Before we started building, we had our design ready on paper so we always knew what we needed to do. We took our materials list to the hardware store, where we bought the materials for our spacecraft.
We first started by building the base of the spacecraft, which was originally three PVC pipes and three pieces of plywood on each corner. We knew we wanted to make a triangle with the same length on each side. Dad cut the plywood into triangle pieces but we did everything else ourselves. We drilled the PVC pipe and the plywood and screwed them together.
Then, we figured out how to attach our components onto each plywood triangle. These included a GoPro camera, the SPOT GPS tracker, and the Eagle Flight Computer and Temperature/Pressure sensor, and a Lego R2D2 minifigure, and a picture of our cat, Loki. Then we attached a rope to each triangle and joined them at the top with a big ring.
At that point, we weighed our partially built spacecraft with a spring hanging scale, and discovered to our dismay that it was way too heavy. The balloon would never lift the spacecraft with the weight of the PVC. We thought about different options for a while, and then we undrilled the PVC and took the whole thing apart. We looked around the garage, and found some slightly bent archery arrows that weren’t being used. They were no longer good for archery, but they were light and strong. We then attached those to our triangles by using hot glue and zip ties. When we weighed it again, it was much lighter than the first version!
We were thinking about the possibility of a water landing; it’s mostly farmland where we were planning on launching, but there were a few lakes and rivers around. To prevent it from sinking, we attached half of a styrofoam ball on the bottom of each triangle with wire. We tested to see if the balls would float; they floated easily by themselves and would probably keep the spacecraft afloat, but only if it landed upright.
We went to the park to test the flight computer. We attached the batteries and inserted the SD card, and turned it on. The blue light started flashing every six seconds, which meant that it was recording data. When we returned home, we removed the SD card and looked at the data on the computer, and it showed that we were in one place the whole time and that we were just above sea level. So then we knew that our flight computer was working.
We also tested the parachute by dropping it from our second floor, but it was such a short distance, it wasn’t a very good test. We also got a tank of helium from a local welding supply store; we ordered 56 cubic feet of helium. After that, we started to look on a few different websites for launch sites.
Loki Lego Launcher 