Biggest problems with interstellar human flight

What do you think will be the most significant problem going to even the nearest star?
In my opinion, based on reading a lot of articles about the issue, my prognostication is this: in the coming century or two, I think we will be surprised by the power of future space drives, mainly in the area of anti-matter drives. Here is my reasoning: while the idea of humans manufacturing anti-matter is within the realm of the possible, it would be extraordinarily expensive for us to make enough for an interstellar flight, I am thinking maybe 1000 Kg or so, maybe less. But it has already been discovered there is a huge supply of anti-matter already present in the solar system, due to the ratio of matter to anti matter in the universe in general, about 10 billion atoms of matter to one of anti. So it has been shown a collector, a mesh charged properly and an antimatter trap in the center, maybe a klick long, like a giant soccer ball (football for you Euro's) but no outer skin, just wire where the pattern is, will collect kilograms of the stuff if over the course of a year or two.

The interesting thing about all this is the engineering on antimatter rockets have pretty much already been done, they are much further along than it's little brother, fusion rockets, and a thousand times more powerfull potentially. If you give a significant amount of antimatter to a present day rocket scientist, he or she will be able to built a nice rocket right now. That said, if there was a large amount available, then it would have the capability to accelerate at about one g or so continuosly for years on end, then halfway to AC, decelerate the rest of the way. I think it will be shown we can do exactly that, maybe in 200 years, maybe less.

But it looks like the biggest problem will not be food supplies, hydroponics, or any of that. It looks like maybe the show stopper for human flight anyway, is the sheer radiation of just traveling at even half the speed of light. There was a design for an interstellar craft designed in the '60's that fed a bunch of small atomic bombs to a giant pusher plate with shock absorbers that would give a huge pulse of accel, say once a minute or so, don't know the exact timing, but it was calculated to be able to get up to maybe ten percent of C. Now you would think the radiation shielding would be a big problem to keep it away from the humans and it would be, but that could be designed in alright, we now know stuff like ordinary plastic is a very good radiation shield and such. The BIG problem is not the radiation coming from the back by the engine, whatever it may turn out to be, but the radiation coming from in FRONT as you get up towards relativistic velocity. Remember, as you increase in velocity, the wavelength of incoming radiation is blue shifted in front. So infrared may become Xrays when you get close to C. That radiaton may be the killer of interstellar flight, way to powerful to be deflected by magnetic fields or plastic shielding, at least thats what it looks like now. But if they get around that problem I have no doubt we will be an interstellar going species in a couple hundred years IF we live through the coming climate shifts that may kill high technology in the first place. That is a much bigger challange right here and now than getting enough anti matter for a flight to Alpha Centauri, surviving the coming climate battle with our technology for spaceflight still intact.

Originally posted by sonhouse
What do you think will be the most significant problem going to even the nearest star?

The distance.

We will not be traveling to stars in rockets. It takes too long, however, you look at it.

Originally posted by Wheely
The distance.

We will not be traveling to stars in rockets. It takes too long, however, you look at it.

If we want to go to the stars, we have no choice but to use rockets at least with our present understanding of science. I think it's safe to forget wormholes or some such sci fi effect. Anti-matter rockets will have unbelievable power. Power to get to at least half the speed of light. That makes a trip to Alpha Centauri in maybe 20 years or less,
so anti-matter is probably the only thing that will get us there in 20 years or less. Generation ships could do the job but if it takes 500 years to reach AC, we would not see the results of such a journey for 1000 years, like a return sample kind of thing. We could have radio/laser contact after the 500 year trip but all that would still be 500 years into our future, way too long a view for it to work, too many ways for a spaceship to screw up to last 25 generations. If it proved too harsh to send humans at 0.5C because of radiation, robot probes could certainly be sent, at least to get sample/return/pictures, etc.
One more technique I hear mentioned: Send no humans but have viable eggs and sperm in special radiation resitant containers and grow the humans before you get there with robot nannies. That could be a way to seed humanity to the stars if humans can't go because of the conditions of flight, too much radiation or some such.

Originally posted by sonhouse
If we want to go to the stars, we have no choice but to use rockets at least with our present understanding of science. I think it's safe to forget wormholes or some such sci fi effect. Anti-matter rockets will have unbelievable power. Power to get to at least half the speed of light. That makes a trip to Alpha Centauri in maybe 20 years or less,
so anti-m ...[text shortened]... stars if humans can't go because of the conditions of flight, too much radiation or some such.

Twenty years there and twenty years back eh.

What would be the point?

Originally posted by Wheely
Twenty years there and twenty years back eh.

What would be the point?

sonhouse would happily go on a one way trip i think ....
and then go 20 years further on again ...

Originally posted by Wheely
Twenty years there and twenty years back eh.

What would be the point?

You wouldn't just go for the hell of it. That kind of undertaking would of course be preceded by robot scouts to get an up close look at any planets and if one or two were found to be interesting for whatever reason, only then would humans get involved. All the problems I mentioned, especially radiation, would be much less of a problem for robots, no food needed, etc.
So they would make a preliminary survey of the system in question, my favorite being Alpha Centauri for the simple reason you get three stars for the price of one and that triple system is the closest to boot. So The robots scout it out, they can get there much faster because they could take 20 g's and not even feel it. So if they took close up images of some earth like planet there, you can bet your boobie humans would want to follow, of course it would take longer for mere humans to get there than the robots which preceded them.

Its not really feasible to use rocket-propulsion to travel to other stars. It is even a large burden to use it to travel to other planets like Mars.

I think that within the next 100 years we will make massive steps forward in our understanding of gravity and electro-magnetism which will allow us to travel through space faster-than-light.

Maybe we could even somehow harness the hawking's radiation from the center of the galaxy? AKA Zero Point Energy?

Its hard to say...

Thats the only way I can see human interstellar travel it to be practical with any regularity to other star systems. With some type of readily available energy source that doesn't weigh much coupled with the ability to bend space-time to travel faster-than-light.

We are really going to see some advancements in the next 10 years when the Large Hadron Collider comes into operation. We may see mini-black-holes and new types of anti-matter... super-symmetry or a number of other things.

Therefore, my answer to the biggest problem to interstellar flight today is: Our lack of understanding of gravity and its relationship with matter!

Originally posted by sonhouse
If we want to go to the stars, we have no choice but to use rockets at least with our present understanding of science. I think it's safe to forget wormholes or some such sci fi effect. Anti-matter rockets will have unbelievable power. Power to get to at least half the speed of light. That makes a trip to Alpha Centauri in maybe 20 years or less,
so anti-m ...[text shortened]... stars if humans can't go because of the conditions of flight, too much radiation or some such.

Nuclear Pulse Propulsion systems seem to me to be the best way to go at this time, not rockets. Rockets would be used for fine control I suppose.

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

Originally posted by sonhouse
What do you think will be the most significant problem going to even the nearest star?
In my opinion, based on reading a lot of articles about the issue, my prognostication is this: in the coming century or two, I think we will be surprised by the power of future space drives, mainly in the area of anti-matter drives. Here is my reasoning: while the idea o auri, surviving the coming climate battle with our technology for spaceflight still intact.

"while the idea of humans manufacturing anti-matter is within the realm of the possible"

There is no way we can produce more than tiny amounts of anti-matter. I say not even grams of it, nor milligrams. Yes, we have been able to produce positrons and aniprotons, but more than a few anti-hydrogene? No.

The energy needed to produce anti-matter is much more than we can take out in energy again in a space flight. I don't know the ratio, but I can imagine that you don't have a efficiency more than one percent, probably less.

"But it has already been discovered there is a huge supply of anti-matter already present in the solar system"

I simply cannot believe this. You have to back it up with some source or link. Where is this 'huge supply' of antimatter to be found?

To answer your question about "Biggest problems with interstellar human flight" I would answer: Financing.

Interstellar travel has almost happened anyway. Both Voyager 1 and 2 have crossed the heliosphere boundary. Just a little further to go and they will be in the interstellar medium.

Pioneer 10 should make Alderberan in about 20 million years. No problem!

The whole rocket thing just doesn´t work. Can you imagine a generation ship or a forty year round trip to visit what will be a star and possibly a few completely uninhabitable planets. You might get lucky of course and find a nice planet but the odds are against you.

Better to spend all that cash digging through the ice of Europa or maybe Ganymede. One day maybe we´l find a way to the stars but I suspect it won´t be by rocket and we had probably better get a good idea of whats there before we attempt the journey.

Originally posted by FabianFnas
[b]"while the idea of humans manufacturing anti-matter is within the realm of the possible"

There is no way we can produce more than tiny amounts of anti-matter. I don't say even grams of it, nor milligrams. Yes, we have been able to produce positrons and aniprotons, but more than a few any-hydrogene? No.

The energy needed to produce anti-matter t "Biggest problems with interstellar human flight" I would answer: Financing.[/b]

"But it has already been discovered there is a huge supply of anti-matter already present in the solar system"

I simply cannot believe this....

Yes; and you have good reason to not believe it! Any antimatter particles in interstellar space would be gradually annihilate by collisions with particles of protons and electrons in the solar wind as well as from collisions with interstellar gas molecules and space dust -all of which is made of matter rather than antimatter.

If a huge supply of antimatter was discovered already present in the solar system then that would be headline news and could cause concern within the scientific community since, if that was true, then, given the fact that Earth is made of matter and given the fact that when matter and antimatter meet, they annihilate with vastly greater energy than that released by nuclear fusion of hydrogen in a
H-bomb, there could be serious problems if some of that vast amount of antimatter made contact with the Earth!

Originally posted by Andrew Hamilton
[b]"But it has already been discovered there is a huge supply of anti-matter already present in the solar system"

I simply cannot believe this....

Yes; and you have good reason to not believe it! Any antimatter particles in interstellar space would be gradually annihilate by collisions with particles of protons and electrons in the solar w ...[text shortened]... uld be serious problems if some of that vast amount of antimatter made contact with the Earth![/b]

Perhaps he means Helium-4, which can be found with abundance in the atmosphere of Jupiter. He4 can be used as a nuclear energy source. But this has nothing to do with anti-matter.

The author Dan Brown had anti-matter as an important role in his book "Angels & Demons". But unfortunately he doesn't know what he is writing about concerning anti-matter.

Originally posted by FabianFnas
Perhaps he means Helium-4, which can be found with abundance in the atmosphere of Jupiter. He4 can be used as a nuclear energy source. But this has nothing to do with anti-matter.

The author Dan Brown had anti-matter as an important role in his book "Angels & Demons". But unfortunately he doesn't know what he is writing about concerning anti-matter.

Sorry for being such a nerd but: I think you mean Helium-3 and not Helium-4 !
Helium-4 is the more common isotope of helium and considered to be very hard to use in nuclear fusion.
Only Helium-3 is generally sought for use in nuclear fusion.
Also; the main heavy isotope hydrogen: deuterium: is also sought for use in nuclear fusion.

Both Helium-3 and deuterium do exist in nature but they are reletively rare in nature.

Originally posted by Andrew Hamilton
Sorry for being such a nerd but: I think you mean Helium-3 and not Helium-4 !
Helium-4 is the more common isotope of helium and considered to be very hard to use in nuclear fusion.
Only Helium-3 is generally sought for use in nuclear fusion.
Also; the main heavy isotope hydrogen: deuterium: is also sought for use in nuclear fusion.

Both Helium-3 and deuterium do exist in nature but they are reletively rare in nature.

Right, Helium-3 it is.

Originally posted by Andrew Hamilton
Sorry for being such a nerd but: I think you mean Helium-3 and not Helium-4 !
Helium-4 is the more common isotope of helium and considered to be very hard to use in nuclear fusion.
Only Helium-3 is generally sought for use in nuclear fusion.
Also; the main heavy isotope hydrogen: deuterium: is also sought for use in nuclear fusion.

Both Helium-3 and deuterium do exist in nature but they are reletively rare in nature.

I thought deuterium was fused in many stars instead of hydrogen. If so, there must be a fair bit of it around!