NASA will decide in the next two months whether to keep Dawn in orbit around Ceres or send it to another asteroid. Credit: NASA/JPL-Caltech
WASHINGTON NASA expects to make a decision within the next two months whether to keep the Dawn spacecraft in orbit around the largest body in the main asteroid belt or have it fly past another asteroid.
Dawn completed a one-year extended mission in orbit around Ceres at the end of June, but NASA did not announce whether the spacecrafts mission would be extended again. NASA spokesperson Laurie Cantillo said July 5 that the agencys planetary science division is still reviewing an independent report on the science the mission has achieved at Ceres.
NASAs Planetary Science Division has received and is now reviewing a report from an independent science review panel with regard to Dawns completion of Level 1 science requirements at Ceres, Cantillo told SpaceNews.
That review is required before NASA makes a decision on Dawns future. The spacecraft could remain in orbit around Ceres or use its remaining fuel to travel to another asteroid, she said.
Cantillo said that points of clarification about the report are currently being discussed are part of the overall science review of the mission. Once completed, a decision will be made, most likely in the next 3060 days, she said. Spacecraft operations will continue during the review process.
A project scientist said last month that the mission was considering a flyby. Its an option, Carol Raymond, deputy principal investigator for Dawn at the Jet Propulsion Laboratory, said at a June 13 meeting of NASAs Small Bodies Assessment Group (SBAG). She said then that the mission was in the process of discussing with NASA options for a second extended mission but declined to give additional details about those options.
Project officials proposed an asteroid flyby last year as part of the biannual senior review of planetary science missions seeking extensions. That proposal called for leaving orbit around Ceres in July 2016 and making a slow flyby of the asteroid Adeona in May 2019.
The NASA report that reviewed those extended mission proposals criticized the Dawn proposal for discrepancies, including a lack of specifics and scientific justification, which it blamed on being submitted late in the process. NASA decided instead on a one-year extended mission that remained in orbit around Ceres, in part to ensure that the missions Level 1 science requirements were met.
Dawn, developed as part of NASAs Discovery program of low-cost planetary science missions, launched in 2007. It entered orbit around the main belt asteroid Vesta in July 2011, remaining in orbit there for more than one year. Dawn used its ion propulsion system to leave orbit in September 2012 and travel to Ceres, a body designated by the International Astronomical Union as a dwarf planet, entering orbit in March 2015.
The spacecraft has continued operations despite problems with its reaction wheels, used for attitude control. After suffering the loss of two of its four reaction wheels earlier in the mission, a third wheel malfunctioned in April. The spacecraft went into safe mode briefly, but controllers resumed operations with hydrazine thrusters taking over for the failed wheel.
That failure will eventually lead to the end of the mission when the spacecraft runs out of hydrazine. It does reduce our lifetime because we have to use hydrazine at a faster rate, Raymond said at the SBAG meeting in June.
That lifetime, she said, is dependent on the spacecrafts orbital altitude. Dawn has spiraled out to a higher orbit during its extended mission, which reduces the amount of hydrazine needed for attitude control. The lifetime is now highly dependent on orbital altitude because we need to use the jets to fight the gravity gradient torques, she said.
In its current high orbit, Raymond said that Dawn had sufficient hydrazine, as well as xenon propellant used for the ion engine, to operate at least through the end of 2018. In a lower orbit, like that used by Dawn earlier in the mission for high-resolution mapping of Ceres, the spacecrafts lifetime would likely be limited to weeks.
Original post:
NASA reviews options for Dawn extended mission - SpaceNews
- 2D Laser Profiling Scanner for Detecting Targets - November 8th, 2009 [November 8th, 2009]
- NASA Energy Concept Could Harness the Power of Ocean Waves - November 8th, 2009 [November 8th, 2009]
- Data Acquisition Modules - November 8th, 2009 [November 8th, 2009]
- Dr. Scott Barthelmy, Research Scientist, Laboratory for High Energy Astrophysics, Goddard Space Flight Center, Greenbelt, MD - November 8th, 2009 [November 8th, 2009]
- Laser Tracker Ensures Accurate Alignment of Ares I Components - November 8th, 2009 [November 8th, 2009]
- Dual Cryogenic Capacitive Density Sensor - November 8th, 2009 [November 8th, 2009]
- Advanced Technologies Will Help Hubble Yield More Remarkable Discoveries - November 8th, 2009 [November 8th, 2009]
- Dr. Gerard Holzmann, Senior Research Scientist at the Laboratory for Reliable Software, NASA’s Jet Propulsion Laboratory - November 8th, 2009 [November 8th, 2009]
- NASA Research Will Help Aircraft Avoid Ocean Storms and Turbulence - November 8th, 2009 [November 8th, 2009]
- NASA Awards 2008 Software of the Year - November 8th, 2009 [November 8th, 2009]
- Here Come The Tricorders - Update - November 8th, 2009 [November 8th, 2009]
- China's View on Space - November 8th, 2009 [November 8th, 2009]
- Milsat Coordination and Tracking Issues - November 8th, 2009 [November 8th, 2009]
- Trash Talking and End Runs at NASA HQ - November 8th, 2009 [November 8th, 2009]
- Ares 1-Y is Toast - November 8th, 2009 [November 8th, 2009]
- Beyond Augustine - November 8th, 2009 [November 8th, 2009]
- Analyzing LCROSS' Plume - November 8th, 2009 [November 8th, 2009]
- Live Event: NASA-Sponsored Power Beaming Challenge - November 8th, 2009 [November 8th, 2009]
- JSC Wants To Build a Replicator - November 8th, 2009 [November 8th, 2009]
- USA: Looking For Ways To Hang On - November 8th, 2009 [November 8th, 2009]
- Lunar Lander Challenge Prizes Awarded - November 8th, 2009 [November 8th, 2009]
- Senate Votes To Restore NASA Budget Cuts - November 8th, 2009 [November 8th, 2009]
- New FAA Regs for Commercial Reentry - November 8th, 2009 [November 8th, 2009]
- TEDxNASA: An Invitation-Only NASA Meeting - Unless You Are Lucky - November 8th, 2009 [November 8th, 2009]
- Close Call For Courtney Stadd - November 8th, 2009 [November 8th, 2009]
- Space: A Waste? - November 8th, 2009 [November 8th, 2009]
- Making NASA Cool - November 8th, 2009 [November 8th, 2009]
- Engaging JSC’s Next Gen: A Leadership Analysis - November 8th, 2009 [November 8th, 2009]
- Dumpster Diving for Rockets - November 8th, 2009 [November 8th, 2009]
- TEDx NASA - November 8th, 2009 [November 8th, 2009]
- Reflections On a Business Trip in Huntsville - November 8th, 2009 [November 8th, 2009]
- Staying the Course - November 8th, 2009 [November 8th, 2009]
- The Economics of Space - November 8th, 2009 [November 8th, 2009]
- Ideas at Work - November 8th, 2009 [November 8th, 2009]
- Blah Blah Blah - Why We Should Care About Social Media - November 8th, 2009 [November 8th, 2009]
- Will White House Speak Soon About NASA? - December 12th, 2009 [December 12th, 2009]
- Software Aids Design of Ares V Composite Shroud Structure - December 13th, 2009 [December 13th, 2009]
- ASDX Series of silicon pressure sensors - December 13th, 2009 [December 13th, 2009]
- Industry Update: Analysis & Simulation Software - December 13th, 2009 [December 13th, 2009]
- Battery Will Provide Backup Power for Space Shuttles - December 13th, 2009 [December 13th, 2009]
- NASA Employee Claims To Have Witnessed Hijacking Planning - December 13th, 2009 [December 13th, 2009]
- Big Party in The Mojave Tonight - December 13th, 2009 [December 13th, 2009]
- Looking at Boulders on the Moon - December 13th, 2009 [December 13th, 2009]
- SpaceBook Featured by White House - December 13th, 2009 [December 13th, 2009]
- New Ways to Use Constellation Stuff - December 13th, 2009 [December 13th, 2009]
- LaRC internal Poll Update - December 13th, 2009 [December 13th, 2009]
- Coalition for Space Exploration Does a (Much Needed) Reboot - December 13th, 2009 [December 13th, 2009]
- Lunar Orbiter: Comparing Old and New Images - December 13th, 2009 [December 13th, 2009]
- Boulder Trails On The Moon - December 13th, 2009 [December 13th, 2009]
- Vote for John Grunsfeld - National Geographic Adventurer of the YeAR - December 13th, 2009 [December 13th, 2009]
- Charlie Bolden at WIA/AIAA - December 13th, 2009 [December 13th, 2009]
- Live Webcast From The Lunar Orbiter Image Recovery Project - December 13th, 2009 [December 13th, 2009]
- Big Aerospace Warns of Job Cut Impact - December 13th, 2009 [December 13th, 2009]
- The Boulders of Copernicus - December 13th, 2009 [December 13th, 2009]
- shame on us - December 13th, 2009 [December 13th, 2009]
- 2009 Space Elevator Games - December 13th, 2009 [December 13th, 2009]
- Random Hacks of Kindness - December 13th, 2009 [December 13th, 2009]
- TEDx NASA Tickets Available to the Public - December 13th, 2009 [December 13th, 2009]
- It’s better in person - December 13th, 2009 [December 13th, 2009]
- Leading Amidst the Disruptive Innovation Storm - December 13th, 2009 [December 13th, 2009]
- Space: What’s NOT to Hope for? - December 13th, 2009 [December 13th, 2009]
- Government in the Digital Age - December 13th, 2009 [December 13th, 2009]
- SpaceUp – A Space Unconference - December 13th, 2009 [December 13th, 2009]
- Starfleet Academy? - December 13th, 2009 [December 13th, 2009]
- Crowdsourcing NASA - December 13th, 2009 [December 13th, 2009]
- Bringing Home The Bacon - December 14th, 2009 [December 14th, 2009]
- Anti-Space Mom with Pro-Space Kids - December 14th, 2009 [December 14th, 2009]
- How Quickly We Forget - December 14th, 2009 [December 14th, 2009]
- WISE Launch A Success - December 14th, 2009 [December 14th, 2009]
- Dynetics Buys Orion Propulsion - December 15th, 2009 [December 15th, 2009]
- New NASA Governance Structure Under Development - December 16th, 2009 [December 16th, 2009]
- Bolden Meets With Obama on Wednesday - December 16th, 2009 [December 16th, 2009]
- MSFC Procurement Doesn't Understand what "Open Source" Means - December 16th, 2009 [December 16th, 2009]
- Bolden Meets With Obama - December 17th, 2009 [December 17th, 2009]
- Parker Griffith AT MSFC Today - December 18th, 2009 [December 18th, 2009]
- Why Your NASA Computer May Not Work Properly - December 18th, 2009 [December 18th, 2009]
- Lakes and Fog on Titan - December 18th, 2009 [December 18th, 2009]
- Waterworld Found - December 18th, 2009 [December 18th, 2009]
- Pandora Could Exist - December 18th, 2009 [December 18th, 2009]
- Laurie Leshin Is The New ESMD Deputy AA - December 18th, 2009 [December 18th, 2009]