Nuts and Volts - December 2015

insulate from the cold, its low weight, and its ease of machining. Students — even young ones — instinctively understand how to cut and glue it together. That ease allows students to concentrate on the BalloonSat design and its ability to collect data.

After gluing the airframe together, the teachers mounted the avionics inside the airframe. The flight computer was just glued to an interior shelf since it was lightweight. However, the camera was bolted to the airframe with 1/4-20 bolts. Likewise, teachers built a compartment into the airframe to contain the battery. Both the camera and battery are heavy and dense enough to pose a hazard, should they not be adequately restrained during descent. That’s because initial descent is a very chaotic event and loose objects get thrown around a lot.

We ran short of time this year, so a comprehensive test of the flight articles was skipped. Otherwise, the teachers would have tested their BalloonSat construction by shaking it to insure nothing was free to bounce around, chilling it to make sure it still operated at low temperatures, and starting it to make sure crews would be able to start it up quickly and without errors at the launch site.

By the end of the day, the class had tethered their BalloonSats to the rest of the near spacecraft, checked out the latest prediction, and made plans to rendezvous at the launch site the next morning. It’s pretty awesome to see three days’ worth of work come together in a near spacecraft predicted to reach 90,000 feet and collect data in the near space environment.

Saturday

Everyone met at Treynor High School (Iowa) Saturday morning to begin the balloon filling process. It only takes about an hour to fill the balloon and during this time, teachers prepped their BalloonSats for flight. This included plugging in batteries and starting their cameras. It was an overcast morning and not very promising in regards to seeing the balloon during its flight (we’d still be able to track it over radio).

The flight prediction that morning showed only a minor change to the predicted recovery zone, so most of our driving plan remained unchanged. The largest obstacle facing us was that it had been raining recently and the back country roads and fields promised to be muddy (this is why I carry a pair of tall rain boots in my car when I go on a chase).

After an eventful launch, we made our first stop at Griswold where we could get food and drinks while waiting for the balloon to burst. Fortunately, the clouds opened up enough to let us see the balloon at around 60,000 feet. It was great for the first-time near space explorers to see the balloon as a tiny dot in the sky, and know it was their balloon and its current flight conditions like altitude, speed, and direction.

After the balloon burst at 92,704 feet, we updated our predicted recovery zone and headed out. Remember The landing site turned out to be at one end of the taxiway in Atlanta. We arrived at this surprisingly large airport and made a beeline for the operations office. We were able to get permission to enter the airfield in two cars and recover the near spacecraft. Needless to say, we stayed off the runway since our cars were unable to develop sufficient air speed.

I had a job teaching Quadcopters in Idaho on Monday, so I got right back on the road after having lunch with the teachers and chase crew in Council Bluffs. I want to thank Ms. Squires for sending me

paul@nearsys.com

At an altitude of 3,500 feet, one of the teacher’s BalloonSats took this picture of the airport in Atlanta, IA. It’s quite a nice airport and the managers have that midwest friendliness.