First rotation tests at 1 g

12th July

At last the first tests!

We tested 2 kinds of open loop rotation, with the freeflyer hung with a rope. The goal was to have an idea of the dynamic and to see if the freeflyer was able to stop after a rotation.

For the first test, we used the momentum wheel in open loop, this means without correcting the difference between the accelerating and decelerating time. Unfortunately, the results were as we had calculated: you can see on the video that the wheel's velocity change makes the freeflyer accelerate and decelerate, but the reaction is too slow and the movement too small to be used in our application.

For the second test, we used 4 valves to turn. The rotation is trigged by a 2 seconds thrust. Afterwards, the valves stop during 2 seconds and then, they gives an opposite thrust during 2 seconds in order to stop the rotation. The results were better than expected, as can be seen in the following video.

Thus we decided to use the wheels only for stabilisation and to turn with valves.

050711_TestRotationRouesInerties.wmv Rotation using the momentum wheel
050711_TestRotationValves.wmv Rotation using the valves