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bare with me here.....(spaceships)


hoov100

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Your boys are in my territory now (ex aerospace engineer), so I'm gonna have to school ya.

 

1. You don't need multi-generational spacecraft to get to anyplace inside the solar system, all you need is really really patient astronauts. You can get to Mars in 6-9 months using current heavy-lift boosters and low-impulse chemical motors. Make the injection motors nuclear (SNAP, Nerva class fission, nothing fancy 60's tech) and you'd cut that in half. Saturn would take about twice that (depending on course & fuel requirements). Times get larger with large payloads.

 

2. Artificial gravity is probably not necessary to Mars, but would be for any of the Jovians. It's not hard, but it's expensive in terms of mass. Here's what you'd do:

 

First, you have your vehicle stacked for escape:

Boost_Phase.jpg

With chemical rockets, you're in boost for minutes. With a nuclear it's hours. Pretty soon thought you're in 0g cruise phase. Pop some bolts, some verneers fire, cable starts to pay out ...

separation.jpg

Once the cables are taut, thrusters fire sending the whole thing spinning...

cruise_phase.jpg

Note that the power section is likely the heavier than the crew quarters (needs reactor shielding, plenty of reaction mass), and the comm section is at the center of mass and so only rotating - the antennas are pointed at Earth all the time. Voila, artificial gravity. If you want to thrust the whole time, you put the motors in the middle, let the whole arrangement "sag", doesn't make any difference to the crew, force is force. Reverse the whole procedure when you get to where you're going. Note, though, that the vehicle has to be quite a bit heavier than a 0G can, 'cause it has to be strong enough to take the stresses of its own (and the payload's) weight.

 

3. Zero gravity (actually "microgravity", as there is in fact gravity wherever you go) turns out to be really bad for living things. In humans, it starts the bones degrading very quickly indeed (days), dumping gigantic amounts of calcium into the system, which causes problems all by itself. The cardiovascular system has problems, in humans, 'cause the whole system is designed with five feet of "head" pressure differential. The heart begins to degrade ("If you don't use it, you lose it"). There are some visual problems, as well (more plumbing problems). A certain percent of people experience fairly intense motion sickness, and some of them never get over it, even after some time. Also, there's the problem of radiation: our sun is the source of all light and goodness, true, but it's also a hell of any kind of radiation you could name, none of which is "good" for you (It is rumored that male astronauts/cosmonauts of a certain age going to the ISS are strongly counseled to make a deposit at the local sperm bank. No equivalent option exists for females.)

 

4. jerryb wrote:

I would prefer using solar enegy..light...to push a sail of sorts.

This is a deeply cool technology for moving things around inside the solar system. There are practical problems, though, not the least of which is that you're talking about square miles of material, likely metalized plastic of some kind, kept deployed by a static electric charge. You're talking about very low accelerations (.0005G), so it's not quick (for short trips), but every bit helps, and it pushes for however long you'd like. Also, you can't really steer very much - there's no such thing as a "keel" in a spacecraft, so the best you can do is apply force *away* from the sun. It's useful, for sure, but not very "versatile".

 

5. "Cabin Fever". Note that mission times here are measured in years (3 years Mars, say 6-7 years Saturn?), and we're probably talking about a total volume the size of the average living room for 6 crewmembers. S**t happens when you coop people up for years. What about good old sweaty lovin'? You'd pretty much *have* to have a mixed-gender crew (cause what a person needs, they needs). Married couples? Great idea, but what about arguments, screw you's, "I don't love you any more"'s? What happens if someone dies? What happens if there's an affair? Remember, these are going to be some of the most highly trained, intelligent, aggressive, goal-driven people that ever lived. That kind of mind needs constant challenges, and if nothing challenging is happening, they'll make something challenging happen. Human nature.

 

hoov100 wrote

Say the new Stirling radioisotope generators prove reliable and need limited maintenance. Now also say that they could generate enough juice to power a life support system and an engine

Remember man, we're talking about a couple of different things here. Reactors can have a bunch of different applications. As a reaction device, you just jam them rods together and inject some hydrogen, whoosh, thrust, and lots of it. It was done successfully forty years ago, very very high impulse (which is good). The only problem is that the resulting jet is "hot" in a bad way. Even by 60's standards, you wouldn't want to use it in Earth orbit (yeah, that hot). Needless to say, the old Nervas didn't even have shielding on them (what's the point?), but it made them nice and light.

Then, you can use a reactor to generate lots of electricity, which you can do some cool things with, the coolest of which is an ion drive. You ionize some fuel (hydrogen works good, again) with say a "+" charge. Then you generate a HUGE voltage differential across a series of plates that first attract, then repel, the ionized propulsion mass. If you do it right, you have hydrogen nuclei moving at some serious fraction of the speed of light. Talk about impulse! A couple of hundred pounds of reaction mass can push you to solar exit velocity in a few months! Not much thrust, true, but you can keep it up for months. The downside is that you're talking about gigawatts of current to get that kind of performance - think of a couple of the largest current earthbound coal powerplants working wide open, you'll be in the correct ballpark.

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Master......:hail::hail::hail:...all is PDFd.....but

 

Square miles of anything in space should not be a problem....should it?

 

Your boys are in my territory now (ex aerospace engineer), so I'm gonna have to school ya.

 

1. You don't need multi-generational spacecraft to get to anyplace inside the solar system, all you need is really really patient astronauts. You can get to Mars in 6-9 months using current heavy-lift boosters and low-impulse chemical motors. Make the injection motors nuclear (SNAP, Nerva class fission, nothing fancy 60's tech) and you'd cut that in half. Saturn would take about twice that (depending on course & fuel requirements). Times get larger with large payloads.

 

2. Artificial gravity is probably not necessary to Mars, but would be for any of the Jovians. It's not hard, but it's expensive in terms of mass. Here's what you'd do:

 

First, you have your vehicle stacked for escape:

Boost_Phase.jpg

With chemical rockets, you're in boost for minutes. With a nuclear it's hours. Pretty soon thought you're in 0g cruise phase. Pop some bolts, some verneers fire, cable starts to pay out ...

separation.jpg

Once the cables are taut, thrusters fire sending the whole thing spinning...

cruise_phase.jpg

Note that the power section is likely the heavier than the crew quarters (needs reactor shielding, plenty of reaction mass), and the comm section is at the center of mass and so only rotating - the antennas are pointed at Earth all the time. Voila, artificial gravity. If you want to thrust the whole time, you put the motors in the middle, let the whole arrangement "sag", doesn't make any difference to the crew, force is force. Reverse the whole procedure when you get to where you're going. Note, though, that the vehicle has to be quite a bit heavier than a 0G can, 'cause it has to be strong enough to take the stresses of its own (and the payload's) weight.

 

3. Zero gravity (actually "microgravity", as there is in fact gravity wherever you go) turns out to be really bad for living things. In humans, it starts the bones degrading very quickly indeed (days), dumping gigantic amounts of calcium into the system, which causes problems all by itself. The cardiovascular system has problems, in humans, 'cause the whole system is designed with five feet of "head" pressure differential. The heart begins to degrade ("If you don't use it, you lose it"). There are some visual problems, as well (more plumbing problems). A certain percent of people experience fairly intense motion sickness, and some of them never get over it, even after some time. Also, there's the problem of radiation: our sun is the source of all light and goodness, true, but it's also a hell of any kind of radiation you could name, none of which is "good" for you (It is rumored that male astronauts/cosmonauts of a certain age going to the ISS are strongly counseled to make a deposit at the local sperm bank. No equivalent option exists for females.)

 

4. jerryb wrote:

This is a deeply cool technology for moving things around inside the solar system. There are practical problems, though, not the least of which is that you're talking about square miles of material, likely metalized plastic of some kind, kept deployed by a static electric charge. You're talking about very low accelerations (.0005G), so it's not quick (for short trips), but every bit helps, and it pushes for however long you'd like. Also, you can't really steer very much - there's no such thing as a "keel" in a spacecraft, so the best you can do is apply force *away* from the sun. It's useful, for sure, but not very "versatile".

 

5. "Cabin Fever". Note that mission times here are measured in years (3 years Mars, say 6-7 years Saturn?), and we're probably talking about a total volume the size of the average living room for 6 crewmembers. S**t happens when you coop people up for years. What about good old sweaty lovin'? You'd pretty much *have* to have a mixed-gender crew (cause what a person needs, they needs). Married couples? Great idea, but what about arguments, screw you's, "I don't love you any more"'s? What happens if someone dies? What happens if there's an affair? Remember, these are going to be some of the most highly trained, intelligent, aggressive, goal-driven people that ever lived. That kind of mind needs constant challenges, and if nothing challenging is happening, they'll make something challenging happen. Human nature.

 

hoov100 wrote

Remember man, we're talking about a couple of different things here. Reactors can have a bunch of different applications. As a reaction device, you just jam them rods together and inject some hydrogen, whoosh, thrust, and lots of it. It was done successfully forty years ago, very very high impulse (which is good). The only problem is that the resulting jet is "hot" in a bad way. Even by 60's standards, you wouldn't want to use it in Earth orbit (yeah, that hot). Needless to say, the old Nervas didn't even have shielding on them (what's the point?), but it made them nice and light.

Then, you can use a reactor to generate lots of electricity, which you can do some cool things with, the coolest of which is an ion drive. You ionize some fuel (hydrogen works good, again) with say a "+" charge. Then you generate a HUGE voltage differential across a series of plates that first attract, then repel, the ionized propulsion mass. If you do it right, you have hydrogen nuclei moving at some serious fraction of the speed of light. Talk about impulse! A couple of hundred pounds of reaction mass can push you to solar exit velocity in a few months! Not much thrust, true, but you can keep it up for months. The downside is that you're talking about gigawatts of current to get that kind of performance - think of a couple of the largest current earthbound coal powerplants working wide open, you'll be in the correct ballpark.

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LOL, this is actually super interesting i can only wonder where this would go.. i was half expecting someone to mention something about making a Z go into space... lol That would be kool but i don't see any practical way it would happen. Tie too bumper to bumper to make the sling shot idea. Use an S130 2+2 on the weighted side and a S30 on the lighter side or something lol.

~J

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Your boys are in my territory now (ex aerospace engineer), so I'm gonna have to school ya.

 

1. You don't need multi-generational spacecraft to get to anyplace inside the solar system, all you need is really really patient astronauts. You can get to Mars in 6-9 months using current heavy-lift boosters and low-impulse chemical motors. Make the injection motors nuclear (SNAP, Nerva class fission, nothing fancy 60's tech) and you'd cut that in half. Saturn would take about twice that (depending on course & fuel requirements). Times get larger with large payloads.

 

2. Artificial gravity is probably not necessary to Mars, but would be for any of the Jovians. It's not hard, but it's expensive in terms of mass. Here's what you'd do:

 

First, you have your vehicle stacked for escape:

Boost_Phase.jpg

With chemical rockets, you're in boost for minutes. With a nuclear it's hours. Pretty soon thought you're in 0g cruise phase. Pop some bolts, some verneers fire, cable starts to pay out ...

separation.jpg

Once the cables are taut, thrusters fire sending the whole thing spinning...

cruise_phase.jpg

Note that the power section is likely the heavier than the crew quarters (needs reactor shielding, plenty of reaction mass), and the comm section is at the center of mass and so only rotating - the antennas are pointed at Earth all the time. Voila, artificial gravity. If you want to thrust the whole time, you put the motors in the middle, let the whole arrangement "sag", doesn't make any difference to the crew, force is force. Reverse the whole procedure when you get to where you're going. Note, though, that the vehicle has to be quite a bit heavier than a 0G can, 'cause it has to be strong enough to take the stresses of its own (and the payload's) weight.

 

3. Zero gravity (actually "microgravity", as there is in fact gravity wherever you go) turns out to be really bad for living things. In humans, it starts the bones degrading very quickly indeed (days), dumping gigantic amounts of calcium into the system, which causes problems all by itself. The cardiovascular system has problems, in humans, 'cause the whole system is designed with five feet of "head" pressure differential. The heart begins to degrade ("If you don't use it, you lose it"). There are some visual problems, as well (more plumbing problems). A certain percent of people experience fairly intense motion sickness, and some of them never get over it, even after some time. Also, there's the problem of radiation: our sun is the source of all light and goodness, true, but it's also a hell of any kind of radiation you could name, none of which is "good" for you (It is rumored that male astronauts/cosmonauts of a certain age going to the ISS are strongly counseled to make a deposit at the local sperm bank. No equivalent option exists for females.)

 

4. jerryb wrote:

This is a deeply cool technology for moving things around inside the solar system. There are practical problems, though, not the least of which is that you're talking about square miles of material, likely metalized plastic of some kind, kept deployed by a static electric charge. You're talking about very low accelerations (.0005G), so it's not quick (for short trips), but every bit helps, and it pushes for however long you'd like. Also, you can't really steer very much - there's no such thing as a "keel" in a spacecraft, so the best you can do is apply force *away* from the sun. It's useful, for sure, but not very "versatile".

 

5. "Cabin Fever". Note that mission times here are measured in years (3 years Mars, say 6-7 years Saturn?), and we're probably talking about a total volume the size of the average living room for 6 crewmembers. S**t happens when you coop people up for years. What about good old sweaty lovin'? You'd pretty much *have* to have a mixed-gender crew (cause what a person needs, they needs). Married couples? Great idea, but what about arguments, screw you's, "I don't love you any more"'s? What happens if someone dies? What happens if there's an affair? Remember, these are going to be some of the most highly trained, intelligent, aggressive, goal-driven people that ever lived. That kind of mind needs constant challenges, and if nothing challenging is happening, they'll make something challenging happen. Human nature.

 

hoov100 wrote

Remember man, we're talking about a couple of different things here. Reactors can have a bunch of different applications. As a reaction device, you just jam them rods together and inject some hydrogen, whoosh, thrust, and lots of it. It was done successfully forty years ago, very very high impulse (which is good). The only problem is that the resulting jet is "hot" in a bad way. Even by 60's standards, you wouldn't want to use it in Earth orbit (yeah, that hot). Needless to say, the old Nervas didn't even have shielding on them (what's the point?), but it made them nice and light.

Then, you can use a reactor to generate lots of electricity, which you can do some cool things with, the coolest of which is an ion drive. You ionize some fuel (hydrogen works good, again) with say a "+" charge. Then you generate a HUGE voltage differential across a series of plates that first attract, then repel, the ionized propulsion mass. If you do it right, you have hydrogen nuclei moving at some serious fraction of the speed of light. Talk about impulse! A couple of hundred pounds of reaction mass can push you to solar exit velocity in a few months! Not much thrust, true, but you can keep it up for months. The downside is that you're talking about gigawatts of current to get that kind of performance - think of a couple of the largest current earthbound coal powerplants working wide open, you'll be in the correct ballpark.

 

 

I might have to buy you lunch and talk this a bit more in depth! If i'm not mistaken, didnt NASA have a proposal to send a crew to mars using that setup?

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Google "solar sail" in quotes, you'll get a lot of hits - and there are plenty of pictures in Google Images.

 

If you think that's cool technology, there are some things people are working on right now that qualify as outrageously cool, and doable with current techology - imagine a relatively small sail (say 1000 feet square, a million square feet), small enough to be held together with some structure. You loft and deploy it in a fairly high orbit ('cause you don't want atmospheric problems, which happen even in low orbit). Now imagine you've built a couple of great big continuous lasers on the ground, something in the gigawatt range, ideally in the mountains of Antarctica and up in northern Canada or Russia. You aim your lasers at the spacecraft and pull the trigger, blammo you're pushing the payload with a whole lot more thrust than you'd get from just the sun. The reason you build it near the poles is that you want to be able to hit it 24/7 for months or years at a time. Note that the vehicle is on its own for deceleration at the target, but you've saved a *bunch* of fuel, and at the Jovians you can always use aerobraking maneuvers to slow down. On the way back, the vessel is again on its' own for the initial impulse, but once it gets back near Earth it deploys the sail again, the lasers come back online, now they can decelerate the whole thing, again saving fuel.

 

How about this one: there are literally millions of asteroids in our solar system, with all kinds of ridiculous orbits. You find a medium-sized one (say something a few hundred feet in diameter, made up of nickel/iron and other scruff) that orbits between the asteroid belt and crosses Earth. Such an orbit would take five or six years to complete. You send a series of robots there, to modify the orbit as necessary and to make it a habitable base. Building materials (nickel and iron) are already present by the ton, all the robots have to do is drill holes in it to make airtight chambers, or heat it up and melt it into the shapes you want. You send a series of small payloads up there, possibly over a period of several orbits, each time making the base more and more habitable. Eventually you end up with a fully-stocked habitat on which you can ride in comfort to any part of the inner system. This way, you don't have to loft the materials from Earth, and you don't need as many launches to get the "heavy" stuff where you need it.

 

How about this one: you send a robot to the asteroid belt (between Mars and Jupiter), find a small asteroid (a hundred million tons or so, made of nickel and iron, good stuff and nearly pure) and attach a solar sail. If you have ground lasers per the system mentioned above, all the better, but you don't have to have them. You give it a gentle push in such a way as to slow it down a bit. Its' orbit having been modified, it starts to fall to the inner system. As it gets close to Earth, you send another robot, this time carrying thrusters of some kind so as to fine-tune its' trajectory. You aim it at Antarctica, boom, great light show and you've got a hundred million tons of really valuable, almost pure ore sitting on the ice at the cost of a couple of robots. You think space exploration can't pay for itself?

 

There's all kinds of kewl ideas out there.

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I think that space travel is in severe need of an infrastructure. Our current method of launching satellites into orbit and sending astronauts to service them is pretty 1950s in the area of civic planning. What I'd like to see is an orbital station that is designed for the production and maintenance of orbital vehicles, which could also act as a stepping stone to another station, farther out in orbit that would be our inter-planetary vehicle launch station. This would alleviate a lot of the difficulties we're having in trying to design the 'swiss army knife' space vehicle, and we could focus on creating specialized and efficient transportation.

 

You know, we built one of these, right? We aren't going to use it, but we built it....

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Im not too keen on this idea...what if something goes wrong...WHAMO...a hundred million tons slammes into earth and we go the way of the dinosaur.

 

And what if all goes well with the landing but a chunck of iron the size of spain throws the magnetic poles into skelter causing immediate climate or tidal changes......killing most of us.

 

I am intrigued by the idea of building habitable asteroids...they could be like resorts or even retirement communities......our seniors could travel the galaxy. How about prisontroids....the inmates could mine the minerals for us! After all why use expensive robots when we can use bad ass criminals for free. They can farm their own food for survival.

 

How about this one: you send a robot to the asteroid belt (between Mars and Jupiter), find a small asteroid (a hundred million tons or so, made of nickel and iron, good stuff and nearly pure) and attach a solar sail. If you have ground lasers per the system mentioned above, all the better, but you don't have to have them. You give it a gentle push in such a way as to slow it down a bit. Its' orbit having been modified, it starts to fall to the inner system. As it gets close to Earth, you send another robot, this time carrying thrusters of some kind so as to fine-tune its' trajectory. You aim it at Antarctica, boom, great light show and you've got a hundred million tons of really valuable, almost pure ore sitting on the ice at the cost of a couple of robots. You think space exploration can't pay for itself?
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I'm with Jerry on this one, using asteroids as a source of ore is a good idea, but crashing even a smaller sized asteroid into Antarctica doesnt seem like a good idea at the moment.

 

Say we gather up a couple smaller iron and nickel asteroids and form them into ship, about what thickness would be required as a general rule of thumb? 3 inches thick?

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So, uh, anyone got plans for a dark energy engine? That stuff seems pretty abundant.

 

Of course, the fundamentals of such subatomic physics as string theory and the Higgs boson could be useful in our attempted application of loosening the theoretical string tension on other dimensions and changing their size / the time it takes to travel through parts of them. Though apparently future societies/nature itself are attempting to thwart our studies of such things by sabotaging our current particle colliders. No really, I'm not making that previous statement that sounded utter like nonsense up.

Link to story about the nutters who believe it might be possible:

http://www.telegraph.co.uk/science/science-news/6318034/Could-the-Large-Hadron-Collider-be-held-back-by-its-own-future.html

 

Or are we supposed to feed improbability data into a finite probability generator and give it a really hot cup of tea?

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You know, we built one of these, right? We aren't going to use it, but we built it....

 

I know about the ISS, but it's not what I was talking about. I'm talking about a production/maintenance facility.

 

But I like the idea of using an asteroid, I guess I'm still stuck in the idea that there aren't that many out there near earth orbit but I know better than that.

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http://www.amazon.com/Case-Mars-Plan-Settle-Planet/dp/0684835509/ref=sr_1_2?ie=UTF8&s=books&qid=1255988056&sr=8-2

 

Very interesting book by a guy that worked for Jet Propulsion Labs about how we could be on mars in 10 years with current era technology. He wrote another book about how to extend that philosophy to the remainder of the solar system.

 

This is another book about a project from the 50's that used directed nuclear micro bombs as a sort of external combustion engine. It's written by the son of the scientists involved. Ever see that Star Trek: Next Generation when they find the Dyson Sphere (http://en.wikipedia.org/wiki/Dyson_sphere)? That was named for the guy that worked on Project Orion.

http://www.amazon.com/Project-Orion-Story-Atomic-Spaceship/dp/0805072845/ref=sr_1_1?ie=UTF8&s=books&qid=1255988126&sr=1-1

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  • 2 months later...

Space travel and space flight beyond low-earth-orbit is a concept that ran its course in the 20th century. And I say this as a practicing aerospace engineer.

 

In 2069 we will be celebrating the 100th anniversay of the Apollo moon landing. And we will all be in awe of how people mustered the guts, the foresight and the technology to achieve something so enormous!

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Mike, I was going to say you're being too cynical, but on further reflection (as I am wont to do before posting), some dark part of me is afraid you're probably right. However, I'd restate your sentiment; Americans will indeed look up into the night sky and marvel, folks from some other countries will look through their helmets and do the same. Other countries are just now moving into space, decades behind us, true, but they're doing it for entirely different reasons than us - they don't think of it as a race against some enemy, they think of it as a race against a competitor. Such a sentiment is the kind of thing that can be kept up for generations. It's a long-term investment to them, basically economic ass-covering. And of course, somebody will eventually figure out how to make a whole bunch of money, and then it'll be well and truly on.

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Space travel and space flight beyond low-earth-orbit is a concept that ran its course in the 20th century. And I say this as a practicing aerospace engineer.

 

In 2069 we will be celebrating the 100th anniversay of the Apollo moon landing. And we will all be in awe of how people mustered the guts, the foresight and the technology to achieve something so enormous!

 

that would be assuming, their is not another space or technology race.

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