In a civilization where spaceships are advanced enough to move around in the solar system with relative ease, but without the capacity to actually go to other star systems in any reasonable time, how expensive would lifting things to orbit be? I ran into some figures claiming that with modern technology, the cost of sending something to orbit is about 10,000$ to a kilogram, but I'm not sure how accurate this figure is. Ludicrous cost anyway.
Anyway, given that these people can send cargo across a solar system using hydrogen fusion powered engines, mine pluto (or other planets and asteroids) and built giant spinning orbital stations. However, most of their spacecraft would be built on said space stations, and never actually land on planets with decent gravity.
Given that they have mastered the use of carbon nanotubes and hydrogen fusion powered engines, what would be the most efficient way to ship things off planet? Space elevator? Rocket? I'm trying to keep this particular sci-fi rather hard, and I'm at a bit of a loss on what would make sense here.
Note: Not sure if this belongs in reference desk or here. I put it here because it's a question largely reliant on the quirks of my setting, but it's about physics and economics so....
The cost of lifting things into orbit would change over time. It used to take months to send a letter around the world; now it is practically free. The cost of shipping packages changes with technology. As a writer, you do not have to predict the exact cost - just the relative cost. At some point, when technology and demand get at the right point, the price will be low enough that people will send the same junk into space that they send across the state or country.
The space elevator idea sounds interesting. How about if FedEx had a huge hub at a geosynchronous position, and then shipped things sent up from earth to all points solar system wide?
A space elevator can reduce that to about $100/pound once the cost of the elevator it's self is covered. That's the basic matenence cost and the cost of the energy required to lift on the elevator, so if you have perfect nuclear fusion for power instead of propulsion or some similar low-cost energy, then it would become even cheeper. Add that to the current cost of fedexing a package and you've got a decent guess at space travel.
Ten thousand dollars a pound is the frequently quoted cost to put a pound into orbit. (I verified it with the NASA website.) Given the technology we have, the cost is a reflection of both the hardware and the support staff it takes to do the job. It wouldn't work well for a space going society. (The cost isn't ludicrous, it just reflects the reality of Version 0.1 to 0.6 technology.)
I believe that the 'affordable' target is ten dollars a pound to LEO. (Low Earth Orbit)
A space elevator would work. I've read one story where it paid for itself because of the power it generated.
If you are sending up bulk materials, a mass driver equivalent would work, especially for materials that can take a few Gs on liftoff. It wouldn't be good for people though.
Anti-gravity would be useful because you could go from ground to orbit without putting a lot of stress on the passengers or cargo. Anti-gravity could be part of a technology that allows Star Trek style gravitational fields on board space ships.
With fusion powered engines, a space plane would work too. There might be issues with heat load on the planet though. (It could be used for FedEx 'Got to have it NOW' type deliveries.)
Star Trek style transporters would also be a possibility. They might require teleportation pads at both ends to be cost effective. If their range is two hundred miles or so, you might need to carefully place the ground based stations so they can reach LEO sites. You might even have to schedule things so that the LEO station you end up at varies as they go into and out of range.
You might have a situation where the amount of shipping from Earth is minimal because most of the raw materials and a lot of manufactured goods are space based. About the only things being shipped from Earth are live bodies and specialty items that can only be manufactured on Earth.
Interesting point on the heat load. Given how much space travel will be, it might actually be relevant.
As for antigravity and transporters, I'm going to totally skip the first (trying to make [url=http://tvtropes.org/pmwiki/pmwiki.php/Mohs/OneBigLie]one big lie[/url] (you're welcome) style scifi). Teleportation actually exists, but not in a form that'd be practical for this purpose, though it is the one thing that enables people to colonize other star systems.
As for shipping out of earth/exoplanets, I imagine foodstuffs would be the primary export. Getting a support system large enough to support significant agriculture off-planet would probably be a gigantic waste of time and money.
In theory, in a system with space elevators, getting stuff into orbit may actually be free, and the elevator companies make pure profit on that, on top of charging a fee to bring raw materials down out _of_ orbit.
dude, it's science FICTION. if you are an old school purist who only writes fiction based on current science, put the material on a column of combustible material and send it up, a bazillion years in the future.
if you are more into FICTION than science, invent a new science
( Future hero scientist ) discovers that gravity is caused by the flow of gravitrons. if you interrupt the flow of gravitrons by inserting a thin sheet of ( upsadaisyum ) under the object, it's weightless. a quick blast of compressed air and it goes vertical. a blast of compressed air from the tanks on the upsadaisyum platform and you have horizontal motion.
et voila - orbit. upsadaisyum is a name borrowed from the Rocky and Bullwinkle show. you may want to substitute something less whimsical.
I did invent a new science, but I'm going to stick with just one.
But apart from that... keeping it within established science is kind of the point. That's what hard sci-fi is about. Fiction doesn't mean I have to chuck everything established within science into the trashcan, and besides, the implications of science are actually pretty interesting sometimes.
As I said, I'm trying to keep this sci-fi rather hard.
Look up "Thomas Townsend Brown's gravitator." I know of a useful and easy to understand video on YouTube, but sadly I can't find the link. Sorry. :( If I can find it, I'll send it you. It's pretty hard sci-fi in a sense, with no new spectacular physics involved. Did that help a bit?
There have been some interesting experiments with using lasers to lift objects. I'm not 100% sure on the physics of it off the top of my head but I believe it has something to do with creating an electromagnetic gradient across the object that causes it to repel away from the source of the imbalance, in this case straight up.
Teleporters, unfortunately, basically violate Heisenberg's Uncertainty Principle. (Plus, thanks to E=mc^2, converting, say, a human's mass into pure energy would be like setting off a whole arsenal's worth of thermonuclear devices.)
Lifting things into orbit?
In a civilization where spaceships are advanced enough to move around in the solar system with relative ease, but without the capacity to actually go to other star systems in any reasonable time, how expensive would lifting things to orbit be? I ran into some figures claiming that with modern technology, the cost of sending something to orbit is about 10,000$ to a kilogram, but I'm not sure how accurate this figure is. Ludicrous cost anyway.
Anyway, given that these people can send cargo across a solar system using hydrogen fusion powered engines, mine pluto (or other planets and asteroids) and built giant spinning orbital stations. However, most of their spacecraft would be built on said space stations, and never actually land on planets with decent gravity.
Given that they have mastered the use of carbon nanotubes and hydrogen fusion powered engines, what would be the most efficient way to ship things off planet? Space elevator? Rocket? I'm trying to keep this particular sci-fi rather hard, and I'm at a bit of a loss on what would make sense here.
Note: Not sure if this belongs in reference desk or here. I put it here because it's a question largely reliant on the quirks of my setting, but it's about physics and economics so....
Re: Lifting things into orbit?
Well, how much does it cost to load junk on a sailing ship and setting it out of the harbor? Or for FedEx to make an inside-of-state delivery?
I hope the rates are somewhere along those lines, adjusting for inflation on currency.
Re: Lifting things into orbit?
the cost is 23 hundred space yen.
Re: Lifting things into orbit?
The cost of lifting things into orbit would change over time. It used to take months to send a letter around the world; now it is practically free. The cost of shipping packages changes with technology. As a writer, you do not have to predict the exact cost - just the relative cost. At some point, when technology and demand get at the right point, the price will be low enough that people will send the same junk into space that they send across the state or country.
The space elevator idea sounds interesting. How about if FedEx had a huge hub at a geosynchronous position, and then shipped things sent up from earth to all points solar system wide?
Re: Lifting things into orbit?
A space elevator can reduce that to about $100/pound once the cost of the elevator it's self is covered. That's the basic matenence cost and the cost of the energy required to lift on the elevator, so if you have perfect nuclear fusion for power instead of propulsion or some similar low-cost energy, then it would become even cheeper. Add that to the current cost of fedexing a package and you've got a decent guess at space travel.
Re: Lifting things into orbit?
Ten thousand dollars a pound is the frequently quoted cost to put a pound into orbit. (I verified it with the NASA website.) Given the technology we have, the cost is a reflection of both the hardware and the support staff it takes to do the job. It wouldn't work well for a space going society. (The cost isn't ludicrous, it just reflects the reality of Version 0.1 to 0.6 technology.)
I believe that the 'affordable' target is ten dollars a pound to LEO. (Low Earth Orbit)
A space elevator would work. I've read one story where it paid for itself because of the power it generated.
If you are sending up bulk materials, a mass driver equivalent would work, especially for materials that can take a few Gs on liftoff. It wouldn't be good for people though.
Anti-gravity would be useful because you could go from ground to orbit without putting a lot of stress on the passengers or cargo. Anti-gravity could be part of a technology that allows Star Trek style gravitational fields on board space ships.
With fusion powered engines, a space plane would work too. There might be issues with heat load on the planet though. (It could be used for FedEx 'Got to have it NOW' type deliveries.)
Star Trek style transporters would also be a possibility. They might require teleportation pads at both ends to be cost effective. If their range is two hundred miles or so, you might need to carefully place the ground based stations so they can reach LEO sites. You might even have to schedule things so that the LEO station you end up at varies as they go into and out of range.
You might have a situation where the amount of shipping from Earth is minimal because most of the raw materials and a lot of manufactured goods are space based. About the only things being shipped from Earth are live bodies and specialty items that can only be manufactured on Earth.
Re: Lifting things into orbit?
Interesting point on the heat load. Given how much space travel will be, it might actually be relevant.
As for antigravity and transporters, I'm going to totally skip the first (trying to make [url=http://tvtropes.org/pmwiki/pmwiki.php/Mohs/OneBigLie]one big lie[/url] (you're welcome) style scifi). Teleportation actually exists, but not in a form that'd be practical for this purpose, though it is the one thing that enables people to colonize other star systems.
As for shipping out of earth/exoplanets, I imagine foodstuffs would be the primary export. Getting a support system large enough to support significant agriculture off-planet would probably be a gigantic waste of time and money.
Re: Lifting things into orbit?
Fiddlesticks. Apparently standard hyperlink bbcode doesn't work here.
Re: Lifting things into orbit?
Yeah, it's HTML here, to wit: <a href="link">words</a>
Re: Lifting things into orbit?
Look at http://www.nanowrimo.org/en/forums/tech-help-site-bug-reports/threads/609 to see what is possible an what isn't.
Re: Lifting things into orbit?
In theory, in a system with space elevators, getting stuff into orbit may actually be free, and the elevator companies make pure profit on that, on top of charging a fee to bring raw materials down out _of_ orbit.
Re: Lifting things into orbit?
dude, it's science FICTION. if you are an old school purist who only writes fiction based on current science, put the material on a column of combustible material and send it up, a bazillion years in the future.
if you are more into FICTION than science, invent a new science
( Future hero scientist ) discovers that gravity is caused by the flow of gravitrons. if you interrupt the flow of gravitrons by inserting a thin sheet of ( upsadaisyum ) under the object, it's weightless. a quick blast of compressed air and it goes vertical. a blast of compressed air from the tanks on the upsadaisyum platform and you have horizontal motion.
et voila - orbit. upsadaisyum is a name borrowed from the Rocky and Bullwinkle show. you may want to substitute something less whimsical.
Re: Lifting things into orbit?
I did invent a new science, but I'm going to stick with just one.
But apart from that... keeping it within established science is kind of the point. That's what hard sci-fi is about. Fiction doesn't mean I have to chuck everything established within science into the trashcan, and besides, the implications of science are actually pretty interesting sometimes.
As I said, I'm trying to keep this sci-fi rather hard.
Re: Lifting things into orbit?
Look up "Thomas Townsend Brown's gravitator." I know of a useful and easy to understand video on YouTube, but sadly I can't find the link. Sorry. :(
If I can find it, I'll send it you. It's pretty hard sci-fi in a sense, with no new spectacular physics involved. Did that help a bit?
Re: Lifting things into orbit?
There have been some interesting experiments with using lasers to lift objects. I'm not 100% sure on the physics of it off the top of my head but I believe it has something to do with creating an electromagnetic gradient across the object that causes it to repel away from the source of the imbalance, in this case straight up.
Teleporters, unfortunately, basically violate Heisenberg's Uncertainty Principle. (Plus, thanks to E=mc^2, converting, say, a human's mass into pure energy would be like setting off a whole arsenal's worth of thermonuclear devices.)