* Posts by Entropy_K1d

2 posts • joined 20 Jul 2012

Teflon slips smoothly over LOHAN's mighty rod


Solid body rotation when the motor fires

Slippery indeed. I'm worried that because the thrust vector of the motor doesn't point through the center of mass of the complete truss/vehicle, when the motor ignites, even though there is minimal friction between the teflon and the rod, the resulting moment will cause the complete truss/vehicle assembly to rotate. Of course LOHAN won't be on the rod for very long, but there will still likely be enough rotation to mean LOHAN potentially goes straight up into the balloon.

Readers fret over LOHAN's chilly bits


Launch Rail

I'm slightly concerned about the launch rail. From the sketches, it looks like there is a good distance between the axis of the rocket motor and the rail. Any friction between the hangers and the rail, or any kinks in the rail itself, will result in a moment. I doubt that the connection between the rail and the aluminium support will be stiff enough to resist it, and the control surfaces on Vulture 2 will not work as the speed will be negligible (as well as the air density being very low). The net result will be that the rail deflects upwards into the truss, potentially resulting in the hangers fouling on the truss before Vulture 2 separates. Which would be a shame.


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