New Company Develops Vacuum-Sealed Centrifuge To Launch Satellites Into Orbit (spinlaunch.com) 200
Camel Pilot writes: SpinLaunch is developing a launch system that uses kinetic energy as a cheap method to launch a projectile into orbit. They propose using a vacuum-sealed centrifuge spinning the projectile at near escape velocity speeds and releasing into orbit. A rocket engine would still be used to maneuver and position the satellite. They have built a 1/10th scale prototype in the New Mexican desert and have already launched test objects 10s of thousands of feet.
In a recent interview, CEO Jonathan Yaney said: "I find that the more audacious and crazy the project is, the better off you are just working on it -- rather than being out there talking about it. We had to prove to ourselves that we could actually pull this off."
In a recent interview, CEO Jonathan Yaney said: "I find that the more audacious and crazy the project is, the better off you are just working on it -- rather than being out there talking about it. We had to prove to ourselves that we could actually pull this off."
It should work... (Score:4, Insightful)
Re:It should work. (Score:5, Interesting)
In the seventies (I was told this story in 1980, and they told it as if it happened a while ago) this company was making electronic traction systems for electric trams.
So they wanted to have a realistic load for their motor. So they did the math and made a flywheel. Wel. somehow the flywheel became unbalanced and ended up across the river 1.2km away, No casualties, just a broken roof. (no significant damage where it came down).
Anyway, when this would go wrong... "a couple of miles" is not far enough.
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OTOH, compare to rocket pancakes in your neighborhood.
Re:It should work. (Score:5, Interesting)
I know a similar case.
We had a dam, a power plant, where the timing of the generator went off. It suddenly became a power consumer instead of a generator. So it spun up so fast, that the turbine broke out of the dam.
It rolled several miles up hill. (Distance of curse, not elevation difference).
Re: It should work. (Score:2)
Somehow the tall tales of heavy industry are more fun than their IT and software equivalent.
Re:It should work. (Score:5, Funny)
So it spun up so fast, that the turbine broke out of the dam.
It rolled several miles up hill. (Distance of curse, not elevation difference).
Sounds like a story old generators tell young generators... "When I was young, we had to roll several miles to work... up hill... in the snow..." :-)
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Lol!
You forgot the end: and when we rolled home it was dark already!
Re:It should work. (Score:5, Interesting)
I lived in Berkeley for a while just down the hill from the Bevatron at LBL [lbl.gov] For many years they used a big flywheel to build up and store the energy they needed for the atomic reactions.
At some point someone got around to calculating the damage that would occur if the flywheel [picryl.com] broke loose, and they realized it would carve a swath out of the densely populated area through Berkeley and beyond all the way to the bay several miles away. They decided to reverse the direction of the flywheel which, if failure occurred, would instead destroy some big swath through the valley behind the Berkeley hills.
Energy isn't the problem. Unconstrained energy is the problem.
Re:It should work. (Score:4, Informative)
It is interesting to see the physics involved, because no matter the technique, you need the same level of kinetic energy to get the widget into orbit.
On the plus-side, a centrifugal system is only dangerous along axis so it's easier to mitigate
Maybe I'm missing something - isn't a centrifugal system dangerous in directions perpendicular to its axis? When most people speak of a centrifuge's "axis" I'm pretty sure they're thinking of the axis of rotation.
Also, when dealing kinetic energies sufficient to launch weighty objects into orbit, "mitigation" strikes me as a quaint concept. Best just 'get it right' - or else!
Re:It should work. (Score:4, Interesting)
Mitigation is the dig a large, deep, pit to build the thing in. Then any sharpnel will have a high arc and only cause damage in one small area, rather than a low arc and perhaps demolish a path through a suburb and a bunch of skyscrapers.
Better of course it to get it right, but depending on that isn't exactly wise.
Re:It should work. (Score:5, Informative)
Sadly that's only true without an atmosphere. Something like this, or a relatively short maglev "rail gun" if you wanted to keep accelerations low, would work wonderfully on the moon. There you could even launch payloads to reach Mars or Venus for about the same energy as reaching low Earth orbit.
As soon as you have to travel through Earth's dense atmosphere though you start shedding energy FAST, so you'll need a lot more speed than in vacuum. For a typical rocket launch you need 7.8km/s to reach orbit, and another 1.5 to 2 km/s to compensate for losses to atmospheric drag. But they also don't usually start really pouring on the speed until they're outside most of the atmosphere. Starting at max speed at ground level will mean they lose a LOT more speed to drag - the deceleration is proportional to the density of the air and the square of the speed.
Interestingly, it appears the barrel on their 1/3 scale prototype is pointed almost straight up. That might just be for testing purposes, don't want the test articles to fly too far down range. But it would also make sense that they're actually planning to get through the dense lower atmosphere as fast as possible, and then use aerodynamic control surfaces to redirect that speed to be mostly horizontal before they leave the atmosphere.
The accelerations though... criminy. It looks like the centrifuge itself is about 2/3 of the total 165 foot height, so at 3x the scale the payload in the full size version will probably travel in a roughly 330ft (100m) diameter circle. If they launched at 10km/s to have a decent chance of reaching orbit without rocket power the centripetal acceleration (=v^2/r) while approaching launch speed would be would be 200,000g! Even a 5km/s "starting boost" would have centripetal accelerations of 50,000g!
I can see how that would work fine for sending solid lumps of raw materials, but rockets and satellites? At those sorts of accelerations a typical 250mg resistor would weigh as much as 50kg on Earth - circuit boards would rip apart under the strain, and I don't even want to think about the structural elements. Maybe if you cast everything in a solid block of resin within a thick reinforced steel shell to prevent bulging under the immense forces? My first thought was aerogels, but I don't think even the strongest could even begin to withstand those sorts of stresses.
Re:It should work. (Score:5, Interesting)
Scott Manley has a lot more detail.
https://youtu.be/JAczd3mt3X0 [youtu.be]
After seeing that it looks feasible. He did the numbers. It's certainly challenging but within the realms of possibility.
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I was wondering why they built their test facility entirely above ground.
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I was wondering why they built their test facility entirely above ground.
Not very evil genius is it?
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I was wondering why they built their test facility entirely above ground.
Not very evil genius is it?
I'd have said "not very genius evil" ;-). That said, I agree that Gru wouldn't be out of place in this story...
Re:It should work... (Score:4, Informative)
Re:It should work... (Score:5, Insightful)
It is far worse because with a current launch system, in the case of catastrophic failure that energy is mostly constrained to the launch site. If something went wrong with this, the object could end up being flung with supersonic velocity at the wrong trajectory, with disastrous consequences. You would need to be hundreds of miles away to be safe.
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An exploding rocket tends to vent all its energy at once in place, either on the launchpad with nothing important around or in the sky with even less around. Upon unscheduled rapid disassembly this will launch a massive chunk of metal and composites with a significant amount, probably most, of the energy of that exploding rocket in a direction you really, REALLY don't want to have anything important in.
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The energy unleashed will only be the same as an exploding rocket, so its no worse than any other current launch system.
I'm not so sure about that. An exploding rocket is likely to unleash its energy in multiple directions, thereby minimizing the size of the danger zone. If a rapidly-rotating mass breaks free it's likely going primarily in one direction - so it could go pretty fucking far.
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Of course you can launch a human!
If you insist to retrieve the corpse after wards, I'm sure you can launch a human several times!
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What corpse?
Judging by the photo of the 1/3 scale model, the full-scale version will have a circular path about 100m in diameter. If they launch at 10km/s to have some chance of reaching orbit, that means a centripetal acceleration of about 200,000g. Even just a small 1km/s launch boost would involve 2,000g accelerations, which is the sort of accelerations used by blood-separating centrifuges.
A human would be reduced to jelly, at best, before the centrifuge even got up to speed.
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The image of the centrifuge in the article shows that the rotation axis is horizontal, meaning that the disc is oriented vertically. (This makes sense for a vertical launch - just let go at the precise moment). Given how large the real one would be, and the loads that it will need to contain in normal use (not to mention catastrophic situations), I would not be surprised if they ended up burying
very interesting (Score:4, Insightful)
Re:very interesting (Score:5, Informative)
It really doesn't say. ...
However, the 1/3 scale launcher is 165 feet tall, so some 25 meters diameter (length of the rotating arm).
The launch velocity is unclear too - "many thousands miles per hour", but is this for the final launch platform, for the 1/3 scale demonstration at 100% power, 1/3 scale demonstrator at "20% of the accelerator’s full power capacity", at 20% of the speed (or 4% of energy),
However, what we know is the German 8.8cm Flak 41 (anti aircraft 88mm gun) had a max ceiling of some 15,000 meters with a roughly 10kg shell fired at 1 km/s.
A heavier projectile would suffer less from air drag, but we'll take the gun's 1 km/s launch speed, which 2200 miles per hour.
We're interested in the lateral acceleration ("centrifugal force"), as the "increase the rpm of the launcher arm" is probably significantly below that.
So, the "centripetal acceleration" is speed squared divided by radius, or 1 million / 25, or 40,000 meters per second squared.
Roughly, that's 4,000g (g being the gravity).
So yes, anything not nailed down will break off.
Just for reference, the Project HARP (gun-launched suborbital vehicles) had a 15,000g max acceleration - so 4,000g is basically a solved problem.
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It also looks like this thing is basically acting as the first stage of a rocket though. There's a pretty hefty looking engine and fuel tanks in the projectile.
Something like this would be awesome on the moon for mining though. Even their test model would be enough to deliver stuff into earth orbit.
Project HARP (Score:5, Informative)
Project HARP originated as the brainchild of Gerald Bull, a renowned but controversial ballistic engineer specializing in high-velocity guns and gun propulsion systems.In the mid-1950s, Bull was working on Anti-Ballistic Missile (ABM) and Intercontinental Ballistic Missile (ICBM) research at the Canadian Armaments and Research Development Establishment (CARDE) when he formulated the idea to launch satellites into orbit using an enormous cannon. Bull believed that a large supergun would be significantly more cost-effective at sending objects into space than a conventional rocket. Bull argued it would not need expensive rocket motors, firing a large gun wouldn't require the missile to throw away multiple rocket stages to break through the Earth's atmosphere to reach orbit
https://en.wikipedia.org/wiki/... [wikipedia.org]
https://en.wikipedia.org/wiki/... [wikipedia.org]
Re:Project HARP (Score:5, Funny)
Some french guy in the 1800s wrote a book about using a giant artillery cannon to shoot people to the moon.
You would be better off doing what they did in the 60s with the X-15 and having a payload drop off from a plane flying high and fast before lighting its own rocket engine to get into orbit.
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Yhea, but he correctly predicted that Texas and Florida will vie for the project. In the book, Florida wins the launch site; Texas gets noting. In reality, the need of a command center meant that both states could be satisfied. Houston, we've had a problem!
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Some french guy in the 1800s wrote a book about using a giant artillery cannon to shoot people to the moon.
You would be better off doing what they did in the 60s with the X-15 and having a payload drop off from a plane flying high and fast before lighting its own rocket engine to get into orbit.
Virgin Orbit is doing business satellite launch by a 747. https://www.bbc.com/news/scien... [bbc.com]
No matter how weak the launch capacity in terms of max mass one think it is, air launch system has an advantage of being less weather-sensitive, if only because there are more experience in flying a 747 plane in bad weather than firing up a rocket in those situation.
Re:Project HARP (Score:5, Informative)
Jules Verne, From the Earth to the Moon.
Reaching space is possible with a gun launch - Project HARP had maximum projectile speed out the gun barrel at 2 km/s. Ignoring air drag, this is a 200 seconds climb for 200 km max altitude.
Yet, a one kilometer gun "ride" to 2 km/s would take a second for 200g.
Is this buildable? Yes, the "Angel Falls" in Venezuela is about a kilometer high.
Also, the deepest pit mines are a bit over 1 km deep.
We also have deeper mines - 4 kilometers deep, with apparently an uninterrupted shaft 2 kilometers long.
So, a 4 kilometer gun could be dug (maybe at an angle). The ground temperature there might reach 50+ Celsius degrees though.
A 4.5 km gun with a 1.5 km/s exit speed target has a 6 seconds ride for 25g. That's survivable for some. Maximum altitude (no air drag losses) would be some 225 km high in a 150 seconds ascent.
A 5 km gun with an exit speed of 1 km/s (roughly triple the sound speed) would have a 10 seconds ride for 5g. That's merely bad, and within current limits of space vehicles (3.9g max on the Saturn V/Apollo 11). Maximum altitude reached (no air drag losses) would be 100 km high in a 100 seconds ascent, so at the edge of space.
Re:Project HARP (Score:4, Insightful)
>Yet, a one kilometer gun "ride" to 2 km/s would take a second for 200g.
Still far, far gentler than a centrifuge. A 100m centrifuge (approximately the size of these folks full size version) spun up to impart 2km/s would subject the payload to 8,000g of centripetal acceleration. If they spun up to 10km/s (roughly the typical delta-V for a rocket to reach low orbit while overcoming atmospheric drag) so that their rocket is only used for fine-tuning then you're talking 200,000g's.
I do like the idea of a linear accelerator "gun" on the moon though - no atmosphere to deal with, and 66km of maglev track at 3g would let you escape the moon entirely and enter Earth orbit. And if I did the math right you only need about 20% more track to reach Mars.
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Ah yes, the old globe-spanning floating vacuum maglev railgun... where did I put that...?
At that point, why curve? Just build your railgun as straight as you want it. At 5G in a straight line to 10km/s it only takes about 200s and 1,000km. Far more cost effective, and easily fits on a single continent!
Heck, you want an excuse to build a long "advanced mode" Hyperloop tunnel?
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Bull was murdered by the Israelis when he did some work for Iraq concerning a long-range cannon.
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I was also immediately reminded of this because it has the same problem - whatever you want to launch needs to be able to withstand bone-pulverizing G-forces.
I played a paintball game around what's left of that gun a few years ago.
Yeet (Score:5, Funny)
Re:Yeet (Score:5, Funny)
YEET should totally be the ticker symbol when they go public.
There are some serious issues to overcome here (Score:5, Insightful)
I have to wonder if this is actually a joke - I can think of three issues right off the bat which seems to me that would make this concept impractical:
1. Where does the horizontal velocity for orbit come from? Rockets only go straight up for a few seconds and then they tip over and start accelerating parallel to the ground to get orbital velocity. Check out Newton's diagram of a cannon on a mountain.
2. The G-forces on the payload are going to be enormous. In a normal SpaceX launch they're experiencing around 5g, I would imagine that in the centrifuge they'll be experiencing hundreds at least. Along with that, once they leave the vacuum of the centrifuge, they're going to be slamming into the atmosphere which is going to subjecting the payloads to heavy G-forces in another dimension.
3. They're going to need significant heat shielding for launch. Again, slamming into the atmosphere from the launcher at a minimum 25,000 kph (orbital velocity) is gonna generate a lot of heat.
If they do manage to secure $110M in funding, I'd love to see the presentations that they give to investors - they could probably double it by doing seminars to entrepreneurs in how to get fleece investors.
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2. Won't be sending any bio-experiments
I would make an exemption for sending Boris Johnson into orbit.
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2. Won't be sending any bio-experiments
I would make an exemption for sending Boris Johnson into orbit.
Oh great - now you're advocating for toxic space junk!
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2. The G-forces on the payload are going to be enormous. In a normal SpaceX launch they're experiencing around 5g, I would imagine that in the centrifuge they'll be experiencing hundreds at least.
I think you imagine it wrong. Let's be generous and assume they only need a delta-v of 10 km/s (at the time of release from the centrifuge). Then, for a 100m radius centrifuge, we have 1 million m/s^2, i.e. ca. 100'000g.
Such a large centrifuge (with the vacuum!) is probably not practical. However, making it smaller would increase the g forces in the spin inversely proportional to the radius. They also scale quadratically with the required delta-v, and you need to take the air resistance into account.
Tha
Re:There are some serious issues to overcome here (Score:5, Interesting)
Oh, and there's the question of how to deal with the imbalance arising the moment the payload is released. The best way to deal with it is probably to release a counterweight opposite the payload at the same time and then let the centrifuge spin down gradually.
Problem is, the counterweight would slam into the ground, releasing the energy of a small nuclear explosion.
Seems like a fun place to work at :)
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Problem is, the counterweight would slam into the ground, releasing the energy of a small nuclear explosion.
Nah, merely the energy of a rocket exploding. The energy requirement doesn't really change between modes of transportation. Of course, that's still a LOT of energy, and there's a good reason the folks at Cape Canaveral don't sit anywhere near the rocket.
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Oh, and there's the question of how to deal with the imbalance arising the moment the payload is released.
I think that one is fixable: instead of having the payload at one end of a rotating arm, just eliminate the arm entirely. Instead have the payload on a vehicle that drives around the inner edge of the vacuum chamber and uses centrifugal force to not fall when it's upside down. Same principle as the motorcycles running on the edge of a round cage at various shows, only much much faster. It also means the vacuum chamber could be a doughnut-shaped tube instead of a big flat cylinder.The drawback is that now th
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A part of the wall would need to open, and to open between two successive passes.
Unfortunately, the fastest ground vehicle is at around Mach 1, and is rocket powered. If you already have the rocket, why use a ground track?
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Opening the wall probably wouldn't be a problem - just unlatch it after one pass and the force of the projectile would slam it fully open on the next.
Ground vehicles have their speed limited by air resistance and the unevenness of the ground, neither of which needs to be an issue for a relatively small centrifuge.
You could do a maglev track, but given the many thousands of g's of centripetal acceleration that's probably a challenge. Still, you could use something like a lightweight carbon-fiber cable as th
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You'll need to inflate the wheels to a really high pressure.
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That doesn't actually fix the problem though, just changes it. If you don't have a counterweight then you'll have an imbalance the entire time you're spinning the payload up to speed, which then goes away when it's released. That's probably a bigger problem than an imbalance during the spin-down after release, when the total mass is lower.
One option would be to have the counterweight on the opposite end of the arm be a second projectile. You'd still have imbalanced forces when the first rocket was releas
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Problem is, the counterweight would slam into the ground, releasing the energy of a small nuclear explosion.
You are overstating way too much. It would release less energy (by a factor of about 0.7) than when a conventional rocket blows at launch.
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Let the centrifuge spin down gradually? What are you, an amateur? Don't just release the satellite, but fire it at exactly the right moment with a big ass cannon strapped onto the end of the arm such that the recoil stops the arm dead in its tracks. Problem solved!
Or, you could just use the big ass cannon to launch the satellite, and dispense with the centrifuge altogether... ;-)
Re: There are some serious issues to overcome here (Score:2)
However, it feels like a rail gun approach would allow much longer acceleration lengths, e.g. a 1km long straight tunnel inclined at angle into a mountain.
The acceleration would still be very high (1000G vs 100,000G) but maybe some payload could tolerate it? Precision satellite equipment couldn't though.
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Re: There are some serious issues to overcome her (Score:2)
Re: There are some serious issues to overcome he (Score:2)
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To (not) answer your questions
1. Where does the horizontal velocity for orbit come from?
They can release the payload at whatever angle they want, so they can generate horizontal velocity.
2. The G-forces on the payload are going to be enormous.
Absolutely. Based only on the very rough figures in TFS, I come up with centripetal forces measured in the hundreds of G's. And note: These G-forces are sideways on the payload. That's going to make for some fun engineering issues...
3. They're going to need significant heat shielding for launch.
Probably, although it depends just how high they can get this beastie before launch. That seems like the smallest of problems, however...
All that sa
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Their plan is to have a rocket booster on the satellite that kicks in at around 61km up, and provides enough horizontal acceleration to reach orbital speed.
Of course that means they have to accelerate both the satellite and a carrier vehicle with rocket engine up to the kinds of speeds they are talking about. They mention forces of 10,000g which is rather extreme for such an engine.
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1. is answered in TFA. The launch vehicle carries a rocket engine that will be used to circularize the orbit.
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>1. Where does the horizontal velocity for orbit come from
They're traveling through air - if the rocket has aerodynamic control surfaces it can change it's direction in flight. I'd assume a vertical launch to get through the dense lower atmosphere as fast as possible, and then it curves so that it's traveling almost horizontal as it leaves the atmosphere. Then the rocket engine only needs to give it a little extra boost at apogee so that it doesn't re-enter the atmosphere, rather than needing to delive
investor alert (Score:3)
Max Q (Score:5, Informative)
Normal rockets reach max Q at around Mach 1 after one minute of acceleration. That would happen about 10km up where the air pressure is only about 1/3rd of what it is at the surface. From there on, the air density drops faster than the increase of the forces due to going faster.
For normal rockets, this is such a critical event that they accept longer pull of gravity and throttle back to reduce the stresses on the vehicle. (At least Falcon 9 and Space shuttle do this).
So these guys are going to accelerate stuff to 8000m/s at ground level and then throw it up in the air at ground-level-pressure. Air friction is going to be about 3x (pressure) * 25*25 (speed differential squared!) times more of an issue. That's significant.
Oh.... One more thing... If you give something orbital speed at ground level, ignoring air friction, it will go into an orbit with at best the lowest point at the place where you started. In that case you're launching horizontal, meaning you'll encounter about 200km of air instead of the normal 10km of air starting mostly up.
One last back-of-the-envelope calculation. Orbital speed is about 8000m/s. Humans riding to space can handle 3G for a few minutes, but lets assume we're talking satellites, so 10G is acceptable. So 100m/s^2. That means max Omega (rad/sec) is max 80. So your launch facilty will need an 8000m/s / 80/s = 100m radius launch facility. Do you know anybody who can make a 200m diameter vacuum chamber? (that you're going to explosively re-compress at launch?)
Throwing stuff hundreds of feet into the air is not a problem. Throwing stuff into orbit is.
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Indeed. This looks like pie in the sky B movie stuff in order to sucker in venture capitalists, blow the money on women and coke for a few years then disappear. The physics just doesn't work.
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but lets assume we're talking satellites, so 10G is acceptable. So 100m/s^2.
Their FAQ is talking 10,000G (I assume they mean lowercase "g"). That's about what an artillery shells experiences when fired, and they have onboard electronics and sensors.
Re: Max Q (Score:2)
For example: "the aircraft performed a 9G turn."
This also disambiguates it from gram (unit of mass).
Lowercase g is also common.
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Do you know anybody who can make a 200m diameter vacuum chamber?
Erm? Yes?
You don't?
https://home.cern/ [home.cern]
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You could make an underground chamber, this solves some problems. A 200 meters underground structure is expensive in price but easy to build. It's also naturally temperature-controlled, which is nice.
(we have late mid-evil salt mines with cavities 80 meters tall already).
The recompression of the structure through a rocket sized vent (a couple of meters in diameter) is incredibly unimpressive. You'd need fast opening gates, so you could make them fast closing too.
Maybe you could have two vehicles (one on eac
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Re:Max Q - off by orders of magnitude? (Score:2)
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One last back-of-the-envelope calculation. Orbital speed is about 8000m/s. Humans riding to space can handle 3G for a few minutes, but lets assume we're talking satellites, so 10G is acceptable. So 100m/s^2. That means max Omega (rad/sec) is max 80. So your launch facilty will need an 8000m/s / 80/s = 100m radius launch facility.
You made a mistake. If you would assume only 10G then you would get Omega of 0.0125 and radius of 640 km. Obviously they are aiming for much higher accelerations.
At the proposed acceleration of 10000G, you get Omega of 12.5 and radius of 640 m. Still very big.
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but... but... but... don't tech things scale linearly ?
like... you know... computers?
(ok, now I annoyed engineers AND IT people, I think my work is done for today.)
How do you balance this? (Score:2)
If the 1/3 scale launcher has a 1 km/s launch speed then it has some 6-7 rotations per second (400 rpm).
How do you compensate for a significant weight at the end of the arm just missing?
Do you launch two vehicles, one from each end and "eat" the imbalance for the half circle it rotates with a single vehicle?
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You pull in the other arm, or stretch the throwing arm, or both.
Needs to try spinning something (Score:2)
Seriously, anyone who has ever stuck their finger through a keyring and spin something slowly should immediately see the problem of using a centrifuge to build momentum for an object to reach even a fraction of escape velocity.
I just hope the only thing which dies here is funding instead of some accident when the centrifuge unbalances.
vacuum-chamber will explode (Score:3)
How is the projectile supposed to leave the vacuum chamber? You cannot open the valve in a fraction of a second without letting air pour in ... the projectile would have to fly against a wall of air which gets sucked in at ultra-high speed. The vacuum chamber will explode as soon as the projetile has left the chamber.
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The number of ways this can fail is impressive, though.
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No way! This will fail - I cannot imagine how opening such big airlocks in a fraction of a second could work. Even if it would work, there's no time to adapt the pressure between the two airlocks. Note: the projectile shoots at an impressive high speed through the tube.
A solid wall (Score:2)
If you hit atmosphere at ground density from vacuum at escape velocity, air would be like a... please someone do the calculations, I'm too lazy.
If water at terminal velocity is concrete, I figure air at escape velocity would be pretty harsh.
6000 gs (Score:3)
Different idea (Score:4, Interesting)
Launch rockets the normal way (or this way). Use this system to fire a series of 'propellent slugs' (perhaps ahead of time).
These mate with the ascending rocket, then light up to propel it part of the way.
Well, probably not anytime soon (Score:2)
Surprising as that sounds, space vessels and payloads are _flimsy_. They cannot withstand high G forces, especially sideways. Hence while this works, it needs everything to be massively re-engineered and that includes the payloads. On the plus-side, once that is done (in a few decades), this may be a lot cheaper for some types of payloads. But it is a long-term project and it needs a lot more than just the launcher.
I'd love to see it but... (Score:2)
Maybe, just maybe, you could construct everything out of tungsten and CFRP, make sure any soft materials are fully hydrostatically constrained, and make it work. Mayyyybbe. 500 MPa is a LOT of stress. Your Factors of Safety would be pretty low. Id be really interested to see the design of a rocket engin
Not satellites (Score:2)
If this thing works, it most likely won't be used for shooting up delicate satellites full of squishy and bendy electronics but construction materials for building stuff in space and consumables.
I'm skeptical (Score:2)
Seems like it would be a better weapon than putting various cargos in orbit. Air Launch to Orbit seems like a better approach, but the reality is that you have a very small reduction in what is necessary for the first stage that you really can't make a plane big enough to do anything practical. I think SpaceX has the right approach with reusable rockets. Launch them from locations at a higher elevation, closer to the equator and you get even more of an advantage. Maybe we can do a space winch instead of a r
Sensitive instruments (Score:2)
Aren't sattelites supposed to be flimsy little things to minimize weight? It sounds like someone's trying very hard to dislodge small mechanical parts like gyroscopes or just basically turning a probe into a pancake.
More like a first stage (Score:2)
sure (Score:2)
wake me when it works
Re: vacuum... (Score:3)
Only the fast bullets. Pistol bullets go in the deepest, about 2 meters, then they just stop and sink. I believe the pistol bullet speed is about 600 m/s. High-speed bullets, e.g. cal. 50, break apart after 20-30 cm.
Arrows go in pretty deeply, you can actually kill people on the bottom of the lake with those.
Escape velocity is one order of magnitude higher (about 10 km/s, give or take). But then again, air is not water.
Water is essentially incompressible, and a lot heavier per sq. mm, so turbulence forces a
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Re: vacuum... (Score:2)
That's pretty much the point: air doesn't become that "hard", it compresses. Water doesn't. This is why you have to move (i.e. accelerate) water out of the way at Mach 33 to penetrate it. Not so with air: there ought to be some kind of equilibrium between the pressure you're building up and the mass of the quantity you're diaplacing, making things a lot "softer".
Also, water is a lot heavier, so it's even more difficult to accelerate than air.
And last, but not least: we have things successfully going through
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Only the fast bullets. Pistol bullets go in the deepest, about 2 meters, then they just stop and sink. I believe the pistol bullet speed is about 600 m/s. High-speed bullets, e.g. cal. 50, break apart after 20-30 cm.
It's quite a bit slower, 100 - 200 m/s for pistol bullets. I've used 6.5 mm ammunition for rifles with an exit velocity of 870 m/s or so, and an assault rifle (5.56 mm ammunition) with exit velocity of 930 m/s.
Escape velocity is one order of magnitude higher (about 10 km/s, give or take). But then again, air is not water.
Water is essentially incompressible, and a lot heavier per sq. mm, so turbulence forces are a lot more unforgiving. The air will pose a problem because of drag, but I'm guessing it's a heating problem first and foremost, not so much a structural-ripping-apart problem. As far as I know, recently developed railguns of the US Navy (?) have around 30 km/s speed. I'm guessing they're shooting around tungsten nails, and apparently they do reach their targets. So I guess the whole slingshot-into-orbit stuff seems... doable?
At the very least, it's science fiction, in the worst case; not outright phantasy :-p
You only need something like 7.7 km/s (or maybe 7.3 km/s, I can't quite remember) to put something in LEO for a polar orbit. You gain a few hundred metres/second for free if you launch along the equator. It's about 11.2 km/s to escape Earth's gravity (and maybe 17 km/s to escape the solar system - don
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I did RTFA and even went visiting the company website. So I can supplement information for you.
What they plan to swing and launch is a small rocket, totally encapsulated in a carbon fiber shell including the nozzle, so nothing is exposed before escaping atmosphere. After exiting atmosphere and the shell jettisoned, the small rocket will fire and put the payload into orbit. Their shell design does include tail fins.
And yes, their orbital plan is to launch the rocket in an angle.
Re:vacuum... (Score:4, Informative)
Sounds like reentry, except maximum velocity happens in the densest atmosphere instead of the thinnest.
Does seem like a fun project. I've always wanted to build a giant trebuchet. This turns it up to 11.
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Elon Musk's vacuum tube has so far amounted to taxi's in tunnels driving 30 miles an hour.
I feel like you're perhaps mixing up two entirely different projects.
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>I wonder what happens in terms of physics when the projectile is launched into the atmosphere, thereby breaking the vacuum.
It immediately slams into a wall of superheated plasma and starts decelerating very quickly.
Honestly though, I don't think that will be a problem, aside from the heat. Just spinning up to 10km/s (so they have some chance of reaching orbit despite the deceleration) in what sounds like it will be a roughly 100m diameter centrifuge means that the rocket and payload will be subjected t