On Sunday, March 19 2000, we released a second scientific balloon, designated ITA-2, from our school yard in Rifton, New York. This one carried a payload with two temperature sensors and a battery monitor, connected to a PIC 12C671 microcontroller which sent the data in Morse code via a "fireball" transmitter on the 10 meter amateur radio band. The downlink audio was recorded on cassette for later analysis.

One thing I wanted to determine on this flight was how effective the insulation would be at keeping the payload warm in the extremely cold air of the stratosphere. The heat dissipation was under a quarter watt, and the insulation consisted of an inch of "Ultra-R" building insulation all around. The data showed this to be quite effective, holding the payload 30 to 40 degrees C above the outside air temperature. Unfortunately, the LM50B temperature sensors bottom out at -50C so we never saw how cold it really got outside. The next flight will use sensors which can handle lower temperatures.

The flight started at 1654Z, after a bit of trouble with the helium regulator and an almost-empty tank. The weather could not have been better, with light winds and clear skies. After completing the final checklist and verifying the downlink, we let her go!

Specifications:

Envelope: 300g Kaysam latex weather balloon
Payload weight: 96g
Flight time: 3 hours 9 minutes until LOS
Distance traveled: undetermined (est. 100 miles ESE)
Burst altitude: undetermined (est. 93,000 feet)
Minimum outside temperature: below -50C (-62C on NOAA forecast)
Minimum payload temperature: -25C

Estimated flight path based on published winds aloft

Temperature and battery voltage listing

Temperature graph (inside and outside)

Click here to hear the CW near peak altitude. (slightly fuzzy 8 KHz WAV file, 128 KBytes)