The video recording shows a successful launch of the TU Delft V3 kite from an upside-down hanging position on 2 August 2012 at the former airfield Valkenburg, Leiden, Netherlands. The GoPro camera is taped to the rear side of the leading edge tube of the wing, between the two center struts, looking at the kite control unit. As for all previous mast-based launch attempts, the hanging kite is first steered into a pendulum motion, before taking off with an upswing maneuver. This upswing is not continuous, however, with the kite stagnating several times, falling back down somewhat, then picking up speed again and climbing a bit higher, eventually reaching a stable flight position above the mast head. The tether is then reeled out continuously and the kite works its way up to higher altitude, while occasionally performing subtle crosswind maneuvers. The ground station is visible at the top of the field of view. When reaching the highest point at around 2:10 to 2:20 minutes into the video, the maneuvers are terminated which leads to a drop in tether tension and consequently a more pronounced tether sag. The tether is reeled back in. At about 3 minutes into the video, the tether starts to progressively loose all tension and eventually goes entirely slack. As a result, the kite further descends in a paragliding mode, moves upwind and towards the end of the video, overflies the ground station before hitting the ground.This launch was also covered by data recording, by a regular photo camera and by a second GoPro video camera that was positioned on the ground, next to the launch mast. Because the time of the GoPro video camera was incorrectly set, we used the short initial pendulum motion of the hanging kite as a clearly identifiable event in the video and the data recording to determine the correct starting time of the video, 20:45:10, which was then set in the video metadata. |