POLICY CHANGES FOR THE MEDIUM-CLASS EXPLORER (MIDEX) PROGRAM

The National Aeronautics and Space Administration (NASA) Office of Space
Science has targeted May 2004 for release of an Announcement of Opportunity
(AO) for Medium-class Explorer (MIDEX) missions and Missions of
Opportunity. Although release of a Draft MIDEX AO has been delayed,
several significant changes in policy from recent Explorer Program AOs are
discussed on the MIDEX Acquisition Additional Information Page located at
http://explorer.larc.nasa.gov/explorer/midexacq.html.

Questions or comments may be addressed 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: paul.hertz@....