We spent the majority of our time weighing the individual components and estimating the volume of the balloon. From this, and using density and pressure calculations (see below), we were able to work out the required temperature of the air inside the balloon in order for it to rise
Lift = external air pressure – internal air pressure
r = air pressure at sea level (kgm-3)
q = temperature (˚K)
Therefore lift of Vm3 balloon with internal air temperature t2 in ambient air temperature t1.
Due to the balloons irregular shape, we estimated it to be composed of a cone segment and half an ellipsoid (3d-ellipse).
This cone can be given the following equation:
Total volume is 1.841m3.
The final weight of the balloon and all of its attachments was 283.4g. Assuming an ambient temperature of 20˚C the temperature required inside the balloon is 342.2˚K or 68.9˚C.
Unfortunately a lot of assumptions were made during the calculations, and we have no way of actually verifying whether or not this figure is at all accurate.
For the rest of the time, we were involved in calculating the intricate measurements needed to securely attach the camera and its holder at the correct angle to the balloon itself. This allowed the camera to be able to take accurate pictures of the designated area rather than everyone watching.
Finally, we connected up all the different parts of the balloon and tweaked it until it all fitted together perfectly.