"DRAFT" ANNOUNCEMENT OF OPPORTUNITY FOR THE MEDIUM-CLASS EXPLORER (MIDEX)
PROGRAM


RELEASE DATE: DECEMBER 15, 2003
COMMENT DUE DATE: JANUARY 16, 2004


The National Aeronautics and Space Administration (NASA) Office of Space
Science is releasing a DRAFT Announcement of Opportunity (AO) for community
review and comment for the next missions in the Medium-class Explorer
(MIDEX) program. Selections of proposals through the final AO, once
released, are intended to provide two mission launches by August 2011. A
Mission of Opportunity, long duration balloon mission, International Space
Station payload, or new science mission extension may also be
selected. The science objectives covered by this AO include those in the
currently defined Office of Space Science themes of the Astronomical Search
for Origins, the Sun-Earth Connection, and the Structure and Evolution of
the Universe.

Participation is open to all categories of organizations, foreign and
domestic, including industry, educational institutions, nonprofit
organizations, NASA centers, and other Government agencies. NASA welcomes
critical review and comment of this DRAFT AO, which will be available from
December 15, 2003, through January 16, 2004, via the World Wide Web
site: http://research.hq.nasa.gov/research.cfm/. For those not having
access to the Internet, a printed copy may be obtained by written request
to the address below.

Send comments to Dr. Paul Hertz, Explorer Program Scientist, Office of
Space Science, Code SZ, NASA Headquarters, Washington, DC 20546-0001. FAX:
(202) 358-3096; or E-mail: phertz@.... Comments are preferred in
writing and may be sent by fax or E-mail; the character string "MIDEX DRAFT
AO" (without quotes) should be included in the subject line of all
transmissions. The identity of those submitting comments will be held in
confidence.