Pictured: View near space from weather balloon, which ascended to more than 15 miles in elevation on February 7, 2017.
A group of Jr. Bills, led by Environmental Science teacher Bill Anderson '78, successfully launched a homemade weather balloon to study the climate for the second time this school year. The balloon reached an altitude of more than 80,000 feet and speeds in excess of 180 miles per hour before exploding and returning gently to Earth via parachute.
"The students in the Introductory Environmental Science class decided what variables to examine, what data to obtain and what probes were available to gather the data," says Anderson. "They designed the payload container, which was a Styrofoam cooler in its previous life. We had three different tracking devices so we could follow and locate our payload."
The balloon was a large latex balloon filled with enough helium to lift the payload. They used nearly 200 cubic feet of helium. As the balloon rose the pressure of the atmosphere decreased—from 101 kPa (kiloPascals) to 2 kPa—and the balloon expanded. Eventually it got so large that the balloon burst—at an elevation of 80,862 feet, or 15.3 miles—and the payload started to fall. The parachute opened and gently returned the payload to Earth.
ABOUT THE PROJECT
This year SLUH introduced a new one-semester Introduction to Environmental Science course, which is based on three units of the Healing Earth text, climate change, energy, and water. The course began the unit on climate change with a discussion of what the students thought they knew about weather and climate.
"This led to a discussion of how we know what we do know and how that data is collected," says Anderson. "This eventually led to the concept of weather balloons that carry instruments up into the atmosphere. At that point I basically told them that that sounded interesting, how about we do that. That was followed by complete silence, followed by 'Are you serious?' And we took off from there."
This project was possible in large part because of a grant that SLUH received from the Toshiba America Foundation, which facilitated the purchase of the equipment needed. As described in the grant application, SLUH plans to launch biannually, once in August and once in February, of each year. This allows the students to look for seasonal variations and long term patterns as more and more data is gathered each year.
This project is an excellent example of collaboration and cooperation between a variety of groups within the school. The students received support and advice from Jon Dickmann (technology), Andrea Nunziante (technology and Electronics Club), Scott Schoonover (Theater Tech), and Rob Chura (SLUHTube).
"What I have really tried to impress upon the boys is how truly remarkable what they have accomplished is," says Anderson. "They sent an object up into the stratosphere, were able to track and retrieve it. They have first hand data, data that they collected, that the vast majority of us, myself included, have only experienced through textbooks and journal article."
Students made their first balloon launch in August 2016. The most recent launch in February 2017 featured one notable addition: Jr. Bills learned to program Raspberry Pi computers to take photos during the launch. Three of the Pi cameras were included on this flight in order to get photos from a variety of perspectives.
ABOUT THE FINDINGS
Two interesting findings surfaced from the most recent launch. According to Mr. Anderson, "There were significant differences in upper atmospheric wind patterns between the August and February launches. We don't know if that is a weather phenomenon or a seasonal pattern. More study is necessary. The second significant finding was a difference in the structure of the atmosphere. There was a significant difference in the altitude of the tropopause, the boundary between the troposphere (lower atmosphere) and stratosphere (the next layer up, where the ozone layer is). We suspect that that truly is a seasonal difference, but more study is necessary."
Following are notable statistics from the weather balloon project.
- Max altitude 24,674 meters or 80,951 feet
- Coldest temp recorded -53.7 C
- Lowest pressure reached was 2112 Pa or 0.0208 atm. Normal air pressure is 1.0 atm
- Landed about 10 miles east of Vandalia, IL
- Landed in a tree again. We are two for two with trees. Both times there was lots of open space surrounding the trees and yet it lands in the tree.
"I am really excited about our launches, especially because of the long term focus," says Mr. Anderson. "This gives our students a chance to do some incredibly exciting science and at the same time experience science as a process and not just a source of all the answers. Each year adds a bit more to the overall understanding of that group of students."