I think I read somewhere that it is possible to clamp a parachute's shroud lines together at some point: This partially collapses the parachute and increases the rocket's descent rate. Has anyone ever tried this before? I've had it happen to one of my rockets unintentionally (it has a rotating parachute and its swivel had too much friction . . . I need to put on a better swivel), but I've never partially collapsed a parachute one purpose.