
I don't recall the official Reg unit for temperature
... but I'll bet it's not Fahrenheit
4 publicly visible posts • joined 21 Feb 2012
Didn't spot this mentioned anywhere above...
Single balloon seems to me to be unavoidable, so put this with a long cable, as suggested, and suspend the beam vertically - i.e. from one end only.
The rocket could have a nice long launch rail (to give you some confidence that it'll go where it's pointed), starting from the bottom and just missing the cameras at the top, at whatever angle you see fit.
(PS @Equalise pressure?: Glad someone is awake!)
If you had a pneumatic connection between the two balloons (i.e. a hose), that would keep the pressure equal in both...
What I can't say is whether that would mean they had the same buoyancy - anyone?
Perhaps overcomplicated at launch time (or perhaps easier as you could fill both at the same rate?), but no moving parts!