[meteorite-list] Dawn Spacecraft to Enter Asteroid's Orbit on July 15

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 14 Jul 2011 08:23:01 -0700 (PDT)
Message-ID: <201107141523.p6EFN1vT028118_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2011-208

NASA Spacecraft to Enter Asteroid's Orbit on July 15
Jet Propulsion Laboratory
July 14, 2011

[Image}
Asteroid Vesta NASA's Dawn spacecraft obtained this image of the giant
asteroid Vesta with its framing camera on July 9, 2011. Image credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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 available 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 (1 a.m. EDT Saturday, July
16). 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 (2:30 a.m. EDT
Sunday, July 17). 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. So the Dawn team will need a few days to refine the exact
moment of orbit capture.

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 a current image of Vesta and more information about the Dawn
mission, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov
.You also can follow the mission on Twitter at:
http://www.twitter.com/nasa_dawn .

Priscilla Vega/Jia-Rui Cook 626-298-3290/818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
priscilla.r.vega at jpl.nasa.gov / jccook at jpl.nasa.gov

Dwayne C. Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown at nasa.gov

2011-208
Received on Thu 14 Jul 2011 11:23:01 AM PDT