Final Bottle Rocket Post

Yesterday we launched our bottle rockets for the last time. Our final rocket consisted of four cardboard fins that were completely duck taped, a nose cone made out of a top of a bottle, and a parachute made out of a small trash bag. We used a nose cone so that our rocket was aero dynamic and it served as a housing unit for our parachute. Our parachute was made out of a cut trash bag, which was attached, by four pieces of string. Our triangular shaped cardboard fins were positioned as far down on the bottle as we could so that the center of pressure of the bottle would be toward the bottom of the bottle. This would cause the rocket to stabilize it in the air. If the fins were toward the top of the bottle the tail of the bottle would turn around and be facing the wind. The nose cone of our rocket was weighted by gluing a few pennies into the top of the nose cone. By doing this, the center of mass is located in the top of our rocket, which also increased the stability of our rocket so that the rocket did not go tumbling in the air. The cone we had was tied down on one side so that it could pop of and the parachute could deploy. On the first day of our launches we launched with 50 ml of water and around 60 psi of pressure with a plain bottle. For our second attempt we used different water pressure and air combinations to find the most efficient combination for our final launch. We launched twice and had times of 3.6 second and a 4 second launch. We quickly realized that we can get the rocket higher by stabilizing it, and that is when we added our nose cone, fins, and parachute. The next class the objective was to get one 5 second launch. With our modifications done we were able to get it in the air for 9.3 seconds after hitting a tree. On the final day it was really windy and rainy. Our school was pretty much in a big cloud. Our first attempt got a time of 8.3 seconds before flying down to the tennis courts. Our second attempt got a time of 4.6 seconds with a pump that did not hold the air very long. And our third and final attempt had a time of 9 seconds before floating its way down to Akahi hillside. At the end it was pretty satisfying to see our rocket doing well and having our modifications serving the purpose we built if for. Overall we did well on the rocket project but bad weather made our rockets perform worse than expected. 

Today was our final launching day. The day that really mattered. The rules of launching today was to make the time of at least ten seconds. Our first launch was 8.2 seconds. Our parachute actually deployed, but it was too late, because it passed Koniaʻs ground level. We went to look for our rocket and ended up finding it all the way by the tennis courts. Our second launch didnʻt work out too well, because it was only in the air for 5.2 seconds. The final launch we did before we called it a day was in the air for 9 seconds. Our parachute didnʻt work too well, but I think the reason why our rocket stayed in the air long was because of our wing designs and nose cone. Here are the videos of our launch, and then finding our rocket.

Today we had to launch our rockets again. Our goals to meet were 5 or more seconds in the air. We forgot our rocket again today, so we had to make a new one with what we had. We glued two bottles together to make it longer, and also glued on wings. To make sure the wings didnʻt fall off this time, we also duck taped them. We made a parachute out of a small trash bag, and some string. We tape the string onto the bottle, and neatly wrapped the parachute up. For our nose cone, we cut the top off of a bottle and taped one part on. We put the nose can as loosely on the top as we could so that it would be able to fall off, and allow the parachute to deploy. Our launch was a success. It was in the air for 9.5 seconds. It was pretty cool to see because our school was in a cloud, so you couldnʻt see the bottle. As it was coming back down, we were afraid it would get stuck in the tree, but the tree actually caused the parachute to deploy. This added one to two seconds on to our air time. We need to improve our parachute, and I think we should be good. I will post the video when it loads!

Today our task was to launch our rocket with another modification, which was a parachute. We also added fins to our rocket. The launch had to stay in the air for a minimum of three seconds, but the parachute did not have to work. We launched the rocket with 700 mL of water. We didnʻt know exactly how much pressure we used, because the pump was broken, but I think it was around 50 PSI. When it launched, right 3 out of 4 of our wings fell off and our parachute ripped. We are going to try to glue the wings on better and then duck tape them on. We also have to do a little more research about parachutes. Here is a video of our failure.

Today our task was to launch the bottle rocket again with modifications. What we decided to do was to try different amount of air pressure and the different amount of water to use. We tried launching it a few times and what we noticed in the end is that it launched high with 700 psi. The pump we used did not have any gauge on it so we pumped it around twenty times. We plan on using pretty large fins toward the bottom of the bottle to place the center of pressure toward the bottom. We also want to put the fins slightly at an angle so it gives the rocket a little bit of spin so it goes directly upward. But we do not want to use to much spin because by spinning the bottle, it also loses some energy. we also plan on using a weighted nose cone to have better aerodynamics and to make the center of mass toward the top. For the parachute we plan using a small trash bag at putting either in the nose cone or second bottle  In this last class our first launch was about 3.5 seconds and our second launch was around 4.5 seconds with a little bit more pressure.