Picokeystoning this week

This is our first blog entry. In order to do this expeditiously, these will be stream-of-conciousness blogs, with little or no wordsmithing, so please forgive spelling mistakes, ungrammatical sentences, and so on. I’m just writing this as if I’m writing an e-mail to a colleague. Which, effectively, I am.

We’re doing picokeystoning practice here at SSL in preparation for another trip to JSC the week of Oct. 8 to practice picokeystoning in the Stardust flight spare. We set up a picokeystone in the cleanroom on Monday afternoon on a practice tile of aerogel, but when we came in on Tuesday morning, it looked strange. After scratching our heads for a bit, we realized that the undercutting needle was trying to do the vertical cut, and the result was a strange-looking keystone that had the vertical cuts backwards. We realized that it was a port configuration problem, and fixed it. We set up a new picokeystone on Tuesday afternoon, and on Wednesday morning realized that the vertical cut was not quite deep enough, so Dave (Frank) restarted it with a deeper vertical cut. This cut turned out to be too deep — the picokeystone popped out and was lost! Obviously we can’t tolerate this kind of problem with the real interstellar grains. We’re busy today preparing a cometary sample for FTIR analysis at the ALS. After we finish that, by tomorrow morning, we’ll set up a new practice picokeystone, going back to a technique that we used before the return of Stardust. We’ll do most of the keystoning procedure, up but not including the final cut that separates it from the tile. We’ll remove the undercutting needle and replace it with a micropicklefork, and place the fork gently on the keystone to hold it in place. Then we’ll do the final cut, put the fork into its final place, and lift it out. This is a good reminder that this is really as much art as science.

Stay tuned!

— Andrew