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SpinLaunch is building a centrifuge to launch satellites into orbit
- sneak 6y agoHow does this prevent the satellite from being damaged when it transitions from 5000mph in vacuum centrifuge to less-than-5000mph-in-troposphere 1 meter later just out of the door? That's gotta be one hell of a fairing.
- spicybright 6y agoOh wow, I was wondering why bother building housing around it. That seems incredibly expensive to build and maintain. Your comment is very on point. If they slowly even out the atmosphere, they loose the speed. So they'll need to coordinate the door opening at exactly the right moment. And if it doesn't the whole instillation goes boom. I feel like it would be better just to use the money to buy more rocket fuel at this point. This is so much alike to "game changing ideas" like the hyperloop, solar roadways, and other "disruptive" tech that make a cool headline, but break down the second you think about the real world logistics and cost. I hope they prove me wrong if they can get it to work though, cheaper space flights could help the world in so many ways.
- sneak 6y ago> And if it doesn't the whole instillation goes boom. The projectile is going to go boom when it hits the thick lower atmosphere going many times the speed of sound when it exits the vacuum chamber regardless.
- themgt 6y agoReaching max q at T+0.0001 seconds while 1 inch away from the launch site's massive expensive centrifuge. It's a bold strategy, Cotton.
- greypowerOz 6y agoI hear you :) but IIRC the US "rail guns" are generating muzzle velocities in this speed range (?) I've seen very spectacular footage of these rounds tearing a hole in the atmosphere ... so maybe our shared intuition isn't reliable... or maybe once you get a cross section bigger than a playing card, things become.... interesting at these speeds at sea level;)
- blhack 6y agoHere's a video of the CEO at some ground breaking they did: https://www.youtube.com/watch?v=lmO0k7Nv30g&feature=emb_title https://www.youtube.com/watch?v=lmO0k7Nv30g&feature=emb_titl... Maybe it's a minor thing, but it's a big tell to me. He says: "My team and I", in the possessive, and to me that always betrays something in founders that I don't like. The best founders I know usually focus more on the team than on themselves. It's subtle, but I think it's meaningful.
- deleted 6y ago[deleted]
- mlindner 6y agoNo they're definitely going to fail. The founders don't seem to understand how difficult this is. If you're going to build an accelerator you want it to accelerate over a very long distance and have it exit the vacuum well into the stratosphere if you can.
- mrfusion 6y agoPack it up, boys. Mlindner on hacker news says said you’re going to fail.
- avs733 6y agoI mean, the general consensus seems to be that this is the juicero of space launch systems...not 'impossible' just not realistic or useful I have heard them say repeatedly that the physics work. Physics are 'easier' than manufacturing/building something...lab scale/bench scale are exponentially easier than full scale...full scale is exponentially easier than building something consistently. Ask Tesla. I have yet to hear them talk about how they are manufacturing parts for the full size centrifuge. When I hear them mention forging or the heavy press program or similar I'll take them slightly more seriously. I'm trying to conceptualize what the arm would look like and the force it would have to withstand and honestly can't. Right now, they have been stuck for years on 'trust us this doesn't violate the laws of physics' which is not comforting when I only ever hear that from cooks.
- nradov 6y agoI think they're going to make it pointy.
- dboreham 6y agoPerhaps relevant https://www.businessinsider.com/fastest-object-robert-brownlee-2016-2 https://www.businessinsider.com/fastest-object-robert-brownl...
- mlindner 6y agoThey're going to need an ablative heat shield or make it out of pure titanium.
- beervirus 6y ago“The reason it's hard to get to orbit isn't that space is high up. It's hard to get to orbit because you have to go so fast.” https://what-if.xkcd.com/58/ https://what-if.xkcd.com/58/ Sounds like this solves the easy part (getting to high altitude), but makes the hard part (getting to orbital velocity) even harder.
- spicybright 6y agoI'm still scratching my head thinking of how much force will be crushing the rocket and satellite for an hour. I know space stuff needs to be super durable, but surely the G's it'll experience over an hour will be more grueling than a traditional rocket, no?
- bfuclusion 6y agoTo get a rough idea of the numbers if this was a rail gun and accelerating linearly: 1G is 32 feet/second 32 feet /second is ~22 mph They're accelerating to 5000mph so they need to crush things at 1G for ~230 second or just under 4 minutes. If I understand correctly, this would hold for angular acceleration too, since they'd just release at some point. Can someone correct me if I'm wrong?
- jseutter 6y agoYou're probably correct, but there is more. Take a 200 pound payload, add some rocket to it, let's say 10x the weight to be generous, then spin it in a circle 200 feet in diameter. You're looking at 18 thousand tons of force spinning it at 5000mph. So you're spinning 4 navy destroyers worth of force in a circle, which means you need a latch mechanism that can not only hold that much force, but release it at the exact moment to exit the biggest vacuum chamber ever created through a door that just opened at the right time, generating a mach 6+ shock wave at about 0 meters distance from the door and somehow not destroying it in the process. I don't know that it is impossible, but it is highly improbable. They'd probably have a burst disk rather than a door, because that would let you use the capsule as a bullet to penetrate the exit. In the article they mention the payload experiencing 10000g, so they must be planning on a circle greater than 200 feet in diameter. I can't find numbers on existing satellites, but I remember reading that rockets typically top out at 6g acceleration and figure on a 10x momentary acceleration due to vibration. To tolerate 10000g the payload being launched will need to be built like a tank, rather than the relatively light current designs. To ease that requirement you could submerge the payload in liquid, but that would decrease your usable payload accordingly. It would be impressive if they could actually pull it off. I think it would be useful for limited applications. I have watched science fiction shows where mass accelerators could basically nuke planets without radioactive fallout. Maybe this would be something similar.
- DennisP 6y agoI hope it works because it'd be rad, but at $500K per 200-lb payload, they'll cost $2500/lb. That's only half as much as SpaceX Rideshare for the same size payload, today. If Starship works out, then SpaceX costs will drop enormously. Fuel is a minor portion of launch cost. SpinLaunch is saving fuel but throwing away rockets; it's going to be hard to compete with someone who throws away more fuel but saves the rockets.
- NikolaeVarius 6y agoWut? Their goal is to allow the rocket to ignite at 200k ft. Thats only a bit lower than the altitude SpaceX ignites its second stage, which is not reusable
- DennisP 6y ago"If Starship works out," I said. Starship reuses the second stage.
- Cogito 6y agoPutting aside starship, from the very limited information I've seen it's not clear that the operating costs of this system will be comparable to Falcon 9 for the booster phase of flight. It seems like this launch system will be more expensive per kg, and have far greater loads on the payload than Falcon 9. I hope it works out, and they find ways to make it commercially viable, but Falcon 9 really has set the bar for success quite high.
- mlindner 6y agoThe problem isn't altitude, it's speed. Launching from the air has all the same problems of air launched rockets from planes. Except now they're trying to sling a massive rocket up to 200k feet along with all the sloshy liquids inside without anything breaking. It's complete and utter madness. The founders/investors are guaranteed to lose all their investments.
- thombat 6y agoWell somebody is sure to lose their money, but if enough bigger fools can be lured aboard it needn't be the current crew. In other words, the Nikola truck but in space.
- fheilz 6y agoVideo of SpinLaunch founders trying to pitch Hawaii residents: https://www.youtube.com/watch?v=VSSBARd5HhE https://www.youtube.com/watch?v=VSSBARd5HhE
- nohat 6y agoPut this on the moon and we are talking. I'm not sure I see this being too useful otherwise, considering how much extra fairing mass those gforces are going to require
- krasin 6y agoYes, SpinLaunch on Moon launching ore concentrates. No housing needed, g-forces irrelevant; gravity well is smaller. Obligatory link, "Moon is a Harsh Mistress", by Heinlein: https://archive.org/details/TheMoonIsAHarshMistress_201701 https://archive.org/details/TheMoonIsAHarshMistress_201701
- zaroth 6y agoI came here to say exactly the same thing. Perfect for my favorite project to save the Earth - launching refined moon dust at Lagrange points.
- nso 6y agoI swear I either read a book or watched a movie in which they did exactly this.
- mech422 6y agoI loved Heinlein as a kid... I wonder how many geeks today realize he's the origin of the term 'grok' ?
- andrewflnr 6y agoA lot? It's not that big a secret, if the question ever occurs to you. I've known for a while and haven't even read the book.
- mech422 6y agoI don't think its a secret, but I do think it was before a lot geeks time...hell, it was actually published almost a decade before my time :-P P.S. It also appears 'grok' has fallen out of favor over the years. It's too bad, I always liked how subtle it was - the distinction between knowing WHAT something does and WHY it does it(eg fully understanding it)
- black6 6y agoThe Lofstrom Launch Loop[0] is less fanciful than a 5000 mph centrifuge slinging payloads into LEO. 0: http://launchloop.com/ http://launchloop.com/
- definetheword 6y agoHow is this less fanciful?
- paledot 6y agoBecause the physics actually works.
- blackrock 6y agoReally? What will they use to build the legs to support it?
- paledot 6y agoThose aren't legs, they're guy wires. https://en.wikipedia.org/wiki/Launch_loop https://en.wikipedia.org/wiki/Launch_loop I said the physics works. The engineering is a totally different question.
- definetheword 6y ago"I said the physics works. The engineering is a totally different question." So if the engineering is questionable or unrealistic, how is it less fanciful?
- paledot 6y agoIn 50 years or 100 years, there might be a launch loop. There will never be a launch centrifuge, not in 50 or 100 or 1000. Fluid dynamics simply don't allow objects to move that fast at ground level. 0.000000000001 > 0
- hirundo 6y ago1. Build a large superconducting flywheel energy storage system like they have in Japan, right under the launch centrifuge. 2. Use it continually to arbitrage energy prices. Buy low sell high. 3. At launch time divert the rotational energy to the centrifuge. (I'd like to see that clutch.) 4. Profit
- simonebrunozzi 6y agoCouldn't you simply do it with a battery?
- TaylorAlexander 6y agoYes but then how would you raise all the investor funds to funnel to your offshore accounts?
- Cthulhu_ 6y agoNot a scientist, but in theory flywheels or any kind of mechanical energy storage have less energy loss than chemical energy storage like batteries. Then there's wear and tear, switching, etc.
- timpattinson 6y ago5. Forget about the rockets, just buy and sell energy
- supernova87a 6y agoHow does it deal with the sudden inrush of air and the object at supersonic speeds when the hatch is opened? Although, I guess for something about to go 5000 mph through the atmosphere, a little extra air probably isn't a big deal. Maybe the hatch cares though.
- clnhlzmn 6y ago> 5000 mph > a little extra air I think this is actually a big deal.
- ogre_codes 6y ago> At this point the spacecraft will be subjected to a peak force 10,000 times greater than Earth's gravity, something opponents believe will seriously affect its structural integrity and the safety of its complex electronics. These kind of forces are pretty insane compared to even the high G boost you get on a normal rocket launch. I wonder if that is going to put a crimp on their potential client list.
- JumpCrisscross 6y ago> wonder if that is going to put a crimp on their potential client list Solid state electronics and fuel. With respect to the former, nothing that requires stable orientation. I don't know of a propulsion system that can survive those forces.
- ogre_codes 6y agoThat thing where they compress your ashes down and launch them into orbit... that may be their specialty.
- moonbug 6y agoSo the customers who have no way to verify their payload made orbit.
- blackrock 6y agoRaw metal powder for 3D printing laser sintering. Or plastic pellets. Water. Fuel. Clothes. Maybe this is what can kick start the 3D printing in space revolution. Maybe it can also launch radioactive waste into space? One bucket at a time. Then a space towtruck can be launched to hurl it into the sun. But it’ll likely just part a naive investor from their money.
- Cthulhu_ 6y agoNot sure how serious you are with the radioactive waste thing but I'll do the HN thing and bite (nerdsnipe!), because that's not going to work. You can't launch things into the sun, you need to decelerate objects. The earth travels at 30 km / s (70K MPH) around the sun, so you need to decelerate about that much the other way. And orbiting radioactive waste is just asking for trouble. The total amount of radioactive waste on the earth is about the size of a swimming pool (or was that the total amount of gold? I forgot, either way in terms of quantity it's not that much), burying it deep and forgetting about it for the next 100.000 years is the way to go I think.
- absolutelyrad 6y agoAmbitious. Not sure how it deals with the structural impact due to extreme forces.
- ivirshup 6y ago10,000g sounds pretty rough. Are there any existing electronics that we would expect to survive this?
- whalesalad 6y agoNokia 3310
- raasdnil 6y agoGold.
- roamingryan 6y agoYes. Guided munitions. Some artillery shells incorporate guidance electronics that survive these sort of conditions.
- mlindner 6y agoYes but guided munitions are compact lumps of steel, not squishy rocket tanks full of liquid. The forces are also all in one direction, first in the positive direction from launch, and then in the negative direction from atmospheric deceleration. This will have lateral forces, then sudden relaxation of those forces (shock unloading) and then sudden vertical forces when it hits dense atmosphere.
- andrewflnr 6y agoFrom the title, I was hoping this would be about a slingatron. That's still one of my favorite space launch proposals (the launch loop is another), but I wasn't able to quickly find a good reference. :(
- b34r 6y agoI’d rather see them launch junk toward the sun with it.
- elihu 6y agoI wonder what the cost/benefit of using a centrifuge is versus a light gas gun? https://en.wikipedia.org/wiki/Light-gas_gun https://en.wikipedia.org/wiki/Light-gas_gun
- martey 6y agoThe Wired article that this SyFy blurb is based on has more details (and more criticism) - https://www.wired.com/story/inside-spinlaunch-the-space-industrys-best-kept-secret/ https://www.wired.com/story/inside-spinlaunch-the-space-indu... > One former employee, who spoke on condition of anonymity due to their nondisparagement and nondisclosure contracts, acknowledged the gulf between theory and reality. They described SpinLaunch’s prototype centrifuge as a relatively unsophisticated machine that “any average engineering team could put together.” The employee said that scaling up to a functional suborbital launcher is going to be “very challenging” with SpinLaunch’s resources. The employee also cited the inexperience of some of the leaders. “The foresight to predict many of the issues that are going to happen was definitely lacking,” they said.
- dang 6y agoWe've changed the URL to that from https://www.syfy.com/syfywire/spinlaunch-centrifuge-slingshots-rockets-into-space https://www.syfy.com/syfywire/spinlaunch-centrifuge-slingsho.... Thanks!
- absolutelyrad 6y agoThanks, this is what I was looking for. I didn't want to dismiss them fast, but it did sound like the founders don't know what they're up to. Maybe they figured out some advanced materials science we don't know about, but that seems unlikely from this article. > Over the next few years, the team ran hundreds of high-speed tests. Most of them were to study and improve the system, but some were to mollify skeptical investors and potential customers who didn’t believe a payload could withstand the extreme forces. The team sent solar cells, radio systems, telescope lenses, batteries, GPS modules, and control computers whirling at high speeds; they all survived with little to no damage. In one test, Yaney attached an iPhone to the tether and spun it up until it experienced forces 10,000 times stronger than gravity. Afterward, he used the phone to FaceTime a colleague. Each test was a step, however small, toward space. Something tells me that an iPhone definitely cannot withstand forces of 10,000g. Like someone below said, this either has mil implications or a way to separate investors from their money. Juan Alonso, an aerospace engineer at Stanford who did due diligence for one of SpinLaunch’s investors, understood my reservations. “It's an exotic technology, and the first time you hear about it you think there's no way that could possibly work,” he says. But after checking out the math himself, Alonso gave the investment firm the green light. So a Stanford guy is putting reputation on stake. Interesting.
- basicplus2 6y agoI think it would be more practical to build a helium filled temporary plastic tunnel around a rail gun over a few miles with a gradual curve up at the end so humans could use it.
- mlindner 6y agoIt amazes me how many people fall for such ridiculous physics-defying nonsense. I guess this works to deprive fools of their money.
- ganonm 6y agoI'm not really convinced nor reassured by their supposed tests to prove the physics will work. The test involving the iPhone? That's like saying "well, a marshmallow can withstand 1g of forces without being crushed therefore I can build a 3 story apartment building out of them".
- bob1029 6y ago10000g peak forces are a bit of a mess for space travel. Perhaps instead of directly spinning the object up to speed and "letting go", you could build up all of the energy into a heavy rotating mass which then imparts it into the spacecraft over a slightly longer timeframe via some simple mechanical clutch and cable arrangement. You would still have very strong g-forces, but you could control the impulse curve over time to spread out the forces better. Steel cables, flywheels and other members aren't going to care about such forces as much as the delicate electronics on board a spacecraft. Let these parts do the heavy lifting and then transmit the energy into the spacecraft in a methodical manner. You need to decouple the extreme nature of this sort of energy storage system from the spacecraft until it is go time.
- londons_explore 6y agoYou very quickly get to multi-kilometer ropes, and the need to accelerate a far higher mass than the launch mass...
- craftinator 6y agoReminds me of Seveneves by Neal Stephenson. In a future setting, they use long whip like objects to fling objects around in space, with a flywheel to drive them.
- deleted 6y ago[deleted]
- baltbalt 6y agoI hope they actually try, it's going to be a hell of a show.
- avs733 6y agoI'll RSVP no to the in person watch party and happily watch a stream with a room full of engineering students so we can debrief the explosion afterwards.
- mhandley 6y agoI couldn't help wondering what happens to the counterweight. 100kg travelling at 5000mph works out as about 500MJ. For comparison, 1 tonne of TNT is about 4.2GJ, so the energy of the counterweight is about the same as 120kg of TNT. Looks like stopping the counterweight will produce a pretty big explosion, but probably not their biggest problem.
- noitpmeder 6y agoFrom the article "a counterbalance spinning opposite the rocket gets released at the same time, preventing the tether from becoming unbalanced and vibrating into oblivion"
- viraptor 6y agoYes, but where is it released? Because if it's at the same time and the rocket goes up, the counterbalance goes down. And that means a big explosion right under your infrastructure.
- mhandley 6y agoExactly - the energy of the released counterweight will inevitably produce an explosion as it's stopped pretty quickly by something. My question was how big an explosion. The answer is pretty big, but this probably isn't their biggest problem.
- graderjs 6y agoLiquid back stop? Ballistic jello?
- mhandley 6y ago500MJ is enough energy to flash-boil 200Kg of water, so that might work. Would be a sizeable steam explosion, as the 330 or so cubic meters of instantaneously created steam tries to go somewhere, and an interesting pressure wave in the water tank.
- mensetmanusman 6y agoThis lesson describes the fictitious ‘force’ used in this technology: https://youtu.be/rtFnki476cU https://youtu.be/rtFnki476cU
- Jemm 6y agoSo Wired is now Popular Mechanics and Omni.
- mabbo 6y agoI have a hard time believing this is efficient in terms of energy. Air resistance is a function of the velocity squared and the air density. Air density is a non-linear function as well- it gets very thick near the ground. To put all your energy into maximizing your speed while you're at ground level (the spin launcher) you're wasting huge amounts of energy just pushing air out of the way. At hypersonic speeds, you' Rockets, by contrast, go their slowest at ground level and continually accelerate as they get higher. In SpaceX launches, they actually have a period where they throttle back as they go through "Max-Q", the highest aerodynamic pressure point, as it's more efficient to be slower until you're past this point. I guess using electrical energy, which is a much cheaper source than chemicals like rocket fuel, makes the payoff worthwhile? I dunno, I'm skeptical. Oh also you can only launch this somewhere that no one around will mind an insane sonic boom at ground level.
- efreak 6y agoYou seen to have forgotten to finish your third paragraph.
- jccalhoun 6y agoI'm skeptical but I hope they can at least get a test launch or two out. I've always found things like this or using a slingshot to launch something to be interesting ideas and would love to see them tried out.
- jl2718 6y agoI think it’s possible with some tricks. The Mach angle is going to be extremely tight, so the profile of a normal spacecraft design would look like a flat plate at that speed. Normally, the craft is designed with a body shape roughly matching the Mach angle, but that would make it look like a long needle and you’d never be able to spin that up. So instead, you can use a hypersonic projectile to open up the pressure envelope in front of the payload. This would be a big chunk of tungsten in a tear-drop shape. In this case, the shape is not for laminar aerodynamics; it’s for keeping mass in front for positive ballistic coefficient, and maintaining the same shape as it erodes. This is required because it has to stay ahead of the payload. Of course you can also make a train of these increasing in width and spaced to match the pressure cone. The calculation for how much energy this takes is the sum of: 1. Mass to orbit. 2. The atmospheric pressure times the atmospheric height times the area of the Mach cone. 3. Heat losses. We can compute minimum values for the first two to get an idea of how much energy is required. I’m not sure about heat losses, but I think it’s roughly half the energy budget. Overall I’d naively expect this to end up being more efficient than carrying fuel to orbit.
- raphar 6y agoUltimate trebuchet!
- JoeAltmaier 6y agoIs it necessary to survive 10000g to get to orbit? Wrong question. It requires 17600mph to stay in orbit. However you do that. The g's to do that depend entirely on how long the acceleration is applied.
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- ahaferburg 6y agoDoes the rocket somehow counter the spin of the tether? If it's rigidly attached to the tether, I don't understand how it would stop spinning after being released. The rocket itself would spin very quickly, and due to conservation of angular momentum it would keep spinning upon release. Am I missing something? Or do they somehow counter the spinning of the tether, so that the rocket's orientation remains static? If there's another bearing at the attachment point, I don't see how just the outer bearing would withstand the friction at 10000g.
- rcgorton 6y agoIt seems to require a vacuum to spin. And then it needs to launch at Hypersonic speeds and then meets atmosphere. Instant encounter with a solid barrier == blow-up. I am thoroughly skeptical about the technology both on the incredible G forces, and then hitting atmosphere at huge rates of speed.