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

Photo Caption                                     7/31/99

With its technology testing objectives almost fully accomplished, 
NASA's Deep Space 1 mission is about to undergo its most 
comprehensive challenge: the exotic spacecraft is set to fly 
within 10 miles (15 kilometers) of asteroid 1992 KD on July 29, 
the closest encounter with an asteroid ever attempted. 

Deep Space 1 will rely on its experimental autonomous navigation 
system, or AutoNav, to guide the spacecraft past the mysterious, 
little-known space rock at 12:46 a.m. EDT at a relative speed of 
nearly 35,000 mph (56,000 kilometer per hour).

During the encounter, Deep Space 1 will be in the ecliptic plane 
(the plane in which Earth and most other planets orbit the Sun), 
moving more slowly than the asteroid, which will be progressing 
up through the ecliptic plane from below. Thus it may well be 
more apt to say that the asteroid will zoom by Deep Space 1 than 
the reverse.