How on earth to reach space.
How indeed.
It turns out that space is rather hostile to humans. We're going to need alot of new technologies to make this happen.
Problem no.1: Getting to low-earth orbit.
Much more difficult than the recent x-prize winner made it seem, ofcourse -he didn't go to low-earth orbit. He didn't go to orbit at all.
It'll take *far* more power and speed to do it(50 times the power at 10 times the speed).
Chemical rockets are just not powerful enough to ever become economically viable as a means of getting in orbit, for not to mention all that pollution if launches were very frequent(as they need to be).
We need something else to "open up space". We need the ability to haul thousands of tons of stuff into orbit every year. Now were spending God only knows how many years to build the ISS. How long at this tempo before we have an interplanetary spaceship, for not to mention fleets of them? 50 years? 100 years?
What we need is a novel approach. The space elevator is one.
It is a simple concept. Launch a satelite with really long cables. Lower the cables from orbit to the surface of the planet. Send stuff up by attaching carts to the cable, like a vertical train or -indeed, an elevator.
Dirt cheap, nothing can explode.
However we can't build that now, why? 'Cause we need to make that cable really strong and lightweight and we can't. Yet. The solution is nano-carbon, tubes of nano-carbon have superior strength and is very lightweight. The problem is that that strength is lost when you put alot of them together, and a cable reaching up to orbit is really long. Help is at hand though, scientists are getting ever better at manufacturing and are making longer and longer tubes; now, researchers at Los Alamos National Laboratory and Duke University have created nanotubes that are centimeters long, prior efforts have been limited to tenths of millimeters. The scientists say they can make the tubes as long as the chamber they create them in.
In less than ten years we will probably know if this material will suffice to create a space elevator. But what if it doesn't?
Another alternative is lasers.
Lasers pack alot of punch in a focused beam and that could be used to power a spaceship. Experiments are already under way and scientist have already made saucers fly, though this idea also rely on technology we still don't have, such as a powerful enough laser. Scaling up lasers have been problematic and this is why we still haven't seen any widespread military applications yet.
And then there is plenty of outlandish ideas...
So... let's say we made it to orbit with thousands of ton of stuff.
We use it to build an interplanetary space-ship. And then we go tumbling down the gravity well(or rabbit hole if you wish). We need gravity on the space-ship, our astronauts in orbit are losing their bones in zero-g(and they don't spend a really long time there) so in with the large rotating drums. We will also need protection from radiation(much harsher in space than here -a roundtrip to Mars now would virtually guarantee lethal cancer for the whole crew). We don't have any magic here either; I don't know what would be best but I can imagine thick sheets of lead would be helpful, but lead is very heavy to haul up in orbit. I've heard regolith(moon-dust) would be useful in this respect.
To use regolith we'll need to establish a presence on the moon, at the very least we will need automated factories to scoop it up and process it. We'll need humans to build it there and the establishment of a permanent base seems inevitable. On the moon we could also have a space elevator, however due to the much lower gravity we could potentially build one from materials we already have. The moon also have other useful things, like ice. Ice is frozen water, it can be thawed and drunken; hydrogen can be extracted to power fuel-cells or rockets, oxygen can extracted for breating.
All for a fraction of the cost of hauling it up from the earth.
Now, to get anywhere in our near completed ship we'll need propulsion. Chemical rockets eats fuel like fat guys eats burgers. Nuclear powered ion drives are much better in terms of fuel efficiency but they're not anywhere where they need to be as far as weight to power ratio is concerned. We will need to build a much better nuclear reactor for this to work and that will take time.
And so, now, in 2005. We're still not on Mars, or even the moon, and we're not going for awhile either. We need breakthroughs in science. Better materials, better engines, a better way to orbit.
Recent sci-fi describes us as stuck on the earth rather than exploring in deep space in the near future. I guess we'll still be stuck on earth awhile, but I am optimistic about new materials technology. I think we'll see serious breakthroughs in the next few years, perhaps exactly of the kind to enable space research.
anyways
b
It turns out that space is rather hostile to humans. We're going to need alot of new technologies to make this happen.
Problem no.1: Getting to low-earth orbit.
Much more difficult than the recent x-prize winner made it seem, ofcourse -he didn't go to low-earth orbit. He didn't go to orbit at all.
It'll take *far* more power and speed to do it(50 times the power at 10 times the speed).
Chemical rockets are just not powerful enough to ever become economically viable as a means of getting in orbit, for not to mention all that pollution if launches were very frequent(as they need to be).
We need something else to "open up space". We need the ability to haul thousands of tons of stuff into orbit every year. Now were spending God only knows how many years to build the ISS. How long at this tempo before we have an interplanetary spaceship, for not to mention fleets of them? 50 years? 100 years?
What we need is a novel approach. The space elevator is one.
It is a simple concept. Launch a satelite with really long cables. Lower the cables from orbit to the surface of the planet. Send stuff up by attaching carts to the cable, like a vertical train or -indeed, an elevator.
Dirt cheap, nothing can explode.
However we can't build that now, why? 'Cause we need to make that cable really strong and lightweight and we can't. Yet. The solution is nano-carbon, tubes of nano-carbon have superior strength and is very lightweight. The problem is that that strength is lost when you put alot of them together, and a cable reaching up to orbit is really long. Help is at hand though, scientists are getting ever better at manufacturing and are making longer and longer tubes; now, researchers at Los Alamos National Laboratory and Duke University have created nanotubes that are centimeters long, prior efforts have been limited to tenths of millimeters. The scientists say they can make the tubes as long as the chamber they create them in.
In less than ten years we will probably know if this material will suffice to create a space elevator. But what if it doesn't?
Another alternative is lasers.
Lasers pack alot of punch in a focused beam and that could be used to power a spaceship. Experiments are already under way and scientist have already made saucers fly, though this idea also rely on technology we still don't have, such as a powerful enough laser. Scaling up lasers have been problematic and this is why we still haven't seen any widespread military applications yet.
And then there is plenty of outlandish ideas...
So... let's say we made it to orbit with thousands of ton of stuff.
We use it to build an interplanetary space-ship. And then we go tumbling down the gravity well(or rabbit hole if you wish). We need gravity on the space-ship, our astronauts in orbit are losing their bones in zero-g(and they don't spend a really long time there) so in with the large rotating drums. We will also need protection from radiation(much harsher in space than here -a roundtrip to Mars now would virtually guarantee lethal cancer for the whole crew). We don't have any magic here either; I don't know what would be best but I can imagine thick sheets of lead would be helpful, but lead is very heavy to haul up in orbit. I've heard regolith(moon-dust) would be useful in this respect.
To use regolith we'll need to establish a presence on the moon, at the very least we will need automated factories to scoop it up and process it. We'll need humans to build it there and the establishment of a permanent base seems inevitable. On the moon we could also have a space elevator, however due to the much lower gravity we could potentially build one from materials we already have. The moon also have other useful things, like ice. Ice is frozen water, it can be thawed and drunken; hydrogen can be extracted to power fuel-cells or rockets, oxygen can extracted for breating.
All for a fraction of the cost of hauling it up from the earth.
Now, to get anywhere in our near completed ship we'll need propulsion. Chemical rockets eats fuel like fat guys eats burgers. Nuclear powered ion drives are much better in terms of fuel efficiency but they're not anywhere where they need to be as far as weight to power ratio is concerned. We will need to build a much better nuclear reactor for this to work and that will take time.
And so, now, in 2005. We're still not on Mars, or even the moon, and we're not going for awhile either. We need breakthroughs in science. Better materials, better engines, a better way to orbit.
Recent sci-fi describes us as stuck on the earth rather than exploring in deep space in the near future. I guess we'll still be stuck on earth awhile, but I am optimistic about new materials technology. I think we'll see serious breakthroughs in the next few years, perhaps exactly of the kind to enable space research.
anyways
b
posted by bangskij at 13:31
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