
Elon Musk Wants Fully Reusable Rockets–But That Won't Be So Easy - artsandsci
http://gizmodo.com/elon-musk-wants-fully-reusable-rockets-but-that-wont-b-1794330614
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aurizon
Erosion of exposed metal in the combustion chamber and throat will limit the
number of cycles that such parts can go though before being replaced. In fact,
every part needs to be assessed - it depends on the way they get worn/used in
a launch. Test every part and replace them and gradually work out the wear
pattern of every part. Some parts will not wear much at all. Since all rocket
parts are designed for light weight they are already operating at their
limits. The most important thing is vibration resistance. I used to work in an
aerospace place that had a shake table. This was like a huge voice coil
speaker magnet driven by 100,000 watts of power and it could shake a 100 pound
object through 1 inch travel and up to 200 hertz. It could shake common items
to bits. It even shook nuts and bolts apart, so all aerospace items are
usually done with lock bolts. I am sure Spacex has these shake tables and does
this. Might well be bigger than the 100KW ones I used - since they have bigger
items to test than we did.

