Spinlaunch... Can it succeed?

[DougSpindler]

You mean Flubber.

[SiliconWizard]

You mean a trial run or a criminal trial?

As a possible ending, the latter doesn't sound unlikely, but both aren't  mutually exclusive here.

[EEVblog]

Old thread bump because it trended on Twitter.
https://x.com/TechBurritoUno/status/1796560546440847389

So what's the latest update?
Still using their original small scale demo, and only 1000mph vs the 5000mph claimed they need with a 100m diameter launcher.
But they got some payloads up on (very wobbly) flight #10, but no mention of height or if the payloads survived.

My bet is that this is the best they will get. If they go to 100m diameter and 5000mph it's all going to all come-a-gutsa.

[Zenith]

It reminds me of "A Trip to the Moon" 1902.



Or the full version for real enthusiasts.

[ArdWar]

Personally I think this is another case of how non-intuitiveness of orbital mechanics making general public a too easy target to woo with something that sounds impressive.

Getting stuff into space is relatively easy. These days you can even use toy rocket to get several kg past Karman line. Getting stuffs into orbit is the hard part, and you can't do that with single impulse spin launch alone. If most of the work raising perigee is still done with apogee kick motor then this idea is not that much different from what Virgin was doing by launching rocket off carrier plane. This time with fancy addition of extremely high centrifugal stress and spending the highest velocity of your trajectory in the densest part of the atmosphere.

I think just like any mass driver it will work best in thin atmosphere like the moon or probably mars, but less useful in earth. There they can impart much higher orbital speed by launching at shallow angle and not spending even longer time moving through thick atmosphere.

[DougSpindler]

What's the latest news from Spinlauch?  Have they admitted defeat?  Or are they still think they can do it?

[Rick Law]

Old thread bump because it trended on Twitter.
https://x.com/TechBurritoUno/status/1796560546440847389

So what's the latest update?
Still using their original small scale demo, and only 1000mph vs the 5000mph claimed they need with a 100m diameter launcher.
But they got some payloads up on (very wobbly) flight #10, but no mention of height or if the payloads survived.

My bet is that this is the best they will get. If they go to 100m diameter and 5000mph it's all going to all come-a-gutsa.
[... ... ...]

I think high probability the end is near.

They have been around too long for this to be trending again all a sudden.  I suspect that trending is done via paid marketing firms.   Probably because they are running out of money and now needs more "fresh enthusiasm" to bring in more venture capital dollars.

Personally I think this is another case of how non-intuitiveness of orbital mechanics making general public a too easy target to woo with something that sounds impressive.
[... ... ...]

I think it is a good bit worst than that.  General public has a rather low foundational knowledge of basics in math and science.  In my view, hardly adequate to sustain society that relies on high-tech.

Recently, I stumbled onto a free movie on Youtube.  Well, I decided to just let it play.  After some blend drama, the way the hero saved the world was by using an old war diesel submarine to get to the bottom of The Mariana Trench, place a nuke with precision, blow that and shifted the continent adequately.  To have a movie like that, expectation of general public's basic knowledge of basic science cannot be high.

[DougSpindler]

Seems to me Spinlaunch is just another Theranos.  Just as EH was told early on.....  Your product will never work unless you find a way to break the laws of physics and chemistry.

[EEVblog]

I think high probability the end is near.
They have been around too long for this to be trending again all a sudden.  I suspect that trending is done via paid marketing firms.   Probably because they are running out of money and now needs more "fresh enthusiasm" to bring in more venture capital dollars.

They need to build a 100m version. Their 33m version already cost $38M.
Haven't posted anything in 7 months, and that just hiring Neumann space to do some co-op research with. No announcements of any new build at all.
Good bet new money isn't flowing in.

[SiliconWizard]

Maybe they can get a new round of cash if they make it solar-powered.

[DougSpindler]

Needs to be AI solar powered 2 nm technology that's premium artesian hand crafted that's sustainable, ecofriendly, vegan, with a zero carbon footprint and will clean the oceans while creating world peace while solving world hunger and poverty with every launch.

[Rick Law]

Actually, in this case, SpinLauch has the Laws of Physics on it's side, but the mathematics of Economics will kill it.

They don't have to break any Laws of Physics to reach adequate speed.  The cost in resolving all the big things and the little things will add up to be huge and will make it economically non-viable.

The problem is not so much the the simple huge g-force alone, but the magnitude of that force and it introduces complexity to everything else including the payload.  The laws of physics is inconvenient for sure, such as the inherent rotational force upon release that will cause the payload capsule to rotate on release (not just momentum alone but the asymmetry of it, due to the outer side of the payload capsule traveling faster than the inner side).  Adding energy to one side alone is not something difficult.  Nothing a direction-adjustment jet cannot handle but yet it is another "problem to solve" that costs money.  The wobbling can be controlled by better direction-adjustments nozzles, or may be introduce a spin to the launched rocket like rifling in cannons, either way, another solvable problem but needs $ to solve...  Each may have secondary effect such as more adjustment rocket fuel is simple to add but it will move load capacity from payload capacity to operational needs...

All physics related problems are of the theoretically solvable type.  No laws of physics needs breaking.  But the laws of economics here will keep adding the cost up, and up.  Laws of Physics say "can do", Laws of Economics say "only if you don't mind spending way more than you save".  That's my opinion.

[EEVblog]

Actually, in this case, SpinLauch has the Laws of Physics on it's side, but the mathematics of Economics will kill it.
They don't have to break any Laws of Physics to reach adequate speed.  The cost in resolving all the big things and the little things will add up to be huge and will make it economically non-viable.

Welcome to the world of engineering practicality.

[thinkfat]

Their problem are not physics but engineering and economics. Even if they are able to eventually solve the engineering problems, they will have to also beat the economics of already existing solutions. Their niche might be just too small to survive in.

[PlainName]

the economics of already existing solutions

Not forgetting the economics of annoying the climate change lobby when they realise just how polluting existing solutions are.

[Rick Law]

...

Welcome to the world of engineering practicality.

I think they do need the 100m wheel to expose the problems that a 33m miniature wont be able to expose.  As you cited in earlier post, the 33m wheel already costed $38 million, I suspect getting the 100m wheel (and projectile to work) will be many times that.  Since centripetal force is proportional to V², I suspect their problem list will also grown proportional to  V².  Cost for the final system likely would be somewhere between $38² to $38³: $1.4B to $54B.

Then there is the recurring cost...  Even the moving part and the force bearing part will suffer from metal/material fatigue, they will have a limited life expectancy = they are consumables.  (According to public TV documentaries) USN Carriers landing catch cable is taken out of service after 100 use.  _{(An F14 Tomcat is about 40,000 kg empty, about 100x the spin-launch launch vehicle loaded.  The deceleration for carrier landing is below 100G, Spin Launch is about 11000G, about 100x a carrier landing.  So the magnitudes of the force (=ma) is about the same)}.  I would imagine for safety, the wheel and structure's consumable parts will need rebuilding is around 100 use as well.  Rebuilding a by-then known solution is not going to be as expensive as the first-built.  But, it could be another few ten(s) of million dollars every 100 launch or less.

This is like my bath room's old plumbing, every time I think about it, the cost got higher.

Honestly, I do hope they will succeed.  Beyond space technology, it will be a good achievement for technology and engineering in general.  Let's hope they don't solve problems the OceanGate way.

[EEVblog]

I think they do need the 100m wheel to expose the problems that a 33m miniature wont be able to expose.  As you cited in earlier post, the 33m wheel already costed $38 million, I suspect getting the 100m wheel (and projectile to work) will be many times that.  Since centripetal force is proportional to V², I suspect their problem list will also grown proportional to  V².  Cost for the final system likely would be somewhere between $38² to $38³: $1.4B to $54B.

That's what I expect too.
They got seamingly decent results from the 30m test unit (even though they are obviously hiding things, but at least it didn't explode).
But I'd bet the 100m unit is going to come-a-gutsa.

Honestly, I do hope they will succeed.  Beyond space technology, it will be a good achievement for technology and engineering in general.  Let's hope they don't solve problems the OceanGate way.

It would work great on the moon to fling stuff back to earth.

[Phil1977]

What most people forget when talking about spin launch:

The acceleration the projectile gets sideways in the centrifuge is exactly the same as you would need longitudinally in a cannon launcher.

The only advantage you have in the spinlauncher: You have more time to accelerate, you need the same energy as in a cannon but a lower peak power.

But this advantage seems really small compared to all the problems you get if you want to construct a second stage that is able to 1st withstand the enormous lateral forces in the launcher and then start a rocket in lateral direction.

Or in other words, because I experienced a lot of people having questions about this: The centrifuge reduces the peak power you need to accelerate the projectile but it does NOT reduce the absolute force you experience during acceleration compared with an equally sized cannon.

If more people would understand that the forces are the same, no one would seriously favour the slingshot over the use of a cannon.

[Haenk]

you need the same energy as in a cannon but a lower peak power.

I guess the whole idea is to not use chemical power (as in rocket fuel) but to use electrical power (which might be next to free one day and does not pollute the environment).
Still, my bet is on "not going to work", even if millions/billions more are spent.

[PlainName]

The centrifuge reduces the peak power you need to accelerate the projectile
[...]
If more people would understand that the forces are the same, no one would seriously favour the slingshot over the use of a cannon.

The reduced peak power might be worth more then you're considering. Take a 5 lb hammer and notice the difference between banging your hand when there is a wall behind it (peak deceleration) and when there isn't (reduced peak). Same overall deceleration but I know which one I'd chose to demonstrate myself, and which I'd get you to demo

[coppice]

Maybe one day a Spinlaunch type device will be operating horizontally on the moon, sending 2 craft in opposite directions at the same time.

(In case its not obvious, this was a facetious comment. Get rid of the problems of an Earth base Spinlaunch, and you just get a whole bunch of new ones to do something useful on, say, the moon)

[Phil1977]

The reduced peak power might be worth more then you're considering. Take a 5 lb hammer and notice the difference between banging your hand when there is a wall behind it (peak deceleration) and when there isn't (reduced peak). Same overall deceleration but I know which one I'd chose to demonstrate myself, and which I'd get you to demo

But that´s exactly the thing why spinlaunch will never work: In case of your hammer hitting the hand the force you feel is proportional to the acceleration.

In case of spinlaunch it isn't! The force you would feel inside the slingshot is THE SAME as you would feel in a space cannon with the length of spinlaunchs radius. Spinlaunch does NOT make the g-forces less, it only makes you feel that forces for much a longer time. That´s high school physics.

[CatalinaWOW]

What most people forget when talking about spin launch:

The acceleration the projectile gets sideways in the centrifuge is exactly the same as you would need longitudinally in a cannon launcher.

The only advantage you have in the spinlauncher: You have more time to accelerate, you need the same energy as in a cannon but a lower peak power.

But this advantage seems really small compared to all the problems you get if you want to construct a second stage that is able to 1st withstand the enormous lateral forces in the launcher and then start a rocket in lateral direction.

Or in other words, because I experienced a lot of people having questions about this: The centrifuge reduces the peak power you need to accelerate the projectile but it does NOT reduce the absolute force you experience during acceleration compared with an equally sized cannon.

If more people would understand that the forces are the same, no one would seriously favour the slingshot over the use of a cannon.

Wrong. 

Go back to simple physics.  F=ma and v=at.  The cannon uses extremely high acceleration to get high velocity before leaving the barrel.  Acceleration is basically determined by the length of the barrel and projectile velocity.

 Spin launch has low acceleration along the long axis of the projectile, taking many seconds to spin up.  Acceleration on this axis can in principle be as low as you want.

Spin launch projectiles also experience centripetal acceleration due to the continual change of direction of the velocity vector.  The magnitude of the acceleration is determined by the velocity and length of the sling arm.  If the sling arm could be as long as the desired orbital radius this acceleration could be one g, and supplied by the earth gravitational force.

Any similarity in the magnitude of the accelerations in the two systems is a coincidence due to engineering choices.  The constraints on a cannon are very different from those on spin launch.

[coppice]

Spin launch has low acceleration along the long axis of the projectile, taking many seconds to spin up.

I think their blurb talks about 20 to 30 minutes to spin the thing up to launch speed.

[Phil1977]

Wrong. 

Go back to simple physics.  F=ma and v=at.  The cannon uses extremely high acceleration to get high velocity before leaving the barrel.  Acceleration is basically determined by the length of the barrel and projectile velocity.

 Spin launch has low acceleration along the long axis of the projectile, taking many seconds to spin up.  Acceleration on this axis can in principle be as low as you want.

Spin launch projectiles also experience centripetal acceleration due to the continual change of direction of the velocity vector.  The magnitude of the acceleration is determined by the velocity and length of the sling arm.  If the sling arm could be as long as the desired orbital radius this acceleration could be one g, and supplied by the earth gravitational force.

Any similarity in the magnitude of the accelerations in the two systems is a coincidence due to engineering choices.  The constraints on a cannon are very different from those on spin launch.

Absolutely wrong and I'll leave this discussion again.

In spinlauch the acceleration on the axis of the projectile is as little as you want yes. But due to the centripetal / centrifugal forces you generate the Side-aceleration is exactly as big as if you build a cannon with length l instead of radius r.

The problem stays the same: If you want to accelerate an object in a confined space, you need huge accelerations and forces. It makes no difference if you spin it or not.

Over and out - at least for me.