Your ideal Interstellar vehicle/system (no FTL)

[PB666]

4 hours ago, fredinno said:

Yeah, and fusion-electric and antimatter drives still have you screwed if you lose power- because the stuff inside will no longer be contained by magnets.

A bigger problem is stopping the thrust from a black hole- just letting it die will release so much hawking radiation it would destroy the spacecraft.

If your fusion power generator stops you need a backup power, which can easily done by having batteries and a back up TNG. In the life of an interstellar flight the fusion power generator would have to be serviced many time, conceivably if you traveled fast enough you could scoop hydrogen from space and breed it with neutrons in the reactor. FEP craft are not ideal, I admit, but solar is out, the black hole idea is just fantasy, warp drive is super fantasy, so its the most viable at the moment, at least we are never more than 20 years away from a working fusion reactor.

Basically, philosophically speaking a fusion powered interstellar craft you take the whole culture inside the ship (not to say everybody) but major aspects of the culture would go and manufactor, repair, innovate if new technology on the home world was virtually shipped.

[K^2]

I don't think you are picturing a fusion reactor of an interstellar generation ship quite right. It needs to generate tremendous amounts of power to get itself moving. Which means it's not going to be a handful of atoms being pumped through the confinement rings. You'll have literal tons of high energy plasma bouncing through the reactor. If confinement fails, it's not just going to shut down. It's going to rip itself apart quite violently, destroying not only the reactor, but anything around. We are talking kiloton ranges explosion.

If anything, black hole drive is significantly safer. The radiation pressure is pushing along the ship, not the black hole. If you tractor the black hole along with electrostatic charge, and the force gets too weak, you simply leave the black hole behind. It will be years before it explodes, by which time you'll drift to a safe distance. If you pull the black hole in too close, the electric fields will exceed what matter can hold, and there will be an electrostatic discharge, at which point you'll lose traction, and again, leave the black hole behind. In none of these scenarios, do you get a catastrophic explosion in event of the confinement failure. Sure, you're dead in the water with your engine gone, but you're not dead, as would be a case if an equivalent of a nuke goes off in your power core.

Besides, single point of failure is nothing new for us. If an airplane's wing breaks off, everyone aboard will die. You can deal with engine failures and partial control failures, but there are still critical, non-redundant systems. And we choose to live with it, because it makes economical sense. That's not going to change if and when we start running interstellar ships.

[PB666]

1 hour ago, K^2 said:

I don't think you are picturing a fusion reactor of an interstellar generation ship quite right. It needs to generate tremendous amounts of power to get itself moving. Which means it's not going to be a handful of atoms being pumped through the confinement rings. You'll have literal tons of high energy plasma bouncing through the reactor. If confinement fails, it's not just going to shut down. It's going to rip itself apart quite violently, destroying not only the reactor, but anything around. We are talking kiloton ranges explosion.

If anything, black hole drive is significantly safer. The radiation pressure is pushing along the ship, not the black hole. If you tractor the black hole along with electrostatic charge, and the force gets too weak, you simply leave the black hole behind. It will be years before it explodes, by which time you'll drift to a safe distance. If you pull the black hole in too close, the electric fields will exceed what matter can hold, and there will be an electrostatic discharge, at which point you'll lose traction, and again, leave the black hole behind. In none of these scenarios, do you get a catastrophic explosion in event of the confinement failure. Sure, you're dead in the water with your engine gone, but you're not dead, as would be a case if an equivalent of a nuke goes off in your power core.

Besides, single point of failure is nothing new for us. If an airplane's wing breaks off, everyone aboard will die. You can deal with engine failures and partial control failures, but there are still critical, non-redundant systems. And we choose to live with it, because it makes economical sense. That's not going to change if and when we start running interstellar ships.

Nah, my interstellar ship doesn't go that fast, it takes 50,000 years to traverse between the stars, avoiding alot of the troubles of zipping around out at c-fractions. But I do agree with one point, other than solar, most electric power vessels do a poor job of transforming energy, so with an interstellar fusion reactor more than 90% of the net reactor output needs to be channeled or you have an over heating issue, some heat in deep space is good, too much is bad.

As for black hole drive, maybe you pat yourself on the back, until you then discuss how exactly you created that black hole to begin with, see I don't have that problem with fusion reaction, humans have done that and several times. So far as yet we have not created a black hole, nor do we even have an idea of the energetics required to create one. Being dead in the water in a ship with no way of stopping is just as good as being dead, unless you have on board the means of generating another black hole. See, if you can't scribe a way of making one of these things, that means you have to wait until a neutron star degrades to the point inwhich it is of useful size, but if you don't have a drive to begin with how will you reach that star, but with fusion drive you could reach it, just not quickly.

I picture most FEP drives using other forms of energy to get themselves into a hyperbolic trajectory out of our solar system, im thinking maybe 100,000 to 500,000 m/s (again the problem here is to achieve this you need exhaust velocities in the sub-c range and insane ISPs, but with a really large ship this is possible.

[StrandedonEarth]

What is really needed for interstellar travel is some sort of reactionless "space drive" (Rendezvous with Rama), because if reaction mass needs to be carried for both acceleration and deceleration the rocket equation will make the amount of propellant ridiculous, no matter what the Isp is. Anti-gravity (Kzinti gravity planer) would be the best, but I guess that isn't considered "theoretically possible" yet. 

The best bet with near-future technology would be laser-riding solar sail propulsion, with the sail being augmented by some form of nuclear propulsion (fusion pulse or NTR) at least for deceleration at the end of the trip. A nuclear reactor could be used for power generation during the cruise phase, and for thrust as needed, either as a nuclear-thermal rocket or powering fusion-pulse lasers. Launch mass might be conserved by collecting interstellar hydrogen for decelerating, while decelerating.

As for the payload itself, while sending out a scouting probe would be ideal, by the time the results of the probe made it back to Earth the mission may well have been forgotten. That's if there's even someone left on Earth with the ability to "listen" for the message from the probe. Similarly, a manned scouting mission would be pointless. So it may as well be a colony ship. A full generation ship would have to be incredibly massive, so it would be better to have most of the people in deep-sleep. I wouldn't want to rely on machinery to keep everything running and to wake everyone up at the end, so some awake crew would be required. The crew would work in one or more shifts running anywhere from 5 to 20 years, before waking up their replacements and going in the sleep tanks themselves. Ideally, all the crew for all the shifts would be trained on Earth ahead of time, so they would just need to be briefed upon waking before the previous shift goes in the tanks. The "cruise" crews would need the least training with the "arrival" crew needing the most.

[K^2]

2 hours ago, PB666 said:

Nah, my interstellar ship doesn't go that fast, it takes 50,000 years to traverse between the stars, avoiding alot of the troubles of zipping around out at c-fractions.

Do the math on power requirements. Make sure you factor in consumption from the city of 100k+ that's riding on it.

[PB666]

7 hours ago, K^2 said:

Do the math on power requirements. Make sure you factor in consumption from the city of 100k+ that's riding on it.

Sure its bad, but I am assuming that they develop a breeder technology. BTW you make the assumption that the flying Rockpile Explorer X0.1 has a single fusion reactor, actually it would probably need many, and they could be scaled and placed on the surface in such a way that if a serious problem developed they could be jettisoned, you would want them close to the surface anyway so that you could radiate waste heat efficiently.

I have been preaching in this group that for real solar system ventures we need to get an array of 'ride assists' placed in critical places, I would imagine that such a ship would get power assists so that a substantial fraction of its dV came from SEP or other power sources within the inner solar system, once it was beyond the orbit of Jupiter; however it would be FEP.

I take it you decided not to tackle the problem of building a black hole, lol.

lets say it takes 10,000 years, a human generatioin can be protracted to 30 years, that is 333 generations, if we follow the 2N rule thats 666 people, to maintain immune system diversity its around 2000 people. That's effective breeding population, which is about 1/3rd of a normal population that breeds at 30 so we can look at 6000 individuals total should be a satisfactory population size. I figure you would need 10 kw/person so that is going to be around 60 MW, not alot of power. Each person in such a rock pile will need 100 tonnes (being generous) so thats 6 billion kgs.

if we say 2/3rds of the dV came from FEP getting accelerated than thats 70000 dV since we are traveling for 10,000 years we dont really concern ourselves too much with the acceleration rate on Sol escape velocity has been achieved so an acceleration of 0.00001 a is fine. OK so lets see 70000/0.00001 = 7,000,000,000 sec = 8101 days = 22 years; actually I could go with 0.00001 a. OK so now we have a. ISP units are in V, so lets say we specific impulse is 10,000,000 m/s that means N = m * 10,000,000. F = m_ship * a = 6E9 x 0.00001 = 60000 N. looking pretty good. 

m = 60000/10,000,000 = 0.006 kg/s * 7,000,000,000 = 42,000 tonnes of fuel which is not alot considering that we have a ship weight of 6,000,000.

OK so next power, as the other posts have described, power is the real problem. Power for Force = 2 * k * E/sec /ISP  = 2 * 0.8 * w / ISP =  w * 0.00000016.  w = 6250000 =  6.25 MW, we easily could increase the specific impulse by 10 fold and increase acceleration and velocity shortening trip time, but alas we have to factor our reactor fuel into the equation.

Not a problem. So lets say our 100 tonnes per person = 100000 are spread at a density of 0.1 that means we have a 1000000 liters per person. That is 6,000,000,000 liters. if we assume 4/3 pi r 3 then that means we  have a radius of 1.157 km, which means we have a surface area 4 * pi * r2 = 14 Km^2 with which to radiate waste heat (or to insulate).

The reason I prefer this over a fast ship is very simple, no matter were you go you will have to terraform, which in an of itself is risky given you can create snowball planets if you get it wrong. You are going to have to bring animals, plants, everything to rebuild ecosystems in some form (probably as frozen cells in a near absolute zero freezer). So having a ship capable of lasting millenia is the way to go. Terraforming to the O2 will take time, the only zero ready state organisms are going to be a couple of species of cyanobacterium. Land plants for instance require O2 to keep their roots alive, so basically you need a place to hang out to get O2 to a level where the basic land plants will survive.

[ouion]

My Ideal Interstellar Travel Methods:

Generation Ship: A method which a spacecraft has a internal earth like environment and a crew consist of 10,000+(depends on the size of the ship) that stays on the ship for a extended amount of time until the ship reaches its destination. Generations will be born on the ship to sustain the population.This ship type also carries cargo to start a colony on the designated planet. The most plausible concept and the most achievable with our currant technology . Propulsion type is varied for example Nuclear Pulse Rocket, Deuterium fusion engine, and a solar sail.

 

Bussard Ramjet: A spacecraft that harvests hydrogen during its trip and uses nuclear fusion to produce kinetic motion to propel the ship. This concept almost have infinite fuel. 

Anti-Matter Rocket:  The production of full anti-matter atoms are expensive and are only produce in particle colliders. The only real method is to produce anti-protons(Protons with a negative charge) and to have normal protons to produce the energy needed to propel the spacecraft. This will only go 10%-20% the speed of light

       Anti-matter initialed nuclear fusion: The use of anti-matter to initialized fusion. Anti-matter neutralizes normal matter and this turns into energy. If there is a device that converts the energy to thermal energy and pressure. Then nuclear fusion can start.   

[PB666]

1 hour ago, ouion said:

My Ideal Interstellar Travel Methods:

Generation Ship: A method which a spacecraft has a internal earth like environment and a crew consist of 10,000+(depends on the size of the ship) that stays on the ship for a extended amount of time until the ship reaches its destination. Generations will be born on the ship to sustain the population.This ship type also carries cargo to start a colony on the designated planet. The most plausible concept and the most achievable with our currant technology . Propulsion type is varied for example Nuclear Pulse Rocket, Deuterium fusion engine, and a solar sail.

 

Bussard Ramjet: A spacecraft that harvests hydrogen during its trip and uses nuclear fusion to produce kinetic motion to propel the ship. This concept almost have infinite fuel. 

Anti-Matter Rocket:  The production of full anti-matter atoms are expensive and are only produce in particle colliders. The only real method is to produce anti-protons(Protons with a negative charge) and to have normal protons to produce the energy needed to propel the spacecraft. This will only go 10%-20% the speed of light

       Anti-matter initialed nuclear fusion: The use of anti-matter to initialized fusion. Anti-matter neutralizes normal matter and this turns into energy. If there is a device that converts the energy to thermal energy and pressure. Then nuclear fusion can start.   

Both the Bussard Ramjet and the Antimatter initiated fusion explosion rocket are unproven technologies. You already have to be going fast to collect enough protons at the density of space, and your ejection velocities have to be close to the speed of light if your ship is going even 0.01c. Most of the energy goes out with the ejected, big problem.

 

[SargeRho]

44 minutes ago, PB666 said:

Both the Bussard Ramjet and the Antimatter initiated fusion explosion rocket are unproven technologies. You already have to be going fast to collect enough protons at the density of space, and your ejection velocities have to be close to the speed of light if your ship is going even 0.01c. Most of the energy goes out with the ejected, big problem.

 

You could carry the fuel needed for the initial acceleration along.

[StrandedonEarth]

I believe it was proven somewhere that the drag of a Bussard ramscoop would exceed the thrust, but it should still be good for braking at the end of the trip

Edited February 14, 2016 by StrandedonEarth
typo

[SargeRho]

51 minutes ago, StrandedonEarth said:

I believe it was proven somewhere that the drag of a Bussard ramscop would exceed the thrust, but it should still be good for braking at the end of the trip

I read somewhere that the thrust and drag balance eachother out at around .2c, I think it was on Atomic Rockets, I'm not sure. But the idea of the magnetic sail comes from there.

[AngelLestat]

19 hours ago, K^2 said:

If anything, black hole drive is significantly safer. The radiation pressure is pushing along the ship, not the black hole. 

How you focus the black hole radiation to achieve the thrust?  Those things are not impossible but they need higher tech advance than an antimatter drive.
The radiation emitted by a black hole is harder to block and redirect compared to the radiation from some kind of antimatter annihilation.
Feed these stand-up guys with matter is also very tricky and make one in the first place also hard.

17 hours ago, PB666 said:

Nah, my interstellar ship doesn't go that fast, it takes 50,000 years to traverse between the stars, avoiding alot of the troubles of zipping around out at c-fractions.

What is the point of that?
Even if you take into account that our tech increase linearly (instead exponential as it does), let's imagine you make this ship, now in the time it takes to build it, you will be find a much better way of propulsion that can reduce your trip time by a lot, by the time this ship start its travel, just 100 years or 1000 years later, you can have a big part of the human population already living in your planet destination.
Maybe even teleporting between places, but this ship still has 49000 years of trip to go.

Edited February 14, 2016 by AngelLestat

[PB666]

2 hours ago, AngelLestat said:

How you focus the black hole radiation to achieve the thrust?  Those things are not impossible but they need higher tech advance than an antimatter drive.
The radiation emitted by a black hole is harder to block and redirect compared to the radiation from some kind of antimatter annihilation.
Feed these stand-up guys with matter is also very tricky and make one in the first place also hard.

What is the point of that?
Even if you take into account that our tech increase linearly (instead exponential as it does), let's imagine you make this ship, now in the time it takes to build it, you will be find a much better way of propulsion that can reduce your trip time by a lot, by the time this ship start its travel, just 100 years or 1000 years later, you can have a big part of the human population already living in your planet destination.
Maybe even teleporting between places, but this ship still has 49000 years of trip to go.

That is an assumption that has not been panning out, and even if you did find a faster way the folks on the ship basically have all the resources on earth, though I doubt they would build a black hole.

I don't start my plans with technology that does not exist, that is for all of you guys.

My base assumption  is this, there are all kinds of power sources, however there are a limited number that can ever be used around delicate equipment and biologicals.

As for tech increasing linearly movement technologies

1930 limited to a few hundred m/s

1940 limited to about 2000 m/s

1958 7000 m/s

1974 17000 m/s Voyager 1 and 2

2000 15000 New Horizon

Thats about it. Where is the linear increase in speed, where is the astronomical increase in speed, fail.

[AngelLestat]

So is an assumption to think that technology advance??  
According to your numbers we should be going back in technology..  that is how logic works? 

If you think that forget about the technological evolution is an intelligent thing to do when you are planning a 50 years project or even a 50000 years project..   wake up.. is not.  Is the worst choice that someone can make.
An educated guess would be said: "we dont have the technology yet, so we need to wait or these might be possible future solutions".

About me, if I need to find solutions, I always use near future technologies.

On interstellar travel my opinion always was:  manned missions we are far away, but we can send solar sail probes at 5 or 7% the speed of light using just the solar light as propulsión on a close approach (less than 0.05 AU) . These probes would be super cheap and you can sent many.

This book said that if your mission travel time overseed the 50 years then it should not be started at all due tech evolution.

[PB666]

Just now, AngelLestat said:

So is an assumption to think that technology advance??  
According to your numbers we should be going back in technology..  that is how logic works? 

If you think that forget about the technological evolution is an intelligent thing to do when you are planning a 50 years project or even a 50000 years project..   wake up.. is not.  Is the worst choice that someone can make.
An educated guess would be said: "we dont have the technology yet, so we need to wait or these might be possible future solutions".

About me, if I need to find solutions, I always use near future technologies.

On interstellar travel my opinion always was:  manned missions we are far away, but we can send solar sail probes at 5 or 7% the speed of light using just the solar light as propulsión on a close approach (less than 0.05 AU) . These probes would be super cheap and you can sent many.

This book said that if your mission travel time overseed the 50 years then it should not be started at all due tech evolution.

Have you read NASAs web site on where technologies stand, the best NASA has right now is HiPep (9000 ISP), which is fine if you are going to do a mercury flyby on your way out of the solar system, see my thread about the most dV you are going to get is 40000 some of which you will need to use to make that Mercury flyby, needless to say NASA is not using HiPep. The VASiMR produces 17000 ISP, but because of its weight and form factor there is no-where near a powersupply that can push it, even taking a god-awful load of solar panels and flying by mercury.

[AngelLestat]

You read what I said?  Or you read the book in the (travel time) section?
NASA is not planning a manned mission to other stars!  that is the big difference.  But if they will start to think about those..  you will find NASA scientist talking about ships that can make the trip in less than 50 years or at least 100 years, that is what you call a generation ship.

If you have problems with future technologies.. then tell me how you plan to make a ship to survive over 50000 years with a finite number of spares for damage props on use or by being hitted by interstellar rocks?

We need to constantly fix the ISS sending spares, take a look to the external foil layers..
Now multiply that by 50000 years.
It will be easier to find the solution for warp drive in 10 years than find the solution of how to make a ship survive 50000 years.

Edited February 15, 2016 by AngelLestat

[Nothalogh]

Generation ships, big honkin generation ships

[Bill Phil]

Go slow, go fast, or go tricky. Tricky has already been eliminated...

[K^2]

4 hours ago, AngelLestat said:

How you focus the black hole radiation to achieve the thrust?  Those things are not impossible but they need higher tech advance than an antimatter drive.

You don't. You put a damper on your ship that covers 2π of the solid angle, and get 1/4 of max impulse that way. I'm perfectly happy with 25% thrust efficiency on an engine that has 100% mass-to-energy efficiency.

You'll need massive radiators to cool that damper, of course, but you can put some steam generators in between and generate all the power you could possibly need on a ship this side, including powering ship's magnetosphere for rad protection.

11 hours ago, PB666 said:

Sure its bad, but I am assuming that they develop a breeder technology. BTW you make the assumption that the flying Rockpile Explorer X0.1 has a single fusion reactor, actually it would probably need many, and they could be scaled and placed on the surface in such a way that if a serious problem developed they could be jettisoned, you would want them close to the surface anyway so that you could radiate waste heat efficiently.

Sensible. However, you were talking about containment failure. In this scenario, you still get an explosion before you can jettison the reactor. Yes, a smaller one, perhaps in just a few hundred ton range now, but it's going to be enough to breach containment on the next reactor, and a chain reaction is a go. You still have a single point of failure, except now you've reproduced it in every reactor.

Accidents will happen with this kind of ships. All we can do is make them infrequent.

11 hours ago, PB666 said:

I take it you decided not to tackle the problem of building a black hole, lol.

Not even touching that one. My thesis is, "Maybe some day we'll figure out how to make a black hole. Then we can start building reasonably reliable, reasonably fast interstellar ships."

Yes, we can build generation ships either way, and we'll probably build them eventually. They just won't let us build an interstellar civilization. It will be many disjoint civilizations of common origin that might share knowledge with each other. To really call it going to the stars, we need ability for people to reach other worlds within their life times. And short of FTL, that requires torch ships. And there are only two things that can power an interstellar torch ship. Antimatter or black hole. Because these are the only two things known to human kind that allow for sufficiently efficient matter-to-energy conversion.

[lugge]

Each time i read "generation ship" it sounds like pure sci-fi.
 It sounds more sci-fi than talking about FTL-drives, black-hole-drives, beaming and all that stuff. Hell, even a death star sounds more reasonable.

I don't know if FTL is possible, with our current understanding of physics IT IS NOT. But if it's possible, somehow, mankind will master the required technology, because that's something we're good ad.

Generation ships require an unknown amount of cooperation between human individuals. An unknown amount of discipline. A management structure lasting for, say, 20000 years, thats more than huma history. For 20000  you need tens of thousands of human individuals working together for a single goal. No rebelions. I don't see this happening. Never, not in a distant future.

Only way I can imagine this happening are technological augmented humans, linked together into some kind of hive mind (hello Borgs). But that wouldn't be mankind as we know it.

No, FTL is much less sci-fi than generation ships.

[K^2]

7 minutes ago, lugge said:

I don't know if FTL is possible, with our current understanding of physics IT IS NOT.

That's not quite correct. Our current understanding of physics suggests that FTL may very well be possible, but way beyond what we could imagine ever building.

To be even more precise, speed of light has existed as an absolute, impossible to exceed limit in our understanding of physics for about a decade. Between publications of Special Relativity and General Relativity. And for the past 100 years, our understanding of it went from, "There might be ways to achieve this," to "Here are some plausible conditions under which it should be possible." Which doesn't sound like all that much progress for a century of thought, but it is progress. So I wouldn't bury the hope that we'll have it one day. Still, I suspect we'll end up making attempts at interstellar probes, at very least, long before we'll have any practical laboratory experiments on FTL travel. Barring some completely unforeseen breakthroughs in theoretical physics, of course.

[fredinno]

On 2/13/2016 at 10:44 AM, AngelLestat said:

the problem with subatomic black holes is how do you feed them...   Or how you made them in the first place.
Not sure what of those 2 is harder.
For the feed to be practical we should use matter, to not waste more energy that the one you will get back.

Then to make the black hole; you need to concentrate a ""huge"" power of gamma rays in a same instant over a super tiny point.

The last problem but maybe no so big as the first two..  is how you focus that power to get thrust.
Is harder to focus those emissions than a antimatter annihilation.

 

The black holes are actually NOT subatomic.

On 2/13/2016 at 10:44 AM, SurrealShock said:

My idea would be to use an autonomously controlled vehicle to transport astronauts/citizens away from Earth. We would use fission/fusion to travel in deep space and hope to find another planet. Rather than waste mass on life support we would instead put the astronauts into a suspended animation phase where they are still alive, but in a deep sleep as shown in movies like "Interstellar." The rocket would conserve energy wherever possible. I.E. heat from the decaying metals would be used to heat the ship. To use the technology stated that has been stated above, " I would imagine that at that point we might have many giant solar arrays orbiting the sun and beaming power back to Earth." This could be used to power the ship before these lasers become useless because of the distance they are from Earth. CubeSats would be sent to nearby planets via ion thrusters because they can easily be recharged. The CubeSats could analyze the planet and tell us if it could support human life. BUT THAT'S JUST A INTERSTELLAR VEHICLE SYSTEM NO FTL THEORY. (Game theory reference.)

Cubesats are WAY too small, and you can't really get more Xenon for Ion drives anywhere.

[fredinno]

On 2/14/2016 at 7:13 PM, PB666 said:

Nah, my interstellar ship doesn't go that fast, it takes 50,000 years to traverse between the stars, avoiding alot of the troubles of zipping around out at c-fractions. But I do agree with one point, other than solar, most electric power vessels do a poor job of transforming energy, so with an interstellar fusion reactor more than 90% of the net reactor output needs to be channeled or you have an over heating issue, some heat in deep space is good, too much is bad.

As for black hole drive, maybe you pat yourself on the back, until you then discuss how exactly you created that black hole to begin with, see I don't have that problem with fusion reaction, humans have done that and several times. So far as yet we have not created a black hole, nor do we even have an idea of the energetics required to create one. Being dead in the water in a ship with no way of stopping is just as good as being dead, unless you have on board the means of generating another black hole. See, if you can't scribe a way of making one of these things, that means you have to wait until a neutron star degrades to the point inwhich it is of useful size, but if you don't have a drive to begin with how will you reach that star, but with fusion drive you could reach it, just not quickly.

I picture most FEP drives using other forms of energy to get themselves into a hyperbolic trajectory out of our solar system, im thinking maybe 100,000 to 500,000 m/s (again the problem here is to achieve this you need exhaust velocities in the sub-c range and insane ISPs, but with a really large ship this is possible.

http://www.scientificamerican.com/article/scientists-close-in-on-creating-black-hole-in-lab/

You can create black holes in giant particle accelerators- something which got conspiracy theorists riled up when they figured that out, saying it would destroy the entire world (in reality, it would just implode very quickly unless it quickly accreted more mass.)

On 2/14/2016 at 8:23 PM, StrandedonEarth said:

What is really needed for interstellar travel is some sort of reactionless "space drive" (Rendezvous with Rama), because if reaction mass needs to be carried for both acceleration and deceleration the rocket equation will make the amount of propellant ridiculous, no matter what the Isp is. Anti-gravity (Kzinti gravity planer) would be the best, but I guess that isn't considered "theoretically possible" yet. 

The best bet with near-future technology would be laser-riding solar sail propulsion, with the sail being augmented by some form of nuclear propulsion (fusion pulse or NTR) at least for deceleration at the end of the trip. A nuclear reactor could be used for power generation during the cruise phase, and for thrust as needed, either as a nuclear-thermal rocket or powering fusion-pulse lasers. Launch mass might be conserved by collecting interstellar hydrogen for decelerating, while decelerating.

As for the payload itself, while sending out a scouting probe would be ideal, by the time the results of the probe made it back to Earth the mission may well have been forgotten. That's if there's even someone left on Earth with the ability to "listen" for the message from the probe. Similarly, a manned scouting mission would be pointless. So it may as well be a colony ship. A full generation ship would have to be incredibly massive, so it would be better to have most of the people in deep-sleep. I wouldn't want to rely on machinery to keep everything running and to wake everyone up at the end, so some awake crew would be required. The crew would work in one or more shifts running anywhere from 5 to 20 years, before waking up their replacements and going in the sleep tanks themselves. Ideally, all the crew for all the shifts would be trained on Earth ahead of time, so they would just need to be briefed upon waking before the previous shift goes in the tanks. The "cruise" crews would need the least training with the "arrival" crew needing the most.

Reactionless drives are impossible under the current laws of physics.

16 hours ago, ouion said:

My Ideal Interstellar Travel Methods:

Generation Ship: A method which a spacecraft has a internal earth like environment and a crew consist of 10,000+(depends on the size of the ship) that stays on the ship for a extended amount of time until the ship reaches its destination. Generations will be born on the ship to sustain the population.This ship type also carries cargo to start a colony on the designated planet. The most plausible concept and the most achievable with our currant technology . Propulsion type is varied for example Nuclear Pulse Rocket, Deuterium fusion engine, and a solar sail.

 

Bussard Ramjet: A spacecraft that harvests hydrogen during its trip and uses nuclear fusion to produce kinetic motion to propel the ship. This concept almost have infinite fuel. 

Anti-Matter Rocket:  The production of full anti-matter atoms are expensive and are only produce in particle colliders. The only real method is to produce anti-protons(Protons with a negative charge) and to have normal protons to produce the energy needed to propel the spacecraft. This will only go 10%-20% the speed of light

       Anti-matter initialed nuclear fusion: The use of anti-matter to initialized fusion. Anti-matter neutralizes normal matter and this turns into energy. If there is a device that converts the energy to thermal energy and pressure. Then nuclear fusion can start.   

What- you can't use positrons in anti-matter reactors?

9 hours ago, PB666 said:

That is an assumption that has not been panning out, and even if you did find a faster way the folks on the ship basically have all the resources on earth, though I doubt they would build a black hole.

I don't start my plans with technology that does not exist, that is for all of you guys.

My base assumption  is this, there are all kinds of power sources, however there are a limited number that can ever be used around delicate equipment and biologicals.

As for tech increasing linearly movement technologies

1930 limited to a few hundred m/s

1940 limited to about 2000 m/s

1958 7000 m/s

1974 17000 m/s Voyager 1 and 2

2000 15000 New Horizon

Thats about it. Where is the linear increase in speed, where is the astronomical increase in speed, fail.

Voyagers and New Horisons are cheaters for using gravity assists to go faster.

8 hours ago, PB666 said:

Have you read NASAs web site on where technologies stand, the best NASA has right now is HiPep (9000 ISP), which is fine if you are going to do a mercury flyby on your way out of the solar system, see my thread about the most dV you are going to get is 40000 some of which you will need to use to make that Mercury flyby, needless to say NASA is not using HiPep. The VASiMR produces 17000 ISP, but because of its weight and form factor there is no-where near a powersupply that can push it, even taking a god-awful load of solar panels and flying by mercury.

ESA has something better- DS4G, with 30,000s ISP,

[SR]

41 minutes ago, fredinno said:

The black holes are actually NOT subatomic.

Cubesats are WAY too small, and you can't really get more Xenon for Ion drives anywhere

You do get mini black holes about the size of a proton.

And a fleet of cubesats has been suggested for unmanned interstellar flight, then if some get destroyed the mission still succeeds.

Probably wouldn't work for manned flight but the concept of lots of small ships is logical. (big ships are weaker)

I think it will be antimatter engines or m-drive/ other propellantless drive.

Edited February 15, 2016 by SR

[K^2]

1 hour ago, fredinno said:

The black holes are actually NOT subatomic.

A 660,000 ton black hole, which is considered a "sweet spot" for a black hole drive, would have a Schwarzschild Radius of 2.2x10^-19 meters. This is smaller than a single proton. It's not just subatomic. It's sub-nuclear.