Space TopicsDawnDawn Journals: Dawn Project System Engineer Marc Rayman is contributing updates on the status of Dawn to The Planetary Society Weblog! Jan. 31, 2011: ORT ORT ORT Dec. 30, 2010: LAMO (Low Altitude Mapping Orbit) Nov. 30, 2010: Attitude Adjustment Oct 31, 2010: Approaching conjunction Sep 27, 2010: Third anniversary in space, and how to map Vesta Aug 30, 2010: Getting warmer, farther from the Sun? Jul 26, 2010: A Year from Vesta Jun 27, 2010: Dawn 9.0 May 27, 2010: Surveying Vesta Apr 28, 2010: Matching paces with Vesta Mar 28, 2010: It's just a phase Feb 28, 2010: Forever farther from Earth than the Sun Jan 30, 2010: Thruster Two's time to shine Dec 30, 2009: Patiently accelerating Nov 27, 2009: In the asteroid belt, but far from asteroids Oct 31, 2009: Taking up residence in the asteroid belt Sep 27, 2009: Good performance means a longer stay at Vesta! Aug 30, 2009: Earth catches up Jul 31, 2009: Quiet Cruise Jun 28, 2009: Back to powered flight May 27, 2009: Testing Flight Software 8.0 Apr. 29, 2009: Upgrades! Mar. 29, 2009: Safe without Safe Mode Mar. 8, 2009: Safely past Mars Feb. 13, 2009: Mars encounter Jan. 27, 2009: Just missing the bull's eye at Mars Dec. 30, 2008: Conjunction junction Nov. 26, 2008: Aiming away from a bull's eye at Mars Oct. 30, 2008: A pause in thrusting Sep. 27, 2008: One year since launch Aug. 28, 2008: Some explanations of orbital dynamics Jul. 27, 2008: We crave power! Jun. 26, 2008: Cruising past Mars' orbit May 29, 2008: Dawn Journal Apr. 22, 2008: Software updates Mar. 30, 2008: One AU from Earth Mar. 3, 2008: Backup camera checks out Jan. 31, 2008: Safely cruising Dec. 17, 2007: Checkout complete, interplanetary cruise underway Oct. 26, 2007: Testing, Testing, Testing Nov. 14, 2007: Halfway through checkout Oct. 9, 2007: Firing Up the Ion Propulsion System Oct. 2, 2007: Launch! Sep. 21, 2007: Awaiting launch II September 14, 2007: What to expect after the launch II September 5, 2007: Dawn prepares to launch II Jul. 17, 2007: More than one way to leave the launch pad Jul. 6, 2007: More bad weather - Awaiting launch Jun. 26, 2007: What to expect after the launch Jun. 12, 2007: Readying the rocket Jun. 4, 2007: Dawn prepares for launch Between the orbits of Mars and Jupiter circles the main asteroid belt, remnants of the formation of the solar system, millions of rocky bodies with orbits too disturbed by the gravitational pull of Jupiter for them to coalesce into a single planet. Among these are a few big ones, protoplanets that started down the road to terrestrial planethood but failed to thrive. Ceres and Vesta are the most massive of the minor planets, and the Dawn mission aims to visit them both to discover what clues they may hold to how our solar system, and particularly the terrestrial planets (Mercury, Venus, Earth, and Mars), formed. Ceres and Vesta could hardly be more different. Ceres is a spherical, ice-rich world, similar (perhaps) to the icy moons of the outer solar system. Vesta is probably all rock and metal, and is so battered by past collisions with other asteroids that its shape is noticeably lumpy. Both bodies likely formed only 5 to 10 million years after the birth of the solar system, unlike Mars and Earth, which took much longer (30 and 50 million years, respectively). Although both formed in a relatively short period of time, Ceres was left with primordial water, while Vesta was not. The water at Ceres prevented it from developing the internal volcanic activity that developed on drier Vesta. Ceres' water almost certainly melted into a global subsurface ocean, and there may yet be liquid water beneath its icy crust. Dawn will journey to Vesta and then Ceres under the power of an ion engine, technology it inherits from the successful Deep Space 1 technology development spacecraft. The ion engine gives the spacecraft a leisurely cruise. The low speed of the spacecraft relative to the objects in the asteroid belt will enable it to enter orbit at the two worlds, becoming the first spacecraft to enter orbit around two different planetary bodies. Instead of a flyby mission lasting only hours, Dawn's survey of Vesta and Ceres will include many months spent at each. It will initially enter a high-altitude orbit at Ceres, and then shift its orbit downward twice to obtain closer and closer views, and repeat the same sequence as at Vesta. It should obtain photographic and mineralogic maps of the entire surface of each world. Sensitive tracking of the spacecraft as it orbits the minor planets will lead to models of their topography and gravity and a better understanding of their internal structure. Dawn Facts Launch: September 27, 2007 at 11:34 UTC Mars flyby: February 2009 Vesta rendezvous: July 2011 - July 2012 Ceres rendezvous: February 2015 - July 2015 Recent Headlines
31 Jan 11 Mars Exploration Rover Update: Mission Celebrates 7 Years of Exploration
18 Nov 10 Brian Marsden, 1937 - 2010
31 Oct 10 Mars Exploration Rover Update: Spirit Remains Silent, Opportunity Pushes on to Endeavour
31 Aug 10 Mars Exploration Rover Update: Spirit Hibernates Still, Opportunity Pulls into Cambridge Bay
31 Jul 10 Mars Exploration Rovers Update: Spirit Sleeps Soundlessly, Opportunity Turns a Corner
17 Jun 10 Mars Exploration Rovers Special Update: Spirit Team Announces Major Water Discovery |
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