from the FAQ:
What happens if the engine stops?
The Martin Jetpack is equipped with a 'Ballistic Parachute'. If something untoward happens the pilot pulls a toggle and a small propellant (similar to one used in a car airbag) is fired rapidly deploying a parachute. The pilot, Jetpack and parachute descend as one.
Are we all going to be flying to work on these?
Some people will use these for work; most of us will not be able to do this for some time.
The main use for Jetpacks will initially be recreational. This is similar to current ATV, snowmobile, jet ski, and ultralight use.
Are there any restrictions on who can fly one?
Currently the pilot must weigh over 140 lbs and under 240 lbs.
there. now whenever someone notices my weight, i'll just say i'm bulking up for my jetpack.