Winter 2010 Issue

Up in the Air

Launches by the Space
Hardware Club of UAH

By Bill Brown, WB8ELK

Photo 1. The Space Hardware Club’s hi-definition ATVtransmitter payload.
(All photos by Bill Brown, WB8ELK)

The Space Hardware Club of University of Alabama, Huntsville (UAH) has been flying a number of unique high-altitude balloon experiments. The club members meet two nights each week to work on their experiments and often launch a couple of balloons each semester. One of their payloads last year consisted of human and mouse nerve cells in an environmental chamber to see the effects of a trip into the stratosphere. The cells survived! UAH also flies Balloonsats as part of the electrical engineering senior design class, but the Space Hardware Club (SHC) is unique in that students of any major can participate.

This past fall on a beautiful October day the SHC students launched a high-definition camcorder that also downlinked live video. The fast-scan amateur television (ATV) transmitter section (see photo 1) put out 3 watts on the 70-cm band into a horizontally polarized Little Wheel antenna. In addition, there were several APRS (Automatic Packet Reporting System) transmitters on 144.39 and 144.34 MHz for tracking the balloon’s position during flight.

The calm winds allowed a picture-perfect liftoff (see photos 2 and 3) as the students watched their payload rise high above Huntsville, Alabama. Barry Lankford, N4MSJ, brought his portable ATV receiver and antenna to watch the video during the flight (see photo 4). In addition, the Electrical and Computer Engineering (ECE) department at UAH has allowed the Space Hardware Club to set up a great ground station in a room on the second floor that has roof access for their antenna system. The az/el rotor system combined with some custom programming of their ground-station computer allows the antenna to track the balloon by decoding the APRS downlinked position and altitude, calculating the azimuth and elevation bearings and automatically steering the antennas toward the balloon throughout the flight (photo 5).

This first flight of their ATV system had some antenna problems (the Little Wheel had been beaten up pretty badly during a number of earlier missions), so only a few minutes of live ATV signals were received. However, they did get some beautiful high-definition video recorded on the camcorder’s memory card.

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