I recently started a project with a friend to make whats called a solar balloon. The concept is to make a hot air balloon that uses no heat source other than the power of the sun. There have been various attempts over the past few years. Most of them have been small toys or science experiments but some people have able to get full-scale versions capable of carrying a person. If you are interested In learning more, look at this website of one that flew for 2 hours.
My friend, Andy, has been making these for a while and invited me to see what he was working on. We met up at a field one cold morning and spent several hours working to get his Solar Balloon flying. I was impressed how small the whole thing was. deflated, it was smaller than a breadbox but inflated it grew to be as tall as me and much too big to fit my arms around.
we inflated it by means of a hair dryer and kept control of it by means of a fishing pole and fishing line. We had various problems that made flying it much harder than we anticipated, stuff like the tape we used to fill the seams of the trash bags that make up the skin of the balloon coming loose, to the wind making the balloon virtually uncontrollable. After many hours of work, we finally succeeded in getting it flying!
if you want to do the math to find out how high the baloon went, both me and andy are about 6 feet tall.
It was the only flight we got that day and we had a lot of fun getting it to work but we both agreed that there was room for improvement. The next series of posts will be about our process as we strive to improve upon our last flight and to hopefully make one big enough to fly in one day (that’s the goal at least). Some of the things we decided to work on was
- A better method for joining the trash bags together. Ideally, we would like to use a heat seal like in vacuum packing but if that doesn’t work then possibly double-sided tape.
- We need to decide what shape would produce the best lift per gram of weight for our balloon.
- We wanted to see if there was a mathematical way to know how much our balloon will lift so that we know if it will both lift itself but also a cargo (like a person).
- We need to know how hot the balloon is getting on the inside so that we can get trash bags that can handle the heat
- We want to know if it is better to have the back of the balloon be reflective to help trap the heat or if it would be better to keep it all black
- Or is it better to have the side facing the sun be clear like a car window
When we start getting ready to go full scale
- We need to have a way to control of our orientation to the sun and our ascension/descent (up/down)
- We will need to know weather pattern and how things behave differently at altitude
- We will need to know what paperwork we need to do with the FAA (Federal Aviation Administration) and the NTSB (National Transportation Safety Board) so that we know that no airliner will be flying into us while we are testing our balloon.
While we are working toward a full-scale model, we decided to set ourselves intermediate goals (we are guys but we are not complete idiots) and so the immediate goal is to have a balloon that can carry a remotely-controlled camera to a decent altitude and then take pictures for the heck of it. This project will take a while and we will be taking lots of safety precautions so I will be reporting on our progress over the next while. In the meantime, thanks for joining me and happy tinkering!