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SpinLaunch completes first test flight with rocket-flinging launch system
- dang 5y agoWe changed the URL from https://jalopnik.com/a-startup-just-launched-a-rocket-by-spinning-it-really-1848040339 https://jalopnik.com/a-startup-just-launched-a-rocket-by-spi..., which points to this. We changed its hideously baity title as well.
- cee_el123 5y agorelated: skyhook https://sites.google.com/view/sources-skyhooks/ https://sites.google.com/view/sources-skyhooks/ great video: https://youtu.be/dqwpQarrDwk https://youtu.be/dqwpQarrDwk
- mleonhard 5y agoIf one's spacecraft missed the skyhook on arrival, it could not decelerate and would fly off into space. The thought is terrifying. The film Aniara deals with this scenario. Spacecraft relying on skyhooks for deceleration would need lifeboats that can decelerate and return to the destination after a missed skyhook rendezvous.
- cee_el123 5y agosafeguards are of course necessary in any system. here it can be lifeboats, backup hooks, spacecraft with backup thrusters, separate mechanisms for moving people vs stuff, and potentially many more
- deleted 5y ago[deleted]
- panick21_ 5y agoPeople here seem very interested in questions about payload G-forces and basic functioning, but to me, non of those matter. Even if you assume 100% of this works, it has no place in the market. A Starship can launch 150 tons to Orbit, fully reusable. Now ask yourself, if SpinLaunch even if you assume the largest possible ground station can not launch more then a few 100kg to Orbit and still requires a Upper Stage rocket that has to be thrown away. How could it possibly be cheaper? So lets assume an absurdly large SpinLaunch system that can get 500kg to Orbit. You still need 300 launches to match what Starship can do in a single afternoon. In a more practical situation its more like 800 launches to match a single Starship. Now try to think a gigantic stack of 300 SpinLaunch upper stage rockets that would be thrown away including 300 rocket engines, 300 avonics systems and so on. Compared to a Starship that simply lands and is fully reusable. Not to mention that a chemical rocket is far more flexible in regards to orbit and far more versatile in possible payloads. At best it can compete for a very small part of the small rocket launch business. But even then, a lot of the time dedicated launches are used for non-standard orbit and SpinLaunch has far less flexibility then a normal rocket. I really see no way this makes much sense.
- djmips 5y agoMakes me wonder about the military uses of such tech. Remember Gerald Bull and his quest to launch a satellite with an artillery piece? He later was embroiled in a project for Iraq to create a supergun that could potentially provide ICBM tech to a country without rocket tech. https://en.wikipedia.org/wiki/Supergun_affair https://en.wikipedia.org/wiki/Supergun_affair
- walrus01 5y agoseemed to be going okay until he was assassinated by the mossad. https://en.wikipedia.org/wiki/Gerald_Bull#Assassination_and_legacy https://en.wikipedia.org/wiki/Gerald_Bull#Assassination_and_... have seen it described as the "canadian iraqi space gun", which causes some people to do a double take
- riffraff 5y agoWow I never heard of this, a real life Jules Verne story!
- andbberger 5y agohmm doesn't really have the happy ending you'd expect though
- toomanybeersies 5y agoIt was also fictionalised in a Frederick Forsyth's espionage thriller, The Fist of God [1] [1] https://en.wikipedia.org/wiki/The_Fist_of_God https://en.wikipedia.org/wiki/The_Fist_of_God
- theNJR 5y agoNeil Stephenson was just talking about this concept on Lex Friedman’s podcast. https://www.youtube.com/watch?v=xAfdSak2fs8 https://www.youtube.com/watch?v=xAfdSak2fs8
- barbazoo 5y agoScott Manley has made a video about it https://youtu.be/JAczd3mt3X0 https://youtu.be/JAczd3mt3X0
- usefulcat 5y agoThis is fascinating, but I can’t believe he didn’t really address the elephant in the room (for me anyway). The instant the payload is launched, the launching mechanism will still be rotating at several hundred RPM but will no longer be balanced. I don’t see how it wouldn’t proceed to immediately and spectacularly tear itself apart. So they must have figured out how to rebalance it almost immediately. THAT is what I’d really like to hear about; that seems like the hardest aspect of the whole process.
- geerlingguy 5y agoSomething like 10,000g to 0 in an instant—it does seem to be the largest engineering problem with a full-scale design.
- neltnerb 5y agoYeah, I didn't see any explanation for that either. With that much kinetic energy around I wonder if it's designed to simultaneously launch a portion of the counterweight. It's got a lower lever so the overall momentum might be low enough to make that recoverable. Maybe if it's 10% of the rocket's momentum, going into... yeah, it's hard to imagine that being recoverable but maybe it's just weights and that's good enough. I'd love to see a real explanation.
- finnh 5y agoHe mentioned it toward the end, but did not describe the solution. I'm thinking the counterweight on the other end would need to move a very precise distance in effectively zero time. EDIT: hmm, or a supplemental weight on the payload side, moving outward the right distance as the payload releases. It seems like you'd generally want the non-payload rotating bits to vastly outmass the payload, so its release perturbs the whole system to the least amount possible. And then you use regenerative braking to reclaim the energy .
- joshu 5y agoI'm an investor in SpinLaunch and am extremely excited about it.
- JohnJamesRambo 5y agoHow did you invest in it?
- soheil 5y agoI wonder how much lower the g forces would come than from 10k if the radius was larger. The high energy particle accelerator at cern comes to mind. It wouldn't need to be vertical either just at a slight tilt since to go to orbit you need to travel horizontally most of the time.
- rklaehn 5y ago
- HappyMans 5y agoI wonder how big it would have to be to even consider putting people on it, albeit sleeping ones. A younger me would look up the required velocity and do the math. A slightly older me is going to sleep soon and will dream that one day he gets to get into the space flinger. Edit: and not come out as human paste
- kumarvvr 5y agoPeople and many delicate equipment cannot handle such high G forces. I do wonder how a Hyperloop kind of long tunnel, vacuumed out would be a less-G substitute.
- rgmerk 5y agoArthur C Clarke proposed the idea in 1950 in a paper, and wrote a rather excellent short story about the concept (and a wild escape from a launch failure) called "Maelstrom II". In Clarke's story, the launch system is located on the Moon rather than Earth; the lower escape velocity and lack of atmosphere makes the fictional engineering a lot simpler (and allows the climax of the story, which I won't spoil).
- after_care 5y agoI did the math once, and that vacuum hyperloop would be 10s or 100s of km.
- zem 5y agohttps://en.wikipedia.org/wiki/Mass_driver https://en.wikipedia.org/wiki/Mass_driver
- numpad0 5y agoWhen I was younger those devices were called “mass drivers”. The idea was crude materials would be cut up from moons and asteroids, and launched using maglev rails towards civilization centrals. Or it can also be used for recovery, so long that the landing spacecraft can successfully mate the train. Above is portrayed first, in cases with Sci-Fi novels, then of course something terrible would occur, and the story starts to ramp up. A shivering refugee is found inside, one of containers suspiciously veer off course, the crucial docking latch breaks, etc.
- jcims 5y agoCool to see some new ideas here. Saturn V burned nearly 200 tons of propellant by the time it cleared the launch tower. Tsiolkovsky got us to the moon but he won't get us to the stars.
- numpad0 5y agoWhy not just build couple extra O’Neil cylinders on orbit, run checkouts while populating them over 2-3 generations, and shoot it out? No reasons the majority of interstellar crews has to be Earth born.
- thuccess129 5y agoSolid rockets had more carrying capacity at one sixth the cost of Saturn 5 at the time. Is the ultimate launch system rated human-safe a combination of spinlaunch, solid rocket boosters to reach highspeed for airbreathing ram/scramjets and lastly transition from airbreathers to liquid propellants?
- adgjlsfhk1 5y agoNo. Humans don't like 10 gs not to mention 10000.
- tehjoker 5y agoIt's enticing because what if you could use this to put fuel and/or parts into orbit to assemble a second stage rocket for interplanetary travel? That'd be sick. I suppose it partly depends on how high you can reach (LEO?) with this method and whether your spun rocket can carry a fuel payload itself.
- idontwantthis 5y agoPayload needs to include a rocket or else it will come back down. Orbit requires going sideways really fast.
- usefulcat 5y ago
- endisneigh 5y agois this really more efficient than just launching the rocket normally with chemicals? the article doesn't really go into detail but alludes to the answer to my question being "yes". I guess the idea is: you can spin a smaller rocket which requires energy EnergySml. Alternatively you could have a larger rocket which requires EnergyLrg to get out of the atmosphere. So EnergySml + Fuel in rocket to leave atmosphere << EnergyLrg (which is launch + leave atmosphere)? --- other questions I had were: - wouldn't the rocket being spun have to be heavier than the equivalently sized chemical rocket because it has to be able to survive being flung around in a centrifuge?
- walrus01 5y agothe important thing I think is that your energy-consuming device (the spinny part) can be huge and heavy and remain on the ground, so it doesn't need to be designed like a rocket first stage. Even if it's actually really inefficient in terms of watt-hours used to spin the thing, doesn't matter.
- retrac 5y agoYou don't have to lift the fuel. A huge proportion of the fuel in a rocket's first stage is used to lift the fuel in the first stage off the ground for the first few hundred metres of flight. It's almost diabolically inefficient. Using a really big cannon, not entirely unlike in the Jules Verne novel, has been investigated seriously. It has similar efficiency benefits. Some limits on what can survive the acceleration though: https://en.m.wikipedia.org/wiki/Project_HARP https://en.m.wikipedia.org/wiki/Project_HARP
- FpUser 5y agoI knew this would come up in here. Gerard Bull was an amazing character. Unfortunately he was screwed by few governments and at the end he was assassinated (presumably by Mossad).
- kumarvvr 5y ago> you can spin a smaller rocket That could be extremely complex, unless (perhaps) the rocket using solid boosters, in which case, you are spinning a highly volatile mega bomb.
- walrus01 5y agoI couldn't resist mashing these two together http://www.youtubemultiplier.com/618f3abec89ec-you-spin-me-right-round-baby.php http://www.youtubemultiplier.com/618f3abec89ec-you-spin-me-r...
- jessriedel 5y agoJtbc, this was the altitude it made it to with no rocket motor right?
- instagraham 5y agoSo you will only be able to send payloads that can handle such immense G-force pressures, I imagine? Humans can be ruled out then unless you want hominoid scrambled eggs in space
- spicybright 5y agoI can't think of much besides scrambled eggs you could send up.
- CryptoPunk 5y agoBasic supplies, like fuel, and a lot of electronics, like solid state drives, can survive those g-forces.
- whoisthemachine 5y agoI wonder if this could be used in a rifle type design, where the "spinner" would carry an impactor that would push against the space-bound rocket/projectile, to avoid (some) of the high g-forces?
- yjftsjthsd-h 5y agoIt feels like that's worse, because then you have to impart all the acceleration at once?
- whoisthemachine 5y agoYes there would definitely be quite a bit of force at impact time, but the projectile wouldn't have to experience an hour of high g-forces, just a few moments.
- kumarvvr 5y agoPerhaps this can also be used to send a continuous stream of supplies, such that we could have a true, inhabitable space station, where all the components required for space travel are manufactured and assembled in orbit.
- troymc 5y agoYou can build something like this, but much bigger, and with no external casing, on the Moon or anywhere with little or no atmosphere. Professor James Longuski and his students at Purdue University have done quite a bit of research on this idea over the years. They call it a tether sling. To keep the tip acceleration (v^2)/r low, you want a large r. Some papers: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=longuski+tether+sling&btnG= https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=long... Note 1: Professor Longuski was my PhD advisor, but I never did any research on tether slings myself. Note 2: Others have also researched tether slings. The papers linked above give many citations to related research.
- soheil 5y agoSomething like the large hadron collider?
- troymc 5y agoThe LHC uses electric and magnetic fields to accelerate charged particles to near the speed of light inside a circular vacuum tube. To picture a tether sling, imagine a lighthouse on the Moon with a giant arm sticking out of its side, and the arm can revolve around the lighthouse like a merry-go-round. The thing to be launched goes at the end of the arm. Just spin up the arm and let go!
- soheil 5y agoSorry I meant for a solution that would work on earth. Couldn't we use magnets to accelerate the ship like a maglev train inside a version of LHC with wider tubes?
- Waterluvian 5y agoPossibly a silly question: 1000g is 1000g but do things survive better if you slowly bring it to 1000g rather than quickly?
- R0b0t1 5y agoYes. But because the radius on their launcher is tight the object will be experiencing ~10k times gravity as a static load.
- csours 5y agoGravity = Acceleration = Velocity Squared (V^2) After acceleration, you have 'jerk' V^3, which is commonly used, and then 'snap, crackle, and pop' which are less commonly used. https://en.wikipedia.org/wiki/Jerk_(physics) https://en.wikipedia.org/wiki/Jerk_(physics) V^4 is also called jounce, and I know some vehicles have jounce bars, but I don't know if those are truly related.
- thaumasiotes 5y ago> Gravity = Acceleration = Velocity Squared (V^2) That first part is correct; gravity is measured in units of acceleration. But I have no idea what you mean by "velocity squared". If you mean the ordinary sense, of multiplying something by itself, you're wildly wrong. Acceleration is the derivative of velocity with respect to time, dv/dt, and it is measured in units of velocity over time, not units of velocity squared. Its magnitude is unrelated to the magnitude of velocity.
- deleted 5y ago[deleted]
- otras 5y agoThis is probably a silly question, but for the test run, did they launch the rocket straight up? From my limited understanding of gravity, I’d expect it to come straight down if anything went wrong, and it looked like there were quite a few things for it to come down on. Edit: looking at the video closer, it looks like there is a slight angle to the launch, tilting away from the building next to it, which makes sense.
- soheil 5y agoIt most likely has a self-destruct sequence. It's basically the same as firing a missile so I wouldn't be surprised if the same type of persuasions were taken as when military drills take place.
- harpiaharpyja 5y agoEarth is a rotating reference frame. So, no, anything going high enough up won't come "straight down"
- habibur 5y agoWill come straight down even though the earth is spinning... unless atmosphere drags it aside.
- harpiaharpyja 5y agoNo, even if there were no atmosphere it would not. There's a point at which you can no longer ignore the rotation of the earth. Maybe the effect still isn't huge at the scales we're talking about but it's not straight up and straight down.
- AtlasBarfed 5y agoDoesn't the angular velocity of the projectile match the angular velocity of the launcher at launch?
- zapdrive 5y ago
- spoonjim 5y agoThis video is really weird because usually a launch video that has all the theatrics of a Hollywood production (all white launch room with dramatic lighting and shallow depth of field cinematography) would usually be done by trust-fund startup LARPers, but they actually built this shit and launched it which is not characteristic of a LARPer.
- soheil 5y agoThis is getting pretty close to science fiction. I wonder how much crazier future science fiction writers can get. They're running out of imaginary ideas that hasn't turn out to be real.
- Animats 5y agoThis is the scale model. The orbital version has to be several times larger. The idea is, I think, to use this as a first stage. The second stage is a rocket that takes the projectile to orbit.
- penjelly 5y agodamn this is the coolest thing ive seen in a while
- NiceWayToDoIT 5y agoThis is quite interesting, recently I watched video explaining similar rail-gun/cannon concept, end explanation what would it take to work for human payload. https://www.youtube.com/watch?v=Rb6sxy3f7VE https://www.youtube.com/watch?v=Rb6sxy3f7VE Well train human can survive: 38G for 0.5s 9G for 2min 7.5G for 5min https://www.youtube.com/watch?v=-4lVfrTcr0c https://www.youtube.com/watch?v=-4lVfrTcr0c
- bagels 5y agoWhat kind of training is there to survive 38G for 0.5s? Maybe the body can become habituated to accelerations over time or something, but what would you be training to actually do before or during those 0.5s?
- NiceWayToDoIT 5y agoPhysical training I guess, trying different G's for long time, exercising breathing under elevated G's ... I do not know, I just wrote what author said in video.
- mkl 5y agoThis guy worked his way up to 46.2G, the "highest known acceleration voluntarily encountered by a human": https://en.wikipedia.org/wiki/John_Stapp https://en.wikipedia.org/wiki/John_Stapp Not without problems though. He "sustained a fracture of his right wrist during the runs on two separate occasions, also broke ribs, lost fillings from his teeth and bleeding into his retinas that caused temporary vision loss". This is during short periods (of deceleration), so very different from SpinLaunch's launches.
- andbberger 5y agoI see this as a win-win. Either it works (great), or we get to see some truly spectacular explosions
- wly_cdgr 5y agoI went to space on this but I got really dizzy
- track3r 5y agoHere is Carmack's take on it: https://twitter.com/ID_AA_Carmack/status/1458870561606615046 https://twitter.com/ID_AA_Carmack/status/1458870561606615046 TLDR Useless, but fun to work on.
- bagels 5y agoYeah, that's probably the right take. They are removing a stage though, the implied third stage, but SpaceX is already doing that with better rocket engineering.
- Veedrac 5y agoCompare the SpinLanch rocket specs [1] to Electron in [2]. Payload: 200kg vs 300kg Height: 6m (est) vs 18m Wet mass: 11t vs 13t Stage 1 thrust: 75kN vs 230kN Stage 2 thrust: 5kN vs 26kN Engines: Pressure fed vs Electric pump fed The SpinLaunch rocket dumps its shell before turning on its engines, and presumably has much lower gravity losses, so despite shockingly similar wet masses, the rocket and its engines can be greatly downsized. I don't have any solid opinion about the concept, but it does seem like “smaller tanks” is maybe not the best description of what is a fairly significant design change. You do shed a lot of complexity from the propulsion systems, but I'm far from sure the stuff you add is any cheaper. [1] https://player.vimeo.com/video/573539093#t=26s https://player.vimeo.com/video/573539093#t=26s [2] https://en.wikipedia.org/wiki/Rocket_Lab_Electron https://en.wikipedia.org/wiki/Rocket_Lab_Electron
- mrb 5y agoSo what's more feasible: SpinLaunch or a space elevator? Let's argue. Ready, set, go! :)
- mkaic 5y agoanswering "Starship" to this question is the equivalent of being the kid in 5th grade who made a finger gun every time they played rock-paper-scissors and instantly won.
- thaumasiotes 5y agoA space elevator is an example of spin launching. But it's a particularly unstable one.
- bagels 5y agoClearly spinlaunch. They built a scale model. Scale models of space elevators are just ropes, and don't get you any closer to the real thing.
- rixed 5y agoThat giant sling somehow looks more suited to deliver small packages directly into a backyard than Amazon's attempts at drone delivery. The military have probably already tried something like that to send ballistic missiles I guess, and in that case you don't even have to accurately aim as the missile can guide itself to the target. Why isn't this a thing already?
- regularfry 5y agoI like my Amazon deliveries to survive impact.
- dwaltrip 5y agoHow much force is exerted on the rocket / payload when it is released from the vacuum chamber — traveling at full operating speed for an orbital mission — and smacks into the atmosphere?
- guerrilla 5y agoI'm too lazy to do the math: Could you use this with gliders for intercontinental travel or would the acceleration kill the passengers?
- remus 5y agoFrom the Scott Manley vid on it, the full scale orbital version is doing 10000g at the tip when it's at full speed. I guess if you didn't want to go as far you could lower that but by the time you're at something tolerable to humans I don't think you'd have much energy to play with. You could try significantly increasing the radius to lower the acceleration but I suspect you'd need to get impractically large before you had something that wouldn't kill people.
- sandworm101 5y agoI don't think the advantages outweigh the disadvantages. G-loading. Rockets are normally rated for force in one direction (down) the same as gravity and launch acceleration. They can only handle a few small percentages of G laterally. This rocket would need that, plus at least a few G of lateral acceleration for spinup and a massive negative G capability for the impact with the lower atmosphere immediately after launch. Was there a G-meter on this rocket/dart? What did it feel like to go from thousands of mph in a vacuum to suddenly thousands of mph at sea level? 50g? It would be like slamming through concrete. Larger rockets would no doubt feel less of this impact but they would still need structures akin to fighter jets. Those structures would be heavy and likely nullify any fuel savings.
- dcposch 5y agoLot of red flags for Spinlaunch. > The test projectile "goes as fast as the orbital system needs, which is many thousands of miles an hour," Yaney told CNBC This is an evasive statement. The test projectile is nowhere near as fast as their planned orbital system. The challenges scale poorly. Acceleration (and resulting loads during the spin) scales with v^2. Then once you hit the atmosphere, drag and thermal flux increases with speed even faster. -- Here's John Carmack (who ran his own rocket company once, Armadillo Aerospace) on Spinlaunch. https://twitter.com/ID_AA_Carmack/status/1458870561606615046 https://twitter.com/ID_AA_Carmack/status/1458870561606615046
- mkl 5y agoAlso: "reached a test altitude “in the tens of thousands of feet,” according to Yaney." Why so vague?
- bayesian_horse 5y agoWith this system, engine misfires would be spectacularly disappointing.
- GistNoesis 5y agoIn the video of the launch we see the rocket punch through a membrane to go from vacuum pressure to atmosphere, what kind of forces does this involve ? Intuitively it seems like hitting a wall, but thinking more about it, inside the rocket this is just a change of acceleration (jerk) so maybe it's not so bad ? Would a human survive it ?
- krisoft 5y agoA human wouldn’t survive the acceleration before it, so I don’t think surviving the punch through matters. This thing causes 10000 G for a sustained time on the projectile. To put this into perspective above 14 G even fit and trained individuals tend to black out. Blood centrifuges use 1500-3000G for 5 to 10 minutes to separate your blood plasma from the red blood cells. After hours of 10000 G acceleration a human body will be a red goo stratified into density layers at the wall of the vessel. Punching through a membrane won’t faze the goo much comparatively.
- culebron21 5y agoThis is either total scam or the founder didn't do school physiscs. Most of the info is quoted as "founder said to CNBC", hence I see no material proof. A school-level physics calculation is enough to debunk it in a minute. Earth orbital velocity is roughly 8000 m/s. To achieve even a small fraction of it by spinning, the projectile and the device must withstand centrifugal acceleration: a = V ^ 2 / r Let's assume we obtain 1/8th of the orbital velocity, which will give a significant fuel reduction, thanks to fuel is exponential to delta V. r of the full-scale should be 136 m (small-scale diameter is 91 m as in the article, scaled by 3 as said there too, divided by 2) 1000 ^ 2 / 136 = 7352 m/s^2 = 750 g. I leave to the others to calculate how many RPMs should the device make. There's no material that can withstand such forces for extention. Many projects of energy conservation with flywheel were cancelled because sighnificantly heavy and large flywheels (couple of tons and just about 1 meter in radius) tear themselves apart at 2-3K RPM. I've not heard of any devices handling 100g over any significantly long periods of time.
- antimatter15 5y agoiPhones can survive 1000G's
- sandworm101 5y agoNot for more than a microsecond.
- sandworm101 5y agoFan blades in jet engines regularly see 100+ g, in tension. Artillery shells, even the fancy ones with guidance hardware, can handle such loads too, in compression.
- culebron21 5y agoGood point, thanks!
- jillesvangurp 5y agoHave you considered it might be you that's lacking in knowledge rather than the investors and founders? You seem quick to call people out on being scammers for something you clearly don't fully understand. Yes you can cite high school math but than you start making assumptions/assertions, drawing conclusions, etc. that are clearly wrong/baseless. Very sloppy arguing. You, "leave to the others to calculate how many RPMs should the device make"; like the people behind this company that clearly did that math, build a device and then proceeded to launch an object several tens of thousands of feet up. Clearly their math is better than yours. "I've not heard of any devices handling 100g over any significantly long periods of time." You just did.
- GistNoesis 5y agoCan frozen food survive the acceleration ?
- simon_000666 5y agoWhat’s the reason they have decided to couple this with a two stage chemical rocket? - Would the physics/g-forces reason be too much to go all the way or some other reason?
- mkl 5y agoThe goal is orbit, and orbit means going very fast sideways at high altitude, where this launcher can't point (because it's at ground level). So, you can't go "all the way" without putting in sideways thrust to turn your trajectory into proper orbit. Without a rocket to provide that sideways thrust, this launcher will throw things up in a ballistic trajectory, and they'll come back down to Earth with a big crash (given enough sideways velocity, they'll "miss" the Earth and be orbiting).
- krallja 5y agoAn orbit must travel through the last point of impulse: in this case, a few meters above the ground. That’s why they need a second stage.
- Havoc 5y agoNeat concept but don't see how they're going to get around the g forces. Think about it...even a playground wheel can generate enough centrifugal/petal force to make a human feel a little unwell. Non-trivial fundamental problem that you can't disappear by just inventing a new material/technique or something.
- yholio 5y agoThis is clearly a military oriented startup. For sending civilian payloads into space, it has a very low chance to reach a price point that is competitive with reusable rockets. You either need an absolutely gargantuan centrifuge -> high capital costs - or you need to subject your payload to thousands of Gs. "The payload" is in this scenario must include 1 ton liquid fuel rocket for every 200Kg you want to put into space, or 1 ton solid for every 100Kg. You have to ensure this "second stage" will never explode inside your centrifuge despite being subjected to orders of magnitude higher loads than the typical rocket. This is possible but very expensive, you will need huge structural mass to hold what would appear to be thousands of tons of propelant at 1G. So the mass fraction goes down, the costs of the rocket and centrifuge "spin" out of control, and you provide a paltry orbital capacity of a few tens of Kg and only for specifically engineered satellites that no existing manufacturer knows how to build. A commercial dead end. For military applications on the other hand, it's close to perfect. You don't need orbital insertion, you can accelerate your payload silently without allowing for detection in the early phase of the attack, your projectile starts at essentially cruise speed and can only be detected by infrared emissions due to atmospheric heating for a few seconds until the launch ablative heatshields are ejected. It's a fantastic first strike weapon.
- le-mark 5y agoSpacex needs this (or a really large space gun) to refuel starship in orbit. I would not be surprised if Elon is an investor.
- NikolaeVarius 5y agoWhy does SpaceX "need" this
- panick21_ 5y agoNo. Just think about it for a few minutes. Starship can deliver a payload of 150 tons to Orbit, fully reusable. SpinLaunch needs a non-reusable second state and can deliver at best a few 100kg. So what do you think is cheaper, launch 1 Starship or 500+ SpinLaunch non-reusable rockets?
- 5y ago
- lambdatronics 5y agoIf you look frame-by-frame at 0:47 to 0:48 in the video, you can see the projectile is tumbling end-over-end.
- holtkam2 5y agoWhat if they built a giant multiple mile long electromagnetic rail gun that accelerated the payload to a few thousand miles and hour and fired it off into orbit? It would solve the same problem as this spinny thing but would subject the rocket to lower g forces during its launch?
- fho 5y agoI somehow expected this to be some kind of [Skyhook](https://en.wikipedia.org/wiki/Skyhook_%28structure%29?wprov=sfla1 https://en.wikipedia.org/wiki/Skyhook_%28structure%29?wprov=...). Thinking about that, would it be possible to "fling" an object trebuchet-style by flying some crazy maneuver with a "hook-plane" instead of a satellite?
- dredmorbius 5y agoThis concept has been pretty thoroughly rubbished by Thunderf00t (video): Part 1: https://yewtu.be/watch?v=9ziGI0i9VbE https://yewtu.be/watch?v=9ziGI0i9VbE Part 2: https://yewtu.be/watch?v=ibSJ_yy96iE https://yewtu.be/watch?v=ibSJ_yy96iE TL;DW: - Vacuums are hard. - Rotation is hard. - Mach 7 is hard. - Lower-atmospheric thermal ablation is hard. - Promotional videos long on drama, simulation, confetti, and inspriring soundrack, short on actual data and performance shots. - Leadership expertise and experience is profoundly lacking.