The telemetry balloon was launch and retrieved successfully, and as all near space launches are, turned out to be quite an adventure. It all started out as a project to find the cheapest / most reliable / easiest to use balloon launch system for high schools to eventually build and build upon. After some searching we came to the conclusion that near space telemetry systems tend to be the greatest investment and should therefore be examined first.
After pouring over the internet and considering various options, the test group was chosen. It consisted of:
- Byonics MicroTrak AIO: a strong, dependent, long lasting ham radio telemetry system
- Spot Satellite Messenger: a small, proprietary tracker used commonly by hikers
- Motorola i290: super small, super lightweight cell phone custom programmed to sample its gps and transmit data to sensor.network
In addition, a Sun SPOT equipped with an SHT15 temp/humidity sensor and a 3-axis magnetometer was sent up.
Launch:
We took off just a bit north of the Mexican border beside a farmer’s field in 95 degree weather. Things went fairly smoothly, especially considering that we were launching two balloons that day. (We also launched a larger balloon with climate sensors) The Byonics and SunSPOT were placed together in one styrofoam box, the spot messenger and i290 went into a smaller box equipped with strobe lights beneath that. All three trackers had emergency lines directly attached to their casing in case their styrofoam boxes broke, and I built a simple harness for each box and attached it to the main line. A radar reflect, parachute with hoop, and 1000g Kaymont balloon finished it all up.
We let it go at about 9:20, and sought refuge at Best Buy for air conditioning and internet. We also bought lithium batteries. According to google aprs, the balloon was actually bending south and headed towards Mexico, all the time keeping a perfectly consistent altitude of 14324 ft. We were worried, as the Ham beacon was supposed to be more reliable, and the spot messenger didn’t provide much data and the i290 had left cell phone range right after take-off. However, the gps stream corrected itself and the balloon was actually headed north, and all was well.
After a brief escapade to a farm field to pick up the other balloon we waited for this one to drop below 60,000. It had traveled considerably farther than the other balloon, and actually ended up landing in the desert in a bombing range. We got the balloon in the 114 degrees in a 1.5 mile hike and returned, too tired to bother turning everything off right then and there.
End Results:
Byonics:
- Reliable
- Easy to use
- Durable
- Strange initial drift
Spot Messenger:
- Useful for finding the balloon
- lacks altitude
- 10 minute update time
Motorola i290:
- No data from altitude (code may be improvable to fix this)
- Probably works better if it lands somewhere with 3G service (like not in a bombing range)
- Small and cheap
The data we got from the sunspot was somewhat disappointing, since we had turned it on and taped up the boxes, only to take 45 minutes to fill the balloon, wait and fill the second one, discover that we needed more helium and refilled. Consequentially, the spot ran out of space before it even reached burst altitude.
Overall I felt it was still a good launch, and look forward to more work on the perfect high school balloon launch package.
