Team Mechies - Protecting the Payload
TEAM MECHES - PROGRESS REPORT 2
This was the final stride with regards to creating our payload, assembling the mechanics, and running the payload through final testing. Our primary focus was that the payload was sufficient to withstand jet stream winds that were blowing at 150 mph. We were forced to rethink some of our original plans such as adjusting the surface area of the wooden payload structure. We choose to reduce the size of the wooden base structure by at least ⅔ of its original size. The reasoning behind this was to reduce the vertical drag of the payload structure by decrease the surface area of the plywood. We spent most of the class time deciding where the individual instruments were to be placed on the wooden base structure. The Mechies team was inherently focused on geographic placement of each instrument on the wood because we wanted to insure a balanced structure. One of our largest accomplishments in the final half of the class was the presentation of the final payload structure at DigiTech. The payload received fanfare and praise from the visitors at Digitech. We successfully launched the secured payload and retrieved it in one piece thanks to an accurate simulation report of its flight path.
As we put the payload together, we had many problems to overcome. Our first main dilemma was how to ensure stability, while minimizing size. After we built and secured everything on to our first designed platform, we determined that it was too big. We also had to figure out how to secure all of the different tracking and electronic devices to the platform. The radio bug’s long antennas posed an initial drawback, as did the fact that the flight computer would not sit flush with the board. We had to make sure that the cords we chose to attach the parachute and balloon to the platform were strong, but not too strong or they would be in violation of FAA regulations. We had to test several different kinds of string in order to choose the best one. While it may seem like a trivial problem, the wrong string could have caused the entire project to fail.
The first platform that we designed was a square, about a foot and a half on each side. However, we were concerned that this large surface area would cause the payload to be unstable and sway too much in the wind. We instead cut our platform so that it was a rectangle, which reduced the drag on the payload. How to attach our electronic elements to the platform also presented a challenge. The design of the flight computer meant that we had to find a plastic spacer to use when screwing it to the board in order to protect the pieces on the underside of the device. In addition, the radio bug that attaches to the flight computer had very long antennae that needed to have a line of sight to the ground, while also staying out of the view of the cameras. Usually the radio bug is dangled from the bottom of the payload, but this was not possible because we had a rig of cameras attached to the bottom. Instead we had to attach the radio bug - somewhat precariously - to the very edge of the platform. One of the most important parts of the entire project was making sure that it would stay together, so we took special care to select a string that would be strong enough to hold the weight of the payload, but that was thin and easy enough to break that it was deemed safe by the FAA. In order to do this, we tested the strength of several different types of string well past the weight of our payload. We also doubled up on the string attached to the payload and tied many knots.
Our biggest step moving forward is going to be collecting our flight data and camera footage and creating a video that will be entertaining and informational. We should also hypothesize why the cameras died mid-flight and think of possible solutions for the next classes that will be launching their payload into space. Other than that, we successfully built the payload, launched it, and collected it in one piece, so the only other class goal will be setting up the video. To make the video as entertaining as possible we should add graphics that show the flight path, the temperature, and other data. We should also throw in pictures and videos that show us gathering the materials for the payload as well as building and launching it.
