Author Topic: Huge 'launch ring' to fling satellites into orbit  (Read 11703 times)

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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.




http://www.newscientistspace.com/article/dn10180




2000 G's - yeehaw!


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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #1 on: 10/03/2006 10:56 PM »
Aside from microsatellites, the launch ring would be ideal for delivering supplies to support human spaceflight, such as food and water, which are not sensitive to such high accelerations, Fiske says. "Nearly all of this materiel could be shipped via launch rings, resulting in major reductions in the cost of manned space activities," he told New Scientist.

Offline meiza

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #2 on: 10/03/2006 11:53 PM »
You still need to circularize the orbit, one can not do orbital launch with a pure gun (the orbit intersects Earth's surface). And there has to be lots of that 2000 gee supporting track: if the exit velocity is 8 km/s, it's 20 kilometers just for the ring (not counting the ramp) or with 10 km/s velocity, 32 kilometers / 20 miles. And the ramp has to be huge too, for 30 degree elevation it has 1.7 to 2.7 km of track and rises 1.6 to 2.5 km from the ground (depending on exit velocity). Such freestanding structures don't even exist. One has to find a pretty fitting mountain for the exit ramp, or then build the ring completely or partially deeply buried into the ground, which I'm not sure if it has been done either.

Offline Sling Fan

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #3 on: 10/04/2006 12:29 AM »
MXER beats this hands down...and has more abilities.

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #4 on: 10/04/2006 12:35 AM »
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meiza - 3/10/2006  6:36 PM

You still need to circularize the orbit, one can not do orbital launch with a pure gun (the orbit intersects Earth's surface). And there has to be lots of that 2000 gee supporting track: if the exit velocity is 8 km/s, it's 20 kilometers just for the ring (not counting the ramp) or with 10 km/s velocity, 32 kilometers / 20 miles. And the ramp has to be huge too, for 30 degree elevation it has 1.7 to 2.7 km of track and rises 1.6 to 2.5 km from the ground (depending on exit velocity). Such freestanding structures don't even exist. One has to find a pretty fitting mountain for the exit ramp, or then build the ring completely or partially deeply buried into the ground, which I'm not sure if it has been done either.

The track is circular - 2km across, so extreme distances aren't required --

"The advantage of a circular track is that the satellite can be gradually accelerated over a period of several hours. And the setup is technologically feasible and cost effective, suggests a recent, preliminary study of the idea funded by the air force's Office of Scientific Research."

 And a small rocket on the tail adjusts the orbit.

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #5 on: 10/04/2006 12:48 AM »
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Sling Fan - 3/10/2006  7:12 PM

MXER beats this hands down...and has more abilities.

...and requires a substantial on-orbit infrastructure.  The sling is all on the ground.  Now, if you want to build a tether to catch these bullets and sling them on to the moon - I could see that.

Online hop

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #6 on: 10/04/2006 01:53 AM »
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bhankiii - 3/10/2006  5:18 PM
"The advantage of a circular track is that the satellite can be gradually accelerated over a period of several hours. And the setup is technologically feasible and cost effective, suggests a recent, preliminary study of the idea funded by the air force's Office of Scientific Research."

 And a small rocket on the tail adjusts the orbit.
Lots of ideas are "technologically feasible" in general terms on paper, but completely nutty in reality.

The heat shield needed to protect payload traveling at > orbital velocity near sea level is going to be really impressive (and a large fraction of the total mass, most likely).The sonic booms are going to be impressive too :)

They predict huge drops in cost/mass at high launch rates, but so does every other system. Unfortunately for this plan, a large number of payloads will not be able to survive their launch environment, so we would still need conventional launch systems. That makes attaining high launch rates even harder, and having less flights on the conventional systems means their cost per flight will actually go up.

As presented, it will also only be able to launch to a single inclination, which again limits usefulness. You could potentially add more launch ramps, but they aren't going to be cheap.

They mention the possible use as a weapon, but it's hard to see what advantage it has over traditional ballistic missiles. It does have the significant disadvantage of being a single large, fixed target that could rendered completely useless with a nuke or a small amount of well placed conventional explosives. Or a well placed brick, for that matter...

Something like this would make a lot more sense if you were launching a lot of raw materials from the moon.

Offline dbhyslop

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #7 on: 10/04/2006 02:23 AM »
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hop - 3/10/2006  9:36 PM

They mention the possible use as a weapon, but it's hard to see what advantage it has over traditional ballistic missiles. It does have the significant disadvantage of being a single large, fixed target that could rendered completely useless with a nuke or a small amount of well placed conventional explosives. Or a well placed brick, for that matter...

I think it could have a unique military application.  ICBMS have a very high marginal cost but the Pentagon might be willing to pay top dollar for a system capable of placing a 500 lb GPS bomb anywhere in the world in an hour or two.  The conical casing could also serve as a re-entry shroud.

As you pointed out it would be critical to have multiple ramps or be able to change its direction (unlikely since the ramp might be as tall as the Sears Tower).  But if they're talking about having 300 launches a year they might seriously have a small-weapon delivery system in mind.

No matter what, I don't think we can expect to see it built anytime soon :)  I think you're right the moon would be a better place for such a system, and if we are shipping back massive amounts of raw material from there in a hundred years I imagine there won't be a shortage of electrical power to run it!

Dan

Offline meiza

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #8 on: 10/04/2006 10:40 AM »
Quote
bhankiii - 4/10/2006  1:18 AM

Quote
meiza - 3/10/2006  6:36 PM

You still need to circularize the orbit, one can not do orbital launch with a pure gun (the orbit intersects Earth's surface). And there has to be lots of that 2000 gee supporting track: if the exit velocity is 8 km/s, it's 20 kilometers just for the ring (not counting the ramp) or with 10 km/s velocity, 32 kilometers / 20 miles. And the ramp has to be huge too, for 30 degree elevation it has 1.7 to 2.7 km of track and rises 1.6 to 2.5 km from the ground (depending on exit velocity). Such freestanding structures don't even exist. One has to find a pretty fitting mountain for the exit ramp, or then build the ring completely or partially deeply buried into the ground, which I'm not sure if it has been done either.

The track is circular - 2km across, so extreme distances aren't required --

"The advantage of a circular track is that the satellite can be gradually accelerated over a period of several hours. And the setup is technologically feasible and cost effective, suggests a recent, preliminary study of the idea funded by the air force's Office of Scientific Research."

 And a small rocket on the tail adjusts the orbit.

Huh? 1 km radius and 2000 gees, that makes the velocity 4.4 km/s. That's only like a first stage. You don't "adjust" the orbit, you have to actually do over half of the delta vee still, and that's not even counting the aerodynamic losses. And I don't know about the direction of the velocity either. You probably need a two stage solid.
And you have to keep the six kilometer track in a vacuum etc...

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #9 on: 10/04/2006 01:34 PM »
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meiza - 4/10/2006  5:23 AM

Huh? 1 km radius and 2000 gees, that makes the velocity 4.4 km/s. That's only like a first stage. You don't "adjust" the orbit, you have to actually do over half of the delta vee still, and that's not even counting the aerodynamic losses. And I don't know about the direction of the velocity either. You probably need a two stage solid.
And you have to keep the six kilometer track in a vacuum etc...

I'm guessing you haven't read the article.  Final velocity is 10km/s, exit velocity is 8km/s...

I'm also guessing that the significant technical hurdles will be addressed in the next stage of the study, a two year effort led by LaunchPoint Technologies, funded by the air force's Office of Scientific Research.

Stay tuned.

Offline meiza

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #10 on: 10/04/2006 09:08 PM »
Ok, I was hasty, but the article contains some very weird arguments. Basic physics: You run around a circular track of 1 km radius at 10 km/s. That is given in the article.
Now, to stay on that track your acceleration towards the center is a =v^2/r = 100 000 m/s^2 or over 10000 gees. Why does the article talk about 2000 gees?
If you have radius 1 km and acceleration 2000 gees, your speed is only 4.4 km/s. A huge mismatch!

Either I did a mistake or then something stinks here.

(As a sidenote, New Scientist has at least lately been quite sensationalistic, as probably many have noted:
http://golem.ph.utexas.edu/category/2006/09/a_plea_to_save_new_scientist.html )

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #11 on: 10/04/2006 11:59 PM »
Yeah, New Scientist has to be taken with a grain of salt sometimes.  

Here's the abstract from the original AIAA paper:

The Launch Ring – Circular EM Accelerators for Low Cost
Orbital Launch
O. James Fiske, Michael R. Ricci, and Kenneth Ricci
LaunchPoint Technologies Inc., Goleta, CA, 93117
and
John R. Hull
Argonne National Laboratory, Argonne, IL, 60439
[Abstract] Despite huge potential benefits, no electromagnetic Earth-to-orbit launcher
has yet been constructed, primarily due to the difficulty of providing the enormous power
required. The Launch Ring adopts circular acceleration and much of the technology of
modern synchrotrons to achieve orbital speeds without the need for extremely high power.
Superconducting cables and coils are employed to create a passively stable high force
magnetic suspension for a maglev “sled”, which is accelerated around an enclosed,
evacuated circular track of large circumference until it reaches launch speed. A projectile is
then released through a tangential exit tube and, potentially, into orbit. Radial accelerations
exceeding 10,000 g’s and launch speeds exceeding 10 kilometers per second appear
achievable with both a relatively small accelerator for launching 10 kg micro-satellites and a
larger accelerator for 1000 kg projectiles. Development of Launch Rings could lead to
remotely operated assembly facilities in orbit and a radically less expensive approach to
space exploitation.

So, we'll see what the next phase of the study brings in a couple of years.

Offline PurduesUSAFguy

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #12 on: 10/10/2006 12:34 PM »
I don't see such a system as being very useful for launching microsatilites, such a satilite would have to be superhardened to withstand that many Gs making it too heavy to launch, not to mention as was previously mentioned the thermal protection required for such a launch process.

I do however, see this as being a tremendously usefull weapon system to help replace our aging bomber fleet. This system has all the advantages and capabilities of an ICBM armed with a unitary depleted uranium kinetic warhead without the tens of millions in cost of a Trident D3 or Minuteman booster. 300kilos of depleted uranium hitting your breeder reactor (*cough*iran) at mach 20 is enough to ruin your day. Also you don't have to just be doing unitary deep penetrators, imagine if the heat sheild is wraped in explosive cord to petal at lets say 2 kilometets altitude to disperse thousands of tungstun flechetes. That would be one devistating anti armor or anti personal strike.

Offline Marcus

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #13 on: 10/10/2006 05:31 PM »
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meiza - 3/10/2006  4:36 PM
... And the ramp has to be huge too, for 30 degree elevation it has 1.7 to 2.7 km of track and rises 1.6 to 2.5 km from the ground (depending on exit velocity). Such freestanding structures don't even exist. One has to find a pretty fitting mountain for the exit ramp, or then build the ring completely or partially deeply buried into the ground, which I'm not sure if it has been done either.

Dynamic structures. Smaller loops of high-speed magnitized pellets inside evacuated tubes with electromagnets turning the stream of pellets to provide the force to support the launch ramp. Planned carefully, you could even make the support towers mobile enough to shoot payloads into different inclinations.

Never mind that such a structure--even a tiny scale model--has never been built.

Of course, if you're going to go with dynamic structures anyway, why not just build a space fountain or launch loop? My personal favorite is the launch loop. No need for payload fairings, heat sheilds, or any of the dross associated with high-speed atmospheric operation. Then again, who knows if that sort of dynamic megastructure is even possible? Let's build one and see.
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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #14 on: 10/10/2006 06:06 PM »
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PurduesUSAFguy - 10/10/2006  7:17 AM

I don't see such a system as being very useful for launching microsatilites, such a satilite would have to be superhardened to withstand that many Gs making it too heavy to launch, not to mention as was previously mentioned the thermal protection required for such a launch process.

I do however, see this as being a tremendously usefull weapon system to help replace our aging bomber fleet. This system has all the advantages and capabilities of an ICBM armed with a unitary depleted uranium kinetic warhead without the tens of millions in cost of a Trident D3 or Minuteman booster. 300kilos of depleted uranium hitting your breeder reactor (*cough*iran) at mach 20 is enough to ruin your day. Also you don't have to just be doing unitary deep penetrators, imagine if the heat sheild is wraped in explosive cord to petal at lets say 2 kilometets altitude to disperse thousands of tungstun flechetes. That would be one devistating anti armor or anti personal strike.

Hopefully we've evolved past the idea of lobbing chunks of explosive or kinetic materials over long distances to approximate locations.  You still need some intelligent navigation and flight control properties to get your bomb to its target without blowing up the orphanage next door.  And if you can do that, why not go on into space?  And, as the article points out, there are already electronics in munitions that can withstand greater G forces than are proposed here.

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #15 on: 10/10/2006 07:13 PM »
Quote
And if you can do that, why not go on into space?

We are signatories to the Outer Space Treaty which forbids the installation of WMD's in orbit. Whether a precision munition with the kind of KE you're talking about is a WMD or not is debatable.

Just in general, I have to say that the weaponization of LEO is a really bad idea. It wouldn't take too many ASAT engagements to put enough untrackable debris in orbit to deny everyone access for a very long time.

If the monkeys must throw rocks at each other, please keep it ballistic.



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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #16 on: 10/10/2006 10:51 PM »
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PurduesUSAFguy - 10/10/2006  5:17 AM
I do however, see this as being a tremendously usefull weapon system to help replace our aging bomber fleet. This system has all the advantages and capabilities of an ICBM armed with a unitary depleted uranium kinetic warhead without the tens of millions in cost of a Trident D3 or Minuteman booster. 300kilos of depleted uranium hitting your breeder reactor (*cough*iran) at mach 20 is enough to ruin your day. Also you don't have to just be doing unitary deep penetrators, imagine if the heat sheild is wraped in explosive cord to petal at lets say 2 kilometets altitude to disperse thousands of tungstun flechetes. That would be one devistating anti armor or anti personal strike.
How are you going to aim it ? Moving the exit ramp is going to be a royal PITA. To use conventional payloads, you still need terminal guidance that that survives 2000+ Gs and orbital+ velocity in atmosphere. Those things might be cheaper than ICBMs, but I wouldn't call it a sure bet.

You are also left with the problem that this launcher is a huge single target at a known location. It is going to be far more vulnerable than widely dispersed ICBM silos, SLBMs and bombers. That's somewhat OK for todays dirty little wars, but it means that it cannot replace the existing strategic forces.

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #17 on: 10/11/2006 02:54 PM »
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Marcus - 10/10/2006  1:56 PM

Quote
And if you can do that, why not go on into space?

We are signatories to the Outer Space Treaty which forbids the installation of WMD's in orbit. Whether a precision munition with the kind of KE you're talking about is a WMD or not is debatable.

Just in general, I have to say that the weaponization of LEO is a really bad idea. It wouldn't take too many ASAT engagements to put enough untrackable debris in orbit to deny everyone access for a very long time.

If the monkeys must throw rocks at each other, please keep it ballistic.




I think you misunderstand me.  I'm not advocating the use of the ring as a weapon, but simply as a launch system.

Offline TyMoore

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #18 on: 10/11/2006 06:55 PM »
In any case, for a launch ring to work it must use somekind of magnetic levitation as no mechanical support could possibly sustain sliding velocities in excess of 1 km per second, let alone 10km per second. And the only way that could be done would be to use magnetic repulsion because natural compression of magnetic fields increases repulsive forces--so it has a natural positive feedback--but still requires active damping of oscillations. The forces exerted to repell the projectile off the track are enormous: F=mv^2/r

For a mass of 100 kg, moving in a circular track with radius of 1000 m, and tengential velocity 10^4 m/s, requires exerting :
F=10MN (about 2.25 million pounds of force.)

Even using a magnetic sled and using the Meisner Effect to cause it to repell from a superconducting track, the required magnetic field pressure will probably force the trapped magnetic flux to exceed the superconductor's Critical B-Field strength. Exceeding the critical B-field will break apart the Cooper pairs in a superconductor and that causes a superconductor to transition to normal conduction states. If this were to happen, the sled would collide with the repulsive track within milliseconds...

A magnetic launch track would either require a very, very large ring (something bigger even than 50km radius) or will require a lot of energy storage and a track maybe 2-50 km in length. Still an expensive endeavour, but certainly possible as a way of transporting large quantities of material into space such as the Mass Driver concepts for the surface of the moon.

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Re: Huge 'launch ring' to fling satellites into orbit
« Reply #19 on: 10/11/2006 09:09 PM »
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TyMoore - 11/10/2006  1:38 PM

In any case, for a launch ring to work it must use somekind of magnetic levitation as no mechanical support could possibly sustain sliding velocities in excess of 1 km per second, let alone 10km per second. And the only way that could be done would be to use magnetic repulsion because natural compression of magnetic fields increases repulsive forces--so it has a natural positive feedback--but still requires active damping of oscillations. The forces exerted to repell the projectile off the track are enormous: F=mv^2/r

For a mass of 100 kg, moving in a circular track with radius of 1000 m, and tengential velocity 10^4 m/s, requires exerting :
F=10MN (about 2.25 million pounds of force.)

Even using a magnetic sled and using the Meisner Effect to cause it to repell from a superconducting track, the required magnetic field pressure will probably force the trapped magnetic flux to exceed the superconductor's Critical B-Field strength. Exceeding the critical B-field will break apart the Cooper pairs in a superconductor and that causes a superconductor to transition to normal conduction states. If this were to happen, the sled would collide with the repulsive track within milliseconds...

A magnetic launch track would either require a very, very large ring (something bigger even than 50km radius) or will require a lot of energy storage and a track maybe 2-50 km in length. Still an expensive endeavour, but certainly possible as a way of transporting large quantities of material into space such as the Mass Driver concepts for the surface of the moon.



Hence the term, "Advanced Concept".

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