so below a certain height, emergency chutes are useless because they take several hundred feet to fully deploy and slow you down. SO if you have a problem with your shoot and have to open your reserve you have to do it really fast, or you die.
I propose a parachute that has a few sealed tubes in a star pattern. Inside the tubes, would be a CO2 cartridge or the same technology for car airbags, upon pulling the cord the tubes would become rigid creating the parachute shape much faster.
The tubes may also add some rigidity to the parachute to prevent tangling or collapses.
CO2 cans are cheap, airbag tech a little more expensive. Overall this wouldn't add a lot of cost or weight to a parachute and would just require sewing a different pattern.-- metarinka, Sep 01 2011 Ballistic Recovery Systems http://en.wikipedia...ic_Recovery_SystemsRocket launched parachutes for small aircraft [DIYMatt, Sep 01 2011] Martin Baker http://www.youtube....watch?v=MgcPhl1UIhAEjection test from ground level [DIYMatt, Sep 01 2011] Actual ejection from low level http://www.youtube....watch?v=jaWNj-ZkADY*impossible with a regular parachute* [DIYMatt, Sep 01 2011] Airbag technology: the parachute opens after you hit the ground?
Actually, this is a good idea for ejector seats[+]-- Ling, Sep 01 2011 [+] from me.-- MaxwellBuchanan, Sep 01 2011 This would result in an incredible wedgie.
Perhaps the CO2 could give you an upward momentum instead (or as well) to reduce the impulse forces that are normally damped out by a slowly opening parachute.-- mitxela, Sep 01 2011 Given the choice between a wedgie and going in, I'll pick a wedgie.
Also, it probably wouldn't. On a regular chute, at terminal you probably drop 100 or 200ft while the chute is coming out of the bag, pulling out the lines, getting ready to catch air and just beginning to open. Then it takes only maybe another 50- 100ft to go from there to full inflation, which is what causes the opening shock. (I'm thinking of main chutes, which have a slider to slow this final opening; a reserve is a bit snappier, so the final opening is a bit faster.)
This system would accelerate the first stage; I don't think you'd want or need to drive the canopy to full openness in this way.
[Edit: the slider I mentioned is on square chutes; round chutes instead have an apex-vent, which is designed to stop the canopy inflating too violently, by letting some of the air bleed out.]-- MaxwellBuchanan, Sep 01 2011 ... and to minimise the pendulum effect.-- 8th of 7, Sep 01 2011 That too.-- MaxwellBuchanan, Sep 01 2011 Widely known to exist. Ejection seats have had gun-launched parachutes for years and years that allow ejection even at ground level.-- DIYMatt, Sep 01 2011 This is true matt, in a former profession I was a rocket engineer (there's no scientists anymore) and built ejection seat motors.
However I've never seen a device for man potable sky diving use-- metarinka, Sep 02 2011 + but I don't really know anything about parachutes.-- pashute, Sep 02 2011 Base jumpers will have a hayday with this one.-- 2 fries shy of a happy meal, Sep 02 2011 //there's no scientists anymore// <lewiscarol> What I tell you three times is true </charledogeson>-- mouseposture, Sep 03 2011 random, halfbakery