Interstellar Space Travel - Most Realistic Options?

[marklarson517]

Hello,

I'm a student at Minnetonka High School and am currently doing a short research project on the various methods of interstellar travel. I would like to get in touch with an expert that I may ask questions and be advised by.

In addition, I have a few starter questions:

How are solar sails (LightSails) supposed to stop after having accelerated to roughly 0.1c? Solar sails, based on our research so far, appear to be the most realistic and feasible, however, the issue of stopping prevents a conclusion being made upon this option.

Secondly, what obstacles do we face in terms of support and funding for interstellar space travel? It seems the government's interest in space travel as a whole has declined, and clearly more research is required for any of these methods to be truly feasible. Also, are private corporations such as SpaceX interested at all in interstellar space travel? Or are they still focused mainly on shuttling and going to Mars?

Finally, how has the quest to produce/store/use negative energy/mass progressed in recent years? I know this is required for the theoretical warp drive, however, currently the technology does not permit this.

 

[Hawkstein]

How are solar sails (LightSails) supposed to stop after having accelerated to roughly 0.1c? Solar sails, based on our research so far, appear to be the most realistic and feasible, however, the issue of stopping prevents a conclusion being made upon this option.

Very difficult to stop because the solar sail needs to be extremely low mass, any technology or mechanism on-board the craft to aid in stopping would probably give it too much mass. Maybe you could have a mechanism that redirects the light energy in the opposite direction, no sure.

Secondly, what obstacles do we face in terms of support and funding for interstellar space travel? It seems the government's interest in space travel as a whole has declined, and clearly more research is required for any of these methods to be truly feasible. Also, are private corporations such as SpaceX interested at all in interstellar space travel? Or are they still focused mainly on shuttling and going to Mars?

Nobody is really interested in interstellar space travel right now because it's not practical. The fastest any human-made spacecraft has traveled is less than 1/1000 the speed of light. Put that in perspective, it would take more than 4000 years to get to the closest star system.

Finally, how has the quest to produce/store/use negative energy/mass progressed in recent years? I know this is required for the theoretical warp drive, however, currently the technology does not permit this.

There is no such thing as negative mass currently. So it's purely theoretical and not yet feasible.

 

[Mental Avenger]

I'm a student at Minnetonka High School and am currently doing a short research project on the various methods of interstellar travel. I would like to get in touch with an expert that I may ask questions and be advised by.

Practical Interstellar travel for us is a long way in the future. Having said that, unmanned interstellar probes could be launched at any time. The problem is that with current technology, they will never be able to travel very fast. Probes launched 50 years from now might simply pass them before they have gone very far, making them a waste of resources. In the future, barring some many orders of magnitude advancement in technology, the most probable manned interstellar missions will be Generation Ships.

How are solar sails (LightSails) supposed to stop after having accelerated to roughly 0.1c? Solar sails, based on our research so far, appear to be the most realistic and feasible, however, the issue of stopping prevents a conclusion being made upon this option.

Solar Sails will have very little Sunlight for power, but will still accelerate slowly. The light energy from the Sun will decrease as the square of the distance from the Sun. At the destination, the Solar Sail will work in reverse, to slow the spacecraft down at the same, but revered rate. Assuming a destination star of equal light output to our Sun, the spacecraft would slow down enough to use minimal rocket power to achieve orbit about a planet there.

Secondly, what obstacles do we face in terms of support and funding for interstellar space travel? It seems the government's interest in space travel as a whole has declined, and clearly more research is required for any of these methods to be truly feasible. Also, are private corporations such as SpaceX interested at all in interstellar space travel? Or are they still focused mainly on shuttling and going to Mars?

Don’t expect any serious funding for Interstellar travel for perhaps 100+ years. Then it will probably be miserly at best. However, huge advances in technology, or verified intelligent transmissions from a nearby Star, could change that dramatically.

Finally, how has the quest to produce/store/use negative energy/mass progressed in recent years? I know this is required for the theoretical warp drive, however, currently the technology does not permit this.

There is no theoretical “warp drive”. That is 100% science fiction. It is a device used to make the characters in SciFi stories able to move great distances in a fraction of their lifetimes. There is no reason to believe that anything remotely resembling warp drive will ever be a reality. I suggest not including that in your report as it would tend to discredit the validity of your research.

 

[voidpotentialenergy]

I think we are a quantum leap from interstellar travel.
Sending probes might be a different proposition but the distances are vast even to the nearest star.

 

[Hawkstein]

For interstellar travel the most realistic option is to go there the same way as SentientKind from another planet would reach here and that would be by a SpaceShip kilometres long full of fuel, food, air and water. The crew would have to be in a deep sleep which is telepathically influenced for muscle movement in order to prevent muscle waste.

If they're not cryogenically frozen their bodies will still age and they'll die.

A second option is unique and this involves wormholes, in order to have access to wormholes the society would have to have made an agreement with Heaven. So Heaven's SpaceShips do fly to Earth regularly, an agreement with Heaven would allow for travel across the Universe to other stars and galaxies via wormholes. It would open the door also for new technology for HumanKind. I am not trying to influence you religiously but I also have to point out that Heaven has helped HumanKind particularly with Space travel.

Sorry but huh

 

[voidpotentialenergy]

Create a void around a ship, then time and space have no meaning and even traveling at 1mph you go infinitely fast.
You might want a tiny bit of fluctuation in that bubble so you have some sort of control

 

[voidpotentialenergy]

In reality the leading technology is what it was in the 60s.
Nuclear propulsion gets you to around 1/4 C, so a trip to alpha system around 20 years.

Hitting a single grain of sand in a 20 year trip at 1/4 C though will be nuclear in itself.

Sending humans we are a quantum leap from it.
IMO someone will have to find a solution to go without either time or distance in time.
My thought is distance is just a property of space so steeping out of it gets rid of time.
Void

 

[rosa u podne]

I'm a student at Minnetonka High School and am currently doing a short research project on the various methods of interstellar travel. I would like to get in touch with an expert that I may ask questions and be advised by.

I am not an expert, but I can offer a couple of links.

How are solar sails (LightSails) supposed to stop after having accelerated to roughly 0.1c? Solar sails, based on our research so far, appear to be the most realistic and feasible, however, the issue of stopping prevents a conclusion being made upon this option.

Looked at the illustration here.

Secondly, what obstacles do we face in terms of support and funding for interstellar space travel? It seems the government's interest in space travel as a whole has declined, and clearly more research is required for any of these methods to be truly feasible. Also, are private corporations such as SpaceX interested at all in interstellar space travel? Or are they still focused mainly on shuttling and going to Mars?

Just to make sure, are you aware of star shot initiative?

Finally, how has the quest to produce/store/use negative energy/mass progressed in recent years? I know this is required for the theoretical warp drive, however, currently the technology does not permit this.

I don't know anything about it.

 

[Ken Fabian]

I think the surest (but slowest) interstellar travel option would involve Leapfrogging, from deep space object to deep space object. I don't think any direct travel is going to work except perhaps very slowly within a deep space object - and I think taking that big a mass with you will be slower than travelling to new ones.

If (still a very big if) self sufficient habitats can be achieved relying only on the resources of deep space objects (asteroid/comet material) and daughter colonies are seeded along the route to a near star then eventually some humans (after however many thousands of generations) reach that star.

It would need a true and complete self-sufficiency of technology and I would expect fusion (without fission triggering or support - unlikely to be nuclear fuels for fission) to be an essential component. Like everything else, fusion technology would have to be manufactured entirely from resources found in asteroids and comets.

 

[Mental Avenger]

I think the surest (but slowest) interstellar travel option would involve Leapfrogging, from deep space object to deep space object. I don't think any direct travel is going to work except perhaps very slowly within a deep space object - and I think taking that big a mass with you will be slower than travelling to new ones.

I think you missed the obvious. What you propose would dramatically increase the time required and the fuel required. ALL of the velocity you gained by accelerating on the way to each “deep space object” would have to be reversed by beginning decelerating halfway to that object. The same would be true for each such “object”. That would increase the time required to reach the final destination by a factor of at least double the number of such objects. IOW, a journey that would take 50 years by the direct route, would take over 500 years if you stopped by 5 such objects.

 

[Ken Fabian]

As an alternative to not being able to get there in one go at all - and I don't think it will be possible without extraordinary technological advances to get there in one go - it would be an improvement in the sense that ultimately people could reach another star that way.

If self sufficient and self perpetuating 'colonies' can survive on a deep space object and grow and spawn new colonies then reaching other stars might be considered an inevitability; even if it may be hard to maintain commitment to the goal - ie they could choose new objects to colonise and exploit in any direction and be happy doing so, an expanding sphere would reach other stars eventually.

Whilst the directional migration idea would ultimately be the most reliable way to spread humanity interstellar an alternative might be sending scouts and foragers ahead of a large ship or fleet and boost supplies up to velocity.

 

[Mental Avenger]

As an alternative to not being able to get there in one go at all - and I don't think it will be possible without extraordinary technological advances to get there in one go.

Any spacecraft attempting to go to a planet outside our Solar System would have to be a Generation Ship. There are literally no “deep space objects” between here and even the nearest start where people could survive better than on the Generation Ship. Even heading for another Solar System would be a huge gamble on finding a planet there where humans could survive.

If self sufficient and self perpetuating 'colonies' can survive on a deep space object and grow and spawn new colonies then reaching other stars might be considered an inevitability;…..

Ok, what kind of “deep space object” would that be?

 

[voidpotentialenergy]

I think the surest (but slowest) interstellar travel option would involve Leapfrogging, from deep space object to deep space object. I don't think any direct travel is going to work except perhaps very slowly within a deep space object - and I think taking that big a mass with you will be slower than travelling to new ones.

If (still a very big if) self sufficient habitats can be achieved relying only on the resources of deep space objects (asteroid/comet material) and daughter colonies are seeded along the route to a near star then eventually some humans (after however many thousands of generations) reach that star.

It would need a true and complete self-sufficiency of technology and I would expect fusion (without fission triggering or support - unlikely to be nuclear fuels for fission) to be an essential component. Like everything else, fusion technology would have to be manufactured entirely from resources found in asteroids and comets.

Take an entire asteroid on the trip
Radiation protection, fuel etc.
Pick one that is mostly water ice.

 

[Ken Fabian]

Any spacecraft attempting to go to a planet outside our Solar System would have to be a Generation Ship. There are literally no “deep space objects” between here and even the nearest start where people could survive better than on the Generation Ship.

Whether it is a generation ship or an asteroid civilisation or a Mars colony, they all have to be of sufficient size for an economy that can support making all the technology survival requires, plus extra to support any additional goals.

You appear to think a relatively small number would be enough (perhaps a few thousand or even as low as hundreds?) but I disagree and think it would need a working population of hundreds of thousands and perhap millions. I would expect every working system and component of an interstellar ship would need to be replaced multiple times over thousands of years. Possibly even the structure itself.

Working civilisations at deep space objects ("What kind would those be?" Those would be asteroid and comet type objects but perhaps up to minor planet sized) could support the kind of remake and resupply that are going to be beyond the capability of what a ship can carry or do.

I think that, in effect, any generation ship has to be it's own fully capable economy or it cannot survive either the journey or the destination - but growing to or sustaining that size will be easier at sources of resources than cut off from them.

Building a generation ship big enough and reliable enough and well stocked enough is far beyond our capabilities but if one were built large enough to carry all that is needed the ship has to be extremely large - and be slow because of all that mass to accelerate. Stopping to restock and refuel and remake is not ideal but nor is loading everything aboard at the start.

I also think that any insterstellar mission that needs a (human) habitable planet is probably doomed; the capability to support human civilisations purely with asteroid/comet type resources looks like a minimum basic capability for supporting interstellar colonies. A planet with native life may prove less capable of human habitation than a lifeless one - for the potential biolological incompatabilities.

Take an entire asteroid on the trip
Radiation protection, fuel etc.
Pick one that is mostly water ice.

So you will have enormously more mass to move than a spaceship so it will be much slower, require much more fuel and bigger engines. And given that overall inefficiency it is still possible multigenerations of occupancy will use up all the essential resources and you will still need a capability for re-supply.

 

[voidpotentialenergy]

Whether it is a generation ship or an asteroid civilisation or a Mars colony, they all have to be of sufficient size for an economy that can support making all the technology survival requires, plus extra to support any additional goals.

You appear to think a relatively small number would be enough (perhaps a few thousand or even as low as hundreds?) but I disagree and think it would need a working population of hundreds of thousands and perhap millions. I would expect every working system and component of an interstellar ship would need to be replaced multiple times over thousands of years. Possibly even the structure itself.

Working civilisations at deep space objects ("What kind would those be?" Those would be asteroid and comet type objects but perhaps up to minor planet sized) could support the kind of remake and resupply that are going to be beyond the capability of what a ship can carry or do.

I think that, in effect, any generation ship has to be it's own fully capable economy or it cannot survive either the journey or the destination - but growing to or sustaining that size will be easier at sources of resources than cut off from them.

Building a generation ship big enough and reliable enough and well stocked enough is far beyond our capabilities but if one were built large enough to carry all that is needed the ship has to be extremely large - and be slow because of all that mass to accelerate. Stopping to restock and refuel and remake is not ideal but nor is loading everything aboard at the start.

I also think that any insterstellar mission that needs a (human) habitable planet is probably doomed; the capability to support human civilisations purely with asteroid/comet type resources looks like a minimum basic capability for supporting interstellar colonies. A planet with native life may prove less capable of human habitation than a lifeless one - for the potential biolological incompatabilities.


So you will have enormously more mass to move than a spaceship so it will be much slower, require much more fuel and bigger engines. And given that overall inefficiency it is still possible multigenerations of occupancy will use up all the essential resources and you will still need a capability for re-supply.

If it's all water ice and we aren't in a rush it will be mostly fuel.
Still long trip time to say the least.
If we can find one asteroid with lots of uranium then that is a fuel of a different speed.
We could always set up a mining ship that mines and refines uranium from a few asteroids and one ship that fuels for the long trip from it.

We have no clue what is between the stars, could have asteroids in it also.
I have my doubts but maybe.

 

[Mental Avenger]

Finding an interstellar asteroid at interstellar velocities, in time to decelerate and stop at it, would be like flying a jet fighter at Mach 2, spotting a mosquito 400 miles away, spinning the plane around and decelerating in time to stop at it, only a LOT more difficult. Without Sunlight to illuminate an interstellar asteroid, you could fly past one 10 miles away and never see it.

As pointed out earlier, even IF you could magically somehow find interstellar objects to stop at, a journey that would take 50 years by the direct route, would probably take over 500 years if you stopped by 5 such objects.

 

[voidpotentialenergy]

Finding an interstellar asteroid at interstellar velocities, in time to decelerate and stop at it, would be like flying a jet fighter at Mach 2, spotting a mosquito 400 miles away, spinning the plane around and decelerating in time to stop at it, only a LOT more difficult. Without Sunlight to illuminate an interstellar asteroid, you could fly past one 10 miles away and never see it.

As pointed out earlier, even IF you could magically somehow find interstellar objects to stop at, a journey that would take 50 years by the direct route, would probably take over 500 years if you stopped by 5 such objects.

You got it.
I think if we are sending a probe it needs whatever it needs before it departs.
We do have the tech right now to send probes but nuclear fuel is the sticking point.
Interstellar space is sure to have dust and probably more and a probe going at 1/10 - 1/4 C a single sand grain in a long trip is a serious problem.

 

[YetAnotherBob]

Take an entire asteroid on the trip
Radiation protection, fuel etc.
Pick one that is mostly water ice.

Those are called Comets.