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The Lack of Space Travel

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Being a resident of the United States, as well as having a knack for all things space-related, the lack of any kind of movement to explore outer space has me not only annoyed, but also genuinely concerned. While I do realize that technically we're in an economic "crisis," the fact that no major manned missions into space beyond Earth's gravitational pull have been made since the 60's has left me wondering if and when we'll get back on track.

 

Logically, space exploration, along with deep ocean diving, is humanity's next step for a major expansion. We've used up pretty much all of the habitable areas on our planet, and while there are a couple more frontiers left like underground, underwater, and Antarctica, expansion into space seems a lot more attractive at this point because, well, there's a lot of space in space. It would solve many of society's problems on a global level: it would provide countless jobs for unemployed workers, completely negate the negative side effects of pollution and the dumping of hazardous materials, and allow for virtually infinite population growth. The many industries formed from space travel would provide unfathomable economic and social benefits, and most importantly it would be downright awesome.

 

So why aren't we going there? I haven't the slightest of clues other than a couple guesses. The sheer cost of it seems to be a major barrier, especially with the rising prices of oil and other fossil fuels.

 

So, how do we go about getting the U.S. (or your own applicable space-hating country) to get going to space? I see two possible solutions:

 

1) Develop a more reliable, inexpensive, preferably renewable source of energy capable of powering spacecraft.

 

2) Lie. Publish in Time Magazine that there is oil on Mars, watch the mad rush to jump onto the space oil bandwagon, and by the time everyone figures out that they've been duped, all the infrastructure for a colony would have been laid out, all the bureaucracy dealt with, and the world expecting something to happen. They would have no choice but to continue on with meager colonization, while Time shrugs and gives themselves a pat on the back.

 

So what about you? Are you concerned about the lack of rocket ships leaving Earth's atmosphere? Any reasons why we aren't going there now, or any proposed solutions to make it happen?

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#1 is pretty much the more likely solution of the ones you posted, although I'm not very confident we can harness a cheap, useful source of fuel. That's probably why space travel isn't cost effective as of now, which explains the relatively low amount of privately owned businesses that focus entirely on manned space missions. There's plenty of resources available in space, but as of now, we don't have much of a way of harvesting them in a way that can return a profit for people who invest in the companies who choose to do so. The cheapest launches (unmanned, light payload) can run tens of millions of US dollars to put in low earth orbit. A space shuttle launch usually ran in the neighborhood of 1.2 billion (http://www.nature.com/nature/journal/v472/n7341/full/472038d.html). Current permanent settlements on the moon are still in the conceptual stage (ex: http://www.nasa.gov/pdf/240373main_06-06-08-LSS%20BAA%20Compilation%20of%20briefings%20teammb.pdf).

 

What can be done about this? Pump more money into NASA? Offer incentives to spacefaring companies?

 

I believe that constructing permanent human settlements in space is the first step towards extending the reaches of humanity. Ukraine is working with the US in producing a Stanford Torus space station (imagine Halo on a small scale: http://www.globalpost.com/dispatch/news/regions/europe/111219/will-ukraine-tilt-east-or-west). I think stations like these will be the best candidates for permanent space habitation. As for colonization of other planets and moons, I think that Mars is the most viable option.

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Actually, Mars isn't at the top of the list for easiest to colonize... That distinction is reserved by some of the moons of Jupiter & Saturn. Mars is just closer, and is closer to Earth's gravity. (slightly)

 

I personally prefer the idea of colonizing the asteroid belt, because then we can also mine the resources from them.

 

Space travel would still be very dangerous outside of Earth's electromagnetic field due to solar radiation, and the all-too-common solar flares.

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Well, I think as a nation we have more immediate problems facing us than space travel. We're becoming barely competent enough to manage our own country; last year we not only threatened to shut down the government, but also came way too close to defaulting on the national debt, which would have rapidly accelerated a global economic depression. We have more than enough resources to fund space travel for a long time, it's just a matter of distribution and what our government sees as a priority for allocating funds. The War in Iraq alone could have funded quite a bit of additional efforts in the space program. Space travel is the sort of thing that is ultimately necessary for the survival of humanity and a great thing to strive for, but it's also the sort of thing we could put off for a million years and still have plenty of time to do something.

 

I personally would like to see a LOT more resources devoted to spotting as many incoming asteroids as possible. I see something like that as the best insurance policy for humanity we can have.

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I really don't mean to sound jerk-ish, Ross, but that's, erm, impossible.

 

Hypothetically, if all the asteroids in the night sky were lit up so that they outshone stars, the entire sky would be white. There are probably billions of asteroids in the sky, coming largely from three locations in our solar system: the Asteroid Belt, the Kuiper Belt, and the Oort Cloud.

 

The Asteroid Belt is basically the Planet that failed. It's in a perfect position for a planet, except that it couldn't really form because of that gigantic nearly dwarf sun nearby, Jupiter. Asteroids there number in the thousands to millions, with about 400,000 kilometers of elbow room apiece, give or take.

 

The Kuiper Belt lies beyond Neptune. The most famous object there, of course, is Pluto. That region is around where comets hibernate. The asteroids there are a lot closer together, and far more numerous than the asteroid belt, because it's basically the edge of the accretion disc that formed the planets. There wasn't a planetesimal able to create a planet, so the stuff kind of hangs out in the same general plane as the rest of the planets.

 

Now for the fun one. The Oort Cloud. It's typically modeled as a sphere around our solar system, mostly made of dust, a few hundred light years away. Luckily, there's no real worry about an asteroid from here.

 

So, back to the two asteroid culprits, Asteroid and Kuiper Belt. The stuff there is pretty steady and actually pretty small. Ceres is the largest, and it seems to be the exception at 900 kilometers across. The vast majority are under a kilometer, meaning they'd burn up in the atmosphere if not just slingshotted into the sun. Anything bigger, and there's some real crazy things that have to happen. First, they have to be slingshotted into the inner solar system, probably by Jupiter. Then, they have to be crossing Earth's path exactly when we're in that position. Assume it's something like a 1/365 chance, though we're moving so damn fast that it's a lot smaller. Then, it can't skim the atmosphere, it has to hit dead-on. Then, it has to be about 10 kilometers to hit the surface and cause destruction. Oh, it has to hit the 30 percent of the planet that's above water, otherwise it'd probably just cause a tsunami. It's such an astronomically small number that its better not to worry about tracking all incoming asteroids. Should be limited to anything that's, say, 5 kilometers or larger. Large enough to cause damage to the surface. Anything smaller's just going to burn up or, at worst, cause a small amount of damage. It might kill you, might ruin the neighborhood's week, but it won't destroy the planet.

 

Sorry if that's long and boring and I sound like a jackass.

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we could put off for a million years and still have plenty of time to do something

 

I've heard this argument many times but I am not convinced it is valid. Mainly due to 2 points:

 

- we are not good at making things perfect at home instead of going out, looking for something interesting. There must be an evolutionary reason behind it somewhere. If you spend all your time cleaning up your cave you are going to miss all the mammoths, which will then become food for a tribe in a nearby cave whose members are not so introverted...

 

- There is less and less scope for the "developed" nations to find sources of economic growth here on Earth. The "developing" countries have learned how to make things, they will learn how to invent things that work well enough not to need the Western "intellectual property", they also sit on the most of the Earth's natural resources. What will the West trade for the labour and manufactured products then?

 

Should be limited to anything that's, say, 5 kilometers or larger.

 

I think you are a bit optimistic about the minimal size needed to do a lot of damage. AFAIK, the Tunguska meteorite is estimated to be much smaller than that - may be 100m or so, yet it could have ruined a major city if it'd hit a denser populated area instead of the middle of nowhere, as it did.

 

Regards

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I think you are a bit optimistic about the minimal size needed to do a lot of damage. AFAIK, the Tunguska meteorite is estimated to be much smaller than that - may be 100m or so, yet it could have ruined a major city if it'd hit a denser populated area instead of the middle of nowhere, as it did.

 

Regards

 

Tunguska is also assumed to be a Comet, and that's a whole different story. Since it was a mix of rock and ice and perhaps a core of deuterium, well, what happened was nuclear fusion. Comet enters atmosphere, shatters because the ice burns away, and then you got a very fast moving glob of extremely reactive material.

 

It's a different story. Different materials. Different results. Like taking a jawbreaker and smashing it into a wall, then a hunk of granola and smashing it. They might both break, but one is going to be far more explosive.

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There are many hypotheses about Tunguska. Fusion is one of the least likely, fringe ones. Most likely is that it was a bunch of loosely bound rocks (perhaps glued together with ice - maybe a comet core, maybe an asteroid) and all of the mass burned up before reaching the surface, resulting in a thermal airburst. Had it been a denser rock it would have slammed into the ground and made a big nice hole, like the one in Arizona. Either way, the result would have been similar as the magnitude of energy released would have been roughly the same (given similar mass and velocity).

 

Regards

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There are many hypotheses about Tunguska. Fusion is one of the least likely, fringe ones. Most likely is that it was a bunch of loosely bound rocks (perhaps glued together with ice - maybe a comet core, maybe an asteroid) and all of the mass burned up before reaching the surface, resulting in a thermal airburst. Had it been a denser rock it would have slammed into the ground and made a big nice hole, like the one in Arizona. Either way, the result would have been similar as the magnitude of energy released would have been roughly the same (given similar mass and velocity).

 

Regards

 

You admit that there are many hypothesis to that event. Why say earlier that it was an asteroid event? It's an outlier - any good astronomer would throw it out when discussing the threat that asteroids play on Earth. There's just too much that makes the event weird - Tree bark samples point to asteroid, but eyewitness events of clouds plus the most recent study point squarely at comet. There's no right answer, and we shouldn't look at the one event that has too much conflicting evidence when we have thousands of events confirmed as asteroids or meteoroids.

 

It's a simple thing. Don't make policy on conspiracy.

 

(For the record, I don't consider Hydrogen core reaction to be the least likely explanation. Come on, Wardenclyffe tower, a UFO, an anti-matter comet, and a damn black hole are the least likely/fringe ones. Deuterium core is unlikely, but it's certainly more likely than things that break the laws of physics.)

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You may note that I did not say whether or not something was an asteroid or cometary impact. All I said was that 5 km lower threshold is a big underestimation of the potential danger of an impactor.

 

Whether Tunguska was solid or loose it does not change the energy. The consensus is that it *was* significantly smaller than your minimal size. In all likelihood there are plenty more where that came from, regardless whether it was a comet or a rock or a lump of metal.

 

Regards

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You may note that I did not say whether or not something was an asteroid or cometary impact. All I said was that 5 km lower threshold is a big underestimation of the potential danger of an impactor.

 

Whether Tunguska was solid or loose it does not change the energy. The consensus is that it *was* significantly smaller than your minimal size. In all likelihood there are plenty more where that came from, regardless whether it was a comet or a rock or a lump of metal.

 

Regards

 

Like I said, it seems to be the exception, not the rule. For general, rocky asteroids, it's best to assume that a 5 kilometer threshold is a good start. Otherwise, a red alert would be occurring every twelve hours. There hasn't been a Tunguska-like event since Tunguska.

 

How's this. Split the difference, only look for asteroids 1 kilometer or larger in diameter. This says that even those events are rare. Last impact event that was 1 kilometer or greater in the original rock was 65 million years ago. Fact is, most asteroids aren't even that big. 30 million estimated to be less than a kilometer, as compared to maybe 1.25 million to be more than a kilometer. I mean, I don't see the point of looking for every asteroid when it'll cause widespread panic because one's gonna be in Earth's orbit. Waste of resources.

 

My point still stands. Never make a policy around an outlier. Just trim out the outliers, prevent skewed data.

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I really don't mean to sound jerk-ish, Ross, but that's, erm, impossible.
I think there might be some misunderstanding. What I meant was "really dangerous ones as possible." We can't spot more than a fraction of all the ones coming towards us, however it makes sense to look for as many as possible for that 0.00001% chance of finding a devastating one we could potentially deflect in time if it was spotted. Besides spotting "as many as possible" isn't impossible, it's possible. If you can only spot 3 out out of 10,000, that's as "many as possible." If you use more resources and can spot 50 out of 10,000, that's still "as many as possible." Are we really at maximum capacity for the number of dangerous asteroids we could spot even if we had more people / equipment devoted to it?

 

- we are not good at making things perfect at home instead of going out, looking for something interesting. There must be an evolutionary reason behind it somewhere. If you spend all your time cleaning up your cave you are going to miss all the mammoths, which will then become food for a tribe in a nearby cave whose members are not so introverted...
Well I think a more apt comparison would be whether it would be better to work on making a flying machine or hunting for food for the village. Yes, one is more introverted, but it's a lot more practical. Plus, we basically know what's in our solar system. We could probably get additional minerals or gases if we developed our space program enough, but there's not a whole lot out there that's of much practical value to us. To really make space a new frontier for us, I see at least one of two things having to occur first:

 

1. Build some massive biosphere ship that could be sent into deep space that generations could live on. This would require so many resources and cooperation though that I don't see anything like this being possible within our current civilization. We were threatening to nuke ourselves to extinction just 40 years ago.

 

2. Make some magic physics breakthrough allowing us to travel as or faster than light. Assuming this is even possible (which it might not be), this is something that we could figure out on Earth first.

 

Until then, I see space exploration as very interesting, but kind of like trying to cross the Atlantic using only man-powered flying machines.

 

- There is less and less scope for the "developed" nations to find sources of economic growth here on Earth. The "developing" countries have learned how to make things, they will learn how to invent things that work well enough not to need the Western "intellectual property", they also sit on the most of the Earth's natural resources. What will the West trade for the labour and manufactured products then?
That's an excellent question and I see an answer to this happening WAY before our space travel gets much more developed. I think what will eventually happen is we'll either see a repeating cycle of growth and collapse or eventually move towards a system that doesn't depend on perpetual growth to be successful.

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We have no incentives yet to send generation ships anywhere. This may change overnight once a habitable exo-planet is discovered relatively close by.

 

Solar System exploration though is a different matter. Whoever get there first will have access to tremendous resources, potentially break-through micro-G manufacturing technologies and, not least, a great tourism potential.

 

Establish a colony on Mars and/or Moon and/or Asteroid belt, then trade with them - that's how all empires grew in the past.

 

The issues of energy costs and lack of suitable propulsion are valid but not insurmountable, especially if you consider nuclear propulsion (thermal or electric) which promises large enough specific impulse to make a trip to Mars feasible. More like Columbus-time caravel than a hand-powered plane...

 

eventually move towards a system that doesn't depend on perpetual growth to be successful

 

I don't believe it's possible. I think we can either expand or go extinct, "sustainability" is not favoured by nature, it seems.

 

We need an initiator - a country or a private enterprise - to build a mine on an asteroid or a powerplant on the Moon and all of a sudden there will be a gold rush and the West will stand a good chance to lead and gain competitive advantage.

 

Regards

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Establish a colony on Mars and/or Moon and/or Asteroid belt, then trade with them - that's how all empires grew in the past.
The difference is colonies in the past had a lot of native resources to work with. This would be more akin to sending colonies to the Sahara Desert or Antarctica. Unless you want to trade for sand or ice, and at a really high price, there's not any reason to go there on an economic incentive.

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That's a tough one to answer... If I knew exactly what to go for I'd be Elon Musk's partner :-)

 

I'm sure there are fortunes to be made there but on what? Hellas Planitia sparkling mineral water? Martian hematite jewelry? Organic vegetables from the Moon? Eros stainless steel?

 

Regards

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The difference is colonies in the past had a lot of native resources to work with. This would be more akin to sending colonies to the Sahara Desert or Antarctica. Unless you want to trade for sand or ice, and at a really high price, there's not any reason to go there on an economic incentive.

http://www.theregister.co.uk/2011/04/06/wassonite/

 

So you're saying that exotic/new minerals, that don't exist on Earth, aren't an abundant natural resource?

 

How about the various non-exotics that we already know are common in the asteroids, and would be extremely valuable here on Earth? Stuff that when calculated into the costs of R&D + actual harvesting end up paying for itself more than 10x over.

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Solar system trade would totally revamp our economic system.

 

Water on Earth? Cheap as hell. Can't get rid of the stuff, sometimes.

 

Water on the Moon? Worth more than its weight in gold.

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Incidentally, the late Eugene Shoemaker estimated that we get with with about three meteors big enough to cause a Hiroshima-sized explosion every year. Fortunately, they usually explode over water.

 

But imagine one of those exploding close, over land. Or impacting. Over a nuclear-powered nation. One with enemies, or slightly nutty leaders, or both.

 

What do you think the instictive response would be? Wouldn't you expect something like "OMGWTF Someone set us up the bomb! Fire everything!" I would, because people are jerks.

 

Also... an impact in the sea would "only" cause a Tsunami??? Have you been ALIVE at any point since 2004?? (Or read "Footfall?")

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Water on the Moon? Worth more than its weight in gold.
Gold which would also be from Earth. I think the only exportable resource you would have on the moon that wouldn't be something sent BACK to Earth would be moon rock.

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