June 5, 1998 NEW DEEP SPACE 1 TRAJECTORY INCLUDES ASTEROID FLYBY Mission planners for NASA's Deep Space 1 have selected a near-Earth asteroid, 1992 KD, as a flyby destination. Last April, NASA announced that the launch date for this technology validation mission was to be rescheduled from July 21 to October 15, with the launch period extending to October 30. The new launch date precluded flying by planned destinations, including the previously announced asteroid McAuliffe, making it necessary to choose a new target. Deep Space 1 is scheduled to fly by the newly chosen asteroid 1992 KD on July 28, 1999. This asteroid was chosen from more than 100 flyby possibilities. Its elliptical orbit curves within and outside of Mars' orbit of the Sun, at its farthest going out more than three times farther from the Sun than Earth. Although scientists believe its diameter is approximately three kilometers, they know little else about the body. With this flyby, they can learn more about its shape, size, surface composition, mineralogy, terrain and rotation speed. "This new mission offers excellent opportunities for us to test our payload of advanced technologies that are so important for future space exploration," said Dr. Marc Rayman, Deep Space 1's chief mission engineer. "At the same time, the potential for bonus scientific return is extraordinary." Deep Space 1 is the first launch of the New Millennium Program, a series of missions designed to test new technologies so that they can be confidently used on science missions of the 21st century. Among the 12 technologies that the mission is designed to validate is an ion propulsion engine that fires electrically charged xenon atoms from its thrusters; this is the first time it has ever been used as the primary propulsion system in deep space. Also being tested are autonomous optical navigation, a solar concentrator array and an integrated camera and imaging spectrometer. The latter instrument, also known as the Miniature Integrated Camera Spectrometer, or MICAS, will be validated by making science observations of asteroid 1992 KD, among several other methods. The flyby will also help to test both a miniature integrated ion and electron spectrometer instrument, also termed the Plasma Experiment for Planetary Exploration (PEPE), and the spacecraft's autonomous optical navigation system. The remaining new technologies will be tested during cruise and thrusting phases both before and after the flyby. By October, 1999, Deep Space 1 will have completed its primary mission of demonstrating new technologies and will be on a trajectory that could result in a flyby of comet Borelly two years later. Comet Borrelly is one of the most active comets that regularly visit the inner solar system. MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov Contact: John G. Watson