Generation Ships--- Can we build one now?

Baron Opal II · Feb 28, 2019

Hussar said:
I'll see your Apollo 13 with an Apollo 1 and raise you a Challenger. The problem with space travel is that when disaster hits, it's very often catastrophic.

It can be, yes. That's why redundancies and improvisation are important. But the crew of Apollo 13 made it home, seemingly impossible by your thesis.

Communication with home to fix problems just isn't plausible for most of the journey.

True. But it lowers the risk at the beginning.

Yeah, because exploring in a tropical environment where food is plentiful and even water isn't all that difficult to come by in an area where it rains 300 days a year (yes, an exaggeration) is equivalent to space exploration.

From a resource perspective, it is. If you run out of fresh water in your catamaran and you are a week out from the dry land you hope is out there, you're screwed. Yet, many voyages succeeded. And, I'm sure, many did not.

Now we're investing in multiple generation ships? Where exactly would the resources for this come from? We're talking an undertaking that, currently, would eat up the entire global output for decades just to create a single ship. And you want to make several?

It seems prudent to me to have multiple bites at the apple. Each ship is probably going to be a hollowed out asteroid- this would give sufficient shielding and volume for resource storage. Water is probably going to be the key resource and there is a lot of it out there.

Hussar · Mar 1, 2019

You're missing my point. What is a generation ship? It's a closed, self sustaining ecosystem that will support thousands of people for many, many generations.

Once you have the ability to make something like that, there's no need to send it to another star. Why bother? Orbit it around our star and you're good to go. 5 billion years from now when the sun begins to expand? Move the orbit out a ways and enjoy the resources of an entire solar system.

This is the fundamental problem with all the "alien invasion" stories. Once you have the ability to travel between stars, you don't need to anymore.

Baron Opal II · Mar 1, 2019

Hussar said:
You're missing my point. What is a generation ship? It's a closed, self sustaining ecosystem that will support thousands of people for many, many generations.

Once you have the ability to make something like that, there's no need to send it to another star. Why bother?

...Once you have the ability to travel between stars, you don't need to anymore.

I find this to be a reasonable criticism. At least for the next 10-20,000 years or so. If there truly is no means of FTL then robotic probes will need to be the answer to see what is out there. If we are going to actually build a generation ship, we would need to have a solid destination planned.

Because once we find and confirm that there is another planet out there with life, or could support ours? Getting 10K volunteers would be trivial.

Why bother? How could you not?

Eltab · Mar 1, 2019

Samloyal23 said:
So what would be a good option based on current knowledge for a possible destination? Where should we go?

Proxima Centauri hosts a planet of about the right size and about the right distance. We don't know its composition yet. This is the closest possible destination.
Sirius probably will be a dud unless your sponsoring organization is named National Geographic, due to previous nova (Sirius B) that likely messed up any planets' orbit.
Tau Ceti has a big dust cloud around it, with ripples that suggest planets in the right places.
Other nifty-looking systems are much farther out. There seems to be a 'shell' of interesting exoplanets at distance 40 light-years.
The Kepler probe was pointed in one direction only and has found exoplanets up to 33,000 light-years out. That will be a LONG trip.

It seems to me that asteroid belts would be more interesting to the generation ship crew than landing on a planet. They might want to mine the resources and build landing craft, rather than carrying the gear all that way.

The website SolSystem.com has known data for nearby stars and planets. It looks like the data has not been updated for a while but it can serve as a rough first guess of system astrography.

Hussar · Mar 1, 2019

Baron Opal II said:
/snip

Why bother? How could you not?

Because the expense is just far, far more than it's worth. Again, if you have the ability to create closed, self-sustaining ecosystems, then things like terraforming become an option. Mars has as much land as Earth even if you flood the lower parts of it with water (possibly by crashing a few ice comets into the planet). Never minding things like hollowed out asteroids which could yield living space comparable to Earth's.

At a certain point, it's just not really necessary. Far easier to send unmanned probes. Safer, cheaper and far, far faster. Meanwhile, the living space for humans in the Solar System is effectively unlimited, so long as you can keep creating new habitats.

It would take hundreds of millions of years to actually exhaust the resources available in the Solar System by that point. Far longer than the life expectancy of a species.

Baron Opal II · Mar 1, 2019

Hussar said:
Because the expense is just far, far more than it's worth.

At a certain point, it's just not really necessary. Far easier to send unmanned probes. Safer, cheaper and far, far faster.

No, it would well be worth the expense and time.

I will absolutely concede that there might be an easier way to do it as a large dome on Mars, or dropping millions of tons of ice on Venus. That we know of today. There might be a reason that we haven't thought of that would make being planetside on a non-Terran world undesirable.

But to touch an alien world... a glorious thing. Even if I can't do it myself.

Umbran · Mar 1, 2019

Hussar said:
Because the expense is just far, far more than it's worth.

Oh, really? I mean, you've *calculated* how much a journey to another star is worth? How many dollars is it? Please, tell us! And I am sure NASA wants to see your numbers...

Because, you see, in science and exploration, we don't get to know the value beforehand - leaving your assertion that it would not be worth it ringing rather hollow. Yes, it is a crap shoot. But, NASA has to date shown that exploration efforts pay off for mankind, regardless of whether an individual mission itself succeeds or fails.

Janx · Mar 1, 2019

Hussar said:
Because the expense is just far, far more than it's worth. Again, if you have the ability to create closed, self-sustaining ecosystems, then things like terraforming become an option. Mars has as much land as Earth even if you flood the lower parts of it with water (possibly by crashing a few ice comets into the planet). Never minding things like hollowed out asteroids which could yield living space comparable to Earth's.

At a certain point, it's just not really necessary. Far easier to send unmanned probes. Safer, cheaper and far, far faster. Meanwhile, the living space for humans in the Solar System is effectively unlimited, so long as you can keep creating new habitats.

It would take hundreds of millions of years to actually exhaust the resources available in the Solar System by that point. Far longer than the life expectancy of a species.

The problem is, we don't tend to develop technologies that solve those problems unless we actually try the actual goal.

So while I pointed out that surviving an asteroid strike is easier on earth than getting to Mars, staying there and then coming back to rebuild, we on't get the technology to stay on mars unless we actually go try to stay on mars.

And we're not likely to develop good enough technology in a hurry to survive on earth unless we try something harder, like going to live on mars.

And unless we get out of Sol, our entire species will die out unless we work on getting out of Sol system. Yes, that's very long term, but there is no point to history to art, to learning anything if we don't find a way to pass it on to the next generation. Because all of it will be destroyed when the sun dies, if we're stuck here. Our cumulative lives and accomplishments will be as meaningful as ants. Nobody around to care or learn from it.

Hussar · Mar 2, 2019

Umbran said:
Oh, really? I mean, you've *calculated* how much a journey to another star is worth? How many dollars is it? Please, tell us! And I am sure NASA wants to see your numbers...

Because, you see, in science and exploration, we don't get to know the value beforehand - leaving your assertion that it would not be worth it ringing rather hollow. Yes, it is a crap shoot. But, NASA has to date shown that exploration efforts pay off for mankind, regardless of whether an individual mission itself succeeds or fails.

Well, no, that's true. I haven't actually crunched the numbers. But, I'm pretty sure that harvesting near Earth objects for resources for the next million years (and yes, that's how much there actually IS in near Earth orbit) is probably a whole lot cheaper than building a several million tonne spaceship capable of continuous travel for thousands of years.

Are you seriously suggesting that a generation ship's primary mission would be exploration? Really? I can think of a thousand ways to explore for a fraction of the investment that would give as good or better results than a generation ship.

So, no, I don't think the objections are hollow. They are realistic. The real problem is that people who have devoted so much time to science fiction often have incredibly unrealistic views of space. A single nickel-iron asteroid in near Earth orbit has more iron in it than we have mined in all of human history. And there are literally thousands of these objects in orbit.

Why are we building asteroid colonies in the asteroid belt? If we have that level of technology, why not just deorbit that asteroid into Earth's orbit and mine it here? Saves tons of time, expense and effort. Is it less romantic? Sure. But, reality often is.

Samloyal23 · Mar 12, 2019

Shasarak said:
The Muslims do not have any Gay people without Slavery.

The Muslims do not have any gay people because they lynch anyone they find who is gay.

Generation Ships--- Can we build one now?

Baron Opal II

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Hussar

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Eltab

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Hussar

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Baron Opal II

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Umbran

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Janx

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Samloyal23

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