On May 14, 2014, coinciding with Blue and Gray Day, you may have seen a crowd of people inflating a large helium balloon. The Gilman Robotics Club shares the complete story behind the project.
Last February Rishi Bedi ’13 offered us an interesting challenge. As a member of a group at Stanford called the Student Space Initiative, one of their big projects was to promote the Global Space Balloon Challenge. Their goal: to get as many people as possible, all over the world, to launch high-altitude balloons. After a meritorious performance at the FTC Robotics competition, Gilman’s Robotics Club jumped at the off-season opportunity and started the research.
Here’s how it works: A balloon filled with helium raises up to 100,000 feet, where, due to the very low external pressure, it bursts. A parachute is then deployed to slow down the fall. The balloon must be equipped with scientific equipment in order to carry out an experiment.
We programmed a temperature and a pressure sensor with Arduino (an open source physical computing platform) that recorded temperature and atmospheric pressure every five seconds during the ascent. Our balloon was also equipped with a high-resolution video camera that recorded the rise of the balloon above Carey Hall until it was lost in the clouds. In order to retrieve the valuable equipment, a GPS tracker was also mounted. We designed and 3-D printed the payload to our exact specifications, making it light and durable. Many little details had to be worked out, such as the battery life at extremely low temperatures.
After several months of meetings, research, purchasing equipment, studying weather patterns, programming, and testing, our balloon was ready to launch. On May 14, 2014, a large crowd that had attended the festivities from Blue and Gray Day came to watch us inflate the balloon, cheer us on, and do a countdown to lift-off.
On our first attempt, we had an enthusiastic roar that lasted all of two seconds — the balloon came back down. It was too heavy and the helium did not provide enough buoyancy. An hour later, in front of a smaller crowd, and with an extra 35 cubic of helium, the balloon rose quickly and got lost in the clouds. We immediately turned our attention to the GPS tracker, which unfortunately went silent and made us think that we had lost our balloon for good.
Six hours later, however, the GPS came back to life and told us that the balloon had landed in the woods of Harford County, near Abingdon. The next day, a search party spent an hour in the woods and found the remainders of the balloon. The payload was intact and allowed us to retrieve the camera and sensors. SUCCESS! From our readings of pressure and temperature we corroborated that our balloon rose up to close to 100,000 feet.
Watch the whole experience — from lift off to recovery (lift-off is around the 1:35 mark and it gets really exciting at 3:00).
(Photos by Chris Song ’16)