NationStates Jolt Archive

Looks like we're grounded.

I've read a few serious articles on the subject of interstellar traval. Would be be able to send a probe, a robot, a rocket, or even people, to a star nearby (let's say within 10 light years).

Most people don't have a clue on how far the nearest star is. And on the incredible amount of energy necessary to accelerate, travel the distance, decelerate, and get there within a reasonable delay (let's say, 50 years or less).

OK. First, the distances. Distances in space are huge, beyond imagination.

Currently, if we wish to send a very fast probe to Pluto (the farthest planet in our system), at 20 km/second, it would take 7 years (mean distance to Pluto is about 40 AU).

The fasted human-built object is the Ulysse probe, which travels an elliptical polar orbit around the Sun, and reaches speeds of 36 km/sec. But it's not a sustained speed. So let's say we manage to have a multi-stage probe that keeps accelerating till it reaches 30 km/s, then gets faster by gravity swingby, upto a dazzling speed of 40 km/s.

How long would it take to reach the nearest star, Proxima Centauri (which is probably a boring, empty place anyway) ? 7531 YEARS HOLY CRAP it's so fuckin distant, man. And I haven't included any braking sequence in that.

Of course, it takes so long because the probe (or vehicle) doesn't accelerate all the way through. Or halfway through (which would make sense, if you want to decelerate). The problem is, with chemical propulsion, you would need a tank the size of Manhattan to get to a decent speed (1% of Light Speed, say). We clearly can't do that in the foreseeable future.

Another recent option is ion propulsion, which accelerates very slowly but requires a small amount of fuel. But some people have theorized that we couldn't reach more than 50 km/second with such a system.

Controlled nuclear explosions? The Orion and Dedale projects were rocket science porn in the 1950s-1970s. They looked sooooo cool. But we still don't have a clue on how we could possibly blow up "nuclear pellets" right under a probe's ass without grilling it. And besides, we're talking about a probe the size of a supertanker.

Solar sails are effective for a while (until the heliopause) but then they stop accelerating. And they're fragile. And they can't carry a large payload.

Solar wind surfing? Excellent idea... for local travel.

Sending an emptied asteroid with a human colony inside? Yeah right, like we have what it takes to change its orbit and swing it outside. And even if we do so, such a closed world would deplete its resources too fast, even with near-perfect recycling systems.

Other options? Hmmm... I don't know any.

So do you think we might someday reach the stars? Or are we, until further notice, grounded?

Well, I don't think we have even begun to scratch the surface of nuclear fusion and its capacity for energy, so there is plenty of hopw. Computing systems advance more and more rapidly, and can do more independently than earlier generations of computers. Engineering will eventually allow us to sustain high speeds and control the energy produced. It's a matter of time, really.

Remember, things like the lightbulb or automobile would have seemed impossible to people no less than 150 years ago, who lacked the capacity we have to test and investigate higher level technology, and yet they produced them. Technology 150 years from no will be so advanced we will look primitive in comparison. Just have to wait for a short while (in human species terms)

I think we're grounded for now. In the distant future we might be able to.

Granted, as Vetalia said, in the future there might be some cool, unforeseen advance that will put the stars within easy reach. But I think it will take a while. Even with a fusion rocket, it's a long ride.

Out of the options proposed for interstellar travel, either a really cool fusion rocket or a giant laser sail are probably the best options, although either of those would require a massive engineering investment. I think it would be just as difficult to find an economic incentive for interstellar travel as it would be to develop the technology.

Considering that space aliens have put in the time, energy and resources to conquer these major obstacles just to probe human rectums, shouldn't we be doing more rectal research? We may be ignoring an important resource. A resource so valuable that it justifies a multi-million year journey.

The answer is, quite ironically, the same thing that allowed man to explore the oceans - the sail. In space travel terms, the solar sail. The solar sail allows a ship to gain speed from solar radiation, without having massive storage tanks of fuel. Plus the speed builds on itself allowing faster travel than boosters. Short of an Ion Drive, or some wierd Warp drive or something, the solar sail is the future of space exploration - cheap, effective, and within our level of technology.

For interstellar travel, a laser could be theoretically used to move the ship along in areas where solar radiation is weak. Powered by a small nuclear reactor, or in the future a fusion reactor, the laser would provide the radiation needed for the sail craft to continue moving, and even accelerating.

They were actually going to test a solar sail craft, but they put it in an old russian missle, and guess what, the missle fucked up. They lost the damn craft to a malfunctioning russian ICBM. :headbang:

At least we might be able to explore our vicinity till the heliopause, thanks to the Gallagher Bubble:
http://science.nasa.gov/headlines/y2000/ast04oct_1.htm

That's a pretty cool idea.

""A 15 km-wide miniature magnetosphere one astronomical unit from the Sun would feel 1 to 3 Newtons of force from the solar wind," says Gallagher, "That's enough to accelerate a 200 kg spacecraft from a dead stop to 80 km/s (180,000 mph) in only 3 months."

But once you reach the heliopause, you stop accelerating.
Still, 80 km/s is far better than any other known technology. Yet.

Controlled nuclear explosions? The Orion and Dedale projects were rocket science porn in the 1950s-1970s. They looked sooooo cool. But we still don't have a clue on how we could possibly blow up "nuclear pellets" right under a probe's ass without grilling it. And besides, we're talking about a probe the size of a supertanker.


They did test working models with conventional explosives. And they did underground nuclear detonations to demonstrate driver plate design.

From a technical perspective, they solved all of the real engineering problems. The explosions would only be about 2 kt each. There is a recent book on Project Orion and its technical status by the son of the man who designed the original.

It was within technological feasibility to build a large ship (comparable in size to a modern naval destroyer) that would travel to Saturn and back in a few months.

It is still feasible. The major drawbacks are:

1. The detonation of a nuclear device (albeit small) every half-second in the atmosphere during takeoff and landing.

2. The presence in near Earth orbit of a large "warship" loaded with thousands of nuclear weapons.

It is still feasible. The major drawbacks are:

1. The detonation of a nuclear device (albeit small) every half-second in the atmosphere during takeoff and landing.

2. The presence in near Earth orbit of a large "warship" loaded with thousands of nuclear weapons.
Then, maybe we should send it as "Ikea packages" in space, and have it assembled in low orbit over a couple of months/years. I guess we'll soon have the technology for in-orbit assembly of ships.

http://www.grc.nasa.gov/WWW/bpp/

A good day's worth of reading. It is, however, very worth the time spent.

1. The detonation of a nuclear device (albeit small) every half-second in the atmosphere during takeoff and landing.

2. The presence in near Earth orbit of a large "warship" loaded with thousands of nuclear weapons.
Yes, these two were the major reasons why nuclear rockets weren't developed further. But the concept was tested and works rather well.

It's possible to imagine nuclear ships being assembled in orbit around Jupiter or Saturn in the distant future. It wouldn't be so troublesome over there.

It is still feasible. The major drawbacks are:

1. The detonation of a nuclear device (albeit small) every half-second in the atmosphere during takeoff and landing.Very true. To solve that, though, it would have to be built/pieced together in orbit...which is still very feasible.2. The presence in near Earth orbit of a large "warship" loaded with thousands of nuclear weapons.Therein lies the biggest problem. Just imagine the rabid anti-nuke nut/anti-American backlash if the US were to actually build the ship and put it in orbit with thousands of what ammount to tactical nuclear weapons on board.

It's pretty sad that politics are probably the biggest factor in keeping space exploration relatively stagnant.

If I remember well, the Icarus project (designed in the UK), similar to Orion, would have made it to one of the nearest stars (Barnard I think) in 70 years. And the probe wouldn't be able to brake.
So basically it would only be able to perform minimal science and take distorted measurements before flying past.

http://www.grc.nasa.gov/WWW/bpp/

A good day's worth of reading. It is, however, very worth the time spent.
This is even more depressing. It didn't yield any result. It just measured how far we are from any solution.

http://www.calphysics.org/articles/zpf_millis.pdf

That should make you a bit happier. But Drunk Commies thinks that you'll be wasting your money.

I hate to get all sci-fi-ish on you guys, but theres two main possibilities that could get a person there in less than ten years.

A. Lighstspeed, I know, its impossible. So was breaking the sound barrier, sailing around the world, and going to the Moon. Lots of impossible things happen that fly in the face of modern science when people had proved they were impossible. It may be possible, it may not. Thats what option B is for.

B. Some kind of hyper-driveish thing. Since/if lightspeed travel is not possible, go around this by getting into another universe where it is, or use a kind of wormhole that you somehow created/stabilized.

Basicaly, everything else here is fine, but if we plan on going to the other side of the Galaxy, its gonna take a bit of time. Of course, heading over to Proxima Centuri would take time regardless of what travel method you used, not for the person traveling at <lightspeed, but I suppose that if your colonising a new galaxy everybody you know being dead doesnt really matter.

As a random interesting question, what would happen if you sent a message, traveling at lightspeed, through (the theoretical) hyperspace? Does it travel at about twice lightspeed, or remain the same?
On a secondary note, I wonder what the average lifespan in Star Wars is, since they spend rather alot of time traveling at faster than light speeds. It must be confusing, keeping track of how old you are, especialy for the long haul shippers.

At least we might be able to explore our vicinity till the heliopause, thanks to the Gallagher Bubble:
http://science.nasa.gov/headlines/y2000/ast04oct_1.htm

That's a pretty cool idea.

""A 15 km-wide miniature magnetosphere one astronomical unit from the Sun would feel 1 to 3 Newtons of force from the solar wind," says Gallagher, "That's enough to accelerate a 200 kg spacecraft from a dead stop to 80 km/s (180,000 mph) in only 3 months."

But once you reach the heliopause, you stop accelerating.
Still, 80 km/s is far better than any other known technology. Yet.

Yes, you will stop accelerating, but by that time you'll be going much faster than 80 km/s. and you don't slow down in space.

it's ok, we'll have enough fun in this solar system for centuries. assuming we survive long enough to get even that far, of course.

Yes, you will stop accelerating, but by that time you'll be going much faster than 80 km/s. and you don't slow down in space.
You do, just not very fast.
Space is pretty damn empty, but not totaly. You would gradualy slow down because of impacts/friction with dust, rocks, whatever, it would just take a long time to notice it.

You do, just not very fast.
Space is pretty damn empty, but not totaly. You would gradualy slow down because of impacts/friction with dust, rocks, whatever, it would just take a long time to notice it.
True, you'll also start to slow down faster if you slam into the side of a planet, and it's hard to steer if you cant accelerate.

Yes, you will stop accelerating, but by that time you'll be going much faster than 80 km/s. and you don't slow down in space.
Yes, absolutely. But still, 80 km/s isn't the ultimate speed.
You'd want to reach 1% of the speed of light.
3000 km/sec -- now THAT would be awesome!!!

even at 3000 km/s it would still take 1000 years to go 10 light years

What about those antimatter drives I keep hearing about?

They're much like the nuclear thingies but instead of detonating a nuclear device the throw a bit of antimatter against a bit of normal matter.

There's another design in which a bit of antimatter is used to heat some propellant, like water or ammonia, to shoot the thing off.

Any advances in the small detail of antimatter creation and containment?

Well, rather than get in a funk over not being able to get to Prox within a single human's lifetime, think about it from different angles:

Generational ships - okay, so we don't have FTL drives, or controlled wormholes, or any of the other Deux Ex Machinae of Science-Fiction. We could still get there, it'd just take an incredibly long time. But we'd still get there, eventually.

Cryogenics - Alright, we're still probably talking about multi-generational ships, here, but with the use of cryogenics, it could be possible to reduce the number of generations involved in an interstellar journey. Though still mostly a sci-fi concept, very real advances are being made in this area. Perhaps with further development, we might have viable applications for this nascent technology, especially where interplanetary or eventually interstellar travel is concerned.

Or for a really different approach, maybe we should think of ways to get from point A to point B without actually 'travelling' at all. If we could alter our group consciousness to the extent that we could really perceive Space and Time as one singular event, I submit we could transcend both, and 'be' antyime and anyplace within the singular event of SpaceTime. No need to worry about rocketships, in that case.

Feel free to grind me up and spit me out. That's what laymen are there for. Consider it an exercise in dealing with the unwashed masses.

The problem with Generation Ships is that you have to find lots of people who are willing to commit to spending eighty years in a tube so that their great-great-great-great-great grandchildren can see another planet.
Not easy to do.

Or for a really different approach, maybe we should think of ways to get from point A to point B without actually 'travelling' at all. If we could alter our group consciousness to the extent that we could really perceive Space and Time as one singular event, I submit we could transcend both, and 'be' antyime and anyplace within the singular event of SpaceTime. No need to worry about rocketships, in that case.

Wasn't LSD invented for that purpose?

Anyway, it's possible that, if conciousness can be uploaded to a computer or similar device, we can control how we perceive time. It would still take time to come and go, but it wouldn't matter so much.

The problem with Generation Ships is that you have to find lots of people who are willing to commit to spending eighty years in a tube so that their great-great-great-great-great grandchildren can see another planet.
Not easy to do.
I don't know. Sounds kind of exciting. Especially if they guarantee me a girlfriend or two :D

Any advances in the small detail of antimatter creation and containment?
Sadly.... no.
I've read an article recently. The guy says that we're not able to create more than a few millionth of a gram at a time. And we can't contain them properly.

The energy required to create large amounts would be bigger than anything we know.

But if we manage to create decent amounts, to store it properly, and to shove it into a spacecraft... we'd have a heck of an efficient engine!!!

The problem with Generation Ships is that you have to find lots of people who are willing to commit to spending eighty years in a tube so that their great-great-great-great-great grandchildren can see another planet.
Not easy to do.
Believe me...it wouldn't be THAT hard. I'd sign up in an instant...and there are tons of hard Libertarians that would sign up instantly as well.

http://www.suite101.com/links.cfm/destiny_space

I don't know. Sounds kind of exciting. Especially if they guarantee me a girlfriend or two :D
I wouldnt especialy mind either, but I think you would have to build a REALLY big spaceship to avoid causing everybody to go nuts from claustrophobia.

The problem with Generation Ships is that you have to find lots of people who are willing to commit to spending eighty years in a tube so that their great-great-great-great-great grandchildren can see another planet.
Not easy to do.
A few serious sci-fi authors have talked about this subject. The most well-documented is Kim Stanley Robinson's novel "Icehenge", in which she discusses the requirements for long-time space travel in a closed environment. It's quite interesting (even though the novel itself is boring). Looks like we'd need to recycle A LOT. The problem is not energy but matter; even with near-perfect recycling systems, you end up with a heap of unusable garbage.

A few serious sci-fi authors have talked about this subject. The most well-documented is Kim Stanley Robinson's novel "Icehenge", in which she discusses the requirements for long-time space travel in a closed environment. It's quite interesting (even though the novel itself is boring). Looks like we'd need to recycle A LOT. The problem is not energy but matter; even with near-perfect recycling systems, you end up with a heap of unusable garbage.
True. Initially, you'd have to have a VERY large store of supplies coupled with a 95%-100% efficient recycling system...and we're not even close to the recycling efficiency needed for such an endeavor...yet.

Wasn't LSD invented for that purpose?

Anyway, it's possible that, if conciousness can be uploaded to a computer or similar device, we can control how we perceive time. It would still take time to come and go, but it wouldn't matter so much.

Drugs were thought at one point to be a shortcut to higher consciousness, but LSD unfortunately doesn't alter consciousness in the manner I was suggesting. My apologies if my post left you with the impression I was speaking of drug-induced altered perception.

Though who can say? Perjaps some hitherto-unknown 'magic pill' will eventually be concocted in a lab somewhere that'll do just that. What I was really thinking of, though, was some form of humanity-wide gestalt, a 'leaping forward' in our fundamental grasp of reality.

Personally, I think that's within the realm of the possible. Perhaps not probable - but nonetheless possible. I wouldn't be at all surprised to see both some form of generational ship launched within the next hundred or two years, as well as a human gestalt event - resulting in the great comedy of the generational ship arriving at Prox, only to find humans already there, in numbers. Most likely agents of the Press, waiting to interview the would-be-explorers.

But what do I know?

I wouldnt especialy mind either, but I think you would have to build a REALLY big spaceship to avoid causing everybody to go nuts from claustrophobia.
Meh. Give me a computer and some cool games and I won't notice. Unfortunately, the ship also wouldn't make it to the next generation :)

True. Initially, you'd have to have a VERY large store of supplies coupled with a 95%-100% efficient recycling system...and we're not even close to the recycling efficiency needed for such an endeavor...yet.
Perhaps nanotech will help. Nanobots can roam through the garbage decomposing it into useful stuff.

Perhaps nanotech will help. Nanobots can roam through the garbage decomposing it into useful stuff.
Possibly, but we're still (at least) decades away from having good, predictable, functioning nanotech. That said, once nanotech is up to "sci-fi" speeds, that would most definitely be a viable solution the recycling problem.

Perhaps nanotech will help. Nanobots can roam through the garbage decomposing it into useful stuff.
They require energy or fuel to work. But hey, why not -- if they recharge on ambiant lighting, that could be a solution. But we're still far from this. And I would count more on bio-engineered bacteria and yeasts to do a good recycling/fixing job.

True. Initially, you'd have to have a VERY large store of supplies coupled with a 95%-100% efficient recycling system...and we're not even close to the recycling efficiency needed for such an endeavor...yet.
Or, if you had a large enough ship, you could create a self-sustaining ecosystem. Of course, I dont think that we can afford to build death-star sized ships just yet :)

Or, if you had a large enough ship, you could create a self-sustaining ecosystem. Of course, I dont think that we can afford to build death-star sized ships just yet
That's one of the problems -- we still don't know how big or complete our ecosystem would need to be, in order to function for a long period.
Some researchers say we'd need to carry the whole thing.

I tend to believe we'd need a partial ecosystem with a lot of soil, fertilized from existing soil samples to get the most important micro-organisms (bacteria, viruses, protozoa, fungi, nematodes, and so on). We'd also need fresh water with algae cultures.

I'm currently doing some "unsponsored" research on frozen soil. Keep a very small soil sample frozen for a few weeks/months/years, then mix it with sterilized grey soil (cooked at 800 degrees), add sterilized water, and see how things grow in there.

If we ever want to terraform a planet, we'd have to either bring a whole ecosystem there in one piece... or work with frozen soil samples and seeds. But we need to know how good they are after spending a while in the freezer.

That's one of the problems -- we still don't know how big or complete our ecosystem would need to be, in order to function for a long period.
Some researchers say we'd need to carry the whole thing.

I tend to believe we'd need a partial ecosystem with a lot of soil, fertilized from existing soil samples to get the most important micro-organisms (bacteria, viruses, protozoa, fungi, nematodes, and so on). We'd also need fresh water with algae cultures.

I'm currently doing some "unsponsored" research on frozen soil. Keep a very small soil sample frozen for a few weeks/months/years, then mix it with sterilized grey soil (cooked at 800 degrees), add sterilized water, and see how things grow in there.

If we ever want to terraform a planet, we'd have to either bring a whole ecosystem there in one piece... or work with frozen soil samples and seeds. But we need to know how good they are after spending a while in the freezer.

Can you let me know what you find out? TG or email me if you want any help - I'd be willing to collaborate. I've got a background in soil science and a strong interest in it.

I think it's been proven that some form of warp drive -shrinking the space in front of the ship and stretching it behind to 'move' faster than light without actually moving- is possible. The only obstacle is the amount of energy required to manipulate space in that way. We're talking about something like 'a thousand times the total output of the sun during its entire ten billion year life span' or 'more than the combined output of all stars in the visible universe'. Unfortunately, it seems unlikely we'll find a way to produce and control that kind of power.

And if we did, how long till somebody tried to use it as a weapon and blow up the galaxy? ;)