The main goal of NASA’s New Horizons
mission may be to explore Pluto-Charon and the Kuiper belt beginning in
2015, but first the mission plans to fly by the solar system’s largest
planet, Jupiter, during February-March 2007. The Jupiter flyby would be used
by New Horizons to provide a gravitational assist that shaves years off the
trip time to Pluto-Charon and the Kuiper belt.

During the flyby, plans call for New Horizons to use its instrument payload,
consisting of cameras, spectrometers, radiometers, and space plasma and dust
sensors, to make a variety of scientific observations. Toward that end, the
New Horizons team has formally kicked off its planning of the Jupiter flyby
science observations. Southwest Research Institute (SwRI) and the Johns
Hopkins University Applied Physics Laboratory (APL) lead the mission. Major
partners include Ball Aerospace, Lockheed-Martin, Boeing, NASA Goddard Space
Flight Center and the California Institute of Technology Jet Propulsion

“Every spacecraft must check out its instruments and pointing capabilities
in flight prior to reaching its target,” says mission project scientist Dr.
Hal Weaver of the Johns Hopkins University Applied Physics Laboratory. “By
virtue of the gravity assist maneuver at Jupiter, New Horizons has a unique
opportunity to do its check out on a very worthy and exciting scientific

“New Horizons presents NASA’s next opportunity to study the complex and
fascinating Jupiter system,” says Dr. Alan Stern, principal investigator of
the New Horizons mission and director of the SwRI Space Studies Department.
“To accomplish its gravity-assist maneuver on the way to Pluto-Charon, our
spacecraft will venture at least three times closer to Jupiter than the
Cassini spacecraft did in late 2000 when it used Jupiter for a gravity
assist on the way to Saturn.

“Astronomically speaking, we will fly just outside of the edge of Jupiter’s
large, planet-sized Galilean moon, Callisto.” From its closer range, New
Horizons will perform a number of Jupiter system studies not possible from
Cassini’s greater flyby distance.

Science planning is going forward to ready the mission for its planned 2006
launch, at the same time that required environmental and safety reviews are
also being done. Through the summer of 2004, the New Horizons science team
will prioritize its Jupiter science activities from objectives provided by
team members as well as interested scientists from around the world. To
accomplish this objective, Stern has appointed mission co-investigator and
imaging team lead Dr. Jeff Moore of the NASA Ames Research Center to lead
the New Horizons Jupiter Encounter Sequencing Team (JEST).

“New Horizons will be the next mission to Jupiter, and it is carrying a
sophisticated instrument complement,” says Moore. “We intend to cull and
then schedule the most critical needs for scientific observations of
Jupiter, its satellites, its magnetosphere and its rings.

“Following that,” Moore continued, “the mission team will design and
implement a five-month-long sequence of observations of the Jupiter system
to be made from late 2006 through early 2007 as the spacecraft approaches
and then recedes from Jupiter.”

“Exploring the Jupiter system is a coveted scientific bonus for New
Horizons,” adds Weaver. “It also provides us with a valuable opportunity to
check out the instrument payload and many of the flyby procedures we will
later use at Pluto-Charon.”

New Horizons is proceeding toward a January 2006 launch, with a planned
arrival at Pluto and its moon, Charon, in the summer of 2015. The
465-kilogram (1,025-pound) spacecraft will characterize the global geology
and geomorphology of Pluto and Charon, map the surface compositions and
temperatures of these worlds, and study Pluto’s atmospheric composition and
structure. It will then visit one or more of the icy, primordial bodies in
the Kuiper belt where it will make similar investigations.

In July 2002, the National Research Council’s Decadal Survey for Planetary
Science ranked the reconnaissance of Pluto-Charon and the Kuiper belt as its
highest priority for a new start mission in planetary science, citing the
fundamental scientific importance of these bodies to advancing understanding
of our solar system.