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Space Elevator Conference Wraps Up
slavitos writes "The
Space Elevator: 2nd International Conference,
organized by the
Los Alamos National Lab
and the
Institute for
Scientific Research
has just finished its work in New Mexico.
To be sure, most people still think
it's absolutely ridiculous to even consider building
such a thing.
However, that's exactly what organizers
wanted - an open discussion on the issue, plus
some free PR."
I can't help but think that, if we ever start building this thing, people are going to be like, "There are starving children that need food, and we're spending how much on a frickin' elevator to space?!?!" or "With that much money, we could buy 10 aircraft carriers!".
Seriously, to many people, a "space elevator" is going to sound like the "escalator to nowhere" from the Simpsons - a fairly frivolous-sounding projet, and not as inspiring as rockets. Okay, so it'll make space exploration cheaper - what benefits does it have for ordinary people?
An attack on a remote freight elevator that happens to extend out to geosynchronous orbit would not engender the same psychological effect.
This reminds me of consulting with clients anout Internet security. The common attitude is "nobody would want to hack me". I always tell them that every reason they can think of for them not to be a target, somebody out there will interpret the other way.
Really, if I were a terrorist, I'd be opportunistic. If I had the opportunity to destory a project like this, I would. Is there any doubt it'd get people's attention? After all, that's what it is about.h In fact looked at as part of a campaign, it would make a great deal of strategic sense. The enemy should not feel that anything is safe, especially anything that costs a lot of money. By forcing him to spread his attention over many different kinds of targets, I not only cost him, but I also dilute his efforts. Maybe I'd like to crash a plane into the Sears tower, but chances are its too hard at the moment. Certainly a high profile attack will tighten security in the short run, but eventually efforts will wane, and its hard to police your own side when you have so many places to look after.
Taking this into account, if I hypothetically wanted to attack the Sears tower, and the Space Elevator existed today and was an easier target, I'd go for the SE. In the short run, the Sears tower would be a tougher target, but in eighteen months to two years it might actually become an easier target. You never know, just keep trying the enemy's defenses until they start to collapse.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
"a large target in wartime"
Flip it around. It's a means to get cargo to space (and maybe the only one) that can't readily be used as a weapon.
The base is fixed geographically. The cargo going up is dead slow, visible, and easy to track.
This is a good thing in wartime. Combatants can agree it's not a threat, and leave it alone.
Display some adaptability.
Eat at Joe's.
The pacific ocean near the equator is fairly calm, and is most likely where it would be anchored. Oil rigs are built to survive some of the harshest ocean conditions imaginable, and the cable base station would be a similar structure. Plus, there are ways to avoid a disaster. Just off the top of my head I came up with one, i'm sure there are others.
You put enough weight on the cable to equal the tension that's holding the low end down, then detach the end. Then the weight climbs up above the storm, rolling the cable behind it, and when it's all over lower the cable and reattach. It would be tricky but there's no reason it couldn't be done. You could pull the end right out of the atmosphere and use ion engines at each end to keep the orbit stable indefinitly while detached.
Um, yeah granted, but the aerobraking window at Mars is particularly narrow- the 'atmosphere' of Mars is very tenuous. Let's put it this way: Buzz Aldrin doesn't like it at all.
:) Yes, it's difficult, and the margin is small, but you can do it, and I believe they have in fact done it already.
Hence the reason that a computer should be the one to do it. Computers don't have to like it. They just have to do it.
Mommy state will help you out? Maybe, if there's votes in it.
Nah, this is simple economics. If you've got 5 missions planned to Mars in the next 5 years that cost $1 billion dollars, and the elevator would save you, say, $400 million and cost you $250 million, obviously, you're going to use the elevator. Hell, the government doesn't even have to okay it, depending on how it's budgeted, since it's the same amount of money and the same amount of science gets done. The point is that it's an immediate obvious cost benefit.
Well, the tether is millimeters wide, and you can't hit it with any speed otherwise you cut the tether and possibly open your vehicle to a vacuum. You're approaching it from thousands of kilometers away with an initial approach speed of maybe 1km/s or so. It's pretty much the same as docking with the ISS, only slightly harder and the stakes are even higher.
No no no - you're missing the point. The point is that the elevator is traveling at different velocities at different points along its length (i.e. its linear velocity is omega*R, since its rotational velocity is constant), and you choose the point of approach that will have the same linear velocity as you do when you're at the same point. So you're not approaching it with an initial approach speed of 1 km/s: you've got the same speed it does. There's going to be a little differential speed difference between you since it's rotating, and you're not -quite- rotating (it's got centripetal acceleration from tension, and you've just got gravity), but over a reasonable time frame, that should be minimal, since to a reasonable degree of accuracy, you're both going around the Earth. The differential velocity between you would be VERY minimal - probably meters an hour, not meters a second. Plus if your velocity isn't quite what you thought it would be, you just aim higher or lower.
The obvious addition here is that you could easily put a capture platform at the Mars approach point to make it safe. The main reason this is easier than docking with the ISS is because you're using gravity (and very simply kinematics!) to match velocity, rather than using thrusters.