The National Aeronautics and Space Administration (NASA) Office of Space Science has previously announced its intention to release an Explorer Program Announcement of Opportunity (AO) in May 2004 to solicit Medium-class Explorers (MIDEX) and Missions of Opportunity. As a result of the reprioritized NASA activities, the Explorer Program budget has been reduced and the release of the MIDEX AO will be deferred until no earlier than October 2006.

Questions may be addressed to Dr. Hashima Hasan, Explorer Program Scientist, Science Mission Directorate, Universe Division, Mail Suite 3W39, 300 E St. SW, NASA Headquarters, Washington, DC 20546-0001. FAX: (202) 358-3096; or E-mail: hhasan@nasa.gov.