On October 2, 1998, the Jet Propulsion Laboratory's Dr. Stuart
Shaklan and Dr. Steven Pravdo used the Stellar Planet Survey (STEPS)
instrument on the Palomar 200" telescope to make astrometric observations of
asteroid 1992 KD in a background of stars.
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Asteroid 9969 Braille
October 2, 1998
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Dr. Donald Yeomans and Eleanor
Helin of JPL provided the predicted ephemerides. Because the team was
tracking on the motion of the asteroid, the stars appear to be elongated in
the image. On the left edge of the image is the trail of an artificial
satellite that coincidentally streaked across the field. Dr. Andrea Boattini
and JPL's Dr. David Rabinowitz reduced the astrometric data from three
images. The field of view is 150 arc seconds or 2 = arc minutes across, or
approximately 0.04 degrees. Top of the image is north, and east is to the
left.
In July 1999, NASA's Deep Space 1 technology validation mission is
scheduled to fly by 1992 KD at a distance of 199 million km (124 million
miles) from the Sun and 188 million km (117 million miles) from Earth.
Although this flyby is not a required part of the mission, it will assist in
the further validation of several of the mission's dozen new technologies.
The asteroid, which was discovered in May, 1992, by astronomer
Eleanor Helin, has a highly elliptical orbit; the closest it gets to the Sun
is a point midway between Earth and Mars, whereas at its most distant it is
more than three times farther from the Sun than Earth, or more than halfway
out to the giant planet Jupiter. This image, comprised of the first reported
observations of 1992 KD since 1996, has helped to refine the asteroid's
orbit and provide a more accurate target for the Deep Space 1 encounter.
During the encounter, Deep Space 1's autonomous optical navigation
system will attempt to guide the spacecraft to within 10 km (6 miles) of the
asteroid's surface, making it the closest flyby of a solar system body ever
attempted. Just before the flyby, the system will analyze approach images to
determine if an even closer encounter is safe, and, if so, the systems will
reduce the closest approach altitude to just 5 km (3 miles).
Deep Space 1 is the first mission under NASA's New Millennium Program
testing new technologies for use on future science missions. Among its 12
new technologies are a xenon ion propulsion system, autonomous navigation, a
high-efficiency solar array and a miniature camera/spectrometer.
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