Don Savage Headquarters, Washington, DC January 26, 1999 (Phone: 202/358-1727) RELEASE: 99-7 FIVE EXPLORER MISSION PROPOSALS PICKED FOR FEASIBILITY STUDIES Spacecraft that will help answer some of the biggest questions in space science have been chosen as candidates for NASA's medium-class Explorer (MIDEX) program. The spacecraft will observe the largest explosions and brightest galaxies in the Universe; study the link between the Earth's aurora and the solar wind; search for planetary systems around 40 million stars; and investigate magnetic eruptions in the Sun's corona. The five proposals will undergo detailed study over the next five months in the first step of a two-step process. NASA will select two of the missions for flight under the MIDEX program, designed to foster lower-cost, highly focused, rapidly developed scientific spacecraft. "Once launched, these missions will provide insights into some of the biggest questions in space science," said Dr. Ed Weiler, Associate Administrator for Space Science at NASA Headquarters. "However, MIDEX missions not only return impressive science results, they continue NASA's trend toward greatly lowering mission costs with innovative mission planning and operations." Following detailed mission concept studies, which are due for submission by June18, 1999, NASA intends to select two of the mission proposals in September 1999 for full development as the third and fourth MIDEX flights. The two missions developed for flight will be launched in 2003 and 2004. The selected proposals were judged to have the best science value among 35 proposals submitted to NASA in August 1998 in response to an Explorer Program Announcement of Opportunity. Each will now receive $350,000 to conduct a four month implementation feasibility study focused on cost, management, and technical plans, including educational outreach and small business involvement. The selected MIDEX proposals are: * The Swift Gamma Ray Burst Explorer, a three-telescope space observatory for studying the position, brightness, and physical properties of gamma ray bursts. Although gamma ray bursts are the largest known explosions in the Universe, outshining the rest of the Universe when they explode unpredictably in distant galaxies, their underlying nature and the cause of the explosion are true mysteries of astrophysics. Swift would use its gamma ray telescope, X-ray telescope, and ultraviolet/optical telescope to determine the nature of gamma ray bursts by probing distant regions of the Universe. Swift would be led by Dr. Neil Gehrels of NASA's Goddard Space Flight Center in Greenbelt, MD, at a total mission cost to NASA of $135 million. * The Next Generation Sky Survey (NGSS), a four-channel, supercooled infrared telescope designed to survey the entire sky with 1,000 times more sensitivity than previous missions. This infrared survey should discover millions of new cosmic sources of infrared radiation including the brightest galaxy in the Universe, the closest star to the Sun, every asteroid between Mars and Jupiter that is larger than two miles across, and protoplanetary discs in the process of forming planetary systems around nearby stars. NGSS would be led by Dr. Edward L. Wright of the University of California, Los Angeles, at a total mission cost to NASA of $139 million. * The Full-sky Astrometric Mapping Explorer (FAME), a space telescope designed to obtain highly precise position and brightness measurements of 40 million stars. This rich database would enable numerous science investigations, including accurately determining the distance to all of the stars on this side of the Milky Way galaxy, detecting large planets and planetary systems around stars within 1,000 light years of the Sun, and measuring the amount of dark matter in the galaxy from its influence on stellar motion. FAME would be led by Dr. Kenneth J. Johnston of the U.S. Naval Observatory, Washington, DC, at a total mission cost to NASA of $138 million. * The Auroral Multiscale Midex Mission (AMM), a formation of four identically instrumented small satellites in a near-polar, highly elliptical orbit. AMM would study the electrical connection between Earth's ionosphere and the distant magnetosphere and how that connection gives rise to the occurrence, structure, and rapid variations of the northern and southern lights. The four-satellite constellation will, for the first time, permit observations to be interpreted unambiguously in terms of variations in space or time. AMM would be led by Dr. Barry H. Mauk of the Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, at a total mission cost to NASA of $130 million. * The Advanced Solar Coronal Explorer (ASCE), a powerful solar telescope which would reveal the physical processes in the Sun that lead to the solar wind and explosive coronal mass ejections. ASCE would carry two solar instruments that are 100 times better than previous solar coronographs. It would be deployed on a recoverable satellite from the Space Shuttle and retrieved two years later. ASCE would be led by Dr. John L. Kohl of the Harvard- Smithsonian Center for Astrophysics, Cambridge, MA, at a total mission cost to NASA of $131 million. NASA has also selected instruments from two proposed MIDEX missions for technology development funding. Dr. Richard Rothschild of the University of California at San Diego will develop an X-ray detector for studying black holes of all sizes. Dr. Gary Swenson of the University of Illinois at Urbana-Champaign will develop detectors for studying waves in the Earth's upper atmosphere. Both researchers will receive $700,000 over the next two years for their work. The Explorer Program is designed to provide frequent, low- cost access to space for physics and astronomy missions with small to mid-sized spacecraft. Explorer missions are required to advance the goals and objectives of the Structure and Evolution of the Universe, Sun-Earth Connection, and Astronomical Search for Origins science themes within the Office of Space Science. The selected MIDEX science missions must be ready for launch before June 30, 2004, within the Explorer Program's NASA cost cap of $140 million. The Explorer Program is managed by NASA's Goddard Space Flight Center, Greenbelt, MD, for the Office of Space Science, Washington, DC. - end - * * * NASA press releases and other information are available automatically by sending an Internet electronic mail message to domo@hq.nasa.gov. In the body of the message (not the subject line) users should type the words "subscribe press-release" (no quotes). The system will reply with a confirmation via E-mail of each subscription. A second automatic message will include additional information on the service. NASA releases also are available via CompuServe using the command GO NASA. To unsubscribe from this mailing list, address an E-mail message to domo@hq.nasa.gov, leave the subject blank, and type only "unsubscribe press-release" (no quotes) in the body of the message.