How far are we from colonizing off Earth?

[Merkuri]

Regarding colonizing exoplanets, Voyager I was launched in the 70s, and it's just barely breached the edge of our solar system. Our long-scale transportation technology hasn't improved much since then. At least, we're still nowhere near other star systems.

I think sci-fi shows like Star Trek have spoiled a lot of us into not realizing how huge our own solar system is. Carl Sagan sums it up best in his comments about the Pale Blue Dot photo taken by Voyager I. Voyager had turned its camera around and taken a picture of Earth from the edges of the solar system, and our planet was just a single pixel. To quote Sagan:

From this distant vantage point, the Earth might not seem of particular interest. But for us, it's different. Consider again that dot. That's here, that's home, that's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

Before we go colonizing other planets, not only do we need to greatly advance our travel technology, but we need to find those other planets. I believe someone earlier in the thread said that the nearest known exoplanet was orbiting Epsilon Eridani, but I'm pretty sure that this planet is a gas giant, not suited for humans to land on (never mind live on). In fact, just about every exoplanet we've found so far is a gas giant. I don't think we have the technology yet to detect tiny earth-like planets.

So not only do we need to find a way to get to exoplanets, we need to find them first. We're a very long way away from that unless there are a couple of major scientific breakthroughs in the next few years.

 

[Plane Sailing]

The Project Orion. It would get you to Proxima Centauri in 85 years.

Is that in "objective" time1 from the point of view of the observer on earth, or subjective time1 from the point of view of the astronauts on board the Orion?

Time dilation due to special relativity makes it somewhat less boring for the travellers if you get fast enough.



1. Yes, I know it is all subjective to the frame of reference, but I hope that phrasing it this way might make the question more generally intelligible

 

[El Mahdi]

How far are we from colonizing off Earth?

Well, on average, about 240,000 miles from the Moon and varies between 35 million and 250 million miles for Mars...




Okay, all kidding aside...

For the last few years it looked like we were maybe about 10 or 15 years from "colonizing" the Moon, and maybe as little as 30 years from "colonizing" Mars - but then the Constellation program was cancelled...

We have the technology to be able to do it (or at least the ability to develop the technology), but like others are saying, we don't seem to have the motivation.

Right now, it looks like the leading impetus for any type of colonization on the moon might be commercial tourism. As for official research and exploration type colonization, it seems to be on permanent high-speed hold. Until the world's economies significantly improve, I just don't see it happening. Perhaps it won't happen at all until population pressure and resource shortages make it necessary? It could even be the next century before it happens...

 

[Pbartender]

Technically, we have the know-how to colonize the local solar system now, though as Umbran said, it would take a few years at the least to build the necessary equipment to do it with.

The problem is that, as others have said, there's no good reason to do it, other than to say we we did it.

It's going to be a long, long time before shipping exploitable resources in from other planets becomes cheaper than trying to squeeze more out of the Earth. At this point, it's a far better use of our time to advance reclamation and recycling technology, than off-world mining technology.

And as far as population concerns go... How many people do expect to ship off-world? The world-wide population growth is something like 75 million people a year. Right now, we can put about a half dozen people into orbit at a time.

So, while it feasible that it could be done, there's no real terribly good reason to do it, other than for exploration's sake.

 

[jonesy]

Is that in "objective" time1 from the point of view of the observer on earth, or subjective time1 from the point of view of the astronauts on board the Orion?

I took the most optimistic estimate of the Orions speed, which is 5% of the speed of light. At that speed 1 day for crew equals 1.001252 days for Earth. 85 years for the crew is then 85.1 years for Earth.

Edit: one needs to remember that the Orions speeds are all rough estimates. One of the reasons why it's so slow (hah!) is that it's not a linear speed. The Orion works by repeatedly accelerating itself with repeated nuclear detonations. It takes time to reach certain speeds. Nobody knows what the actual top speed would have been because the tests were cancelled because of the nuclear test ban treaties in the 60's.

 

[Umbran]

The fastest theoretically viable stardrive at the moment seems to be nuclear pulse propulsion (correct me if you find something faster, please). The Project Orion. It would get you to Proxima Centauri in 85 years. If you used the Ion drive we now have working, 8000 years. Yeah.

One small note: you're comparing a drive system that is theoretical (a nuclear pulse drive that we've never built) to something that currently exists (the ion drive we have now). Type mismatch.

The next generation of ion drives that are being tested produce thrust 10 to 100 times greater than the current ion drives we've actually used on missions. They are not, as I understand it, near the theoretical maximum.

 

[jonesy]

One small note: you're comparing a drive system that is theoretical (a nuclear pulse drive that we've never built) to something that currently exists (the ion drive we have now). Type mismatch.

Yup.

The next generation of ion drives that are being tested produce thrust 10 to 100 times greater than the current ion drives we've actually used on missions. They are not, as I understand it, near the theoretical maximum.

80000/100 = 800 years. I hope the theoretical max of those is a lot better.

By the way, there is something theoretical that is actually faster than the Orion. Remember the cool ship at the beginning of Avatar? That's actually based on the Valkyrie antimatter propulsion model. It could get you to 92% lightspeed. Guess what the downside is? Antimatter is expensive enough to bankrupt the entire planet several times over.

 

[jonesy]

Oh, and if you're wondering about relativity at 92% lightspeed: 1 day for crew would be 2.551552 days for Earth. Still not that bad, but after that point the ratio is going to start going up pretty darn fast. When you get past 98% even fractions of fractions will add weeks to the difference.

 

[TanisFrey]

Yeah, until there's some kind of economic benefit or need to colonize I don't see it happening any time soon.

If a Mars probe found a valuable material you could have governments up there in no time.

As an aside. Is buying land on the Moon actually recognized as your property?

There is an international treaty preventing any nation from claiming any portion of the lunar surface as part of their territory. (I think that it extended to other portions of the solar system also) This pretty well kills anyone ability to buying land on the moon.

 

[hafrogman]

There is an international treaty preventing any nation from claiming any portion of the lunar surface as part of their territory. (I think that it extended to other portions of the solar system also) This pretty well kills anyone ability to buying land on the moon.

Or you land there and declare independance as a sovereign nation, unconstrained by treaties you're not a signatory body to. Of course, this leaves all the other nations of the planet free to invade you ... but given the prohibitive cost of getting bullets, guns, soldiers and tanks to the moon ... you could be pretty safe.