[meteorite-list] NASA's Asteroid Photographer Beams Back Science Data (Dawn)
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 11 Aug 2011 16:38:52 -0700 (PDT)
NASA's Asteroid Photographer Beams Back Science Data
Jet Propulsion Laboratory
August 11, 2011
The Dawn spacecraft has completed a graceful spiral into the first of
four planned science orbits during the spacecraft's yearlong visit to
Vesta. The spacecraft started taking detailed observations on Aug. 11 at
9:13 a.m. PDT (12:13 a.m. EDT), which marks the official start of the
first science-collecting orbit phase at Vesta, also known as the survey
Survey orbit is the initial and highest orbit, at roughly 1700 miles
(2700 kilometers) above the surface, which will provide an overview or
"big picture" perspective of the giant asteroid.
The primary objective of survey orbit is to image the surface with
near-global coverage in visible and infrared wavelengths with the
mapping spectrometer, also known as VIR. Dawn also will be using its
framing camera to collect image mosaics that complement the VIR spectral
data to produce geologic and compositional maps of Vesta's surface.
Ultrasensitive measurements of the spacecraft's motion using radio
signals will allow improved understanding of the giant asteroid's
gravity field. Dawn's gamma ray and neutron detector will continue to
collect background data.
The survey phase is planned to last 20 days. Each orbit takes almost
three days, which will provide the spacecraft seven trips around Vesta.
After survey orbit, Dawn will resume thrusting, taking about a month to
spiral down gently to its next science orbit for an even closer view.
That orbit, known as High Altitude Mapping Orbit, or HAMO, begins in
late September. Dawn will spend about a month in HAMO, circling around
Vesta in half a day, rather than three. Dawn will orbit more than 60
times during HAMO, allowing the camera to fully map the illuminated
portion of Vesta at even higher resolution, and enable the science team
to generate stereo images.
For more information about Dawn, visit: http://www.nasa.gov/dawn and
Dawn launched in September 2007 and arrived at Vesta in July 2011.
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, Ca., 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.
Jet Propulsion Laboratory, Pasadena, Calif.
Priscilla.r.vega at jpl.nasa.gov
Received on Thu 11 Aug 2011 07:38:52 PM PDT