I've got it ! This is how we will colonise space !

[Tyrannical]

Of course the biggest problem to space cities is launching a city size object into space,even if done a small piece at a time. I don't think even the nuclear / fusion engines theorized for long distance space travel produce enough thrust to escape into orbit. Jetting around a frictionless void is easy.

http://en.wikipedia.org/wiki/Project_Or ... pulsion%29

Of course you could launch a truly massive ship by shooting out nuclear bombs out the back and riding the blast wave!

A 3,350 ton Saturn V can drop 52 tons of cargo on the Moon.

A 4,000 ton Orion can drop 1,200 tons on the Moon, or 800 tons on Mars and return to Earth.

The 8,000,000 ton Super Orion could land a permanent manned colony on Mars.


But Nooooooo, the eco-wackos won't let us detonate nuclear warheads in the atmosphere anymore

[mistermack]

Of course the biggest problem to space cities is launching a city size object into space,even if done a small piece at a time.

True, but there are ways around that problem.
You mine the moon for your materials. It takes very little energy to lift off from the moon.
Or, you capture a comet or asteroid and divert it into a solar orbit similar to the Earth's.

Mining the moon is probably the most practical.
If there's water on the moon, then you can also get your rocket fuel from the moon.

[Atheist-Lite]

A couple of regular regional nuclear conflicts will accustom people to nukes in the atmosphere again. The survivors won't take any shit from greenies.

[Tyrannical]

Of course the biggest problem to space cities is launching a city size object into space,even if done a small piece at a time.

True, but there are ways around that problem.
You mine the moon for your materials. It takes very little energy to lift off from the moon.
Or, you capture a comet or asteroid and divert it into a solar orbit similar to the Earth's.

Mining the moon is probably the most practical.
If there's water on the moon, then you can also get your rocket fuel from the moon.

A manufacturing / industrial complex is huge. But not too huge to launch into space with low yield "clean" fission bombs

Possibly it could also be done with the ship firing fission reactor powered high energy lasers to detonate a clean fusion bomb. But nothing that we know of besides a nuclear explosion could produce enough power to launch anything truly massive.

[mistermack]

A manufacturing / industrial complex is huge. But not too huge to launch into space with low yield "clean" fission bombs

Possibly it could also be done with the ship firing fission reactor powered high energy lasers to detonate a clean fusion bomb. But nothing that we know of besides a nuclear explosion could produce enough power to launch anything truly massive.

I admit that getting going would be difficult in the first place.

But there is the possibility of building a space elevator. I saw a tv program this evening about wireless power transmission by laser. You can have a vehicle climbing up a space elevator cable using electric motors, with it's power beamed at it by laser light so that it doesn't have to carry it's lift-off fuel with it.

Once it's reached orbit distance, it would be able to go huge distances on a small amount of fuel.

[MiM]

Of course the biggest problem to space cities is launching a city size object into space,even if done a small piece at a time.

True, but there are ways around that problem.
You mine the moon for your materials. It takes very little energy to lift off from the moon.
Or, you capture a comet or asteroid and divert it into a solar orbit similar to the Earth's.

Mining the moon is probably the most practical.
If there's water on the moon, then you can also get your rocket fuel from the moon.

According to this article/blog the work on getting to mine asteroids has already stated
http://blogs.discovermagazine.com/badas ... can-do-it/

[Gawdzilla Sama]

I rather think it's a good thing that we'll probably not get off this planet.

[mistermack]

I rather think it's a good thing that we'll probably not get off this planet.

We definitely will. We have. And I don't think there is anything out there that we can fuck up.
I think eventually there will be people all over the Moon and Mars, mining them. But they will be living on space stations.

I don't think there's much advantage in mining asteroids. Unless they just happened to have an orbit that was perfect for access from Earth, and that's incredibly unlikely.

I used to think that Mars would be too difficult to land on and take off from to be any value, but in the far future, it probably won't. A space elevator is actually far more practical for Mars than Earth, because of the lower gravity.
The materials that we have NOW could build one. And the same applies to the Moon.
So instead of needing rockets to take off from or land on Mars, you would just drive up and down a cable.
That would open it up completely.

[Gawdzilla Sama]

I rather think it's a good thing that we'll probably not get off this planet.

We definitely will. We have.

We didn't get off this planet, we just walked out to the sidewalk and back to the house. We didn't even have a descent sitdown at the curb.

[mistermack]

I rather think it's a good thing that we'll probably not get off this planet.

We definitely will. We have.

We didn't get off this planet, we just walked out to the sidewalk and back to the house. We didn't even have a descent sitdown at the curb.

Yeh, but it was nice to get a bit of sunshine and fresh air.

[Gawdzilla Sama]

I rather think it's a good thing that we'll probably not get off this planet.

We definitely will. We have.

We didn't get off this planet, we just walked out to the sidewalk and back to the house. We didn't even have a descent sitdown at the curb.

Yeh, but it was nice to get a bit of sunshine and fresh air.

Sunshine, check.
Fresh air, not so much.

[mistermack]

Sunshine, check.
Fresh air, not so much.

To be honest, I often prefer tinned to the fresh item. It's always there when you fancy some.

[Gawdzilla Sama]

Sunshine, check.
Fresh air, not so much.

To be honest, I often prefer tinned to the fresh item. It's always there when you fancy some.

Until you get to the bottle after the last one.

[Blind groper]

A space elevator is actually far more practical for Mars than Earth, because of the lower gravity.
The materials that we have NOW could build one. And the same applies to the Moon.
.

Just a comment here.
Space elevators are definitely the way to go. For Mars, a standard space elevator would work. In the lower gravity, the distance required is about half that for Earth.

For the moon, we have to be sneaky. It is much harder than you think. Geosynchronous orbit round the moon is already past the Earth. So it is impossible to place a space elevator in the classic way, to the geosynchronous point. However, it is possible to place a big lump of rock into one of the two La Grange points, and run the cable from there. Distance, 56,000 kms, which is a lot further than an Earth space elevator, where the geostationary point is 36,000 kms.
http://en.wikipedia.org/wiki/Lunar_space_elevator

[mistermack]

A space elevator is actually far more practical for Mars than Earth, because of the lower gravity.
The materials that we have NOW could build one. And the same applies to the Moon.
.

Just a comment here.
Space elevators are definitely the way to go. For Mars, a standard space elevator would work. In the lower gravity, the distance required is about half that for Earth.

For the moon, we have to be sneaky. It is much harder than you think. Geosynchronous orbit round the moon is already past the Earth. So it is impossible to place a space elevator in the classic way, to the geosynchronous point. However, it is possible to place a big lump of rock into one of the two La Grange points, and run the cable from there. Distance, 56,000 kms, which is a lot further than an Earth space elevator, where the geostationary point is 36,000 kms.
http://en.wikipedia.org/wiki/Lunar_space_elevator

Ah, yes, but it's not all about the length. It's the strength-to-weight ration that's critical.
You need a long cable for the moon, but it doesn't have to be anywhere near as strong, nor as light, as one on Earth.
We don't actually have any material strong and light enough to build a space elevator on Earth.
I think carbon nanotubes are theoretically strong enough, but would need to be continuous without a join, to do the job.
The longest achieved so far is less than a foot long, so they've got a long way to go!

But there are plenty of materials available today that would do for a moon elevator, because of the low pull of gravity. And the same goes for Mars.