A theorem on swirl loss in propeller wakes

method for the 3.5-ft guide surface drogue and 15-ft ribbon parachute. This eliminated the costly ball-lock load plate, and allowed staging by severing a double 5000-lb braided Kevlar pucker cord with a cable cutter fired by the clock timer in the vehicle. The deceleration record from the second drop is shown in Fig. 2. The positive load peaks shown in Fig. 2 are due to the aft parachute load force along the vehicle axis. The velocity decay with time after release, as obtained from phototheodolite tracking cameras, is shown in Fig. 3. Pointmass theoretical trajectory data shown as circles agree well with the diamond-shaped marks for the tracking data.