Does it matter?
Space travel seems like it should be a priority for humanity. More so than the latest iPhone and all that other crap that produces pollution
Space travel seems like it should be a priority for humanity. More so than the latest iPhone and all that other crap that produces pollution
There's also that point where the sun will become a red giant or something and Earth will physically be unable to support life, but there's at least 600 million years before that one becomes an issue, and I'm sure something would have figured out space travel before then.
It's like running a large website and using multiple servers/cloud hosting/multiple datacentres. Or hosting your site, domain and email at different providers. Makes it far less likely the whole system will collapse at once.
> At a constant acceleration of 1 g, a rocket could travel the diameter of our galaxy in about 12 years ship time, and about 113,000 years planetary time. If the last half of the trip involves deceleration at 1 g, the trip would take about 24 years. If the trip is merely to the nearest star, with deceleration the last half of the way, it would take 3.6 years.
24 years is one generation of humans. And 113,000 years is still less than 600 million years. Speed of light is not a problem. Making that ship self-sustainable and even being able to accelerate to 0.999 c might be.
[1] https://en.wikipedia.org/wiki/Space_travel_using_constant_ac...
If we can somehow figure out how to keep astronauts in stasis some way or the other, that would remove the need to get anywhere in under 100 years or so. If humans become cyborgs and lose the need for standard forms of nutrition or air, that helps too. If methods for life extension are found, the same.
And if that fails, well there's always robots. Or potentially colony ships. Nothing says the automated ship has to be 'on' for the duration of the journey, only the launch and destination.
with any of these ideas, the speed of light becomes even less of an issue.
But it doesn't have to mean we put a full stop on all space activity. But rather that we research what the effects are, and take measures to reduce those effects to the extent they can be done at reasonable cost. Say, if alumina and chlorine compounds from solid rocket boosters are bad, maybe we should use liquid fueled rockets. If soot from RP-1 is a problem, maybe think about switching to, say, methane.
This way we can protect our species from getting wiped out with our single habitat, as well as likely solving all our resource and energy issues with the wastly bigger resources of space compared to what we would have available if we never leave the planet.
We'll have to learn to make do with what's on our planet, instead of continuing on the current path in unrealistic hopes of serving on the USS Enterprise.
(1) We use factories and raw materials to build space station modules.
(2) We create and expand space stations in Earth orbit by launching modules via rockets.
(3) We can build and add additional modules to increase the crew capacity of the station.
(4) We grow plants and manufacture things (in small quantities) on the station.
(5) We live (in small numbers) on space stations for years given enough crew space and constant coordination and resupply shipments from Earth.
(6) The amount of people and equipment directly involved in any particular Earth industry is finite.
(7) We protect volumes from the hazards of space (vacuum, temperature, micro-meteors, radiation) by armoring their surfaces with factory-made materials.
(8) We could continue (2 and 7) until the station is armored enough to allow its inhabitants and equipment to survive beyond Earth's magnetic shield.
(9) Given (5), we could continue (2 and 3) until the station has enough people (6) to self-co-administer, at which point it only needs resupply shipments from Earth to sustain itself.
(10) We could continue (2 and 4) until the station has enough factories and refineries for (1), provided it has raw materials from Earth or asteroids.
(11) We could build one or more hospital modules to facilitate safe human births on the station, perhaps in a rotating section, so new humans can replace the old.
To accomplish these points, we require no additional advances in technology, only our sustained effort. Humanity could live and grow endlessly in large space stations that run on solar power and build with raw materials from asteroids, comets, moons, or planets.
We can grow plants on Earth, why would we do it in orbit.
As for some reasons to grow, or manufacture really, things in orbit, landmass is one reason. There is a whole lot of real estate up there that we don't really have access to on earth. There is also the ability to send down materials to anywhere on earth without requiring a huge transportation network that causes things like roadway congestion. On top of those, building facilities that do heavy amounts of nasty polluting become less of a concern. It's not really as much of an issue to dump a bunch of toxic stuff into space compared to say, a river. I suspect nuclear power plants also start to become more viable as there is less of a worry over meltdowns as you're already surrounded by massive amounts of radiation and have no population to evacuate.
The only thing that makes sense? You can't think of any other problems that we might work on first?
Quite apart from not having a suitable planet in reachable range. Mars doesn't really cut it - that puts humanity's future in a sealed tin can or needs terraforming.
There are plenty of things we can do. We can be more harmonious to our planet, for one. We can learn to make the atacama or sahara deserts habitable. We can learn to stop the climate shift we seem to be experiencing. We can be more harmonious to the other humans on this planet.
These are all big ticket items that will still exist even if we found some garden of eden on some far off shore. I can't think of anything worse than taking our mining and destructive natures to an innocent planet. We have created this planet's problems. We should fix them before shooting moonbeams and running away from them.
There are local solutions for global warming, it's simply to consume less, people in developed countries could consume roughly 20x less, which is already more than enough (I can relate), and apply a sort of birth-control globally
Space travel sounds like the apogee of consumerism, it's possible to live differently, durably on this planet