This is the analysis of an actual test flight, where the Databird released at 20km (65000 ft).
3d Visualisation of Flight Path
Once launched the balloon ascended with a gentle south-east breeze until 15km, at which point the wind swung round to a near easterly. (each marker represents 2 minutes)
After reaching the release altitude of 20km (65,000 ft) the DataBird free-fell (lack of supporting athmosphere!) to 12km, gained control, turning left and quickly took a down-wind course towards the designated landing site 15km away.
After approximately 12 minutes, it arrived and started its relaxed circling pattern for about 82 minutes to lose the remaining 9km of altitude. Some extra information from the on-board Flight Summary page: Ascended for 85min at 3.9m/s average, Released at 20001m (msl) due to ALTITUDE condition, (19.8km from Launch site). Flying time of 97min (average descent rate of 3.4m/s). Arrived at site with 9267m of height to spare.
Winds Conditions: 3.7 m/s (7.2 knots) at 2000 m 9.6 m/s (18.7 knots) at 4000 m 6.7 m/s (13.1 knots) at 6000 m 6.7 m/s (13.1 knots) at 8000 m 8.9 m/s (17.4 knots) at 10000 m 8.8 m/s (17.2 knots) at 12000 m 7.8 m/s (15.2 knots) at 14000 m 9.4 m/s (18.3 knots) at 16000 m
