

NASA robotic explorer runs into trouble after launch - gvb
http://www.usatoday.com/story/tech/2013/09/07/nasa-robotic-explorer-moon-va/2779137/

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ANH
The issues have been resolved, according to the NASA Ames Center Director:
[https://twitter.com/worden/status/376345117205876737](https://twitter.com/worden/status/376345117205876737)

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pohl
It always seems to be the reaction wheels. Are they inherently difficult to
get right?

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dwc
Yes and no. They're usually quite good, but they wear out. Reaction wheels are
in continuous use and must remain precise enough to negate spin within some
very tight tolerances. With limited fuel and the inherent work and risk in
doing a burn to cancel spin, reaction wheels are usually spun very fast before
they burn off the spin and let the wheels slow back down.

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brownbat
More details: [http://science.time.com/2013/09/07/nasa-launches-robotic-
exp...](http://science.time.com/2013/09/07/nasa-launches-robotic-explorer-to-
moon-from-va/)

