[meteorite-list] NASA's Dawn Spacecraft Begins New Vesta Mapping Orbit

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sun, 2 Oct 2011 20:35:22 -0700 (PDT)
Message-ID: <201110030335.p933ZMmH004184_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2011-307

NASA's Dawn Spacecraft Begins New Vesta Mapping Orbit
Jet Propulsion Laboratory
September 30, 2011

PASADENA, Calif. -- NASA's Dawn spacecraft has completed a gentle spiral
into its new science orbit for an even closer view of the giant asteroid
Vesta. Dawn began sending science data on Sept. 29 from this new orbit,
known as the high altitude mapping orbit (HAMO).

In this orbit, the average distance from the spacecraft to the Vesta
surface is 420 miles (680 kilometers), which is four times closer than
the previous survey orbit. The spacecraft will operate in the same basic
manner as it did in the survey orbit. When Dawn is over Vesta's dayside,
it will point its science instruments to the giant asteroid and acquire
data, and when the spacecraft flies over the nightside, it will beam
that data back to Earth.

Perhaps the most notable difference in the new orbit is the frequency
with which Dawn circles Vesta. In survey orbit, it took Dawn three days
to make its way around the asteroid. Now in HAMO, the spacecraft
completes the same task in a little over 12 hours. HAMO is scheduled to
last about 30 Earth days, during which Dawn will circle Vesta more than
60 times. For about 10 of those 30 days, Dawn will peer straight down at
the exotic landscape below it during the dayside passages. For about 20
days, the spacecraft will view the surface at multiple angles.

Scientists will combine the pictures to create topographic maps,
revealing the heights of mountains, the depths of craters and the slopes
of plains. This will help scientists understand the geological processes
that shaped Vesta.

HAMO, the most complex and intensive science campaign at Vesta, has
three primary goals: to map Vesta's illuminated surface in color,
provide stereo data, and acquire visible and infrared mapping
spectrometer data. In addition, it will allow improved measurements of
Vesta's gravity.

Dawn launched in September 2007 and arrived at Vesta in July 2011. Since
beginning its first survey orbit in August, Dawn has been extensively
imaging this intriguing world, sending back a bounty of images and other
data. NASA-funded scientists and European scientists on the Dawn mission
team will present a wealth of new findings at the joint meeting of the
American Astronomical Society's Division for Planetary Sciences and the
European Planetary Science Congress next week at La Cite Internationale
des Congres Nantes Metropole, Nantes, France.

These findings about the giant asteroid Vesta will include information
about the new coordinate system and official names of Vesta's prominent
features.

A Dawn mission news conference will be held Monday, Oct. 3, 2011 at
12:15 p.m. CEST (3:15 a.m. PDT/6:15 a.m. EDT). The Division for
Planetary Sciences will provide live Web streaming of this news
conference, at:
http://meetings.copernicus.org/epsc-dps2011/webstreaming/monday.html

"The team has been in awe of what they have seen on the surface of
Vesta," said Christopher Russell, Dawn principal investigator, at UCLA.
"We are sharing those discoveries with the greater scientific community
and with the public."

Following a year at Vesta, the spacecraft will depart in July 2012 for
Ceres, where it will arrive in 2015. Dawn's mission to Vesta and Ceres
is managed by the Jet Propulsion Laboratory, Pasadena, Calif., for
NASA's Science Mission Directorate in Washington. JPL is a division of
the California Institute of Technology in Pasadena. Dawn is a project of
the directorate's Discovery Program, managed by NASA's Marshall Space
Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn
mission science. Orbital Sciences Corp. in 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 international partners on
the mission team.

The image and more information about the Dawn mission are online at:
http://www.nasa.gov/dawn . To follow the mission on Twitter, visit:
http://www.twitter.com/NASA_Dawn

Priscilla Vega 818-354-1357
Jet Propulsion Laboratory, Pasadena, Calif.
priscilla.r.vega at jpl.nasa.gov

2011-307
Received on Sun 02 Oct 2011 11:35:22 PM PDT