[FPSPACE] Dawn Journal for August 30, 2009

[LARRY KLAES]

August 30, 2009
 
Dear Indawnmitables,
 
The Dawn mission remains on course as the spacecraft continues to thrust with its ion propulsion system, patiently, persistently, and gently changing its orbit to keep its appointment with protoplanet Vesta in two years. Meanwhile, closer to mission control and in stark contrast, brave firefighters work hard to protect JPL and the nearby homes of many of its employees and others in the community.
 
The probe has continued in “quiet cruise” since the last log. During this month, engineers did give the robot a few extra tasks to ensure it remains healthy, but these were routine. When each such assignment was conducted the first time or two that Dawn was in space, they were treated as special activities, with even greater diligence than is normally applied to the unforgiving and complex undertaking of flying a spacecraft far from Earth. 

 

Now however, the commands for these activities are stored onboard well ahead of time along with the routine commands for thrusting, communicating with Earth, and carrying out all the other functions the spacecraft normally conducts without the mission control team devoting extra attention.
 
Included in the maintenance procedures were instructions to perform a sequence of movements of the mechanism that points ion thruster #1, to power off reaction wheel #2 and return #1 to service, and to operate the gyroscopes for about 4 days. For readers who do not have their copies of the Dawn operations manuals handy, some information about these 3 kinds of operations was provided in a previous log. 
 
Another event that is now considered routine occurred on August 15. For the second time this year, a particle of space radiation struck a particularly sensitive electrical component on the spacecraft, depositing enough energy to interfere with the operation of a circuit. When this happened in January 2008, it caused Dawn to enter safe mode, interrupting its other activities. Thanks to software the team transmitted to the ship later that year, now the interplanetary explorer is immune to strikes in that formerly vulnerable location.


Full entry here:

 

http://dawn.jpl.nasa.gov/mission/journal_8_30_09.asp

 

 

 
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