[meteorite-list] Dawn Maneuvering to Third Science Orbit

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 20 Jul 2015 16:51:01 -0700 (PDT)
Message-ID: <201507202351.t6KNp192010722_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4659

Dawn Maneuvering to Third Science Orbit
Jet Propulsion Laboratory
Jul 17, 2015

Mission Status Report

NASA's Dawn spacecraft is using its ion propulsion system to descend to
its third mapping orbit at Ceres, and all systems are operating well.
The spiral maneuvering over the next five weeks will take the spacecraft
to an altitude of about 900 miles (less than 1,500 kilometers) above the
dwarf planet.

The spacecraft experienced a discrepancy in its expected orientation on
June 30, triggering a safe mode. Engineers traced this anomaly to the
mechanical gimbal system that swivels ion engine #3 to help control the
spacecraft's orientation during ion-thrusting. Dawn has three ion engines
and uses only one at a time.

Dawn's engineering team switched to ion engine #2, which is mounted on
a different gimbal, and conducted tests with it from July 14 to 16. They
have confirmed that the spacecraft is ready to continue with the exploration
of Ceres.

By the end of the day on July 17, Dawn will have descended to an altitude
of about 2,400 miles (3,900 kilometers). After arrival at its next mapping
orbit -- called the High-Altitude Mapping Orbit, or HAMO -- in August,
Dawn will begin taking images and other data at unprecedented resolution.

More information on the Dawn mission is online at:

http://www.nasa.gov/dawn

http://dawn.jpl.nasa.gov


Media Contact

Elizabeth Landau
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
Elizabeth.Landau at jpl.nasa.gov

2015-238
Received on Mon 20 Jul 2015 07:51:01 PM PDT