Week 3: Construction of Balloon Mapping Equipment

Introduction:
 Nothing great comes without planning. Michael Jordan planned to be the best and worked harder than anyone else in basketball and succeeded. Man landing on the moon was years in the making. And filling a balloon with a camera apparatus attached to photograph campus is a process that took a few hours with 18 people working on it. The plan this week was to analyze schematics from multiple sources and come up with the best functioning apparatus to capture images of campus from a few hundred feet above ground.

Methods:
 The preparation for the balloon mapping project has gone hand in hand with the high altitude balloon launch (HABL). This week the class separated into separate groups to start producing and planning each necessary step for the launch date, which is still tentative at this point. People in the class split up for tasks such as:

• Construction of the mapping rig
• Construction of the HABL rig
• Parachute testing
• Payload weights of both HABL and mapping rig
• Design of implementing continuous shot on the cameras (for mapping rig)
• Implementation and testing of the tracking device
• Filling the balloon and securing it to each rig

 I was a part of a few of the tasks, there was a fair amount of people doing each one so I was able to help with each one for a fair amount of time. The mapping rig construction was created using a few 2-liter soda bottles. The plans we obtained from multiple online sources, here is one:

http://archive.publiclaboratory.org/download/Grassroots_Mapping_English_2_0.pdf

 This site shows all of the items you will need, along with the steps for creating the rig. The soda bottles were cut in half, keeping the neck and bottle cap section, so we could drop string through the top and have it hold the camera. The camera in the rig is only held by the string, so it dangles in the cut open soda bottle.(Figure 3-4) After completing the rig to hold the camera, we had to find a way to make the camera stay in continuous shot mode. My colleagues created a way to hold down the capture button on the camera with a tight rubber band and a piece of plastic on the top of the capture button. (Figure 3-1)
  While a group was working on the mapping rig there was another weighing each item that could or would be used. The group took weights of each individual item and recorded them into a table in excel. (Figure 3-2) It is important to have a precise weight of the payload so we know how much helium to pump into the balloon that will hold up the mapping rig, or the balloon that will take our camera to the top of our atmosphere.
  The parachute test consisted of a bait tackle box with a 2 lb weight inside of it, the projected weight of our payload. Our group went up to the fourth floor of Phillips Science Building and threw the tackle box out the window. (Figure 3-3) after doing the test three times we were pleased to find out the parachute worked properly.
  While the parachute test was being done another group went out and tested the tracking device. The PocketFinder gps device can send out its coordinates at different settings, every second, four seconds, 30 minutes or hour, we decided it would be best to do it every four seconds. The group went out for a walk and we could keep track of his location using the online application that maps out each point for you. This will be used in the HABL rig to help us find it once it lands.
  The HABL rig is still in development as we are going to wait until closer to the launch date to complete the project. We are planning on using a bait tackle box with a view hole cut into the bottom of it for a clear camera view. The camera will more than likely be in video mode as the pictures would be a little less exciting. The rig will consist of a sealed area with hand warmers which is where the camera will be situated in. The tackle box will be attached by a carabiner and string to the parachute and balloon as it rises. Once the balloon pops the payload will fall and it will be supported by the parachute.
Discussion:
 The project for the day was a good way to observe how well our class worked together on multiple different goals. While some were left with nothing to do because of the size of our class, they were being helpful as they documented the processes and took photos for those who were concentrated on their task at hand.
 I was with the group who did the parachute test and as you can see from the video, the payload picked up speed quickly and hit the ground with some force. I am worried that with the lengthy fall, from hopefully above the troposphere, the payload will reach a relatively high velocity and damage the camera as it hits the ground. If that happens hopefully we can recover the memory card and use that for viewing the video, otherwise it would be devastating if we couldn't.
 The mapping rig is created with a slight surprise, the camera just dangles from the balloon. I understand these plans have been refined and tested a handful of times, but it just seems like the camera will be swaying back and forth in the wind and possibly give us blurry pictures, or possibly some of the horizon and not the ground directly beneath. I wonder if there should be a weight to try and stabilize it as we walk around with the balloon 500 to 1000 ft above ground.

Conclusion:
 I am quite excited to be able to create a mosaic of our campus from a pocket camera. The images will hopefully have a high enough resolution that we can use it for other purposes in class. Our class did a great job of working together and splitting into groups to finish each task. In the class period we completed a mapping rig prototype and set up for the completion of the HABL rig. With all the weights and other testing done we should be ready any day to set our project into action. Later posts will have the results of each project.