>> The only thing is whether the crystal(s) can survive
>> the vibrations of the flight, and whether it will stay
>> in tune over the temperature range - unless the craft
>> has the energy budget to keep it at constant temperature,
>> it's quite a challenge!
>
>I used to see a lot of problems with hobby HPR designs,
>and when you'd look at the board, they had the main
>acceleration axis running through the large face
>of the crystal.  Those solid motors are pretty rough.

We use Mil-Spec crystals which are built to withstand the vibration. The
unit I have just been working on had the electronics box vibrated at 17G RMS
energy broadband 10Hz-2kHz for 1 minute in each axis. I forget the exact
frequency distribution, but it is shaped over the frequency range.

We don't take any special precautions with the crystal axis, and I don't
know what precautions are taken inside the crystal to ruggedise it.

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