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Telemetry Received from Orion-I Flight

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KI4NMN-11 APRS data (FindU)
NV4B Telemetry data (raw text, 33KB ZIP)
NV4B Telemetry data (decoded CSV, 38KB ZIP)

NV4B Telemetry data graph
Balloon pictures
Sign on outside of balloon package
Remnants of previous BalloonSat flights
Chaser antennas
Lab where package was constructed


Orion-I flew on 9 April 2006.  Launch was at approximately 10:50 a.m., with burst and descent beginning around 12:12 p.m. (see discussion below).

The payload was recovered in the Macedonia community of Jackson County on County Road 49, just across the line from DeKalb County, at approximately 4:30 p.m.

The landing site was within 10 miles of the predicted landing site.  KI4NMN-11 APRS data (144.39) ended around Ditto Landing, so recovery was accomplished by direction-finding the NV4B telemetry signal (144.34) and once close, the KG4WSV audio beacon (146.64).

The landing site was 39 air miles from the launch site.  The actual path taken by the balloon covered about 50 miles.

Graph and Commentary

This graph depicts the data received by the CPE Telemetry Team:

We believe that Analog 0 and 1 are accelerometer channels, Analog 2 is temperature, and Analog 3 is the gyroscope.

The launch occurred shortly before 10:50.  One can notice the temperature drop off as time goes on, rising slightly around 12:05.  Jason, KG4WSV, attributed this to passing through a layer of warmer air as the balloon continued to ascend.

Between 12:11:17 and 12:12:12, no data was received (this can be seen in the raw data file).  When the signal returned, the data was highly anomalous, as can be seen in the graph.  It is believed that the balloon burst sometime during this period, and the data loss is due to tumbling, as evidenced by the gyroscope data.  After 12:11:17, the temperature first falls, presumably as the balloon falls back into the colder air below, then begins to rise rapidly--at a greater pace than the cooling that occurred after launch--as the balloon quickly approaches the earth's surface.

It is interesting to note that when the gyroscope went extremely negative (<2.5 volts), one of the accelerometers returned highly positive (>2.5 volts) data; when the gyroscope went positive, that same accelerometer channel then went negative.  I'll leave it to the data analysis team to figure that one out!

The data stabilized around 12:15 and remained in the same state until it could no longer be decoded.

The data signal was lost after 12:22:52 as the balloon became too low to the ground to copy.  However, telemetry module continued to transmit until the payload was recovered at 4:30 and power was removed.  Without this nearly-continuous 400 mW signal to guide recovery, the payload might never have been found, as the only other working signal on board was KG4WSV's 40 mW audio beacon, which was too weak to be heard until we were within about 0.5 miles of the package. 

More details of the flight, including a detailed story of the recovery, will be posted here as I have time.

--Chris Arthur, NV4B
CPE Telemetry Team

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