (ESA)
observatory on the International Space Station.

Following detailed mission concept studies, NASA intends to
select two of the mission proposals by early 2003 for full
development as Medium-class Explorer, or MIDEX, flights. The
two missions developed for flight will be launched in 2007
and 2008.

“The MIDEX program provides an excellent opportunity to
explore fundamental questions of science and technology,”
said Dr. Ed Weiler, associate administrator for space science
at NASA Headquarters, Washington. “The missions we’ve chosen
fully support NASA’s vision to understand and protect our
home planet, to explore the universe and to search for life.”

The selected proposals were judged to have the best science
value among 42 proposals submitted to NASA in October 2001.
Each will receive $450,000 ($250,000 for the Mission of
Opportunity) to conduct a four-month implementation
feasibility study. The selected MIDEX proposals are:

* The Astrobiology Explorer (ABE) — a cryogenic telescope
to determine the abundance, distribution and identities of
the chemical building blocks of life. ABE would measure
interstellar organic compounds and would be led by Scott
Sandford of NASA’s Ames Research Center in Moffett Field,
Calif., at a total mission cost to NASA of $180 million.

* The Next Generation Sky Survey (NGSS) — an infrared
telescope designed to survey the entire sky with 1,000 times
more sensitivity than previous missions. NGSS would be led by
Edward L. Wright of the University of California, Los
Angeles, at a total mission cost to NASA of $180 million.

* The Time History of Events and Macroscale Interactions
during Substorms (THEMIS) mission — a study of the onset of
magnetic storms within the tail of the Earth’s magnetosphere.
THEMIS would fly five microsatellite probes through different
regions of the magnetosphere and observe the onset and
evolution of storms. THEMIS would be led by Vassilis
Angelopoulos of the University of California, Berkeley, at a
total mission cost to NASA of $150 million.

* The Advanced Spectroscopic and Coronagraphic Explorer
(ASCE) — solar telescopes that would reveal the physical
processes in the outer atmosphere of the Sun leading to the
solar wind and explosive coronal mass ejections. ASCE would
carry three solar instruments 100 times better than previous
coronal telescopes and would be led by John L. Kohl of the
Smithsonian Astrophysical Observatory, Cambridge, Mass., at a
total mission cost to NASA of $177 million.

NASA also selected an investigation to be flown on the
International Space Station in partnership with the European
Space Agency. At the end of the study, NASA will make a final
decision on participating in the ESA-led mission. The Extreme
Universe Space Observatory (EUSO) would detect the highest-
energy cosmic rays known by using the entire Earth as a
particle detector. As extremely energetic particles pass
through the Earth’s atmosphere they emit a form of blue light
that that would be observed by EUSO’s large telescope from
its vantage point on the ISS. EUSO is under study by ESA for
flight on the Columbus module of the ISS, and NASA would
provide the large Fresnal lens for the telescope. NASA’s
contribution to EUSO would be led by James H. Adams Jr. of
NASA’s Marshall Space Flight Center, Huntsville, Ala., at a
total mission cost to NASA of $21 million.

NASA also selected a proposed mission for technology-
development funding of the proposed instrument. Stephan S.
Meyer of the University of Chicago will develop a frequency-
selective bolometer to study dusty galaxies in the early
universe from a balloon-borne telescope over Antarctica.
Meyer will receive $500,000 over the next two years for his

The current MIDEX missions are the Imager for Magnetopause-
to-Aurora Global Exploration (IMAGE), launched in March 2000,
and the Microwave Anisotropy Probe (MAP), launched in June
2001. The third MIDEX mission is the Swift Gamma-Ray Burst
Explorer which will be launched in September 2003. 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 Explorer Program is managed by
NASA’s Goddard Space Flight Center, Greenbelt, Md., for the
Office of Space Science, Washington.

More information on the Explorer program is available at: