Launch

The launch team is responsible for filling the required latex balloon(s) with helium and ensuring that the total lift is correct for the desired rate of rise. The launch team is also responsible for properly tying together with nylon cord the balloon, parachute and payload package. Upon checking with ground control that the payload is fully functional and ready for launch, the launch team is then responsible for launching the balloon assembly after ensuring that it will safely clear all nearby ground obsticles as it begins its assent.

Ground Control Station

Before a launch, the Ground Control Station is responsible for predicting the landing area.

After a launch, the Ground Control Station is responsible for:

• tracking the balloons location,
• continuously refining the predicted landing area as telemetry data is received,
• keeping recovery teams informed of the current balloon location and predicted landing area,
• collection and logging of all telemetry data,
• payload operation, and
• the sharing of all information to anyone interested via the BEAR web site.

Depending upon the payload, payload operation may include control of onboard crossband repeater radio traffic, of video and still frame cameras, of cut down mechanism, etc. Similarily, the sharing of information via the internet may include streaming audio of crossband repeater radio traffic, live video, still photos, and status reports in addition to telemetry data.

The control station tracks balloon flights using APRS telemetery data to generate flight path displays like this one of the BEAR-1 flight.

Payload Landing Site Prediction

Balloon Track for Windows software using weather office winds aloft data plus lift and descent rates for our balloon package is used to predict the payload landing area before launch. After launch, during the ascent portion of the mission, the weather office data is continuously updated using collected telemetry data to refine the predicted payload landing site. Immediately after the balloon bursts a final prediction is made.

Recovery

APRS telemetry data from the payload allows real time mapping of the balloons course during the flight. However, should the APRS telemetry system fail, backup methods to track the package must be used.

One method is for mobile trackers and stationary base stations with directional beam antennas to use RDF (radio direction finding) techniques to monitor signals from the balloon payload to determine it's position. Multiple recovery team vehicles will deploy into the predicted landing area and hopefully surround the landing site to allow for multiple convergent direction finding radials. For a minimum, recovery teams will have a RDF setup plus maps of the area.

Some recovery teams will use the balloons APRS telemetry data to provide a real time moving map display on a laptop computer in the chase vehicle to track the payload. Coordination between chase vehicles, base tracking stations and the ground control station will be through the payload crossband repeater, local repeaters or on a simplex frequency as need be.