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Argos
2006-Oct-03, 10:51 PM
If it works for protons...

NewScientistSpace Link (http://www.newscientistspace.com/article/dn10180-huge-launch-ring-to-fling-satellites-into-orbit.html)


An enormous ring of superconducting magnets similar to a particle accelerator could fling satellites into space, or perhaps weapons around the world, suggest the findings of a new study funded by the US air force.

antoniseb
2006-Oct-03, 10:59 PM
It couldn't really work too well for satellites, as the acceleration going around in the circle would tear most condensed matter apart. However, you could build a straight linear accelerator. We've been referring to this as Launch-by-rail.

Count Zero
2006-Oct-04, 09:44 AM
Maglifter and the more advanced Star Tram have been among the most detailed studies that NASA has looked at for magnetic launch. Here (http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Spaceport_Visioning_Final_Report.pdf#search='Magli fter') is an overview. As usual, it would save tremendous amounts of money in operational costs, but the price tag for development and construction are high. Of course, development & construction costs for anything are high, but the rocket mafia is quite good at casting FUD at anything that would interfere with their getting paid $100 million each for an endless supply of disposable aluminum tubes.

publiusr
2006-Oct-06, 09:47 PM
HLLV and a simple pad is cheaper.

Ronald Brak
2006-Oct-07, 01:02 AM
Might put an end to people in space, except for tourists for a while. This would give robots a much bigger cost advanatage over what they already have. Of course the robots could prepare the way for humans who would travel to their new colonies in high speed ships as fuel will be cheap to launch into orbit.

Glom
2006-Oct-07, 01:49 AM
How long would this thing have to be? It would have to deliver some acceleration if it was space limited and I'm sure most payloads are loading limited.

On the other hand, if the maglev system launched the SV vertically, as a rocket launches, it could save a lot of lift off fuel. It could fling the SV to a bit of a height with a bit of a speed.

True it wouldn't save much, but if you knew you were going to be launching often, the savings in fuel could be worth it.

antoniseb
2006-Oct-07, 12:18 PM
How long would this thing have to be? It would have to deliver some acceleration if it was space limited and I'm sure most payloads are loading limited.

You could save a lot of lift-off fuel. One of the problems is that once you get over a few hundred miles an hour it is quite difficult to punch through the lower atmosphere with a small object. So unless the probes are very aerodynamic AND dense, you don't get much advantage launching them from ground-level.

As to how long the thing would have to be, for a linear track you can determine the maximum acceleration that your probe can tolerate (lets say 5g if there are people on board or 50g for ruggedized electronic equipment), and the desired end velocity. You then use the formula
V = V0 + AT
where V0 is set to zero for this application. This lets us solve for the number of seconds that the probe needs to be accelerated (T).

We can then use the formula S = S0 + V0T + 0.5AT2

Where V0 is zero again and S0 is our initial position, which we can take as zero. So knowing A and T from the previous formula we can determin S (the length you're asking about).

Let's for a simple example assume no atmospheric resistance.

An unmanned probe that can tolerate 50g (500 meters/second2) and needs to get to orbit, and so needs to get up to 8000 meters/second.

Using the first formula T = 16 seconds.
Using the second formula S= 64 kilometers.

As you say, we don't need all of that acceleration to come from the track. We could simply use the track to get a fraction of it. I leave it to you to make a suggestion that makes sense for how much should come from the track.

Argos
2006-Oct-07, 12:47 PM
Now it would be a good idea to build one of these on the Moon, to get to the outer planets and beyond...

antoniseb
2006-Oct-07, 01:01 PM
Now it would be a good idea to build one of these on the Moon, to get to the outer planets and beyond...

Yes, I agree. This is one of the many long term reasons for building bases and industrial capacity on the moon.

mugaliens
2006-Oct-14, 04:35 PM
Might put an end to people in space, except for tourists for a while. This would give robots a much bigger cost advanatage over what they already have. Of course the robots could prepare the way for humans who would travel to their new colonies in high speed ships as fuel will be cheap to launch into orbit.

Stick the people into people-shaped containers filled with a few extra ounces of water, and the G forces magically disappear, with a very slight addition of around 10 to 15 pounds. Highly doable.

Probably denounced by the rocket mafia as "voodoo."

antoniseb
2006-Oct-14, 04:49 PM
Stick the people into people-shaped containers filled with a few extra ounces of water, and the G forces magically disappear, with a very slight addition of around 10 to 15 pounds.

With the modification that they also breath the deep-sea diver fluid (some kind of fluorocarbon) I suppose that would work up to some limited g level. I grant that it would permit higher g's than just sitting in a chair would, but there is some density difference in the human body tissues, and we do not have the structure to protect us from them being exaggerated too much.

So, very useful idea, but it won't get us up to 50 g's.

SAMU
2006-Oct-14, 06:07 PM
10 Gs flat on your back is easily sustainable. In water it is much easier. At 10 Gs you would need a track of about 300 miles to get to orbital velocity. If built on a framework suspended from high altitude balloons it could launch from 60,000 feet or more which would eliminate 99 percent of air resistance. In a tube filled with helium would eliminate even more.
This also puts it in the tropopause http://en.wikipedia.org/wiki/Tropopause where there is no weather and little air movement to bend or otherwise disturb the structure.

Ronald Brak
2006-Oct-15, 02:28 AM
You could put people in fluid and put tubes down their lungs to keep an oxygenated liquid moving as the stuff we have now is too thick for humans to breath. Then you should be able to accelerate people faster than a cosmonaut on a defective rocket sled, or over fifty G. Don't think it would be very healthy, however. Strangely enough, people with high blood pressure might be more likely to survive.

mugaliens
2006-Oct-15, 03:48 PM
With the modification that they also breath the deep-sea diver fluid (some kind of fluorocarbon) I suppose that would work up to some limited g level. I grant that it would permit higher g's than just sitting in a chair would, but there is some density difference in the human body tissues, and we do not have the structure to protect us from them being exaggerated too much.

So, very useful idea, but it won't get us up to 50 g's.

Try more than 100 Gs.

I think that's enough to compensate for any linear induction system we're likely to use to send people and supplies into orbit.

antoniseb
2006-Oct-15, 04:02 PM
Try more than 100 Gs.
100 g's? That would be amazing, and useful (distant future). Can you point to some research that shows this is possible to do without injury? So far it sounds like gut answers (including mine). I'd like to know where if anywhere real research on this has been published.

mugaliens
2006-Oct-15, 06:01 PM
100 g's? That would be amazing, and useful (distant future). Can you point to some research that shows this is possible to do without injury? So far it sounds like gut answers (including mine). I'd like to know where if anywhere real research on this has been published.

The Air Force concluded, and rejected, a similarly proposal for fighter cockpits. The reasoning behind the rejection had to do with the fact that unmanned aerial vehicles had proven they could do more with less.

The limiting constraint, as it turns out, wasn't the G-forces that could be survived by the pilot given a fluid suspension system, but rather, the G-forces that were economical for the aircraft. We can build aircraft that can take 60 Gs, but the trade-off is that they're very inefficient because they have to carry a lot of additional structural mass. This reduces payload, fuel supplies, etc. Currently, manned aircraft can handle around 9-12 Gs, but that design constraint is build around the pilot's ability to safely handle 6 Gs, sustained, while wearing a G-suit.

UCAVs, by comparison, can handle far more Gs, and the total "pilot" package weighs in well below that of the pilot, instrumentation, ACES-II ejection seat, and support equipment required of a typical fighter.

Try convincing the F-22 Mafia that this is the best route to go, however, and you'll find it's a stiff road to hoe.

Still, reality will prevail! It always has, it always will. Just takes some time, often, more than we like.

Van Rijn
2006-Oct-16, 08:55 AM
The Air Force concluded, and rejected, a similarly proposal for fighter cockpits. The reasoning behind the rejection had to do with the fact that unmanned aerial vehicles had proven they could do more with less.

The limiting constraint, as it turns out, wasn't the G-forces that could be survived by the pilot given a fluid suspension system, but rather, the G-forces that were economical for the aircraft.


That's very interesting. Like antoniseb, I'd be very interested in the Air Force research on extreme high g forces for human or animals in a fluid. Do you have references?

ASEI
2006-Nov-03, 06:39 PM
I wrote a bit about this concept on my blog. I called it "Verne's Cannon" rather than star-tram, because I found the idea somewhat similar. (Getting all your velocity from a ground-based piece of infastructure, like Jules Verne's cannon).

If you wanted to launch people in this thing, the track would need to be 1000km long or so for <5g acceleration. However, we don't necessarily have to launch people with this thing.

Even if we still have to launch the people the old fashioned way, on capsules with rockets; it would still make placing equipment mass into orbit radically easier. Far from biasing space towards unmanned vehicles (which were always driven by mass-efficiency bottlenecks), it would enable giving people enough equipment to embark on interplanetary expeditions, construct decent spacecraft, ect.

However, this track would require a substantial amount of power during operation. Quite possibly, you would have to burn fuel and blow it through turbines just to get the required number of MW to run it!

I find it somewhat more realistic than space-elevator ideas commonly touted, because it can be accomplished with modern material technology. We could start building one of these things today if we had the funding allocated for it.

Of course, due to the large fixed costs of building one of these tracks, it only makes sense to do so if you intend to put significant quantities of mass into space, as part of a colonization or base-building effort or something. I doubt it's an evil rocket mafia conspiracy. (I should know. One day I intend to be running the evil rocket mafia. :D )

mugaliens
2006-Nov-03, 07:20 PM
ASEI nailed it. Great for G-resistant equipment, but not so good for non-G-resistant people.

Howevr, liquid cradles have been developed which enable people to withstand 20-30 Gs with little effect and with no more than a 20% increase in human body mass, so I'm not sure what all the fuss is about.

Larry Jacks
2006-Nov-03, 07:30 PM
You can't launch directly into orbit using a maglev system. You'll still need an apogee kick motor to raise the perigee enough to keep from reentering the atmosphere. If you try to achieve orbital velocity using a maglev, you'll have to add heat shielding to keep from burning up on your way up through the atmosphere.

A better trade off probably would be to accelerate the rocket enough to achieve a real weight savings, then fly the rest of the way into orbit using rocket power. For example, if you boosted the rocket to around 2 KM/sec or faster, the rocket power necessary go the rest of the way into orbit would be much less than a conventional ground launch. In effect, the maglev becomes your first stage.

As for the G loads, I read recently that the Gemini astronauts pulled as many as 8 Gs during the flight to orbit (max load right before 2nd stage burnout, IIRC). Pulling that many Gs can be uncomfortable, but high transverse Gs are the easiest to withstand.

ASEI
2006-Nov-03, 07:57 PM
You can just build the thing with a thick steel shell, which blows off after the vehicle is above enough of the atmosphere. Then you could have a small apogee kick motor kick it into orbit. I doubt a steel shell to handle atmospheric loads is going to be anywhere near as expensive or difficult to produce/maintain as a rocket stage or high performance liquid engine.

Seeing as how if something uses the maglev system, it has to be built to handle atmospheric loads that a conventional rocket cannot, I can't quite imagine a hybrid rocket/maglev vehicle being as good as either a pure maglev vehicle or rocket. The answer to a tradeoff doesn't always involve compromise!

Larry Jacks
2006-Nov-03, 11:06 PM
Maglev straight to orbit has a lot of problems. For one, your choice of launch locations is pretty limited. Depending on the G loading you're willing to use, you can easily need a launcher several hundred kilometers long. You'll have to make sure it fires over the ocean because the shock waves created by doing at least Mach 25 will be intense. You can't simply launch vertically because that won't leave you in an orbit that circles the Earth. Instead, you'd need to launch at an angle (say 30 to 45 degrees), making establishing the track even more challenging. Since you have to fly at extremely high speed through the atmosphere, the heat loads would be high (thick steel is quite heavy, too). The drag loads generated by flying at very high speed through the lower atmosphere would likely mean your launch velocity would have to be quite a bit higher than normal orbital velocity. In short, the challenges are immense. Since you couldn't move the track, you'd be limited to a single orbital inclination.

On the other hand, a vertical launch at perhaps 2 KM/sec would get you past the high density air quickly. The rocket could then fly into any orbital inclination that the site supports (range safety considerations would still apply, of course). If you could effectively replace the need for a first stage with a maglev type launcher, you'd cut the launch weight by well over 90% in some vehicles. It's the first stage that requires the biggest engines, the most propellant, and heaviest structure. As an example, here's a link to the Delta IV Medium (http://www.astronautix.com/lvs/deledium.htm) specifications. The total launch mass is 249,500 kg (550,000 lb). Of that, 226,400 kg (499,100 lb) is the first stage. 2 KM/sec wouldn't be enough to completely do away with the first stage, so the savings wouldn't be 90% of total vehicle mass. However, it might easily exceed 50%.

Getting rid of that would cut launch costs substancially without requiring nearly so much investment in the maglev system or all of the operational limitations of a direct-to-launch system.

ASEI
2006-Nov-03, 11:44 PM
Instead, you'd need to launch at an angle (say 30 to 45 degrees), making establishing the track even more challenging. How about 5 degrees? You'll get out of most of the atmosphere within a very short period of time (less than a minute). In the vehicle-following ground oriented frame 5 degrees of orbital velocity is something like 700 m/sec upwards, and without the usual gravity acceleration decreasing that component. You'd be at 100km altitude after 2 minutes

Yep, it'll have to exit over the ocean.

The weight of the steel shell isn't important in the same sense that weight is important in normal aerospace vehicles, since the track will be doing the accelerating. It is an advantage to have a relatively dense vehicle - it helps punch through the atmosphere. And having the shell ablate as the vehicle ascends will help with the heat dissipation.

You could even do it completely horizontal, and have some sort of lift force skip the shell up to the upper atmosphere as it travels.

SAMU
2006-Nov-04, 08:14 AM
The key reason for reducing launch cost to weight ratios is to be able to build cheaper spacecraft but just as or more reliable using heavier materials.

For example a humble bolt able to hold 300 pounds that has been tested by x ray, ultrasound and other methods to insure purity and strength of material adds a lot of cost to the bolt. Do that to every nut, bolt, bit of wire and metal and you can see where some of all that money goes. A heavier bolt is just as strong and reliable but far cheaper.

The launch cost to weight ratio for maglev has such a large margin from the cost of rocket launches that spacecraft can be built stronger, more reliable and still for lower cost than even jet airplanes let alone NASA spacecraft. They will simply be heavier.

If suspended from balloons at or above 60,000 feet the apmospheric stress is reduced by 99 percent. Rocket sleds have gone to over 4000 mph on a track on the ground by just wraping the track in plastic and filling with helium to reduce air friction. We could then get the friction down to 0.17 percent of sea level.

Since it would be in the air we could turn it to any orbital incination if stationed on the equator. We could also have some degree of flexability in upward incline.

If launching at 10 Gs the track would have to be about 300 miles long. To turn it from an equatorial orbtal inclination to a polar inclination we would pivot it on its center of mass about 150 miles from the ends. The ends would have to move 230 miles. Moving at 10 mph would take less than a day to turn it. 2 mph would take about 4 days to turn it.

3rdvogon
2006-Nov-09, 03:27 PM
I may just be a simple guy but to me the idea of a 300 mile long heavy duty induction motor enclosed in a helium filled tube somehow made to hover by dynamic positioning beneath balloons at 60,000 feet seems to me to be one hell of an engineering challenge, and that presumbably does not include the power plant to drive the motor. It would also need filling with a lot of helium, with some wasted during each launch.

On the Moon or Mars and other nearly airless places, I think a launcher like this might have potential.

On earth I could see it being used if you employed a vehicle whose primary engine was some sort of scramjet and you wanted a way to get it up to supersonic speeds before it started climbing away to orbit under its own power. However in that case I think you would be looking for an island close to the equator with a high mountain up the side of which you could build the launcher track.

I somehow feel that if you had the technology to build, power and control this 300 mile balloon track at 60,000 feet then you probably would have the technology you need to build the space elevator, which surely would be a much be a much better way of getting into orbit.

In the meantime would it not be better to invest money in developing new materials and engines to be able to build reliable fully reusable launch vehicles that get up to LEO under their own power?

Larry Jacks
2006-Nov-09, 04:31 PM
I may just be a simple guy but to me the idea of a 300 mile long heavy duty induction motor enclosed in a helium filled tube somehow made to hover by dynamic positioning beneath balloons at 60,000 feet seems to me to be one hell of an engineering challenge, and that presumbably does not include the power plant to drive the motor. It would also need filling with a lot of helium, with some wasted during each launch.

A couple nights ago, there was a good program on aerospace balloons. They showed just how difficult it was to launch a single large aerospace balloon - it took days to get the right weather conditions. That being the case, it'd be at least a couple orders of magnitude harder to launch a train of balloons streatching over 300 miles. Not to mention the challenge of lowering it safely and repeating the launch every time you wanted to use it again.

tofu
2006-Nov-09, 05:00 PM
Just out of curiousity, how much fuel does the shuttle use just clearing the launch tower? If the shuttle road a rail to that height, comming off the end of the rail at the same velocity that it normally has at launch tower height, how much fuel would be saved?

ASEI
2006-Nov-09, 05:32 PM
If you just build the track on the ground though, and punch through the atmosphere in some heavy expendable shell, you don't have to worry about all this aereal acrobatic stuff with balloons.

Larry Jacks
2006-Nov-09, 05:36 PM
Just out of curiousity, how much fuel does the shuttle use just clearing the launch tower? If the shuttle road a rail to that height, comming off the end of the rail at the same velocity that it normally has at launch tower height, how much fuel would be saved?

Interesting question. Let's suppose it takes 3 seconds from SRB ignition to clearing the tower (I don't know the actual number but that's in the ballpark).

According to Wikipedia (http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster), Each SRB has an initial thrust of approximately 3.3 million pounds with a specific impulse of 242 seconds at sea level. Firing together, that works out to roughly 27,270 pounds of propellant per second, or almost 82,000 pounds in 3 seconds.

Each of the SSMEs ignite a few seconds before liftoff. Let's suppose they reach full power 3 seconds before liftoff. Again, using info from Wikipedia (http://en.wikipedia.org/wiki/Space_shuttle_main_engine), the engines have a specific impulse of 363 seconds at sea level and produce approximately 400,000 pounds of thrust. That works out to approximately 3,300 pounds of propellants per second, or almost 20,000 pounds of propellants from startup until clearing the tower.

Adding the two values gives us an approximate savings of 102,000 pounds of propellants to clear the tower. You could possibly save another thousand pounds or so by having smaller, lighter SRB casings and ET.

Real world, you'd probably be closer to 90,000 pounds savings because you'd still want to make sure the SRBs are running before firing the mag launcher. Given that the Shuttle has a launch mass of about 4.474 million pounds, a savings of 90,000 pounds isn't all that significant compared to the cost of developing a mag launcher capable of sling shotting the Shuttle stack a few hundred feet high.

3rdvogon
2006-Nov-09, 05:40 PM
If you just build the track on the ground though, and punch through the atmosphere in some heavy expendable shell, you don't have to worry about all this aereal acrobatic stuff with balloons.

That is true but it does mean you will need to get the object up to orbital velocity while it is still in dense air probably below 15,000 feet.

Even if you can make the vehicle robust enough for that and do not care about the electricity bill then you are surely going to generate one heck of a shock wave at a very low altitude.

3rdvogon
2006-Nov-09, 05:44 PM
Real world, you'd probably be closer to 90,000 pounds savings because you'd still want to make sure the SRBs are running before firing the mag launcher. Given that the Shuttle has a launch mass of about 4.474 million pounds, a savings of 90,000 pounds isn't all that significant compared to the cost of developing a mag launcher capable of sling shotting the Shuttle stack a few hundred feet high.

However it might be a different story if your mag-track could get your shuttle up to just below Mach 1 before it fired up its own engines.

Larry Jacks
2006-Nov-09, 05:57 PM
However it might be a different story if your mag-track could get your shuttle up to just below Mach 1 before it fired up its own engines.

Definitely. In that case, the savings would be huge, as would the R&D costs for developing the track.

3rdvogon
2006-Nov-10, 11:16 AM
Definitely. In that case, the savings would be huge, as would the R&D costs for developing the track.

Mind you if the Japanese/Germans/French/Chinese or whatever do continue to push forward with MagLev systems and prove they can build tracks that can move large vehicles close to sonic speeds then the space programme could save some of that R&D money and grab some of the technology from the rail industry. I expect Jules Verne would be pleased to see a railway company assist in the development of a orbital launch system.

Ronald Brak
2006-Nov-10, 12:31 PM
Or you could use linear induction motors from high speed elevator companies. The advantage of flinging a spacecraft at a couple of hundred miles per hour (easily doable) would be to save a little fuel and a little wear and tear on its rockets. It's only a tiny fraction of escape velocity. If that would be economically worth it even if the technology is fairly cheap, I don't know. I have a feeling that orbital craft designers wouldn't be so interested in such a system as they wouldn't want their craft overly dependant on fancy infrastructure on the ground as that would reduce their appeal to many nations and companies.

SAMU
2006-Nov-17, 10:15 PM
I may just be a simple guy but to me the idea of a 300 mile long heavy duty induction motor enclosed in a helium filled tube somehow made to hover by dynamic positioning beneath balloons at 60,000 feet seems to me to be one hell of an engineering challenge, and that presumbably does not include the power plant to drive the motor.

If you see that program on space balloons you will see that they are used to lift some pretty heavy payloads.



It would also need filling with a lot of helium, with some wasted during each launch.

Actually not as it is under such low pressure at that altitude that 1 percent of the volume needed at sea level would fill it.



I somehow feel that if you had the technology to build, power and control this 300 mile balloon track at 60,000 feet then you probably would have the technology you need to build the space elevator, which surely would be a much be a much better way of getting into orbit.
We already have the technology to build a balloon lofted maglev launcher. We are no where near the technology to build a space elevator and there is the problem of conservation of angular momentum that is glossed over in most discussions of the space elevator.




A couple nights ago, there was a good program on aerospace balloons. They showed just how difficult it was to launch a single large aerospace balloon - it took days to get the right weather conditions. That being the case, it'd be at least a couple orders of magnitude harder to launch a train of balloons streatching over 300 miles. Not to mention the challenge of lowering it safely and repeating the launch every time you wanted to use it again.

So you wouldn't want build and launch it from the ground all at once. You would lift the materials a few balloons at a time carrying the material to build it and assemble it up there where it would stay. Then you would bring the payload containers (AKA spacecraft) up to it for each launch.

Also in the documentary about space balloons they were constrained by the weight of the payload they wanted to launch. It was a big payload and thus a big balloon. In this case we can balance the weight of each lift of material against the difficulty of the ground launch to optimize the construction.

The problen with space planes and rockets is that you have to bring the fuel with you and you have to bring the fuel to bring the fuel Not to mention the tank to hold the fuel and the motor to burn the fuel. With the maglev launcher you leave the fuel and most of the motor on the launcher so there is intrisicly less energy needed in the first place and a smaller spacecraft. All resulting in much lower weight to launch and much larger margin for making a heavier, more reliable but much cheeper launch.

The reason that rocket launches are so falure prone is not, as NASA says "space flight is difficult". It's because rocket launches are expensive. Whenever you have that kind of expense you have the inclination to cut costs and cut corners. One of the easiest corners to cut and sweep under the rug is safety. With rockets there is very little margin of safety to begin with. To cut weight in rocket launches they push the strength of materials to the edge of the envelope. Then you put the calls on strength of materials and reliability and use of equipment that should be in the hands of engineers in the hands of managers and you have the recipe for disaster that we see with rocket launches. If any other vehicle was as unreliable as rockets the company that makes it would be put out of buisness by the government and be sued into bankruptcy. But for some reason rockets are given a pass on reliability. So many alternate launch methods that have been suggested since the beginning of the space age are just cast aside.

I suspect that when we do make space flight a really going concern the use of rockets will be looked on as quaint a method for space flight as we look on propeller driven air craft for commercial flight.

mugaliens
2006-Nov-20, 09:19 PM
HLLV and a simple pad is cheaper.

Have you references to substantial proof?

neilzero
2007-Oct-22, 06:54 PM
If we are going to build maglev first stage at all we need to start out small and low budget. A few hundred feet tall lifting less than one million pounds. It may only cut fuel consuption by four percent. By the 3d scale up we might reach 2000 feet, after which the mag lev track needs a steep mountain to lean on. This produces some horizontal camponent as there are likely no verticle cliffs with stable rock over about 4000 feet. Equidor may have 70 degree slopes as long as 12,000 feet with the top over 22,000 feet, but it could cost a trillion dollars to build the equivelent of Cape Canveral at 10,000 feet with essentualy no present infrastructure. Better we should spend the trillion dollars building a space elevator with a ribbon that has a mass of one ton per meter of length near GEO altitude. A high taper ratio is needed with presently available materials. Pray for CNT with fabulous specs. Neil

AndreH
2007-Oct-22, 07:25 PM
ASEI nailed it. Great for G-resistant equipment, but not so good for non-G-resistant people.

Howevr, liquid cradles have been developed which enable people to withstand 20-30 Gs with little effect and with no more than a 20% increase in human body mass, so I'm not sure what all the fuss is about.

Firstly: I am not a member of the F-22 and rocket Mafia. But as far as I understand my basic physics, putting someone into a liquid would not help. The inner organs would still get badly damaged.

As I am always open to learn, I would like to know if you can provide any reliable sources for a 20-30 g liquid cradle. Would like to know how they solved the problem.