Dwayne C. Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown@nasa.gov
Jia-Rui Cook/Priscilla Vega
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0850/4-1357
jccook@jpl.nasa.gov/priscilla.r.vega@jpl.nasa.gov
RELEASE: 11-228
NASA SPACECRAFT TO ENTER LARGE ASTEROID'S ORBIT ON JULY 15
PASADENA, Calif. -- On July 15, NASA's Dawn spacecraft will begin a
prolonged encounter with the asteroid Vesta, making the mission the
first to enter orbit around a main-belt asteroid.
The main asteroid belt lies between the orbits of Mars and Jupiter.
Dawn will study Vesta for one year, and observations will help
scientists understand the earliest chapter of our solar system's
history.
As the spacecraft approaches Vesta, surface details are coming into
focus, as seen in a recent image taken from a distance of about
26,000 miles (41,000 kilometers). The image is at:
http://www.nasa.gov/mission_pages/dawn/multimedia/dawn-image-070911.html
Engineers expect the spacecraft to be captured into orbit at
approximately 10 p.m. PDT Friday, July 15. They expect to hear from
the spacecraft and confirm that it performed as planned during a
scheduled communications pass that starts at approximately 11:30 p.m.
PDT on Saturday, July 16. When Vesta captures Dawn into its orbit,
engineers estimate there will be approximately 9,900 miles (16,000
kilometers) between them. At that point, the spacecraft and asteroid
will be approximately 117 million miles (188 million kilometers) from
Earth.
"It has taken nearly four years to get to this point," said Robert
Mase, Dawn project manager at NASA's Jet Propulsion Laboratory in
Pasadena, Calif. "Our latest tests and check-outs show that Dawn is
right on target and performing normally."
Engineers have been subtly shaping Dawn's trajectory for years to
match Vesta's orbit around the sun. Unlike other missions, where
dramatic propulsive burns put spacecraft into orbit around a planet,
Dawn will ease up next to Vesta. Then the asteroid's gravity will
capture the spacecraft into orbit. However, until Dawn nears Vesta
and makes accurate measurements, the asteroid's mass and gravity will
only be estimates. The Dawn team will refine the exact moment of
orbit capture over the next few days.
Launched in September 2007, Dawn will depart for its second
destination, the dwarf planet Ceres, in July 2012. The spacecraft
will be the first to orbit two bodies in our solar system.
Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science
Mission Directorate in Washington. Dawn is a project of the
directorate's Discovery Program, which is managed by NASA's Marshall
Space Flight Center in Huntsville, Ala.
UCLA is responsible for overall Dawn mission science. Orbital Sciences
Corp. of Dulles, Va., designed and built the spacecraft. The German
Aerospace Center, the Max Planck Institute for Solar System Research,
the Italian Space Agency and the Italian National Astrophysical
Institute are part of the mission team.
For an image of Vesta and more information about the Dawn mission,
visit:
and
You also can follow the mission on Twitter at:
http://www.twitter.com/NASA_Dawn
-end-
To subscribe to the list, send a message to:
hqnews-subscribe@mediaservices.nasa.gov
To remove your address from the list, send a message to:
hqnews-unsubscribe@mediaservices.nasa.gov
No comments:
Post a Comment