APSU student Critchlow sends high altitude balloon into the stars

Give Austin Peay State University student Dominic Critchlow a balloon and a camera and he can quite literally show you the world.

A senior in APSU’s Department of Physics and Astronomy and a 2015-16 Presidential Research Scholar, Critchlow has spent quite a bit of time researching a simple solution for the complex problem of computer assisted image remote sensing through high altitude balloons.

Or in layman’s terms, how do you send a balloon, a camera and a bunch of computers 100,000 feet in the air without violating FAA regulations?

“The physics and astronomy department has been working with high altitude balloons for years now, but they’ve always had a problem with weight,” Critchlow said. “They’ve got radios and scientific equipment, each with their own batteries and data storage, and all of that equipment weighs something.

“FAA regulations say that the ‘payload’ of a balloon cannot weigh more than six pounds, so my goal was to design some kind of equipment that could combine all of those separate functions into one piece, while still staying within the standards set by the FAA.”

Critchlow found an answer in the form of an Arduino board, a low-cost microcomputer that can serve as the “brain” for any number of projects, from acting as an automatic night light to letting you open your garage door with a smart phone, to logging data for altitude, pressure and temperature, as well as managing a magnetometer, an accelerometer and a Geiger counter -- all tied to latitude and longitude obtained from a GPS.

In short, Critchlow found a $30 solution to a problem that had been kicking around the department for years.

“The Arduino board is designed for things like this, so I went out and found the parts I needed, then sat down to see if I could write computer programs for the board that did the things we needed,” Critchlow said.

The goal of Critchlow and his team is to explore better solutions to the problem of remote sensing, or the scanning of the earth by satellite or high-flying aircraft in order to obtain information. Purposing satellites to obtain high quality images of the Earth is costly, so the work of Critchlow and other researchers is going a long way toward providing a more effective, low-cost alternative for researchers and amateur enthusiasts.

In early April, Critchlow and a small team gathered at the APSU farm near the Kentucky/Tennessee border to launch their high altitude balloon – along with an array of cameras powered by Critchlow’s Arduino board. The goal of that morning’s launch was to get a bird’s eye view of the clarity of water in the region.

“We used an array of cameras that are controlled by a small computing device, inside of the payload,” Critchlow said. “The flight computer determines optimal times to capture images, when the payload is at specific altitudes and is experiencing a low amount of forces, that could distort the image. The cameras capture images in different wavelengths that can be directly superimposed. This allows us to determine the clarity of water in the region, as clearer water reflects more light in the blue ranges and murky water reflects more light in the infrared ranges.”

The launch was a success, as the balloon reached a maximum height of 100,000 feet – high enough to see the layers of the Earth’s atmosphere, as well as the curvature of the Earth – before the thin atmosphere caused the balloon to shred and send the payload back to the ground.

“We can’t control the payload’s decent because anything that goes above 60,000 feet and is controlled remotely is considered a missile, so we just had to use GPS to track where the payload had landed,” Critchlow said. “It turns out that it landed in Kentucky, about 130 miles away from where we launched.

“(When the payload was recovered), we discovered that the cameras didn’t quite work as we hoped, but they did work, so that proof of concept means we can continue to keep improving the process.”

Sending a camera to the outer reaches of Earth’s atmosphere is just the most recent accomplishment for Critchlow. Over the past two summers, he has interned as a researcher at Georgia Tech, as well as Vanderbilt University. A winner of APSU’s Robert Sears Award for Excellence in Physics, Critchlow is currently interning as a data science researcher at the University of Notre Dame.

Prestigious academic accomplishments aside, Critchlow said that his work on high altitude balloons scratched an itch he’s had since his childhood. With funding from APSU and the help of University faculty, Critchlow was able to do a lot more than simply look up at the stars.

“Sending a camera to space is kind of the next best thing to actually going there yourself,” Critchlow said. “And to know that I was partially responsible for the project and that I was the last person to touch something before it went up into space is really a cool accomplishment.”

For a video of Critchlow's launch, visit https://www.youtube.com/watch?v=b9_RsAldhXk.