Solar Balloon Part 5-Up, Up, and Away!
The day is finally here, the day that we have been dreaming of for months now. It was time to fly our solar balloon! The sun is hot, the wind is present but manageable, and the skies are clear. We arrived at a local park at about noon on Saturday and immediately started filling up the balloon with an nervous excitement that is to be expected with a maiden voyage. The wind was slightly gusty so while we were waiting for the wind to die down, we scoured the surface of the balloon, patching any holes we could find. Because the wind was blowing decently strong so we were forced to hold the balloon down in an effort to limit the pull the wind had on the large surface of the balloon, however, as a result, we couldn’t get a good idea of exactly how much lift was being generated. In fact, we were considering refilling the balloon with hot air to try to boost the lift a little higher. We honestly didn’t think it would fly very well, not with the thermal test from last week and the amount of air that had leaked out of the balloon by this point. By rough estimate, the balloon was only about 3/4 full when the wind finally let up enough for us to give it a test flight. We made sure the balloon was tied to the fishing line which was attached to the fishing pole we used to control the balloon while it was in the air, and it was time for a test!
When we finally let the balloon go, it beautifully formed into a sphere and instantly started rising, much faster then our last balloon did. We knew that we needed to keep the balloon under 300 feet for legal reasons so after only going up maybe 200 feet, we locked the fishing line so it wouldn’t fly any higher and that is when it happened.
At first, I didn’t know what happened but it soon became apparent that our fishing line broke and as a result, we had lost control of the balloon. In hindsight, using a small Gage fishing line to hold a balloon designed to lift at least several kilograms was not a very smart idea, but this balloon was about the same size as our last balloon and that sting had handled the stress beautifully so we didn’t think anything about it. In desperation we chased after our balloon as it continued to rise, hoping that it would sink to an altitude that we would be able to recapture it. It quickly became apparent that not only were we not running fast enough to catch the balloon, but it had no intentions of returning to the earth anytime soon. Even chasing it in a car would not have been plausible as it quickly rose higher and higher, quickly shrinking unto the blue sky, leaving us with nothing to do but take pictures.
Our feelings at this moment were very mixed as the balloon worked much better then either of us had predicted it would. As I said earlier, just before we released the balloon, we were about to go reinflate it with hot air to try to make it fly better. The fact that it had enough lift to break our line was exciting because that meant that our balloon was working as good, if not better then intended. That feeling was mixed however as we were watching over 7 hours of hard work float away into the sun.
The experience was not a total waste either because we now know that, while a sphere generates the most lift of all the shapes we could have used, it is not the easiest to make. Andy has, on his own, make rectangular balloons of similar size in only a few hours while a sphere took two people over 7 hours to complete. Also, we now know that we need a stronger rope to hold our balloons how with. Right now we are researching the possibility of using paracord or deep sea fishing line for our next balloon. In the meantime, however, we got to enjoy watching our balloon shrink into a dot in the distance and then finally disappear in the clear blue sky. I hope you found this post interesting, we will be doing more building in the next Solar Balloon post so if you are interested in that then I hope to see you in the next one. Untill then, Happy Tinkering!