jet pack - not rocket science

I remember that there was an article in the new scientist about the
return or the jet pack.

The core argument of the article was that the kinds of jet packs you
might have seen where powered by the decomposition of hydrogen
peroxide. The argument was that the 60 second flight time was mostly
a function of poor efficiency of the hydrogen peroxide fuel.

The reason for using hydrogen per oxide fuel was the safety ( non
toxicity ) of something which was so close to human flesh.

Clearly what was needed was something which is both safe ( or safer )
and yet more powerful.

I also remembered that Scale Composits makers of SpaceShipOne used
nitrous oxide ( laughing gas) and solid HTPB (rubber) propellant.
The big advantage of this is that the products are safe and can be
stored and used at room temperature. I hope that the NO/HTPB would
have a higher Specific impulse than the decomposition of hydrogen per
oxide ("The Isp of a LOX/HTPB hybrid motor is comparable to solid
propellant motors and LOX/kerosene rocket booster") ( see
http://www.spacedev.com/newsite/templates/subpage3.php?pid=185 )

Clearly the idea is that we should use a small hybrid rocket engine
on a rocket pack.

The combustion happens in side the rocket tube so I hope the reaction
would not have too extreme a hot exhaust. If not why not try to
figure out a way to handle it.