I have not uploaded my AO-40 directory yet. It is insufficiently complete. I have pictures I think almost no one else has seen and I want to flesh these out a bit before I upload them.
In the Phase 3A, AO-10, AO-13 directories you will see curved tubes in the arms of the spacecraft near the tips. These tubes have their ends welded closed. They have glycerin in them.
As the spacecraft undergoes maneuvers from the motor firings to magnetorque attitude control adjustments, the spinning spacecraft tends to wobble. When the launcher pops us off the vehicle, it can easily impart a wobble. This wobble is called nutation. By placing the curved tubes in an arc parallel with the principal spin axis for the spacecraft, when there is this wobble, it causes the glycerin to move up and down in the tube. This movement of this viscuous fluid in the tube converts the angular momentum of the wobble into heat and "dampens" the wobble out. This wobble is called nutation, and these tubes are called nutation dampers. The shape, placement, etc. are optimized to maximize coupling with the spinning frame and to get enough damping so that the wobbles are gone in a few minutes.
Bob N4HY
Jim Jerzycke wrote:
Yes, nostalgis seems to be part of getting older. I have one question concerning the AO-40 pictures. I see a curved pipe with "crimped" ends in many of the pictures. What is/was it for? 73, Jim KQ6EA
--- Bob McGwier n4hy@idaccr.org wrote: