TV Payload Results

Summary

Weak TV pictures and audio telemetry were received a short time after the anticipated payload ejection. The TV camera was consistantly aimed down, indicated some drag from the starute, however it is clear from the video that the payload ended up in Lake Michigan after approximately 8 or 9 minutes. The payload was undergoing a rotation of about 1 to 2 Hz about the vertical axis. The rotation period varied by a factor of two from time to time, but was always in the same direction. These observations are consistant with a failure of the starute to deploy properly.

As the payload's altitude decreased, the images became clearer. Some wave structure on Lake Michigan is evident just before the signal was lost. Signals were received for just over 10 minutes from launch (8 minutes from payload ejection).


Details


At higher altitudes, the Wisconsin shoreline was seen on the edges of the images. Later, only the lake was visible.


The following video clips are not of high quality, but give you some idea of what was seen.

If necessary, use the "Back" button to return from the video clips.

From high up, the signal was too weak to get color, however you can see the circular motion of the payload and on occasion you can see the shoreline in Video Clip 1 (4MB AVI).

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Farther down, the blue of Lake Michigan shows up with the bright glare of the Sun as seen in Video Clip 2 (3.2MB AVI).

Listen to a bit of the audio telemetry from the payload here (489 kB, WAV) or here (489 kB, AU).


Telemetry Data:

Thermal fuses: The lowest thermal fuse (91C) was open on descent. The remainder were closed (121C and above). Hence, either there was a mechanical failure of the lowest fuse, or the payload experienced temperatures somewhat above 100C during ascent. Given that the payload temperature after ejection was not high, exposure to temperatures above 100C would have had to have been brief.

Battery Voltage: The battery voltage remained relatively constant during descent, rising about 10% from just after ejection until signal was lost. This rise is consistent with the increase in the battery temperature. The batteries in this payload were not heat sunk to the payload chassis. Some thermal connection between the batteries and the chassis in the future would reduce the range of temperatures experienced within the payload.

Temperatures:


(Each telemetry frame is approx. 10 seconds)

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