Note: most of the first half of this post may be made irrelevant by the Orion space laser proposal. Most of the last four paragraphs are valid, though. Still, the architects of the laser acknowledge that it would be useless for large pieces of space debris. I also added the phrase "in the near term" in the sixth paragraph.
Two satellites, Iridium 33 and Kosmos-2251, slammed into each other at 12 km/sec on Tuesday, obliterating one another and creating a major junk cloud. The junk cloud will probably continue orbiting the Earth until we deploy a mote of utility fog hundreds of miles wide to clean it up. This is the first step on the road to the dreaded Kessler Syndrome, a phenomenon whereby more and more fragments of space junk are created in collisions giving rise to more collisions. The eventual result will be that it will be impossible to launch spaceships that aren't heavily shielded, and you won't be able to engage in extra-vehicular activity without a thick, unflexible, and well-armored power suit. We sure as hell won't be able to build a space elevator without major risk, because a cable a couple centimeters thick will get snapped easily by space junk with that much kinetic energy, unless heavily shielded.
The Liftport FAQ gives a 1/625 chance of catastrophic failure of a space elevator given a heavy meteor shower from the Leonids, and those rocks are about 3 inches big at most. Space junk can be much larger. You can move the anchor around to dodge most pieces of junk, but at some point it gets difficult, plus, if tourists are risking their lives every time they go up there, who will want to use it? Bits of space junk going at 12 km/sec travel about 10 times faster than a bullet, which gives them not 10 times as much kinetic energy, but, you guessed it, 100 times as much. That can hurt, even if you did the smart thing and replaced all your bones and muscles with fullerenes before going up there.
Space elevators, space elevators, space elevators. Who says transhumanists are excessively optimistic about technology? Here I am, criticizing space elevators and constantly going on about the risks of nanotech, robotics, synthetic biology, and AI. Meanwhile, yesterday I read an article by some conservative Christian who is criticizing transhumanists by saying we are "embracing any and all forms of the new technologies", with "almost no qualms about all the controversial technologies of the day". Working for the Lifeboat Foundation, qualming is practically all I ever do all day. What else? Two weeks ago, when I published the benefits of uploading post, some people were going on about how I was only focusing on the upsides and not the downsides. But notice how the category "risks" on this blog has the second-most posts out of any tag, second only to "transhumanism". I act positive for one minute, write a post short enough that people might actually read it, thereby necessitating my leaving out the potential downsides, and someone's there to jump on me.
In fact, there's been points in the past where all I do is talk about risks and possible roadblocks and people say I'm being too Apocalyptic. Then, I write something about the benefits of some possible future technology, and get people who say I'm being too Utopian. Make up your mind! If I had to choose one, I would definitely take Apocalyptic. Given the stupidity of humans and the power of our technology, I think you'd have to be uneducated not to be Apocalyptic, frankly.
Back to the space situation. The more we colonize space, the more junk we will create and the more heavily shielded every craft will need to be. So you can forget rockets. We're already just throwing away money right now by even bothering to send people up into space on rockets, which have the terrible tendency of spontaneously exploding (what else would you expect from a bomb with a hole poked in the side?) We should be investing all our money in novel ways to get to space, like developing better manufacturing technologies to actually build spacecraft that are truly strong and light. Meanwhile, all the articles on the satellite collision are saying, "Litter in orbit - caused in part by the break-ups of old satellites - has increased to such an extent that it is now the biggest threat to a space shuttle in flight." If it's a threat now, when there's only been one major satellite-satellite collision, I can't wait to see what it will be in a few decades, when we see more of these events occurring. Of course, even if we start making spacecraft out of fullerenes, fullerene debris will be generated soon enough.
It's hard to get around it -- space junk is going to be a showstopper when it comes to colonizing orbit in the near term. That's alright, though, because we have a lot of other colonization to do. How about colonizing the oceans? They're empty. Or hey, what about colonizing the deserts? Barely anyone lives in them, and they're brimming over with solar and thermal energy. How about mountains? 25% of the world's land area is mountainous, including 67% of Asia, but barely anyone lives on the things. How about colonizing Antarctica? Way, way, way easier and cheaper than colonizing space. People don't think of these wonderful opportunities because they grew up letting television (Star Trek) think for them.
Space has no air, warmth, water, life, pressure, or much matter to speak of. Antarctica has all these things. Before we colonize space, we should be able to colonize Antarctica easily. If we can't colonize Antarctica, then what are we doing in space? Without molecular manufacturing, it will lead to nothing but tears and broken dreams. Even with it, colonizing Antarctica would be much more exciting. Of course, there's the Moon, but the Moon is freezing, geologically boring, and there's nothing there that isn't already here. Plus, there's the danger of solar storms, which can kill anyone in the open in mere minutes. That will ruin your day.
The excitement of space will end when people go there and get over the novelty of eating M&Ms in weightlessness and the ability to see the Earth. People will realize the shocking fact that there's nothing there. Hence the term space, as in empty space. What matter does exist up there will be constantly threatening to punch a hole right through your body, like a rail gun, moving at 12 km/sec. If you think the Earth is crowded now, try living in a space station. Until we gain the ability to create huge (miles wide or larger) air bubbles in space enclosed by rapidly self-healing transparent membranes, it will be cramped and overwhelmingly boring. You'll spend even more time on the Internet up there than down here, and your connection will be slow.
Why life extensionists would want to go up in space without advanced molecular nanotech (MNT) to protect themselves is beyond me. If you take a look at the history of space exploration, it often consists of people dying in unpleasant and unexpected ways. Death by depressurization. Death during launch. Death during reentry. If the Apollo 13 crew didn't stir their oxygen tank on the way to the Moon, earlier than they planned, then they would have stirred it while one astronaut was in lunar orbit and the other two were on the surface. The astronaut in lunar orbit would have died due to freezing to death, meanwhile the two on the Moon's surface would be stuck there until their oxygen ran out. Imagine the impact that would have had on getting the new generation excited about space travel. How many more have to die before we realize that sending people into space without MNT is stupid?