How do you keep a camera pointed when attached to a balloon? I've done a similar balloon launch, but very much on the cheap. Our payload had no stabilization, so it just acted as a pendulum under the balloon, and would spin as the torsion of the rope commanded. I've had thoughts after seeing those results, but just never had the opportunity to try it again. Based on the pics on your link, my balloon looked very similar. I'm guessing you'll be using a totally different balloon than those on the landing page.
Our payload has no stabilization either, and in past launches we've had quite a bit of rotation and swinging. Here's a video of one of last launch, for reference: https://peertube.scd31.com/w/7CQCYB4BmJzngoZTiMociY
To point the camera we have a lot of clever software and hardware. I didn't have any part in it, so I'll try to explain it as best I can. There's a diagram here, which hopefully will help you to follow along: https://eclipseplus.ca/Project_Details/Payload_Design/
We have a fixed camera mounted above a mirror. The mirror is on a special gimbal, which can be maneuvered using two servos and a bit of math. For coarse aiming, we have an IMU on board which uses the magnetic field of the Earth to figure out its orientation. For fine aiming, we do a bit of image processing to try and center the sun in the field of view of the camera. It's not perfect, but since we're only capturing still images, it's okay if not all the images have the sun in view.
Also of note is the filter, which starts in-place (to protect the optics) and automatically moves out of the way during totality. It also moves back into place afterwards so that we can continue safely taking images after the eclipse.
The balloons on the landing page are accurate! Those pictures are from past launches, which used the same payload (with some changes between each launch)
That's a much more hacker way that my thoughts of adding a swivel to the rope and some sort of tail on the payload to attempt to keep it oriented with the wind. I will definitely keep an eye on your project to see how it works out. It sounds like an interesting idea to be sure. Good luck! Just remember that whatever is happening with the balloon to at least enjoy the event for yourself as well
I wonder if you could attach multiple lines to a bar/triangle that's fixed under the balloon. This would eliminate the rope twisting/untwisting, but of course nothing stops the balloon itself from rotating.
to 90000'? that would be a tall order no pun intended. the bar would be heavy. one thing to keep in mind is that the gas will continue to expand, so that the size of the balloon visible in the GP's comment show it about 8' on the ground which is similar to my experience. by the time the balloon reaches burst altitude, it has increased in size to about 45'. this is part of the reason for needing such a long rope which allows for the swinging and torsion to this extent
