Magnetic Ring Could Launch Satellites, Weapons 612
MattSparkes writes, "A new study funded by the US Air Force has suggested a cheaper method of sending satellites (possibly missile weapons) into orbit. A 2-km-wide ring of superconducting magnets would contain and propel a payload, accelerating it over a period of hours, before suddenly flinging the satellite into space at 23 times the speed of sound. The satellites would be engineered to withstand the g-forces encountered (2,000 g), and be cased in an aerodynamic shell. A two-year study has been commisioned and will begin within a few weeks at LaunchPoint Technologies in Goleta, California." New Scientist points out that if such a launch ring were built, it would instantly become "one of the most important targets on the planet."
"Moon is a Harsh Mistress" anybody?? (Score:5, Insightful)
Sounds Good, except (Score:3, Insightful)
that gauss density could be fatal and/or affect instruments.
I know there's a relationship between bird migration and magnetic fields, too, as a lot of them blindly smack into the brick walls at a local MRI center.
Nuclear fueled payloads... (Score:1, Insightful)
A few points (Score:5, Insightful)
New Scientist points out that if such a launch ring were built, it would instantly become "one of the most important targets on the planet.
What a moronic comment.
You have a STATIC launcher.
It can toss things into ballistic trajectories.
One at a time.
With a warm-up of TENS OF HOURS.
I don't know if New Scientist realized this, but we have launch technologies that are
a) less vulnerable
b) more accurate
c) mobile
and
d) a little quicker to fire than that.
On another note, and not that this will mollify the crowd that fears a weapon in every technology, but in regards to the difficulty of punching something through the atmosphere at Mach 23, I seem to recall SDI experiments where a high-power laser was used to heat a 'track' through the atmosphere (in that case, to fire a particle beam weapon down the track with less atmospheric attenuation ). Couldn't a similar idea significantly reduce the air resistance for this sort of a projectile?
Re:Lost in space (Score:5, Insightful)
Indeed. Also, accelerating it in a 2km circle over several hours to 23 times the speed of sound is not fraught with peril.
Re:math? 2000g for hours? (Score:2, Insightful)
Re:A few points (Score:2, Insightful)
Most important target.... (Score:5, Insightful)
Anywhere the capability exists to put a payload into orbit is a target.
That "most important target" bit was a simple piece of scaremongering.
Re:math? 2000g for hours? (Score:3, Insightful)
You forget that it's circular. It's accelerating by changing direction as well as increasing speed.
Re:"Moon is a Harsh Mistress" anybody?? (Score:3, Insightful)
It could be made more economical by making it dual use. Build it between two important land sites. Then it can also be used for cargo. Acceleration for 50% of the travel time, 50% deceleration transports cargo between point A and point B. 100% acceleration is an orbital launch.
But an addtional advantage to a ring is that it gives you basically a 360 circle of choice for launch directions. A linear accelerator gives you basically two.
Gerald Bull (Score:4, Insightful)
Gerald Bull had a vision and an obsession, a vision that led to estrangement from his native Canada, prison in America, and ultimately assassination by Israel. His vision was of an entirely new way to get into space: small rockets boosted by giant guns. To achieve it he worked for some of the worst regimes on earth: South Africa, China, and ultimately Iraq. His work affected the course of two modern wars and revived the ancient field of artillery.
Re:Lost in space (Score:5, Insightful)
Plus, the containers are already going to have to be strong just to survive normal stresses. I wouldn't be surprised that they already will be specced to survive most catastrophic releases.
I say this because it's important that people not think that radioactive waste is so magically dangerous that we always need to add "just one more layer" of protection before we're somehow 100% from the radioactivity bogeyman, and thus never take advantage of one of the better energy sources we have. It's an engineering problem, nothing more.
Ultimately, this point is moot, because the general public already does see radioactivity as magically dangerous and the magical thinkers are going to put themselves into the situation where they'd rather have the (magically dangerous) waste with them on the planet, but out of sight, rather than actually removed from our living space, but briefly and highly-visibly in the air.
Re:Lost in space (Score:5, Insightful)
Well, a few thousand cremated bodies would probably fit inside one single launch, so you would need millions to get that price. Because I seriously doubt the $189/kg figure assumes 1 kg payload/launch.
Re:"Moon is a Harsh Mistress" anybody?? (Score:3, Insightful)
Bones are pretty tough.
Re:"Moon is a Harsh Mistress" anybody?? (Score:4, Insightful)
but since we're going in a circle, speed would have a very important effect. the acceleration pushing you back in your seat (the 2-3 gees you mentioned) might not be harmful, but the centrifigural acceleration pushing you out from the centre of the circle could be, as going by the article, you'd be moving at about 28,000 kph, so i would imagine that force could be rather substantial.
Re:Why not reduce acceleration? (Score:5, Insightful)
Re:A few points (Score:2, Insightful)
Why electronics? (Score:3, Insightful)
Re:"Moon is a Harsh Mistress" anybody?? (Score:5, Insightful)
Re:"Moon is a Harsh Mistress" anybody?? (Score:3, Insightful)
But as the article pointed out, this could also be used to launch intercontinental weapons - so assuming it is the U.S. building it, they probably aren't going to want it located outside the U.S.
Assuming the inside of the ring is kept at near-vacuum (otherwise they'd be losing a hell of a lot of energy to drag, so I assume that's what they plan - I don't think the article actually said) you could probably design the loop on an incline, say up the side of a mountain, but you'd need a pretty gentle slope (otherwise you'd need a huge structure to maintain a constant curvature of the ring as you near the top of the mountain) - something like the Hawaiian shields would probably work pretty well (but I somehow doubt the population of the Big Island, never mind the observatories at the tops of the dormant volcanoes, would be real happy about launching something at 23 times the speed of sound 10 times a day - might be a little noisy).
Re:a_c = - \omega^2 r (Score:5, Insightful)
You don't need to fling the capsule upwards, you need to fling it horizontally such that it doesn't hit anything. To get into orbit you do not go "up", you go sideways as fast as you can. The advantages of being high up are:
Being "in orbit" is essentially falling without ever hitting the ground.
MJCRe:"Moon is a Harsh Mistress" anybody?? (Score:3, Insightful)
You would need 1/2 * 5 * 9.8 * 180^2 = 800 km of track
Of course, a hybrid approach using a rocket assist after launch could make the track shorter.
Re:"Moon is a Harsh Mistress" anybody?? (Score:5, Insightful)
Re:"Moon is a Harsh Mistress" (Score:3, Insightful)
"and be cased in an aerodynamic shell"
So, yes, it's a problem, but it's one they've noticed and considered. It will have to be a very impressive aerodynamic shell to withstand travelling at escape velocity through ground level air pressures, but it's purely an engineering problem, not a physics one.
Re:"Moon is a Harsh Mistress" anybody?? (Score:3, Insightful)
Privatization world should jump on this (Score:3, Insightful)
The current crop of privateers, yes. If a space-oriented VC could envisage a suitable marketing plan, this would be the ideal private space infrastructure project. Most of the existing cheaper-faster-better startups focus merely on making a cheaper tube 'o fuel. Our current crop of missile makers are still basically building their product by hand. When a launch vehicle and payload go BOOM, a good portion of the contractor's and customer's capital goes with it. It's like watching the auto industry before Ford.
If a Paul Allen or consortium were to bankroll something like this, they wouldn't be betting the farm on each test launch.