NASA space ship

Lord Skimper wrote:With a small space wagon you can't spin it slow enough to make artificial gravity without causing disorientation for those aboard.

Actually, we could.

Let's put the "wagon" of your and some counterweight - for example, nuclear reactor (good reason to place it far from the habitable area - economy on radiation shielding!) - on the opposite ends of some truss beam or cable. Then rotate all construction around the center of mass. With sufficient lenght of truss beam/cable, there would be mo disorientation.

A big ship spinning along its axis allows one to accelerate the full way, if you are tumbling end over end you have gravity, sort of, but you lack acceleration unless the engine is perpendicular to the rotation and the engine is in the middle of the ship. Of course your little ship is pretty big and instead of having a hundred little ships in train you end up with one big ship.

A few days wihtout gravity the crew could manage, during acceleration. Or we could just place engines in the centre of mass and rotate the structure around them.

And my ship is big, but not HEAVY.

Lord Skimper wrote:A big ship spinning along its axis allows one to accelerate the full way, if you are tumbling end over end you have gravity, sort of, but you lack acceleration unless the engine is perpendicular to the rotation and the engine is in the middle of the ship. Of course your little ship is pretty big and instead of having a hundred little ships in train you end up with one big ship.

Lets just do a little arithmetic as to how fast and far apart you have to be to get a reasonable gravity simulation.

From basic physics: a = v^2/r. v = 2*pi*r*(rev) where rev is the rotation rate in rev/second.

So a = (2*pi*rev)^2*r. Assuming you want 1/2g as your gravity at the end of your tether, that's 4.9 m/sec^2. Substituting the numbers you get r*(rev)^2 = .12411. If you want 1 g, the later constant is .24822.

Assuming a radius of 50 meters (cable length of 100 meter) we get

rev = sqrt(.00248) or .05 revolutions per second or about 3 revs/min.

You have to decide if that's too fast a spin rate. Because revs is a square component in the formula, to half the rotation speed, you have to either quadruple the radius, or cut the required acceleration by a factor of 4 or a combination of both (double the radius and half the acceleration).

Assuming the power plant engine is a steam thing, which is a bad Idea in my mind but still propels your ship if need be, what keeps the lights on, the further away from the sun the less your Solar panels work. Where as an Ion Nuclear powered engine solves the keeping the lights on power needs as well.

Although I do have a fancy gravity powered generator which while it doesn't work on Earth, due to how gravity works here, in a spinning ship it should work great. A Backup nuclear power plant might still come in handy as might emergency steam engines etc...

I just can't see shooting water into space. Breaking the Hydrogen and oxygen down for other uses sure, but not shooting it into space to make a thrust effect.

Lord Skimper wrote:Although I do have a fancy gravity powered generator which while it doesn't work on Earth, due to how gravity works here, in a spinning ship it should work great. A Backup nuclear power plant might still come in handy as might emergency steam engines etc...

Why do you think that this contraption of yours would work in pseudogravity when it doesn't work when subjected to the real thing?

Also, fundamental question time: Why do we need to send canned monkeys all the way out into the Jupiter or Saturn systems? Why is a permanent Mars base desirable? What can be done on other planets in the solar system that can't also be done (at much reduced risk) inside the Earth/Moon system?

Lord Skimper wrote:Assuming the power plant engine is a steam thing, which is a bad Idea in my mind but still propels your ship if need be, what keeps the lights on, the further away from the sun the less your Solar panels work. Where as an Ion Nuclear powered engine solves the keeping the lights on power needs as well.

Although I do have a fancy gravity powered generator which while it doesn't work on Earth, due to how gravity works here, in a spinning ship it should work great. A Backup nuclear power plant might still come in handy as might emergency steam engines etc...

I just can't see shooting water into space. Breaking the Hydrogen and oxygen down for other uses sure, but not shooting it into space to make a thrust effect.

An ion engine is very well suited for unmanned probes that can take their time to get to their target, a manned probe not so much since the thrust is so low that the crew has to spend a lot of time in transit which means they need a lot more supplies which equals more mass to move.

Using a nuclear engine to superheat water for propulsion is actually a good idea when speed matters; especially climbing out of a gravity well, since it has 5x magnitudes more thrust than an ion engine (ex. VASIMIR). Since you have a nuclear engine producing heat you use a bog-standard heat-exchanger for power, no need for solar panels.

In the end, what decides what engine to use is mass to move + time to target.

And re you gravity powered generator, if it uses the spin of the ship to produce energy you are just using the energy stored in the spinning mass which means the ship will eventually stop spinning.

The E wrote:Also, fundamental question time: Why do we need to send canned monkeys all the way out into the Jupiter or Saturn systems? Why is a permanent Mars base desirable? What can be done on other planets in the solar system that can't also be done (at much reduced risk) inside the Earth/Moon system?

Room to expand and another place for the human race to live. It gives added insurance of the human race to survive, and it also gives us added resources and a base closer to the outer system.

I for one am very sure, (almost with a religious level conviction or level of faith) that mankind will eventually settle our own system and then, one way or another, none of which have even been dreamed of yet, will eventually get to the stars. Time, time, time is on our side.

But ... it will not be a easy or quick process. Nor will it be cheap, both in material and human life. Consider future space exploration as a rough parallel with ocean travel here on earth. It has taken about 3000 years for us to get from the earliest ocean going voyages of to where we are today.

Lots of brave sailors and seemingly strong ships were lost. Towards the end of ocean going sail boat ship travel, we actually liked heavy weather as it sped up the speed of the trip. Then the steam ship changed everything. Now we fly from nation to nation in hardly any time at all.

Future space travel will be no different, as I see it. It will take time and tremendous expense for any of this to happen. Again, I think we will not go back to the Moon for another 100 years. Just me. But we will return. It will just take time and effort ... and again ... a very good $greed$ oriented reason for doing so. That is the way we are.

Our human history here on Earth or Sol/3 Terra has been marked with several important technological advances. Gun powder, the printing press, steam tech, electricity, radio, nuclear energy, the micro chip ... we have come a long way baby. And ... we ain't seen nothing yet. Hang onto your hats and away we will go. Flash forward 3000 years from today.

Discoveries that will knock our socks off and viewed from today will be very very close to magic itself. Power sources beyond our wildest imagination and I have a lot of that. Private Star Ships that can go ANYWHERE, are self aware and are no larger nor more $expensive$ than a private car. Multi dimensional. Smart, Safe. Fast. Cheap. That is our future.

HB of CJ (silly old coot) Cm. I love this Forum and thank you.

Zakharra wrote:Room to expand and another place for the human race to live. It gives added insurance of the human race to survive, and it also gives us added resources and a base closer to the outer system.

There is no room to expand there, unless we build it. Which is easier to do in the Earth/Moon portion of the solar system than it is out by Mars or Jupiter.

Again: What is out there that you can't get closer to home?

HB of CJ wrote:Discoveries that will knock our socks off and viewed from today will be very very close to magic itself. Power sources beyond our wildest imagination and I have a lot of that. Private Star Ships that can go ANYWHERE, are self aware and are no larger nor more $expensive$ than a private car. Multi dimensional. Smart, Safe. Fast. Cheap. That is our future.

Oh god. You do realize that putting enough energy to do space travel in the hands of J Random Moron is a really bad idea, right? There's a reason why flying cars haven't taken off.