Travelling between solar systems...

[ghost03]

"hyperspace" type travel is actually quite possible.

the common misconception is that your speed is faster than light--this is not the case. you do however, get from point a to point b faster than light.

imagine a sheet of paper--to travel from one side to the other you could walk across the sheet of paper. you could also fold the sheet in half and jump from one fold to the other. the second way you travel similar speed but much less distance to arrive at the same point.

it is proven throuhg physics to be possible to warp space--the only problem is that currently it takes more energy that we can provide. space anchors and the like.

 

[RelaxTheMind]

lots of energy. guess it makes sense then that sci-fi ships are like half the size of the planet. The solar panels and ion thrust would probably make a couple people commit suicide. "please fasten your seatbelts and return your trays to the upright position. We will come to a complete stop in about 80 years.

Actually the trip alone would. hyperspace travel would not only be a good type of travel, but an ideal way (other than running into the unknown, such as dark matter). You can imagine with our standards of living today and being stuck on a ship knowing you would never see where you were going. You would seriously have to have an army of counselors.

Fossil fuels are already out of question. Some type of energy propulsion is possible, then again we dont really even have a "space age" efficient way to create domestic power on earth. Using the particles floating or emmiting in space seems to be a feesible.

Then again as the years pass Star Trek doesnt seem so sci-fi does it?

excuse the nonsense im try to pass time on the train...

 

[Rainsford]

Here's my thought...the "huge amounts of energy" problem is obviously a result of sustained acceleration up to the high speed necessary, not the speed itself. This is also the exact definition of the light speed limit...as mass accelerates to the speed of light, it takes more and more energy until accelerating that last little bit to the speed of light would require infinite energy.

To "solve" this problem, I think the big breakthrough would be an acceleration shortcut, so to speak. The idea is that there is nothing, AFAIK, that requires an object to accelerate to it's present speed...if we could somehow get an object moving 100mph from 0mph without accelerating through 30mph, 50mph, etc, and without using the energy that would otherwise be required, we might be able to travel fast on the cheap...and maybe even break the speed of light.

Of course the problem is how we would do that...I suspect it would involve some pretty non-conventional means

 

[TGHI]

The shortest distance between two points is a straight line...so I suppose that what I mean is that if we could in effect 'warp' space, we could make two distant places become very close to each other...meaning that propulsion wouldn't necissarily be an issue.

 

[DrPizza]

Originally posted by: Machupo

Originally posted by: flashbacck
I think when matter and antimatter collide the only thing that's suppose to be released is gamma radiation, which wouldn't really propel you anywhere.

i believe that's what a nozzle is for...

Anyway, where are you going to get the stuff? If you had the energy and tech to make it, you probably wouldn't need it!

CERN currently stacks a little over 11 nanograms of antiprotons per year... quite a small amount, but then for certain antimatter engine designs you only need a dozen times that to get to the Oort cloud...

m = 11 nanograms *12 *2
(2 for including the mass of the protons)
= 264 nanograms.

E = m c^2
= 264 E-9 grams * (3E8 m/s) ^2
= 2.376 E10 grams m^2/s^2
times 1 kg/1000 grams = 23,760,000 Joules.
Wow, at first I thought you were off by an order of magnitude or so... but, it doesn't sound bad to me now.

Converting that to kinetic energy for a 1000 kg object... (roughly 2200 pounds) and ignoring any relativistic effects on the mass... we get a velocity
(KE=1/2 m v^2) of 218 meters per second. (around 480 mph).

Cut the mass to 10% of that mass.. 689 m/s (around 1500 mph)

Hmmmm... on 2nd thought. maybe an order of magnitude off.

 

[puffff]

Originally posted by: TGHI
The shortest distance between two points is a straight line...so I suppose that what I mean is that if we could in effect 'warp' space, we could make two distant places become very close to each other...meaning that propulsion wouldn't necissarily be an issue.

Heh, have you read "A Wrinkle in Time"? Tesseract!!

 

[cheesehead]

I still say a self-contained ecosystem would make more sense. That way, you would have a perpetual base of operations that could sustain itself without supplies from earth.

 

[Xyrrus]

Anyway, where are you going to get the stuff? If you had the energy and tech to make it, you probably wouldn't need it!

CERN currently stacks a little over 11 nanograms of antiprotons per year... quite a small amount, but then for certain antimatter engine designs you only need a dozen times that to get to the Oort cloud...[/quote]

The energy is all there, its just a matter of harvesting it. I've seen designs in (admitedly far out) books for a 'cloud' of many spherical solar collectors in orbit around the sun. That energy is used to fuel the creation of antiprotons.

Yes it is a massive engineering project, but by the time we're ready for honest to goodness interstellar travel it shouldn't be any more difficult than other feats that were accomplished such as the creation of nuclear weapons in the 40s.

Antimatter is probably the most realistic method for interstellar travel: The technology to create it already exists, it is small enough that it doesn't create exponental increases in fuel reqired (a self contained fusion rocket ends up being 99% fuel 1% payload or worse), the physics behind it are more or less understood and it would be capable of driving a reaction that could bridge the gap between stars in years instead of lifetimes. The problems are mostly ones of scale - collecting the billions of gigawatts needed to make the stuff en masse is "non-trivial"

-Xy

 

[flashbacck]

Originally posted by: iwantanewcomputer
if you collide matter and antimatter the energy released goes in all directions, and thus does not propel stuff forewards. if you cause this explosion inside some sort of chamber with only one opening (through a nozzel on one end) energy will escape that way and propel the chamber foreward. it's newton's law of equal and opposite forces

That was my point regarding the gamma radiation. If the energy is mostly in the form of gamma radiation, then there's no way to focus it. Even if you could, it's an electromagnetic wave, it's not going to propel you anywhere fast.

 

[everman]

A method of folding space-time would seem to be the best, since theoretically it is faster than light. I don't know of anything that could yield more energy than an antimatter device to generate the energy. Currently we are working on how to easily store antimatter. The US Air force is working on it.
http://www.sfgate.com/cgi-bin/.../10/04/MNGM393GPK1.DTL

 

[Smilin]

Originally posted by: TuxDave
Wow... I actually never heard of that idea. I'm guessing the primary reason why we're considering Ion/Photon/Whatever propulsion systems is because of its ability to put out thrust for a very very long time?

Not really. Thrust "for a long time" is just our answer to the downside of "not much thrust" What we really gain out of ION drives is the amount of thrust for the given amount of fuel.

The total thrust of a large rocket engine would put it so far ahead of an ION engine that it may take years for an ION engine to catch up. At the end of say a decade the ION drive will have produced far more total thrust having burned only a fraction of a percent of the same weight in fuel. It will have left the rocket behind and still have enough fuel for several more decades.



When you talk about interstellar travel it doesn't really matter how advanced your propulstion system is. You're still talking about DECADES of time to get there. One of the most crucial aspects for manned travel to another solar system is finding a way to hibernate people. Without doing so you will need to bring along an entire life environment for your astronauts. Food water and oxygen will not be enough. A nintendo and treadmill are only going to occupy someone for so long.

 

[gsellis]

I actually like Alan Dean Foster's 'engine'. If we ever figure out gravity... His ships in the Humanax worlds create a temporary singularity at a point in front of the ship. The ship is drawn towards that point. Create another one further ahead and so on and so forth.

 

[DrPizza]

Originally posted by: Xyrrus
Yes it is a massive engineering project, but by the time we're ready for honest to goodness interstellar travel it shouldn't be any more difficult than other feats that were accomplished such as the creation of nuclear weapons in the 40s.
-Xy

Originally posted by: everman
A method of folding space-time would seem to be the best, since theoretically it is faster than light. I don't know of anything that could yield more energy than an antimatter device to generate the energy. Currently we are working on how to easily store antimatter. The US Air force is working on it.
http://www.sfgate.com/cgi-bin/.../10/04/MNGM393GPK1.DTL

Hmmm... Hmmmmmmmmmmm...
Antimatter bombs anyone?
There's a scary thought.

 

[DrPizza]

Originally posted by: DrPizza

Originally posted by: Xyrrus
Yes it is a massive engineering project, but by the time we're ready for honest to goodness interstellar travel it shouldn't be any more difficult than other feats that were accomplished such as the creation of nuclear weapons in the 40s.
-Xy

Originally posted by: everman
A method of folding space-time would seem to be the best, since theoretically it is faster than light. I don't know of anything that could yield more energy than an antimatter device to generate the energy. Currently we are working on how to easily store antimatter. The US Air force is working on it.
http://www.sfgate.com/cgi-bin/.../10/04/MNGM393GPK1.DTL

Hmmm... Hmmmmmmmmmmm...
Antimatter bombs anyone?
There's a scary thought.

Wow.

here
I guess I was right. Antimatter bombs.

 

[silverpig]

A few things:

1. Solar sails are designed to use the sun's photons (not ionic wind) to propel you through space. Google "poynting vector" and you'll see why it works. I heard of a russian prototype that was supposed to work using a carbon fibre sail a few sq km in size, but haven't heard much for a while.

2. Gamma rays produced via matter-antimatter are of course electromagnetic, but they WILL get you somewhere, and fast. Again, poynting vector is your friend. For photons, p = E = h(nu), and for gamma rays, nu = big. This means a lot of energy, and thus, a lot of momentum. Shoot them out the back of your ship and you're moving. Of course you'd need a lot of them to work.

Solar sails look great to me.

 

[everman]

Originally posted by: DrPizza

Originally posted by: DrPizza

Originally posted by: Xyrrus
Yes it is a massive engineering project, but by the time we're ready for honest to goodness interstellar travel it shouldn't be any more difficult than other feats that were accomplished such as the creation of nuclear weapons in the 40s.
-Xy

Originally posted by: everman
A method of folding space-time would seem to be the best, since theoretically it is faster than light. I don't know of anything that could yield more energy than an antimatter device to generate the energy. Currently we are working on how to easily store antimatter. The US Air force is working on it.
http://www.sfgate.com/cgi-bin/.../10/04/MNGM393GPK1.DTL

Hmmm... Hmmmmmmmmmmm...
Antimatter bombs anyone?
There's a scary thought.

Wow.

here
I guess I was right. Antimatter bombs.

Indeed....once we figure out how to store antimatter well, and produce it cheaply, we will have the makings for antimatter weapons and energy generation. I guess it could eventually be an infinite source of energy, maybe in 200 years.

 

[Cawchy87]

In terms of solar wind, mabye it would be enough to get out of our solar system. But once we are out there is no garentee that we will be close enough to another star like a sun or that possibly more than one star could cause havok in terms of direction. Very interesting question no doubt.

 

[JF0603]

i do not recall seeing a wormhole or another alternitive a nuclear powered engine

 

[Paratus]

To help clear some stuff up.

An gas core antimatter engine is the best engine we can at least speculate on today. We have the science to create the antimatter and the magnetic fields to contain it. We're just a couple of orders of magnitude off on production as Dr Pizza said. Your still looking at of course a minimum of 4years to the nearest star -- of course for the crew the closer C you get the shorter the time they spend in transist - ain't relativity wonderful.

And on the gamma ray thing Flashback is right and wrong. I don't remeber which particle pair it is but one set of particles ie. electron / postitron pair creates gamma rays but proton/anti proton creates gamma rays and highly energetic electrically charged particles you can accelerate.

One other option for antimatter is ICANN which use a very small amount of antimatter to boost an inertial fusion engine like deadalus. I think Penn State proposed this.

On Solar Panels - take it from someone who knows - they suck. Large, unwieldy, low power and they constrain your attitude. For example at assembly complete the International Space Station will have about a football fields worth of arrays at will have ~100KW of power availble for user loads. This is the power found in a small internal combustion engine. You are not going to the stars in a Ford Focus. I guess I shouldn't say they suck for use in earth orbit or even out to mars but they can be a pain sometimes.

The coolest near term engine is VASIMR (VAriable Specific Impulse Magnetoplasma Rocket). This is the brain child of 7 time astronaut Dr. Franklin Chang-Diaz. Its based off his fusion research. Basically you use 2 different types of radio waves ,one to create a low energy plasma by exciting the elctrons in a gas, the other to excite the ion/nucleus of the power to up the energy into the 10mil deg range and a magnetic mirror trap to accelerate the plasma through a magnetic nozzle. This setup basically acts like a car transmission. It can provide a fair amount of thrust at low isp ~3000isp or "1st gear or up to 30000isp but low thrust using the second radio attenna at "5th gear".

I've seen the test rig and Dr Chang-Diaz has said if you give him a 15MW nuclear reactor he'll get us to Mars in 3-4months. Give him 200MW and he'll get us there in 30 days

 

[flashbacck]

Originally posted by: Paratus
And on the gamma ray thing Flashback is right and wrong. I don't remeber which particle pair it is but one set of particles ie. electron / postitron pair creates gamma rays but proton/anti proton creates gamma rays and highly energetic electrically charged particles you can accelerate.

The link DrPizza has says positron/electron is the one that is primarily gamma rays.

Do you know what % of the energy is in gamma rays (for protons/antiprotons)? One thing you have to worry about: How much shielding is the crew going to need? 1cm of lead should reduce the gamma rays by 50%. But we're talking about hundreds of millions of joules. How many cm's of lead are you going to need?

 

[monzie]

A couple of problems have been overlooked (regardless of propulsion systems).

1) Navagation. How would you plot a course to 'x', you cant just go and buy a fully mapped 3D atlas from the local bookshop can you? Travelling in a straight line would also not work (and would be impossible anyway).

2) Navagation (again). Any 3D model used as a map (if such a thing exists) would need updating constantly (how? from where? verified by?) as you travelled away from the point (the Earth) on which the map was originally based. Simple things like North and South would no longer exist and any map would also be incorrect from the outset as even at the speed of light any reference point (like a bright star) could well be millions if not BILLIONS of miles from our 'percieved' position of said star...plus of course the universe is expanding adding even more to the complications of deep space navigation.

As for time travelling, well when we look at the stars on a clear night we are in fact viewing time from a few years to many thousands of years ago so it should be concluded that although time TRAVEL may not be possible, time VIEWING most certainly is....which would mean if we had a powerfull enough 'telescope' we could 'see' a distant (not of our solar system) planet and 'view' what was going on at 'x' time in their history, zooming towards their present as we approached.

 

[TitanDiddly]

I read a Heinlein book about interstellar travel once. Basically, they used the Orion Drive to get off the planet somewhere in the pacific, with giant tanks full of seawater on board. They had an onboard reactor engine to fiss all the water, using it's maximum energy potential. The ship was shaped like a turnip. The main track of the book is that they used telepathy to communicate with earth outside of radio range. Of course, they got some time issues once they got close to the speed of light... Good book. I probably just disgraced it trying to explain it.

Edit: Title of book is called 'Time for the Stars". Enjoying a txt right now.

 

[Paratus]

Originally posted by: flashbacck

Originally posted by: Paratus
And on the gamma ray thing Flashback is right and wrong. I don't remeber which particle pair it is but one set of particles ie. electron / postitron pair creates gamma rays but proton/anti proton creates gamma rays and highly energetic electrically charged particles you can accelerate.

The link DrPizza has says positron/electron is the one that is primarily gamma rays.

Do you know what % of the energy is in gamma rays (for protons/antiprotons)? One thing you have to worry about: How much shielding is the crew going to need? 1cm of lead should reduce the gamma rays by 50%. But we're talking about hundreds of millions of joules. How many cm's of lead are you going to need?

No. There used to be really interesting page of the JPL home page on this but they took it down a couple of years ago.

 

[Paratus]

Originally posted by: monzie
A couple of problems have been overlooked (regardless of propulsion systems).

1) Navagation. How would you plot a course to 'x', you cant just go and buy a fully mapped 3D atlas from the local bookshop can you? Travelling in a straight line would also not work (and would be impossible anyway).

2) Navagation (again). Any 3D model used as a map (if such a thing exists) would need updating constantly (how? from where? verified by?) as you travelled away from the point (the Earth) on which the map was originally based. Simple things like North and South would no longer exist and any map would also be incorrect from the outset as even at the speed of light any reference point (like a bright star) could well be millions if not BILLIONS of miles from our 'percieved' position of said star...plus of course the universe is expanding adding even more to the complications of deep space navigation.

As for time travelling, well when we look at the stars on a clear night we are in fact viewing time from a few years to many thousands of years ago so it should be concluded that although time TRAVEL may not be possible, time VIEWING most certainly is....which would mean if we had a powerfull enough 'telescope' we could 'see' a distant (not of our solar system) planet and 'view' what was going on at 'x' time in their history, zooming towards their present as we approached.

Well considering we managed to send the Pioneers, Voyagers, Cassini, et al on journeys of billions of miles with dead on accuracy I don't think navigating will be a problem. Astronmers can pinpoint the motions of stars pretty well using the doppler shift, repeated observations, etc. So just assume you'll need a few minor course corrections on your way to the nearest star and you'll be fine.

 

[Smilin]

Yeah, you're going to have to be making observations the whole way. Inserting yourself into final orbit around the planet is going to take some mapping as you approach.

No one's really elaborated on what astronaughts are supposed to do for 5-50 years while they travel though. For a five year trip a large craft with artificial gravity and an X-Box might work. For longer trips you'll need a whole habitat. For a 50 year trip you're going to need human hibernation.