Generational craft (split from Terraforming the Solar System)

[Airbrush]

Terraforming planets will take a back seat to building spacecraft that can be "all the comforts of home."  Why make the effort to terraform Mars when you could much easier build a giant spacecraft that can travel for decades without needing anything, except to stop occasionally at an asteroid to collect water-ice for water, air and fuel, and some useful minerals.

Edited September 2, 2020 by Airbrush

[swansont]

2 hours ago, Airbrush said:

Terraforming planets will take a back seat to building spacecraft that can be "all the comforts of home."  Why make the effort to terraform Mars when you could much easier build a giant spacecraft that can travel for decades without needing anything, except to stop occasionally at an asteroid to collect water-ice for water, air and fuel, and some useful minerals.

Easier? That’s just an assertion.

Convince me. 

[Area54]

5 hours ago, Airbrush said:

Why make the effort to terraform Mars when you could much easier build a giant spacecraft that can travel for decades without needing anything, except to stop occasionally at an asteroid to collect water-ice for water, air and fuel, and some useful minerals.

Why? Planets are more robust than spacecraft.

[Dord]

3 minutes ago, Area54 said:

Why? Planets are more robust than spacecraft.

Some planets.

I can't imagine terraforming a gas giant will be easy! 

[Area54]

3 minutes ago, Dord said:

Some planets.

I can't imagine terraforming a gas giant will be easy! 

Irrelevant to the question as to why one would favour a planet over a spacecraft. And while gas giants may be impractical to terraform they are certainly more robust than spacecraft.

[Ken Fabian]

The line between spacecraft and space station/habitat blurs but I can't see even attempting terraforming without an existing full capability of living in artificial space habitats, using asteroid/cometary - ie non-planetary- resources; ie that if we are capable of doing so we will not need to. So terraforming planets is going to be optional.

I think terraforming lifeless planets will be extremely unlikely and candidates are more likely to be planets with simple life and atmosphere's not too different; ie kill off what is there and supplant it with selected/engineered terrestrial life. And I think that any non-terrestrial life presents both extraordinary opportunities (for study, for potential biological materials and biochemical processes) and extraordinary challenges - cross contamination, disease, parasitism, allergens, poisons. And a very big ethical dilemma. Like I said I think any future humans capable of doing it will be capable of thriving without doing it.

I think multi-generation spacecraft won't last long enough or be capable of carrying everything they need and will need periodic resupply, refitting, whole rebuilds and - if population grows - new builds. I think that the most achievable kind of interstellar travel will be thousands of generations of hopping from deep space object to deep space object, each time building a local economy and population capable of doing that resupply, refitting, rebuilding; as I've said elsewhere I think nothing short of a large, advanced industrialised economy (and population) can manage the complexity and exacting standards that kind of high tech existence requires. Which view is a key deviation from most of the optimists.

Whether a clear goal could be sustained that focuses onwards exploration and occupation of DSO's in a target star's direction when DSO's, not planets, are the source of all resources is a question. Indoctrination and social conditioning? I think some serious ethical questions arise when considering some of the possibilities.

I do think that for enduring safety and security, that space habitats will beat any planets barring Earth. Earth still beats all of them and probably will for millions of years yet.

Edited September 3, 2020 by Ken Fabian

[Airbrush]

5 hours ago, swansont said:

Easier? That’s just an assertion.

Convince me. 

How long would it take to terraform Mars?  Mars is a nice place to visit, but you wouldn't want to live there.  Terraforming Mars will be too costly and a lower priority, compared to giving humanity mobility around the solar system.  My spaceship can orbit Mars in the comfort of one G with temperature controlled, video games, all you can eat, and shielded from cosmic rays, like in Star Trek, but not to the stars, just around our neighborhood.  We can visit Titan, Enceladus, Europa, and other fine destinations. 😃

The next few hundred years may be very tough for humanity considering population growth, climate change, nuclear terrorism, natural disasters, etc, all point to doing more with less.  Humanity will become very budget conscious.  Terraforming Mars, and Terminator robots, should be a lower priority than comfortable mobility around the solar system.

After you have your comfortable spaceships, you can visit asteroids that have water-ice and minerals you need, then hollow them out.  Live inside of asteroids.  They would rotate providing one G for people standing inside with their heads pointing towards the center of the asteroid.  That would be better than terraforming Mars. 

Edited September 3, 2020 by Airbrush

[Phi for All]

12 hours ago, Airbrush said:

How long would it take to terraform Mars?  Mars is a nice place to visit, but you wouldn't want to live there.  Terraforming Mars will be too costly and a lower priority, compared to giving humanity mobility around the solar system.  My spaceship can orbit Mars in the comfort of one G with temperature controlled, video games, all you can eat, and shielded from cosmic rays, like in Star Trek, but not to the stars, just around our neighborhood.  We can visit Titan, Enceladus, Europa, and other fine destinations. 😃

 

!

Moderator Note

The thread is in Astronomy, so let's back up these assertions if we're going to make them, yes? Science discussion is frustrating without rigor.

 

[Airbrush]

I am not suggesting generational craft.  Remember what Stephen Hawking said, that humanity has about 100 more years before our extinction.  So how do you want to spend the next 100 years?  Terraforming Mars, building Terminator robots, or exploring the solar system?  People going to other stars seems farther and farther away than ever.  Even sending high-speed probes to the nearest stars seems less likely than just being content to view evidence of life on other planets in the time we have left.

https://futurism.com/stephen-hawking-humanity-only-has-100-years-left-on-earth-before-doomsday

 

[dimreepr]

5 minutes ago, Airbrush said:

I am not suggesting generational craft.  Remember what Stephen Hawking said, that humanity has about 100 more years before our extinction.  So how do you want to spend the next 100 years?  Terraforming Mars, building Terminator robots, or exploring the solar system?  People going to other stars seems farther and farther away than ever.  Even sending high-speed probes to the nearest stars seems less likely than just being content to view evidence of life on other planets in the time we have left.

https://futurism.com/stephen-hawking-humanity-only-has-100-years-left-on-earth-before-doomsday

 

We could try to fix this planet, sounds a lot easier than trying to fundamentally change another planet or blindly jump off a perfectly sevicable one...

[Airbrush]

29 minutes ago, dimreepr said:

We could try to fix this planet, sounds a lot easier than trying to fundamentally change another planet or blindly jump off a perfectly sevicable one...

Certainly priority #1 is FIX THIS PLANET.  After that is done (tall order), what can we do for fun?  What is your NEXT priority for space exploration?  Terraforming Mars or building Terminator robots?  Remember we may have only about 100 more years to do it.

Edited September 3, 2020 by Airbrush

[dimreepr]

13 minutes ago, Airbrush said:

Certainly priority #1 is FIX THIS PLANET.  After that is done (tall order), what can we do for fun?

Have a BBQ?

[swansont]

3 hours ago, Airbrush said:

I am not suggesting generational craft.  Remember what Stephen Hawking said, that humanity has about 100 more years before our extinction.  So how do you want to spend the next 100 years?  Terraforming Mars, building Terminator robots, or exploring the solar system?  People going to other stars seems farther and farther away than ever.  Even sending high-speed probes to the nearest stars seems less likely than just being content to view evidence of life on other planets in the time we have left.

https://futurism.com/stephen-hawking-humanity-only-has-100-years-left-on-earth-before-doomsday

 

How is "a giant spacecraft that can travel for decades* without needing anything, except to stop occasionally at an asteroid to collect water-ice for water, air and fuel, and some useful minerals" NOT a generational craft? You expect people to live that long and spend all of their time not having sex? People are going to magically live to ~125 years of age, and be able to actively run a spaceship and do these missions you describe?

*which you later clarified to be 100 years

[MigL]

16 hours ago, Airbrush said:

How long would it take to terraform Mars?  Mars is a nice place to visit, but you wouldn't want to live there.

I suggest you watch The Martian. It should be available on Netflix.

3 hours ago, dimreepr said:

We could try to fix this planet, sounds a lot easier than trying to fundamentally change another planet

How do you fix the problem of too many people, without giving them another place to live ?
Exterminate all those you don't like ?
( and more importantly, would I be on that list ? )

[Airbrush]

40 minutes ago, swansont said:

How is "a giant spacecraft that can travel for decades* without needing anything, except to stop occasionally at an asteroid to collect water-ice for water, air and fuel, and some useful minerals" NOT a generational craft? You expect people to live that long and spend all of their time not having sex? People are going to magically live to ~125 years of age, and be able to actively run a spaceship and do these missions you describe?

*which you later clarified to be 100 years

Ok you are correct, it would by necessity be a generational spaceship.  I confused interstellar travel for generational travel.  But do you agree with Hawking that we don't have much time for anything but to try to fix Earth and maybe build another generation of telescopes to detect planets with life on them?  Forget about sending probes to other stars, much less sending people to other stars.  Will 100 years be enough time to BEGIN terraforming Mars?  Maybe a few settlements can be established on Mars, but what will a few meager colonies do AFTER Earth is done?  No more help from home.  They won't be able to terraform Mars, just survive for a while.

Edited September 3, 2020 by Airbrush

[MigL]

13 minutes ago, Airbrush said:

Maybe a few settlements can be established on Mars, but what will a few meager colonies do AFTER Earth is done?

Maybe Douglas Quaid will find the ancient Martian reactor, which will sublimate the underground 'glacier', and give Mars a breathable atmosphere again.
( Total Recall, 1990 )

That's the problem when you start your sentence with 'maybe'.

[Ken Fabian]

11 hours ago, Airbrush said:

I am not suggesting generational craft.  Remember what Stephen Hawking said, that humanity has about 100 more years before our extinction.  So how do you want to spend the next 100 years?  Terraforming Mars, building Terminator robots, or exploring the solar system?  People going to other stars seems farther and farther away than ever.  Even sending high-speed probes to the nearest stars seems less likely than just being content to view evidence of life on other planets in the time we have left.

https://futurism.com/stephen-hawking-humanity-only-has-100-years-left-on-earth-before-doomsday

 

I don't think Stephen Hawking was ever a reliable source on how long humanity has left on Earth, no matter his brilliance with respect to black holes and cosmology. I think the reality of moving to space is not anywhere even close to being a viable option - and without a healthy wealthy Earth economy, not likely to ever be one. Failing to go all out to fix our problems here will ensure failure to establish a reliable, colonial foothold in space; space colonisation is not an alternative to Earth, it depends absolutely on Earth. If it achieves true self sufficiency, that will be an emergent outcome of success as an enduring part of Earth's greater economy.

What I think with respect to our looming doom is we face the prospect of our civilisation - such as it is - failing us in the face of cumulative problems. Good governance looks thin on the ground to me - and large elements fiercely resists deep, long running foresight and planning.

Any collapse of what we see as civilisation won't be the end of humanity by any means, but it likely will put all grand space dreams on hold and make getting back to the wealth and prosperity we now enjoy much harder in any distant future - and what we have is IMO probably unsustainable and overly a product of and dependent on resource over-exploitation in the present at the cost of future resource availability. I am not sure that unrealistic optimism about space and abundant space resources helps with keeping our eyes on this road, hands on this wheel.

I am not optimistic either way - because I think it wasn't planning and foresight that got us the civilisation we have here on Earth but for getting space colonies on a sustainable footing the minimum population and economy and infrastructure needs to be very large to be able to reach reliable self sufficiency; self sufficiency in space will be very hard to achieve without those natural ecosystems to do so much stuff we depend and thrive on for free.

 

7 hours ago, MigL said:

How do you fix the problem of too many people, without giving them another place to live ?

I don't think space - even being more optimistic even than most optimists - will ever offer mass migration opportunities; mostly the idea seems to be a smallish number get to colonise space, to go on (we hope) to survive and thrive there and Earth's population gets to survive or not (we hope not) as the case may be. We are suppose to be vicariously comforted by this - enough to not resent paying for it. I remain unconvinced that this "some will survive" motivation can be sufficient to support the scales of construction and investment a viable space colonisation program needs. And we could (real possibility) see significant population decline here on Earth - whether we want it and plan it (still possible, over several generations), or not (possibly catastrophically).

Interstellar colonising would be much, much   harder than Mars - and I think Mars is still way beyond our capabilities. And Mars would be much harder than Asteroids. And those are still extremely hard. I would probably go for Asteroids and free flying space habitats over planets.

Edited September 4, 2020 by Ken Fabian

[zapatos]

12 hours ago, Airbrush said:

Remember what Stephen Hawking said, that humanity has about 100 more years before our extinction. 

Yeah, somebody is always predicting the impending demise of humanity.

Barring some extinction level event that had not been identified by Hawking, I'm betting my grandchildren will not be among the last humans.

[Endy0816]

We have a ton of area and volume  available to us on Earth still. We could also potentially relocate bits to free up space, depending on what people are okay with and available technology.  I think we'll be good for a long time yet as long as we're smart about it. That's really the part that remains to be seen.

Main issue with Earth-like planets is  always eventually going to be their Sun expanding, close secondary concern would be the difficulty in defending them. Of course this is still assuming there's no developments in technology that allows to easily handle these problems.

I read some talk about disassembling planets to repurpose them for the greater area in O'Neill cylinders but I don't know if it'll be really necessary.  Stations/vessels that are mostly air and cargo nets offer even more living space for less effort

 

[swansont]

18 hours ago, Airbrush said:

Ok you are correct, it would by necessity be a generational spaceship.  I confused interstellar travel for generational travel.  But do you agree with Hawking that we don't have much time for anything but to try to fix Earth and maybe build another generation of telescopes to detect planets with life on them?  Forget about sending probes to other stars, much less sending people to other stars.  Will 100 years be enough time to BEGIN terraforming Mars?  Maybe a few settlements can be established on Mars, but what will a few meager colonies do AFTER Earth is done?  No more help from home.  They won't be able to terraform Mars, just survive for a while.

That's beside the point. 

The technology does not exist to build a ship that would let people survive the way you describe. We haven't even come close, and you have not given any details that would suggest there is a viable solution in the offing. Your content is far, far more wishful thinking than it is technology and science. This is not a "wishful thinking" discussion board.

I don't think terraforming is in the offing, either, but I think there are fewer obstacles to overcome in living on another planet. 

 

18 hours ago, MigL said:

I suggest you watch The Martian. It should be available on Netflix.

It's fiction and also not terraforming.

[MigL]

14 minutes ago, swansont said:

It's fiction and also not terraforming.

Right.
But entirely doable for small ( temporary ? ) colonies.

Edited September 4, 2020 by MigL

[swansont]

1 hour ago, MigL said:

Right.
But entirely doable for small ( temporary ? ) colonies.

Sure. I think you could have quasi-permanent bases like that (more structurally sound, though), but you would have to remain indoors or be in a suit outdoors, like in the movie. 

If the choice is between terraforming and a generational ship and we have 100 years, then I think we're toast. If it's a choice between living on a spaceship and living on another planet or moon, I think the planet option is easier to achieve. (Power and dealing with gravity wells/orbits are two main reasons why)

[Airbrush]

13 hours ago, Ken Fabian said:

I don't think Stephen Hawking was ever a reliable source on how long humanity has left on Earth, no matter his brilliance with respect to black holes and cosmology. I think the reality of moving to space is not anywhere even close to being a viable option - and without a healthy wealthy Earth economy, not likely to ever be one. Failing to go all out to fix our problems here will ensure failure to establish a reliable, colonial foothold in space; space colonisation is not an alternative to Earth, it depends absolutely on Earth. If it achieves true self sufficiency, that will be an emergent outcome of success as an enduring part of Earth's greater economy.

What I think with respect to our looming doom is we face the prospect of our civilisation - such as it is - failing us in the face of cumulative problems. Good governance looks thin on the ground to me - and large elements fiercely resists deep, long running foresight and planning.

Any collapse of what we see as civilisation won't be the end of humanity by any means, but it likely will put all grand space dreams on hold and make getting back to the wealth and prosperity we now enjoy much harder in any distant future - and what we have is IMO probably unsustainable and overly a product of and dependent on resource over-exploitation in the present at the cost of future resource availability. I am not sure that unrealistic optimism about space and abundant space resources helps with keeping our eyes on this road, hands on this wheel.

I am not optimistic either way - because I think it wasn't planning and foresight that got us the civilisation we have here on Earth but for getting space colonies on a sustainable footing the minimum population and economy and infrastructure needs to be very large to be able to reach reliable self sufficiency; self sufficiency in space will be very hard to achieve without those natural ecosystems to do so much stuff we depend and thrive on for free.

 

I don't think space - even being more optimistic even than most optimists - will ever offer mass migration opportunities; mostly the idea seems to be a smallish number get to colonise space, to go on (we hope) to survive and thrive there and Earth's population gets to survive or not (we hope not) as the case may be. We are suppose to be vicariously comforted by this - enough to not resent paying for it. I remain unconvinced that this "some will survive" motivation can be sufficient to support the scales of construction and investment a viable space colonisation program needs. And we could (real possibility) see significant population decline here on Earth - whether we want it and plan it (still possible, over several generations), or not (possibly catastrophically).

Interstellar colonising would be much, much   harder than Mars - and I think Mars is still way beyond our capabilities. And Mars would be much harder than Asteroids. And those are still extremely hard. I would probably go for Asteroids and free flying space habitats over planets.

Excellent post!  Just what I wanted to hear.  Thank you.  +1 for that.  Hawking should not be thought as the expert on human survival prospects.

Humanity may survive much longer than 100 years, but as you pointed out, it could be post-apocalyptic survival of a few, or even many people surviving, but grand plans for space exploration would be put on hold.  Arthur C Clark thought in 1982 that by 2010 we could have a huge spacecraft orbiting Jupiter.

Edited September 4, 2020 by Airbrush

[dimreepr]

20 hours ago, MigL said:

How do you fix the problem of too many people, without giving them another place to live ?
Exterminate all those you don't like ?
( and more importantly, would I be on that list ? )

But the problem isn't one of too many people (so you're safe), it's about a suitable place to live; at some point in the future human's will run out of options, whatever we do... Immortality is for God's.

[swansont]

26 minutes ago, dimreepr said:

But the problem isn't one of too many people (so you're safe), it's about a suitable place to live; at some point in the future human's will run out of options, whatever we do...

Aren't those overlapping issues? What options do we run out of that's not related to overpopulation?