Last Tuesday, the High Altitude Solutions at the University of Michigan successfully launched and recovered a high altitude balloon. It is the first balloon that has been launched of 2010.
We launched from a little town in Michigan just south of another little town called Pulaski and landed in another little town (although MUCH bigger than Pulaski!) called Dundee. The balloon actually landed about 3 miles away from Cabella’s, which is a gigantic outdoor hiking/fishing/hunting store.
There was relatively little drama on this flight, since the winds were not too strong. The launch went smoothly. We chased with little trouble. Most of the four communication systems on the balloon worked well. There were a few minor issues, but nothing bad: (1) the AeroComm system’s GPS stopped reporting position at some altitude; and (2) the radio in our car stopped working, so we couldn’t track the balloon using that method. The GPS problem has been seen before, and it seems like it might not be an issue with the GPS, since this is a totally different GPS than was flown before. It is a real head-scratcher. The radio mishap was probably caused by one of my kids sitting on the radio or something. It wasn’t broken, just the settings were all wrong, so we couldn’t get it to receive signals. No one in the car knew how to change the settings so we were stuck. Luckily, we had my cell phone, which I tethered to my computer and used aprs.fi to track the balloon. This is where the track above comes from.
This is a picture of people filling up the balloon with Helium.
There were four communication systems on this balloon. The one closest to the bottom of the photo is the AerComm system, which is our two-way communication system. The one just up from that is the MicroTrack, which is a simple beaconing system (simply sends GPS coordinates over a radio). The last package (yellow) is another MicroTrack system, but a little more sophisticated, with a computer and data logger on it, to monitor temperature, and record the actual position and raw GPS data.
Here is a picture just after launch:
From top to bottom, you can see the balloon, the flight termination unit, the parachute, radar reflector (gold disk thing), video camera box (pointed down), AeroComm, MicroTrack, Cell Phone Tracker, and enhanced MicroTrack.
Here the students are debating what to do. The balloon was at about its peak altitude, and drifting dangerously close to the Lake Erie. The tried to initiate the Flight Termination Unit, but it didn’t work. It turns out that the Niachrome wire that heats up and cuts the rope got broken in the launch. So, the computer was telling it to heat up, but it couldn’t. The balloon actually popped around then anyways, so it turned out fine. We were in Tecumseh at that point.
Once it started coming down (after reaching about 85,000 feet), we jumped into the cars and continued chasing it, although we were actually ahead of it the whole time. I am hoping that the students develop some better prediction software that will tell up where the balloon is going to land. We typically take the decent rate, figure out how long it it going to be until it hits the ground, then forward project its current trajectory by that many minutes. I do this in my head while driving, which is challenging. This time, the balloon jogged south in the last few minutes, which threw me off a bit. But, we ended up going down the right dirt road and arriving at the field just as the balloon was touching down.
The balloon burst, but did not shred completely, which is too bad. It means that the decent is a little faster than expected, since it has a little too much mass on it and the balloon interferes with the parachute a bit. But, it was fine. The theory behind the flight termination unit is that it disconnects the balloon from the packages, so the leftover balloon won’t interfere with the parachute at all. I have actually seen the balloon completely tangled up in the parachute, which is not good news. But this time it was fine.
So, in summary, successful flight! For more pictures, see my picture site.