[meteorite-list] Dawn Sets Course for Higher Orbit

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?feature=6608

Dawn Sets Course for Higher Orbit
Jet Propulsion Laboratory
August 31, 2016

After studying Ceres for more than eight months from its low-altitude 
science orbit, NASA's Dawn spacecraft will move higher up for different 
views of the dwarf planet.

Dawn has delivered a wealth of images and other data from its current 
perch at 240 miles (385 kilometers) above Ceres' surface, which is closer 
to the dwarf planet than the International Space Station is to Earth. 
Now, the mission team is pivoting to consider science questions that can 
be examined from higher up.

After Dawn completed its prime mission on June 30, having surpassed all 
of its scientific objectives at Vesta and at Ceres, NASA extended the 
mission to perform new studies of Ceres. One of the factors limiting Dawn's 
lifetime is the amount of hydrazine, the propellant needed to orient the 
spacecraft to observe Ceres and communicate with Earth. By going to a 
higher orbit at Ceres, Dawn will use the remaining hydrazine more sparingly, 
because it won't have to work as hard to counter Ceres' gravitational 
pull.

"Most spacecraft wouldn't be able to change their orbital altitude so 
easily. But thanks to Dawn's uniquely capable ion propulsion system, we 
can maneuver the ship to get the greatest scientific return from the mission," 
said Marc Rayman, chief engineer and mission director, based at NASA's 
Jet Propulsion Laboratory, Pasadena, California.

On Sept. 2, Dawn will begin spiraling upward to about 910 miles (1,460 
kilometers) from Ceres. The altitude will be close to where Dawn was a 
year ago, but the orientation of the spacecraft's orbit -- specifically, 
the angle between the orbit plane and the sun -- will be different this 
time, so the spacecraft will have a different view of the surface.

The mission team is continuing to develop the extended mission itinerary 
and will submit a full plan to NASA next month.

Dawn's mission is managed by JPL for NASA's Science Mission Directorate 
in Washington. Dawn is a project of the directorate's Discovery Program, 
managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. 
UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., 
in Dulles, Virginia, designed and built the spacecraft. The German Aerospace 
Center, Max Planck Institute for Solar System Research, Italian Space 
Agency and Italian National Astrophysical Institute are international 
partners on the mission team. For a complete list of mission participants, 
visit:

http://dawn.jpl.nasa.gov/mission

More information about Dawn is available at the following sites:

http://dawn.jpl.nasa.gov

News Media Contact
Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
elizabeth.landau at jpl.nasa.gov

2016-227