Robert -
In free-fall (i.e. before opening the parachute), a parachutist
falls extremely quickly. Using a parachute slows them down - but it can
only do it so fast. It takes a certain amount of time for the parachute
to slow them down enough to land safely. This is why they can't release
it too late. They can release it earlier, though. But this would mean
that they would be spending less time in free-fall, which is what most
parachutists are sky-diving to get.
-Tamara
(published on 10/22/2007)