A platform is built out in the middle of the ocean, in fairly deep water. The structure of the platform is such that the legs act as guides for a giant plunger, designed to be as large and heavy as possible while still buoyant. A rocket is placed atop the platform, and the plunger is weighted down with heavy debris or what have you until it sinks to the ocean floor.

At launch time, the weight is removed from the plunger, which, being hydrodynamic, rises rapidly to the surface. When it reaches the top it slams into the rocket, transferring its momentum and causing the rocket to shoot up into the air (imagine the experiment where you drop a tennis ball atop a basketball, causing the tennis ball to fly incredibly high). When the rocket reaches the apex of its boost, the thrusters activate, and it continues its journey towards the final frontier.
-- ytk, Sep 06 2012

Redundant water_20launcher
[Marked-For-Deletion] [MechE, Sep 06 2012]

hmm, interesting. The rocket could also sit on a top of a piston in a shaft that had water pumped out of it, and is then driven up by flooding. Not sure that the energy cost would make it cost effective, though
-- theircompetitor, Sep 06 2012


Why not just sink the rocket with a big weight to the bottom of the ocean and then release the weight, and the rocket would shoot upwards?

Perhaps because I'm hungry, I misread this as "Buoyancy Assisted Lunch".
-- hippo, Sep 06 2012


// slams into the rocket //

… causing the thin, fragile light-alloy structure to crumple and tear, rupturing fuel lines and tanks, spillng volatile fuel and oixdiser around the launch pad, and generally being unhelpful.

Launchers as described are designed to take a couple of g's of sustained acceleration, not a big multi-g whack of impulse.
-- 8th of 7, Sep 06 2012


Nothing that a bit of bungee cord can't fix.
-- Wrongfellow, Sep 06 2012


/not a big multi-g whack of impulse/

Maybe if these flying Ming Vases would grow some hair and toughen up they could keep from wetting their britches with oixidier. A buoyant boot to the backside is good medicine.
-- bungston, Sep 06 2012


//Redundant//

Hardly. This mechanism uses buoyancy to help launch a craft. The linked idea, on the other hand, uses something called “bouyancy”, whatever that is (which also explains why the standard pre-posting search didn't turn up anything).

Amusingly, a Google search just revealed that the, erm, “interesting” spelling “bouyancy” returns about 15% more hits than the “generally accepted” spelling.

Are the ideas otherwise similar? The linked idea describes a craft that is designed to be towed underwater, whereas this one involves simply designing a platform to launch a standard craft. I grant, however, that the actual physical principle involved is substantially similar. Alright, alright—it's a fair cop.
-- ytk, Sep 07 2012



random, halfbakery