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Case Study - 10km Release |
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Wednesday, 31 May 2006 |
This case-study shows a typical launch from10 km (33,000 ft) altitude.
The following map shows the ground track of an actual balloon ascent to 10300m (33,800ft), where the DataBird released itself and flew back to the best alternative site (the pre-programmed alternative sites are marked as red dots). The ascent took 36 minutes, while the flight back took 55 minutes. (tick marks are at 2 minute intervals)
The DataBird released when it was 18.2 km away from the launch site. During its flight back, the plane made a sharp turn as it calculated that it would not make it back to the launch site safely and so choose the nearest alternative site. There is circled to loose the remaining height (about 800m) before landing.
The altitude profile shows a near constant ascent, then a steep dive just after the release followed by a gentle descent of about 2.2 m /s. At the bottom of the dive the plane reached a maximum ground speed of 55m/s (198km/hr).
Wind conditions:
9.1 m/s (17.7 knots) at 3km
10.6 m/s (20.6 knots) at 8km
25.0 m/s (48.6 knots) at 10km
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