As the launch day approached, we started getting nervous! How were we going to pull this off? So many variables seemed to be out of our control so we focused on what we could control. Preparation is key! Here are some highlights as we prepared for the balloon launch:
Selecting the Launch Site
Meteorology team used Google Maps to survey different launch sites. The site will make or break your launch as it will affect how successful your launch and recovery will be. Your balloon can land more than 100 miles away from the launch location! What to keep in mind for this important decision:
- 10 miles from a major airport
- Balloon should not fly over a major city
- Avoid bodies of water
- Open area for releasing balloon in up to 10 mph winds
You can predict your possible landing site with this website: Balloon Trajectory Forecast. This allows you to create a Google Earth KML file to see your trajectory over land using Google Earth. Students really enjoyed looking at the trajectories using various weather data! I recommend doing this for a couple weeks leading up to the site to get a range of possible landing sites. You won't have very accurate weather data until the day before the launch, but you can at least get an idea.
Selecting an Experiment
As I detailed in a previous post, you can have fun coming up with an interesting experiment to send to space! A first idea was to send popcorn to see if it would pop. However, after doing the calculations, it was determined that the pressure differential would not be enough. The students instead decided on sending a flower. An artist has done this previously, but students were looking to collect scientific data. What are the effects of near-space? The balloon will reach the stratosphere and experience the following conditions:
- Pressure: Air is 1/4% density of sea level
- Temperature: Ranges from -60 to 0 degrees Celsius
- Radiation: Balloon will travel through ozone layer and experience increased UV radiation
Mission Control focused on preparing the payload for launch. This included adding all the hardware, prepping the Go-Pro camera, and attaching the flight train. Students also developed launch procedures and practiced how to inflate and tie off the balloon. This part of the launch is the most intimidating. High Altitude Science had some good tutorials here. Another concern was the Go-Pro camera battery. After some research, we bought a battery extension pack to increase the battery life.
In order to show off the awesome footage from our launch, we have to retrieve the payload! A Spot II tracker was used, but this proved to be very unreliable. I spent a couple of weeks practicing using the GPS tracker to get a feel for how it operates. The GPS tracker is supposed to update the location every 10 minutes, but this was often not the case. Whenever the tracker was on the move, such as in my car, it did not transmit a location. Only when I stood stationary was I guaranteed an updated location. You must also be out in the open for it to connect to a satellite to transmit a position. So we were very stressed about this crucial piece of hardware!