February 28, 2014
Dawn on Course and on Schedule as Ion Thrusting Continues
Dawn has completed another month of ion thrusting toward Ceres. After it is captured by Ceres's gravity early next year, it will continue descending to an altitude of 8,400 miles (13,500 kilometers) for its first intensive observations. Continuing the preview of the explorer's mission at the dwarf planet, the February Dawn Journal explains what the spacecraft will do during that orbit phase.
January 31, 2014
Dawn Continues Spiraling to Ceres
Dawn continues its spiral outward from the sun, heading for Ceres. The spacecraft is gradually changing its orbit so that it matches Ceres's orbit around the sun. In a little more than a year, this will allow the probe to be captured by the dwarf planet's gravity. Thanks to its ion propulsion system, Dawn's gentle, graceful entry into orbit is very different from the tense, whiplash-inducing method used by conventional missions. To learn more, visit the latest Dawn Journal for the second in a series of previews of how the ship will accomplish its ambitious mission at the alien world of rock and ice.
December 31, 2013
Dawn More than Halfway from Vesta to Ceres
Dawn resumed ion thrusting early this month and ends 2013 by continuing to thrust toward its 2015 rendezvous with the dwarf planet ahead. The spacecraft is now closer to Ceres than to Vesta. For the first in a series of previews of what the probe will do when it reaches the mysterious alien world, visit the latest Dawn Journal.
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.