November 30, 2013
Dawn Accomplishes Special Assignments While Coasting to Ceres
Dawn is in an unusual part of its interplanetary trajectory during which coasting is preferable to ion thrusting. Engineers took advantage of this period to operate in a new "hybrid" mode, in which the spacecraft uses its two healthy reaction wheels plus its hydrazine-powered jets to control its orientation in space. This successful test paves the way for using hybrid when Dawn is in its lowest orbits at Ceres, where the system may extend the limited supply of hydrazine. Mission controllers also confirmed the health of the sensors that will investigate Ceres. Visit the Dawn Journal for details on Dawn's latest activities and intriguing milestones the spacecraft will pass in December.
October 31, 2013
Dawn Plans a Hiatus in Ion Thrusting
Dawn completed another month of ion thrusting and is making excellent progress to Ceres.
Although a great deal of thrusting is required to reach its destinations in the main asteroid belt, the flight plan requires Dawn to coast soon for four weeks. See the latest Dawn Journal for details.
September 27, 2013
Dawn Completes Sixth Year of Flight
Dawn celebrated its sixth anniversary of spaceflight by continuing to thrust with its ion propulsion system on the long journey from Vesta to Ceres, just as it has most of the last year.
The probe has thrust for 1,410 days so far in the mission, or 64 percent of the time since launch. Its effective change in speed is more than 8.7 kilometers per second (19,500 miles per hour), well in excess of what any other spacecraft has achieved under its own power. Thanks to the efficiency of the ion propulsion system, all this thrusting has consumed only 318 kilograms (701 pounds) of xenon propellant.
To see more about the spacecraft's progress in six years of interplanetary flight, visit the latest Dawn Journal.
August 30, 2013
Dawn and Earth on Opposite Sides of the Sun
As Dawn travels through the main asteroid belt independently of Earth's motion around the sun, the spacecraft and planet were on opposite sides of the solar system's star this month. Dawn was well in excess of one million times farther from Earth than the International Space Station. Visit the August Dawn Journal to read more about this extraordinary alignment.
July 29, 2013
As Spacecraft Continues to Ceres, Engineers Test Its Solar Array
Dawn continues to thrust with its power-hungry ion propulsion system to rendezvous with dwarf planet Ceres in 2015. To keep the spacecraft on course and on schedule, engineers need an accurate prediction of how much electrical power its solar arrays will generate as it recedes from the sun. The probe recently conducted a special test in which it rotated its huge wings so they would experience the same illumination they will receive later in this deep-space mission. For more information on why Dawn craves power and how this activity was performed, visit the July Dawn Journal.
June 30, 2013
Dawn Sailing Smoothly With a Different Ion Engine
After relying on ion engine #3 since August 2011, engineers decided to command #2 to take over this month, and the ship is continuing to propel itself to dwarf planet Ceres. For more information on Dawn's three engines, and a comparison to a familiar ship from science fiction, see the June Dawn Journal.
May 31, 2013
Dependable Dawn Continues Ion Thrusting
Dawn has completed its longest uninterrupted thrust period of the mission, more than 31 days. Thanks to the probe's dependability, controllers were able to devote time not only to preparing for Ceres but also to practicing how to recover from a spacecraft problem. Details are in the latest Dawn Journal.
April 30, 2013
Dawn Closer to the Sun than Vesta as it Travels to Ceres
The spacecraft has accomplished another month of thrusting with its ion propulsion system, and it is making good progress to Ceres. In order to catch up with the dwarf planet, which is even farther from the sun than Vesta, Dawn temporarily has to go in closer to the sun than Vesta. The most recent Dawn Journal explains why.
March 29, 2013
Mission Controllers Keep Dawn Flying to Ceres
With another month of ion thrusting complete, Dawn remains healthy. As it spends most of its time in powered flight, mission controllers spend most of theirs ensuring operations continue smoothly and preparing for Ceres. To learn more, see the latest Dawn Journal.
February 28, 2013
Persistent Ion Thrusting Provides Tremendous Change in Velocity
Dawn has devoted another month to thrusting with its ion propulsion system as it heads for Ceres. The spacecraft has now changed its speed by more than 7.7 kilometers per second (17,000 mph) since it was launched, far more than any other spacecraft. That's about the same that it takes for a rocket to go into Earth orbit, but that is not what Dawn's thrusting has accomplished, and it is not the spacecraft's speed. For an explanation of this extraordinary velocity change, see the latest Dawn Journal.
January 31, 2013
Dawn Continues Ion Thrusting to Ceres
Dawn has devoted the entire month of January to thrusting with its ion propulsion system to reach dwarf planet Ceres in 2015. Dawn has traveled far enough from Vesta that the protoplanet would appear to the spacecraft only as a bright pinpoint of light.
January 3, 2013
Dawn Completes a Spectacular Year and Continues toward Ceres
Dawn ended its extraordinarily successful 2012 by smoothly continuing to thrust with its ion propulsion system to its 2015 rendezvous with dwarf planet Ceres. In December, as Earth and Dawn followed their independent orbits, they were at their closest distance in more than a year. As the spacecraft continues its interplanetary adventure, you can locate its position in the sky using the moon as a guide on Jan. 21. For more details, see the most recent Dawn Journal.