Hydrogen Engines

[All Seeing Eye]

Imagine a spaceship powered by a nuclear reactor supplying copious amounts of power, now imagine a tank full of water and a grid of wires running throughout the tank, would it be possible to send electrical current through the wires and through electrolysis seperate the Hydrogen from the Oxygen and then ignite the hydrogen in an engine to propel the craft forward? I know more energy is required to create the hydrogen then gained from it but we're not trying to get power from the hydrogen just a big bang to propel the craft and a nuclear reactor would give us enough power for the ship anyway. The engines wouldnt be burning constantly but would instead work in big bursts now and again.

Would burning the Hydrogen with oxygen create water again? if so the supply of water could last longer if the water could be re-harnassed.

 

[Bill Morris]

Anything you expel out the back of a spaceship in order to move forward is gone, and catching it basically cancels the forward motion you have created. So you don't get to reuse that water.

 

[All Seeing Eye]

How about sound wave engines? the universe is not entirely devoid of matter and a sound can infact travel through space (although our own ears wouldnt detect it) so would it be possible to build a huge speaker on the back of a ship and create huge high intensity sound pulses to create some sort of thrust?

 

[TerriO]

Sound waves really need air to push on to have an effect. I doubt it would work that well in space as a propulsion method.

I'm still on the "solar wind sail" notion, myself, but that would really only work for inner planetary travel.

 

[JustAFriend]

Do you REALLY want to try to concieve, engineer and then power a loudspeaker 2 light-years across????

...SO much easier to build a Project Orion nuclear pusher...

 

[SamuraiBlue]

You know it will be much easier if you super heat water with the nuclear reactor and release the steam as propellant.

 

[syc]

^ Yeah, Yeah.

I saw something like that a while ago, a interplanetary spaceship could use a giant ring full of water, convert it into steam using a nuclear reactor and then expel it out the back. Isn't water already one of the solar systems most valuable commodity though?

Sure we did find a frozen hydrogen section on the lunar south-pole but even that amount would barely fill lake Michigan.

...I'd go with VASIMR or Orion or Daedalus. Hell look up Prof. Heim's theoretical hyperdrive. < just use that.

 

[SamuraiBlue]

syc said:
^ Yeah, Yeah.

I saw something like that a while ago, a interplanetary spaceship could use a giant ring full of water, convert it into steam using a nuclear reactor and then expel it out the back. Isn't water already one of the solar systems most valuable commodity though?

You can always go comet hunting where there is considerable amount of water.

 

[All Seeing Eye]

JustAFriend said:
...SO much easier to build a Project Orion nuclear pusher...

Fair enough but thats not much use for sattelites and just how many nuclear explosions would a human crewed ship need to reach mars? and if this propulsion is so good why arnt they building one right now? if its something to do with a treaty about countrys not allowed nukes in space surely this could be overcome by global co-operation on the project?

 

[Ronald Held]

Eventually use space elevators for satellites higher orbiting than the elevator.

 

[RobertVA]

Regarding those space elevators:

What keeps all the assorted satellites, spent boosters and other man made junk in orbits below the upper anchor from hitting, thus severing, the tether? Remember that, no matter what the inclination, the object would cross through the equatorial plane (where the tether would have to be) twice in every orbit. As many objects as there already are up there I doubt it would be long before something crosses at the wrong time.

 

[Ronald Held]

You have to remove them before you build the elevator or move them into higher, safe orbits.

 

[RobertVA]

Between satellites that have run out of propellant, ones that malfunctioned and assorted debris now in orbits that will take centuries to decay (some for most purposes never) that's going to be a LONG, difficult and expensive cleanup. Thousands of items are already being tracked, and there are lots of smaller bits that for various reasons aren't being tracked.

The ISS benifits from being at an altitude with a small amount of atmospheric drag that makes orbits decay if there isn't an occasional rocket boost.

A lot of present satellites wouldn't work as well above geosynchronous altitudes either. Things like GPS, satellite phones and resource/pollutant photography.

But unless someone comes up with stronger material to make the tether out of we won't have that worry. I gather long nanotube material fabrication still isn't feasible and there isn't much certainty even those will be strong enough.

 

[All Seeing Eye]

Would it not be possible to build at the top of the tether a scanner to track any objects on an intercept course with the tether and using a built in laser or projectile weapon target the object and either blast it apart or knock it into the atmosphere where it will burn up?

 

[SamuraiBlue]

Fire said:
Would it not be possible to build at the top of the tether a scanner to track any objects on an intercept course with the tether and using a built in laser or projectile weapon target the object and either blast it apart or knock it into the atmosphere where it will burn up?

Have you ever heard of "Kessler Syndrome”?
Blowing something up close up near only creates more problem.
Here is a link concerning Kessler syndrome.
http://en.wikipedia.org/wiki/Kessler_Syndrome

As for cleaning up debris you'll have to do it the old fashion way.
A very interesting anime takes up this problem called "Planetes" I highly recommend watching it.

http://en.wikipedia.org/wiki/Planetes

 

[All Seeing Eye]

SamuraiBlue said:


Have you ever heard of "Kessler Syndrome”?
Blowing something up close up near only creates more problem.

Who said anything about close up, the range of the scanner and laser should be more than efficient to safely knock it into the atmosphere, it might not even need blowing up, a gentle push in the right direction may be sufficient.

 

[SamuraiBlue]

Fire said:

Who said anything about close up, the range of the scanner and laser should be more than efficient to safely knock it into the atmosphere, it might not even need blowing up, a gentle push in the right direction may be sufficient.

Yeah, hitting a spinning object that is smaller than a car with relative velocity more than mach 7, 5Km away concentrating the beam at center of gravity at the right trajectory long enough to apply enough momentum but not too long so it doesn't burn a hole through the outer shell.

 

[Meredith]

OK, you make a ship with a front wall and a back wall, then you shoot your potal gun on each wall, move object through it and you can re-capture your propellant.


I guess you could use the cake as a propellant, but it is so moist and delicious it may fall apart.

 

[Timo]

The orbital tether could in theory be used for anchoring a "bumper" ahead of it, on the most dangerous altitudes at least. Just trail a series of horizontal tethers ahead of the vertical one (that's where the "orbital pull" will take them anyway), connect them to a vertical mass, and have it catch and blow to thin mist the incomings. You wouldn't have to worry much about the mass of the system, so you could build the bumper so that it will assuredly catch all of the resulting shrapnel. Say, a few thousand mylar sheets in a widely spaced stack to absorb the bits of the initial hit without creating an unmanageable cascade of secondary shrapnel.

The sheets might also provide some maneuverability to the tether, bending the midsection out of the way of unmanageably large (but/and easily predictable) incomings using the lightsail principle.

Timo Saloniemi

 

[GodThingFormerly]

SamuraiBlue said:
As for cleaning up debris you'll have to do it the old fashion way.

Project Orion.

TGT