Slingatron to hurl payloads into orbit


July 28, 2013

Artist's concept for a slingatron space launcher to hurl payloads into space

Artist's concept for a slingatron space launcher to hurl payloads into space

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People have been shooting things into space since the 1940s, but in every case this has involved using rockets. This works, but it’s incredibly expensive with the cheapest launch costs hovering around US$2,000 per pound. This is in part because almost every bit of the rocket is either destroyed or rendered unusable once it has put the payload into orbit. Reusable launch vehicles like the SpaceX Grasshopper offer one way to bring costs down, but another approach is to dump the rockets altogether and hurl payloads into orbit. That's what HyperV Technologies Corp. of Chantilly, Virginia is hoping to achieve with a “mechanical hypervelocity mass accelerator” called the slingatron.

Invented by Derek Tidman in the 1990s, the slingatron replaces rockets with a more sophisticated version of the sling famed in the story of David and Goliath, and still used today by enthusiasts to hurl pumpkins across fields.

A sling works by spinning in a circle about the user’s head. The thong on the sling keeps the stone in place and the slinger spins it faster and faster before releasing it. The limiting factors are the speed of the slinger’s arm and the strength of the thong. The slingatron uses a slightly different principle. If it tried to spin the entire machine fast enough to hurl a projectile into orbit, the forces generated would tear the slingatron to bits. Instead, as its name implies, it acts more like a cyclotron, which is a very simple particle accelerator.

A cyclotron is a flat, hollow metal cylinder inside of which is a vacuum. There are also a pair of magnetic or electrostatic plates of opposing charges. An atomic particle, such as a proton, is introduced into the center of the cyclotron and is attracted to the negative plate. The polarity of the plates flips and the proton rushes toward the other plate. As the frequency of the flipping is increased, the proton moved faster and faster in a series of ever widening spirals until it reaches the rim of the cyclotron and shoots out a window at extremely high velocity, though the machine itself never moves.

The slingatron achieves the same result mechanically. Instead of using charged plates or spinning around, a spiral tube gyrates in circles around its axis. It is similar to the way someone swirls wine in a glass, so that the wine spins around the glass although the glass itself doesn't spin at all. If the glass is swirled at a low frequency, the wine swirls in a leisurely fashion, but by increasing the frequency slightly, the wine is soon shifting up the sides of the glass and slopping over the brim.

Inside the slingatron is a spiral tube, or a series of connected spiral tubes, depending on the design, that gyrates on a series of flywheels spread along its length. As the slingatron gyrates, a projectile is introduced into the tube and the centripetal force pulls the projectile down it. As the projectile slides through larger and larger turns of the spiral, the centripetal forces increase as the the frequency of gyrations increases to up to 60 cycles per second. By the time the projectile shoots out the muzzle in the rim of the slingatron, it is traveling at kilometers per second.

Friction is an obvious problem with such a setup, but this is reduced at first by a Teflon skin, which rapidly wears away, and then by means of a substance, such as a polycarbonate, with a low boiling temperature, wrapped around the projectile. As the projectile spins around inside the tube, the substance vaporizes and forms a frictionless layer of gas. In addition, unlike conventional payloads, the projectile needs a heat shield for leaving the atmosphere.

The goal is to build a slingatron big enough to fire a projectile at 7 km/s (15,600 mph, 25,000 km/h), which is enough to put it into orbit. Actually, it will have to be traveling faster than that when it leaves the muzzle because it has to travel through the atmosphere, where it will lose some velocity. There’s also a need for a small rocket on board for final orbit insertion and course corrections, which highlights the strengths and weaknesses of the idea.

With rapid turnarounds and thousands of launches per year while all of the launch system remains on Earth, the developers say the slingatron promises lower costs for getting payloads into orbit. Unfortunately, the G-forces involved are tremendous with the projectile subjected to up to 60,000 times the force of gravity.

It’s questionable whether any rocket system could survive such stresses and there’s certainly no chance of a slingatron being used on a manned mission because it would turn an astronaut into astronaut pudding. Only the most solid state and hardened of satellites built along the lines of an electronic artillery shell fuse would have a chance of survival. The developers say that a larger slingatron would reduce the forces, but even with a reduction by a factor of 10,000, it would still be restricted to very robust cargoes. This makes it mainly attractive for raw materials, such as radiation shielding, fuel, water, and other raw materials.

Currently, there have been three one-meter (3.2 ft) prototypes built ranging from a tabletop demonstrator to a semi-modular design capable of firing a 0.5 lb (226 g) projectile at 100 m/sec (328 ft/sec). HyperV Technologies Corp. has launched a Kickstarter campaign that aims to raise $250,000 to build the modular Slingatron 5, which will be 5 m (16.4 ft) in diameter. It is designed to launch a 0.25 lb (113 g) projectile at 1 km/s (0.62 mi/sec) and later be capable of launching a one-pound (453 g) payload at 2 km/s (1.24 mi/s). Eventually, the team hopes this will lead to a full-scale version capable of launching a payload into orbit.

In addition to the Slingatron 5 demonstrator, the developers also hope to host the Slingatron Applications Workshop to discuss further applications of the technology and related topics.

The video below outlines how the slingatron works.

Source: Kickstarter

About the Author
David Szondy David Szondy is a freelance writer based in Monroe, Washington. An award-winning playwright, he has contributed to Charged and iQ magazine and is the author of the website Tales of Future Past. All articles by David Szondy

How quickly will this be weaponized ...

Jeff Rosati

we need a good , long tube on the side of a big mountain , and accelerate the projectile in vacuum - this would mean far lower Gs , longer acceleration , bigger projectile , cheaper reach to orbit . let me see , starting from 0 height , up to 10kms , we may choose a 45 degree angle . the resulting distance would be a bit over 14kms . adding an angle at the bottom , curving the trajectory will give us a cannon with a 20-30km long tube . this way the accereation could stay even stay within the human limits . besides that the shuttle used most of it's fuel in the first few kms , to go through this atmosphere , accelerating etc . getting it to 10kms, at say 5km/s as a start would make it far more efficient .

Károly Hőss

Love ideas like this, it's all about thinking laterally. I look forward to hearing more on this subject over the coming years.

Jules Tipler

@Károly: Robert Heinlein's been there, done that: Starman Jones, 1953.

The slingatron's an evolutionary deadend for initial launch propulsion system from a gravity well that has an atmosphere.

It might be useful out of atmosphere for shooting small cargoes between planetary orbits, though.


Well if the scientists can work out how to overcome gravity then this technology could become more practicle. That said, i can really see this technology being used as a weapon instead. Think about it ...

Nathan Jeffree

Impractical for launching scientific / mechanical payloads into orbit, but I do very much like the idea of sending up raw material, resources and system components (while a rover might not survive a launch, it's individual wheels, arms, etc (disassembled) should be more than capable, being little more than solid bits of metal).

Joshua Smallwood

Or this, "Ram Accelerator" which I worked on for my Master's -- with nearly 3km/s achieved in a laboratory basement sized device in the '80s.

John Zulauf

I hate that my instinct is to weaponize this concept, but it has good potential with military applications. The Mark II launches 1/2 pound at 100m/s which puts it in light cannon territory, but without the need for a traditional propellant it could be considerably more quiet. If you could continuously feed payloads into the machine without spinning it down essentially have an electric automatic cannon.

Neil Cox

I'm not quite sure how you could launch something into Earth orbit with a device like this. Even if you discount air resistance, any projectile would either follow an elliptical path and land somewhere else on the planet, or reach escape velocity and end up orbiting some other body.

Nathan Holmes

A hypervelocity gun. Somehow I imagine this will become a missile defense weapon long before it is a launcher.

Bob Ehresman

i think this nazca lines picture is really similar to this project, very interesting:

Guillaume Buisson

What is the maximum shock profile of a single point on the track?

James Bowery

Jeff R, I had the same thought. Naval gun, for example.


The slingatron approach might be useful for stuff like building materials. Another poster suggested using a mass driver embedded in a mountain. That proposal has some merit. Another idea I think is worth considering: combining a "skyshaft" with a long mass driver. A skyshaft is a large, lighter than air structure. In the upper atmosphere wind isn't that much of a factor so you might be able to house a mass driver 10-15Km long. That would get you a high degree of vertical velocity-and height. You could have another 10-15KM long mass drive in orbit that would help attain the appropriate horizontal velocity to maintain orbit. The orbiting mass driver could need to either launch both clockwise and counterclockwise payloads to maintain its momentum or be used for both accelerating and decelerating payloads. The thing is: once you have a way of getting building materials to orbit inexpensively, large, orbital structures become much more practical. Once you can get payloads to orbital velocity inexpensively, you can us high ISP propulsion like ion drives to get into the orbit you really want. The approach I'm outlining here could limit acceleration to 8-10G or so so it is applicable to a wider range of payloads. This is all stuff that can be built with existing materials-but I am sure there are huge engineering problems. The thing is: this kind of infrastructure might dramatically lower launch to orbit prices.

Randall Burns

Suppose the objects launched were completely submerged in fluid that had a roughly similar specific gravity, or even water. That would cushion the G forces. The object would feel increased pressure for all sides, but not G forces.

David Leithauser

Isn't orbital velocity 17,000 mph? Then wouldn't the object being slinged into obit have to have at least that, before leaving the device, or, would this be more of a "boost" phase to get it past "max Q", then use a rocket engine on board to get it to higher orbit? I don't know physics, but it seems you'd really have to have it at some sort of escape velocity before it leaves the device?

Rusty Harris

How about a high flying airplane to take it up and a mass driver onboard to send the payload the rest of the way? It may not need such high speeds thus could carry more diverse payloads.


Why not send up a large space ship with a long cable to reach back to earth. Then you could pull up an elevator full of pizza or whatever. In fact you could tie the moon to Earth with such a cable and have a trolly for sending up various vehicles which could jump off wherever you wish. This idea has just as much merit as the idea in this article. Ha!


One of the fastest man made object outside of atom smashers is a 2 ton manhole cover inadvertently launched by an underground nuclear test. it left the ground at at least 66 km/s about 6X the escape velocity of earth. best guess is that it was destroyed by impacting with the atmosphere because it has never been found.

re; ezeflyer

For every action there is an equal and opposite reaction. The recoil on this thing will be terrible. I don't think a plane would survive it.


Since quite a bit of energy for a rocker is the initial takeoff what is wrong with a steam catapult like the one used on ships for fighter planes. But one that is vertically up, maybe 300-400m tall.

Give the rocket that initial launch to 200km/hr to assist its conventional rockets. You can charge the steam catapult with a solar concentrator, which gives the green credentials.

The jig is more or less proven for decades, just needs upscaling. If they can make a rifle into a 155mm with the same accuracy they can do this Reusable and green which is sustainable Relatively low tech, and easy to maintain. Excuse to adorn some Steam punk clothing for the occasion. Nairda

@kj7u: Hey Hal, The Space Elevator, as imagined by ACClarke, is as realistic a solution to the problem of delivering large quantities of materials into orbit (and beyond) (and back) as any that I have ever seen. Ultimately, it all comes down to showing somebody the money. That is what is so appealing about these "slingshot" ideas. Cheap exit from the gravity well. This works (in theory) when you have something ALREADY IN ORBIT around a planet or star. But . . .but . . . I am not an engineer, so I continue to wonder: Who will profit from a solution to this problem?


They fail to recognize two significant problems. First of all the payload, whatever it is, will be rotating at enormous RPM when released from the device. Secondly the payload will be pressed, by tremendous centripetal force, against the outside of the track and then that pressure is instantaneously released when the payload exits the track. Both of these forces, the rotational force and the centripetal force, will likely result in the payload explosively flying to pieces.

These guys clearly have no clue as to what they're doing.

Roger Garrett

OK, I'm trying to get a handle on your numbers. You say that this device revs up to 60 Hz, so that each "gyration" takes 1/60th of a second. And you say that the exit velocity is 7,000 km/s. That means that the projectile has to be traveling at 7,000 km/sec when it leaves the device. And that means that in the final gyration, which takes 1/60th of a second, in the final loop of the channel, the projectile has to be going approximately 7,000 km/s. Since it has just 1/60th of a second to make it around the loop, that means that the loop must be 7,000 km/s divided by 60, which is about 116 kilometers.

Am I calculating this correctly? This device has an outer circumference of 116 kilometers, with a diameter of 37 kilometers?

That's one HUGE device!!

Roger Garrett

What kind of machinery worthy of orbit is going to sustain 60,000 G's before launch?

The Jules Verne gun company had a much better idea, and they at least were saying an 880 pound satellite once a day into polar orbit.


There is Jorden Kare's Lazer Launch system as alternate or as boost, since the LLS needs a already flying projectile to boost. It has been tested on models.

Gödel Fishbreath

Escape velocity of Earth = 11.2km/s.

@ Károly Hőss - If the tube was in a vacuum, the payload would go even faster, therefore the G's would increase. That's the whole point of the vacuum. Just because something's in a vacuum, it does not detract from its mass. There is a problem though, as soon as it hits the air at that speed it will explode. Best to not have a vacuum and let it build up to that speed in air pressure first.

@ Nathan Jeffree - If we could somehow overcome gravity, we wouldn't need the device in the first place...

Gareth Butler

Some really great comments on this one. Roger Garrett is correct. At that size, what will power such a device. I must apologize in advance for this comment. As an aerospace engineer and NASA contractor, I feel that this project should be seen to its completion by Myth Busters. Or better yet, Duck Dynasty's Robertson family. As a reality show, no more money would need to be spent on this questionable project and it would generate millions in revenue from sales of T-shirts, videos, appearances at county fairs and working models in kit form for marble chucking contests.


talk about somebody searching for a funding grant from the Feds ... useless and dangerous ... yes, it could possibly work but that doesn't mean it a useful idea ...

Jeffrey Carlson

re; Randall Burns

The space elivate could be built using high tensile steel. It has to be tapered and at the point of highest stress the "Cable" would have to be absurdly thick. (100 miles springs to mind but it has been decades since I read the essay.) but that is a logistical problem not a material problem. Carbon nanotubes brings the mass down to much more reasonable levels.


The big issue with a space elevator: it requires creation of materials beyond present technology for terrestrial use. There is a company that is proposing creation of a lunar space elevator-which can be done with existing materials. This may be a practical way to create some large, orbiting structures once there is some basic mining and industrial infrastructure on the moon. The strength of the slingatron is that it allows launch of heavy materials from the earth cheaply as long as those materials aren't too fragile. Still, that allows us to think about creation of large, orbital structures and what might be needed in space. Existing satellites tend to be tiny compared to what can be done.

Randall Burns

Personally I think this could be a great idea for future versions to be fitted to the back of a space craft as a propulsion engine. I don't fully understand it yet, but if it CAN send a 1 Pound weight a speed of 2km/s, surely it could be a nuclear powered system to give that type of thrust over a long time would be something special speed wise, after a month or two of accumulated thrust during space travel.


BTW I also think this could make a superb propulsive generator for artillery shells instead of the few hundred year old designs they are still using. That figure of a 1 pound weight travelling at 2km/s sounds a helluva impact with an armour piercing shell.


As an alternative to ship based rail guns this might have some potential but it looks to heavy and bulky to be uses as land based mobile artillery.


There is a lot of "good ideas" i kinda have a couple my self. But i would suggest to back with funding to this project this project because this now, instead of years, if not 10's into the future. Maybe they will be able to make a prototype within this year, that can reach orbit. maybe make a 100 m radius one that can do much more, ofc there is a limit there, but just haveing a form of cheap access to space is nice either way.

I would recomend you guys fund this on kickstarter. I would not "lobby" and waste my time if i didn't belive it was worth some funding, and opens a lot of oppertuneties.

What i see in this application, is not satelite launch but refined material transport(ofc that too, in the closest future).But i think, It can be very well the foundation for a rapid build up of a moon base. Or simply prepare a site for building many places in our solar system if needed.

Lets put some light to why im suggesting this. Building every details of a building and then sending it out to selestial bodies or space. would be a waste of fuel. Building the structures at the place you are, much more beneficial, for reduceing fuel costs. Lets say f.example. you bomard the whole area, where you which to make a base with all the nessesary payload you need. Steel, iron, solid refined(base components for makeing fuel then combine them afterwards), List goes on?. How to build? thats, where the otther issues comes in but is possible to solve, either robots, makeing the first things to make a place to be for astronauts. Or you could transport a inflateable dome(and that would the the only thing needed to start), to the moon where construction could take place, by both humans and robots.

When you first have a moon base, or a large facilities on the moon, where can we go next?, yes space. and maybe acctually build a space station arround earth, it would be cheaper going to the moon first- then go for earth. All the problem of an atmosphere and giganic gravitationaly pulls, will be reduced by considderbable amounts.

Moons escape Velocity: 2.38 km*/s Earth escape Velocity : 11.3 km/sec *note and that is(ignoring air friction), +++heat issues of an object leaving earth at high speeds, and list goes on. Tarjei Grønstad

Kickstarter is the most hilarious website on the internet. Thanks David for finding more wacky stuff.


Robert Heinlein showed why no one will really build a moon colony or harvest asteroides because the moon colony can go independent or the nation that controls it can throw rocks capable of deviation equal to or greater than nuclear weapons without radiological problems thus ruling the Earth same problem with Asteroids if you can shift orbits and harvest them you can wipe out any nation on Earth.

Joseph Mertens

So instead of building it on Earth, take it to a point in the asteroid belt, plant it on a large body such as Ceres and use it as a staging ground for shooting payloads of raw mined material back to Earth. Everyone is looking for ways to make Asteroid Mining profitable. This could significantly reduce costs.

Robert Hill

re; Joseph Mertens

Because of the possibility of using the tech as weapons means that the tech will never be used. that would mean not using any tech. Besides the lesson of The Moon is a Harsh Mistress is don't oppress your colonies. Oppressed colonies rebel, unoppressed colonies do not. So the moon and asteroid colonies can throw rocks, earth can throw nukes and presumably it is easier to stop rocks because they can not make high G evasive maneuvers.


"How quickly will this be weaponized ... Jeff Rosati"

Yeah that was my second thought after, "can we throw nuclear waste at the sun".

Yani Haigh

Give them props for seeing the right problem at least. Today's space transport is terribly inefficient. We use rockets one time and then throw the whole expensive superbly engineered mess away. The weight of those rockets is mostly fuel and most of that fuel is spent lifting the weight of the fuel. See? Not so efficient. The solution to the problem may be some type of launcher, just not THIS one.

Seth Miesters
It will not work as designed as it has a basic flaw. A rocket launches at low speeds and gradually gains speed at altitude as the air thins. This device will deliver its greatest velocity at the exit point of the missile. That means it will fire into dense atmospheric pressure. It will simply burn or melt. It would make a wonderful weapon as it apparently could deliver a molten slug at a target at great velocity. Perhaps a very tall mountain could be used for a launch but better yet a place like the moon would be perfect. Jim Sadler
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