Update: 08 Jun 2007 - Extraction Tests at JSC

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bmendez
Stardust@home Team
Stardust@home Team
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Update: 08 Jun 2007 - Extraction Tests at JSC

Post by bmendez » Fri Jun 08, 2007 6:47 pm

As we mentioned in the March 27th Update we are planning to extract candidate tracks identified by Stardust@home volunteers from the aerogel collector directly for analysis.

We've just completed a round of testing our extraction equipment on the Stardust interstellar flight spare tray (a back-up tray manufactured for the Stardust mission just in case something went wrong with the first tray before launch).

Last week, Stardust@home team member Zach Gainsforth traveled to the cosmic dust lab facilities at Johnson Space Center in Houston, Texas to practice extractions from the collector. The process involved mounting and controlling a micromanipulator to the side of the collector tray.

The micromanipulator holds and controls an armature that stretches out over the tray. The armature holds a superfine glass needle that is used to perforate the aerogel into the shape of a keystone. The micromanipulator has to control the armature to a precision smaller than a micron. The images below shows the set-up.

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Note in the image above that the microscope we used in the tests is the same one that has been used to scan the actual interstellar dust tray.

One concern was that because the armature needed to be so long there might be significant vibrations in it that would make controlling it to the needed precision impossible. Luckily, this was not the case. The tests showed vibrations to not be a problem.

The needle used is glass, and it is made so that its width at the tip is smaller than a micron. That is very sharp!
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The needle cuts a wedge-shaped piece of aerogel, that we call a keystone, with the particle track contained at one corner. Holes are cut from the keystone that are used to insert microforks that pull the keystone out of the aerogel tile and then are used to hold it in all further analysis. For tracks as small as those produced by interstellar dust particles we further excavate a smaller wedge at the corner of the keystone that we call a picokeystone. Having less aerogel surrounding the track makes analysis easier.
Image

During the tests we did not successfully extract any picokeystones. However, as a result of the tests, we are now confident that we will be able to do so successfully with only a little further development.

Stay tuned!

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