# Self contained U transit drive for spacecraft

First of all this is not a perpetual motion machine. This type of transit drive works in theory by having two combustion chambers positioned parallel to the spacecraft's width and perpendicular to its length. Each of the two exhaust nozzles are also positioned parallel to the spacecraft's width and perpendicular to its length. Fuel is pumped into the combustion chambers and goes out the two exhaust nozzles at high velocity, and each fuel exhuast half next travels through a half of the U shaped tunnel until they both collide against the ship's midship bulkhead pushing the spacecraft forwards. The fuel is made up of multitudes of theorized systematic new elements in which each element provides an incremental acceleration when it combusts (each latter fuel element is more combustible than the former fuel element). The fuel exhausts don't exit the spacecraft. The structure of the U tunnel, combustion chambers, exhaust nozzles, etc. are made up of a theorized new super element I call superglass (the superglass structure negates the necessity of magnetic fields to contain the exhaust particles to keep them from melting spacecraft structure).

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mgb_phys
Homework Helper
Doesn't work - no net forward momentum change.
Picture a simplified version, gun (pointing forward) fires bullet into a u tube which returns the bullet backwards to a catchers mit next to the gun.

1, Gun fires
The gun, and the ship it is attached to go backward. Bullet goes forward.
Ship receives one unit of backward momentum, bullet gets one unit equal forward momentum.

2, Bullet hits the curve in the u-tube
Bullet exchanges momentum with the tube and changes direction.
Bullet is now going backwards ship is going forward.
Since the bullet direction has changed sign, the ship gets two units of forward momentum the bullet has one backward unit.

3, Bullet caught and reused.
Bullet loses all it's momentum
Catches mit, and the ship it is attached to receive one one unit of backward momentum

4. Everything cancels out - and everything is now stationary in exactly the same place as before.

Note - if you left out the catchers mit and let the bullet go out the back - then the ship would have one unit of forward momentum, this would be exactly the same (ignoring losses) as just firing the gun out of the back.

1. You didn't completely read the first half of my paragraph. I said "two combustion chambers positioned parallel to the spacecraft's width and perpendicular to its length". The combustion chambers aren't parallel to the ship's length and perpendicular to the ship's width. The fuel exhausts move sideways in relation to the ship's forward structure when they exit the combustion chambers & fuel exhausts.

2. No, when the exhausts enter the curves they press forward pushing the ship forward somewhat.

3. When exhausts hit midship bulkhead they push the ship forwards. (Try imagining an open box hit by a volleyball in space - the volleyball enters the box and pushes it forwards).

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mgb_phys
Homework Helper
I was trying to simplify it so you could see where you fundemantally went wrong.

It's the problem with most perpetual motion machines - it's obvious in the simplest cases and then people add wheels-within-wheels or wheels at angles until they have confused themselves into believing it.

Again you failed to read that paragraph. I specifically typed "this is not a perpetual motion machine".

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D H
Staff Emeritus