September 29, 2010
PASADENA, Calif. - Earlier today, navigators and mission controllers
for NASA's EPOXI mission watched their computer screens as 23.6 million
kilometers (14.7 million miles) away, their spacecraft successfully
performed its 20th trajectory correction maneuver. The maneuver refined
the spacecraft's orbit, setting the stage for its flyby of comet
Hartley 2 on Nov. 4. Time of closest approach to the comet was expected
to be about 10: 02 a.m. EDT (7:02 a.m. PDT).
Today's trajectory correction maneuver began at 2 p.m. EDT (11 a.m.
PDT) today, when the spacecraft fired its engines for 60 seconds,
changing the spacecraft's velocity by 1.53 meters per second (3.4 mph).
"We are about 23 million miles and 36 days away from our comet,"
said EPOXI project manager Tim Larson of NASA's Jet Propulsion
Laboratory in Pasadena, Calif. "I can't wait to see what Hartley 2
looks like."
On Nov. 4, the spacecraft will fly past the comet at a distance of
about 700 kilometers (435 miles). It will be only the fifth time in
history that a spacecraft has been close enough to image a comet's
nucleus, and the first time in history that two comets have been imaged
with the same instruments and same spatial resolution.
"We are imaging the comet every day, and Hartley 2 is proving to be
a worthy target for exploration," said Mike A'Hearn, EPOXI principal
investigator from the University of Maryland, College Park.
EPOXI is an extended mission that utilizes the already "in flight"
Deep Impact spacecraft to explore distinct celestial targets of
opportunity. The name EPOXI itself is a combination of the names for
the two extended mission components: the extrasolar planet
observations, called Extrasolar Planet Observations and
Characterization (EPOCh), and the flyby of comet Hartley 2, called the
Deep Impact Extended Investigation (DIXI). The spacecraft will continue
to be referred to as "Deep Impact."
NASA's Jet Propulsion
Laboratory, Pasadena, Calif., manages the EPOXI mission for NASA's
Science Mission Directorate, Washington. The University of Maryland,
College Park, is home to the mission's principal investigator, Michael
A'Hearn. Drake Deming of NASA's Goddard Space Flight Center, Greenbelt,
Md., is the science lead for the mission's extrasolar planet
observations. The spacecraft was built for NASA by Ball Aerospace &
Technologies Corp., Boulder, Colo.
For more information about EPOXI visit http://epoxi.umd.edu/.