Spinlaunch... Can it succeed?

[DougSpindler]

Here me out on my claims.
EH/Theranos and Trevor Milton/Nikola both had good sounding IDEAS in the beginning.  (I still think Trevor's hydrogen powered trucks using excess solar electricity makes on a couple of dedicated trucking routes makes a lot of sense.)  But what both laced was and education to understand the laws of physics/chemistry and the current state of our technology.  When they finally figured out the laws of nature could not be broken is when it turned into a con.  Heck we know EH was told by at least one Stanford professor her idea never work and told her why.

Reminds me of what my college professor would tell young students who thought they were the "first person" to think of something new.  He would listen to their idea, and then say that idea is as good a shovel with a rope for a handle.  (He would then tell them to think about what he said.)  A shovel with a rope for a handle sounds like a great idea, until you try and dig a hole with it.

Hyperloop, I guess I would should have specified Elon's Hyperloop and Virgin's.  Hyperloop technology has been around for well over 100 years.  As a kid I remember hyperloops/phonematic tubes were in common use in department stores.  The technology is proven on a small scale.  It was tested in New York on a human scale in the very late 1800's and was abandoned.  (Not sure why.)

I think if anyone has any background physics and material science they would know Virgin's is just impossible with the materials and technology we have.  Elon built his in Las Vegas and as it turns out one could walk to your destination faster than taking a ride in a hyperloop vehicle.

As for Thorium reactors they have been proven to work on a small scale.  The issue is when scaled up to power a city there are technological issues we are not even close to solving, yet that didn't stop people about a decade ago hyping that this is the solution to our electricity needs.  China stated they would have Thorium reactors online powering cities in 2022.  After about 6 years into the project they realized there were way too many technical issues and pulled the plug on the project....  Yet the hype continues that Thorium reactors are the solution.

Time will tell with Spinlaunch.  I think the science is against them on that scale and they will runout of money and can't succeed.  It's just another shovel with a rope for a handle idea.

[DougSpindler]

Not sure if anyone else has mentioned this before, but what happens when the unleashed payload collides with the self generated sonic boom that it is already travelling outwards from the launch site? Surely there is a sweet spot where the departing shock wave is so dense, it will form a 'brick wall' ahead of the departing launch vehicle? Or are we launching from the Moon to avoid claims for broken windows, 50 miles away?

And even if the launch vehicle has the strength of a bowling ball, the induced spin at "unleash", will turn all but the very center of the payload into mincemeat?

Those issues and many more have been discussed.  They appear to be using the line Elizabeth Holme's used, those are "trade secrets" and cannot be discussed.

[Kleinstein]

I think this is like Thorium reactors, there are a number of technical issues which still need to be solved.  I think like Thorium reactors, Theranos, Hyperloop, and Nikola Trucks until they run out of money they will keep saying it can be done.  Then once they’ve burned through all of the money the employees will come clean saying we knew all along it was never going to work.

It is not just technical problems. It is just a rather stupid idea:  The centrifugal force is impractical high and would require a sattelite that gets way to heavy.  It's close to the point of only usefull for things like steel balls.   If at all the idea of a more classical acceleration is practical for the first part. The idea behind it is that at low speed a rocket is rather inefficient. At an allready high speed it gets OK. So statrting at something like the speed of sound could reduce the size of rocket somewhat.

However a giant sling shot is more like a bad version, as it needs to accelerate quite a lot additional mass (at least the counterweight that is as heavy as the payload and release mechanism). So me a giant gun looks way more practical and could use a barrel longer than the spinner diameter.


As for the thorium reactor part:  There were a few reactors that with a little extrapolation one could consider running on thorium. However the chemical separation part is more on the theoretical side: it works in small scale at high costs. This is with recovering the fissile uranium, but not reusing the fertile thorium. For the forseable future this would be way to expensive (like 1000 times) so they did not even try.  So only a rather small part of the thourium could actually be used economical. The rest (e.g. 99.x % for a thermal homogenous reactor) will end up as medium to highly redioactive waste they maybe reusable in a few 100 years. Thorium per se is cheap, but thorium with sub ppm level of RE impurities gets rather expensive already when starting from natural stock that is essentially for free and even more when you try to reuse highly radioactive stuff that needs remote handling.

[Rick Law]

I would like to remind everyone that GPS guided artillery shells experience accelerations on the order of 16000g. If thats typical in use, then you can guarantee they can withstand more than that for reliability.
If we can build electronics to withstand being blasted out of a short 155mm artillery barrel, then Spinlaunch doesn't seem like so much of a stretch.

16000g is more than SpinLaunch's 11000g, but artillery shell has one advantage over SpinLaunch payload.  Artillery shells can consolidate all g-sensitive parts to the base and all the g-forces points towards the base.  Whereas, SpinLaunch's payload centrifugal g is lateral, it acts toward the side, specifically, the side farther from the center of rotation (ie: outer side).

One can of course reinforce the outer-side to take the load, but that will cause uneven mass distribution causing more headaches (added cost), and payload orientation when loaded is yet another issue (yet more added cost).  The payload reinforcement cost is why I think SpinLaunch has a difficult time making it's revenue viability goals.

The biggest potential SpinLaunch has is StarLink.  StarLink if fully implemented will have 30,000 satellites each with a plan service life of under 5 years due to it's low orbit of just under 350 miles.    Do the math, that is >16 launches a day.  That rate makes it a mass-produced satellite.  As such, it can have high-g tolerance built in at design and spreading the cost over many satellites.  The StarLink low orbit is also a plus for SpinLaunch.    Whereas, other satellite are more likely one-off's (or limited copies) making reinforcement (design + test) cost much higher on a per-satellite basis, and the low 350 miles may only work for some of those other limit copies satellites.

My opinion is: SpinLaunch's viability lies with the viability of StarLink and it's ability to add this payload reinforcement cost while maintaining cost-viable.   If StarLink fizzles, SpinLaunch is toasted.

[wraper]

It is not just technical problems. It is just a rather stupid idea:  The centrifugal force is impractical high and would require a sattelite that gets way to heavy.  It's close to the point of only usefull for things like steel balls.   If at all the idea of a more classical acceleration is practical for the first part. The idea behind it is that at low speed a rocket is rather inefficient. At an allready high speed it gets OK. So statrting at something like the speed of sound could reduce the size of rocket somewhat.

Satellites need to be built with acceleration in mind however it's not nearly as you say. Usual SMD circuit board with no heavy components will survive just fine if it has proper support. SMD parts will not fly off from PCB. For example take 0603 resistor which weights about 2 mg, with 11000G it will be around 220 0.22 N of force on the part (equal to 22 grams at 1G). You need way more force to rip it from PCB.

[wraper]

The biggest potential SpinLaunch has is StarLink.  StarLink if fully implemented will have 30,000 satellites each with a plan service life of under 5 years due to it's low orbit of just under 350 miles.    Do the math, that is >16 launches a day.  That rate makes it a mass-produced satellite.  As such, it can have high-g tolerance built in at design and spreading the cost over many satellites.  The StarLink low orbit is also a plus for SpinLaunch.    Whereas, other satellite are more likely one-off's (or limited copies) making reinforcement (design + test) cost much higher on a per-satellite basis, and the low 350 miles may only work for some of those other limit copies satellites.

My opinion is: SpinLaunch's viability lies with the viability of StarLink and it's ability to add this payload reinforcement cost while maintaining cost-viable.   If StarLink fizzles, SpinLaunch is toasted.

It would totally suck for Starlink. These are complicated satellites not that easy to reinforce and are not small at all. How many it could launch even without considering weight increase? Answer is zero because Starlink satellite has larger mass than max lift capacity of Spinlaunch. And it's without considering V2 satellites are much larger and need Starship to be launched viably. But even if it could lift one, a second stage spent for a single Starlink satellite, really? Even if it would theoretically make 16 launches a day, it still would be barely faster than current launch cadence on Falcon 9. In July alone, 251 Starlink satellites were launched on 5 rockets.

[Kleinstein]

It is not just technical problems. It is just a rather stupid idea:  The centrifugal force is impractical high and would require a sattelite that gets way to heavy.  It's close to the point of only usefull for things like steel balls.   If at all the idea of a more classical acceleration is practical for the first part. The idea behind it is that at low speed a rocket is rather inefficient. At an allready high speed it gets OK. So statrting at something like the speed of sound could reduce the size of rocket somewhat.

Satellites need to be built with acceleration in mind however it's not nearly as you say. Usual SMD circuit board with no heavy components will survive just fine if it has proper support. SMD parts will not fly off from PCB. For example take 0603 resistor which weights about 2 mg, with 11000G it will be around 220 N of force on the part (equal to 22 grams at 1G). You need way more force to rip it from PCB.

There is a small mistake in the math: The weight of 22 grams is more like 0.22 N.
A 0603 SMD part could be OK, though not that much safety margin left. However it gets more tricky with larger parts, like transformers and solar cells.
At 10000 G acceleration the part would have to withstand some 1000 times it's weight sitting on top of the sattelite. That may be OK for a mg size resistor, but not for a > 100 kg satelite that is build from extra light materials not to make it a ton. Many saterlites want relatively large area solar cell for power, that need a kind of rather delicate folding mechanism. They already have a hard time to make it strong enough to survive some 5-10 G for a more normal rocket start.
It does not make sense to offer maybe a 50% price reduction per kg when the satelites need to be 10 times heavier just to survive the start.

The current test reaches something like 10% of the orbital speed - that is 1% of the energy. So it may look impressive, they are still quite a bit behind half there. It is more like just started with the easy part.

[Marco]

Liquid hydrogen trucks have a lot less engineering problems to overcome than spinlaunch, liquid hydrogen refueling/storage system and fuel cells are both at near 100% technological readiness.

The problem is economical readiness, liquid hydrogen is a solution waiting to be forced by 2050 commitments (ie. zero emission). The complete absence of fossil fuels and the massive increase of use of hydrogen in industry if nothing else, will massively reduce the relative cost of hydrogen compared to alternatives as 2050 looms ... but not quite yet.

[Marco]

Many saterlites want relatively large area solar cell for power, that need a kind of rather delicate folding mechanism.

An alternative might become roll out thin film solar cells, either with inflatable rims or simply for rotating satellites.

Also as I said, you could (selectively) freeze parts in water/paraffin. Though gun launch would make it all a lot easier than spin with its complex tidal forces.

[martinr33]

Some decent papers on railgun launch and energy storage flywheels. Flywheels and railguns do not have the vibration problems this solution would have.

https://www.science.gov/topicpages/e/earth-to-space+electromagnetic+railgun

They get close to low earth orbit.

[DougSpindler]

When it comes to railguns the US has gave up after 15 years and half a billion dollars.
https://taskandpurpose.com/news/navy-electromagnetic-railgun-dead/

But China appears to have one.
https://taskandpurpose.com/news/chinas-electromagnetic-railgun-sea-trials/

[Rick Law]

The biggest potential SpinLaunch has is StarLink.  ... ... ...
... ... ...
My opinion is: SpinLaunch's viability lies with the viability of StarLink and it's ability to add this payload reinforcement cost while maintaining cost-viable.   If StarLink fizzles, SpinLaunch is toasted.

It would totally suck for Starlink. These are complicated satellites not that easy to reinforce and are not small at all. How many it could launch even without considering weight increase? Answer is zero because Starlink satellite has larger mass than max lift capacity of Spinlaunch. And it's without considering V2 satellites are much larger and need Starship to be launched viably. But even if it could lift one, a second stage spent for a single Starlink satellite, really? Even if it would theoretically make 16 launches a day, it still would be barely faster than current launch cadence on Falcon 9. In July alone, 251 Starlink satellites were launched on 5 rockets.

Both have business model that is yet unproven when scaled.  Technology may work, but profit generating?  A big "may be" for both.  The two may come to some middle ground.  16 launches a day is a lot.  Savings there should help Starlink and for Spinlaunch a huge customer...  Then again, may be it is another case of: "If you tie the two rocks together, perhaps they will now float..."

Starlink is certainly at a better place.  They have proven their technology, and government subsidies from various un-wired (or inadequately-wired) countries is a good possibly.  That matter is still size of the $ sign.  Whereas, if SpinLaunch doesn't do Starlink,  missing the highest volume launch-user will be a deadly blow.

[wraper]

The biggest potential SpinLaunch has is StarLink.  ... ... ...
... ... ...
My opinion is: SpinLaunch's viability lies with the viability of StarLink and it's ability to add this payload reinforcement cost while maintaining cost-viable.   If StarLink fizzles, SpinLaunch is toasted.

It would totally suck for Starlink. These are complicated satellites not that easy to reinforce and are not small at all. How many it could launch even without considering weight increase? Answer is zero because Starlink satellite has larger mass than max lift capacity of Spinlaunch. And it's without considering V2 satellites are much larger and need Starship to be launched viably. But even if it could lift one, a second stage spent for a single Starlink satellite, really? Even if it would theoretically make 16 launches a day, it still would be barely faster than current launch cadence on Falcon 9. In July alone, 251 Starlink satellites were launched on 5 rockets.

Both have business model that is yet unproven when scaled.  Technology may work, but profit generating?  A big "may be" for both.  The two may come to some middle ground.  16 launches a day is a lot.  Savings there should help Starlink and for Spinlaunch a huge customer...  Then again, may be it is another case of: "If you tie the two rocks together, perhaps they will now float..."

Starlink is certainly at a better place.  They have proven their technology, and government subsidies from various un-wired (or inadequately-wired) countries is a good possibly.  That matter is still size of the $ sign.  Whereas, if SpinLaunch doesn't do Starlink,  missing the highest volume launch-user will be a deadly blow.

What savings??? It's literally more expensive. There are (potential) savings if you want to launch a small payload standalone. If the same payload can be combined to fill a large rocket, there are no savings. Also it's a pretty weird idea Spacex would suddenly use a 3rd party launch service when they are the largest launch provider in the world themselves. Not to say launch on reused boosters, Oldest of which have flown up to 13 times already.

[Rick Law]

When it comes to railguns the US has gave up after 15 years and half a billion dollars.
https://taskandpurpose.com/news/navy-electromagnetic-railgun-dead/
... ...

Launching is a good bit different than what the Navy needs -- Rail Gun space launcher doesn't have to fit on a ship.  On firm ground, rail gun was proven to work for a shell.  The shell's mass is probably in the order of at most few kg.  The spinlaunch payload target is 200kg, so it is a big scale-up.  But, it is a possibility to develop a deploy-able one with 200kg payload on firm ground.

Rail gun launch has definite advantage over spin launch: a lower g-force (merely 1/4 that of a spinlaunch^[1]), and it's g-force is pointing towards the base of the launch vehicle like an artillery shell making hardening a good bit easier.

A 100 meter tall rail gun at the same exit velocity needs only 2750g acceleration (1/4 of 11000g).  100 meter is tall is on par with a building with 30 floors.  At 300 meters (90 floors) tall, you are dealing with mere 917g - pointing at the base instead of point to the side.  That brings hardening down to practically easy comparing to 11000g.

I am not for easy access to low earth orbit because of space junk issues, but if must choose between spin or linear, I would go with linear rail gun.

Footnote [1] :
For the 1/4g assertion there, I will  quoting my own reply that shown the physics and math instead of retyping that:

What would the centripetal g force on the payload be compared with simply shooting it out of a very large gun pointed skyward?

In comparing one force verses another acting on the same mass, since f=ma are true for both cases (Newton's second law of motion), mass cancels out leaving you just comparing acceleration.

For the object orbiting around a center, V is the linear velocity while orbiting, and it equals the velocity at release:
Centripetal /centrifugal acceleration is a = V²/R, here R is the distance to the center of rotation.

For the object being shot out of a barrel (or rail of a rail-gun), V is the exit velocity of the object when leaving the barrel
Shooting out of a gun is difficult to say since acceleration by gas-explosion is not constant while in the barrel.  Let's assume it is constant acceleration like you can do with a linear motor catapult or rail-gun.  With such assumption, while in the barrel, then:
Linear constant acceleration would be  a = V²/2L, here L is the length of the gun barrel.

So, if your gun is half the radius of the centrifuge, your acceleration is the same and thus the force are the same.  Of course, radius is just 1/2 the width (diameter) of the centrifuge.

I don't know about these SpinLaunch folks...  I think building a rail-gun 25 meters in length would be easier than building a centrifuge 100 meters in diameter, and a linear rail is far easier to aim.

[Rick Law]

...
What savings??? It's literally more expensive. There are (potential) savings if you want to launch a small payload standalone. If the same payload can be combined to fill a large rocket, there are no savings. Also it's a pretty weird idea Spacex would suddenly use a 3rd party launch service when they are the largest launch provider in the world themselves. Not to say launch on reused boosters, Oldest of which have flown up to 13 times already.

Well then, may be auto spell correction was trying to tell me something along...  Spin Launch might as well be spin lunch.

They are building something for low earth orbit, and they can't even do the biggest opportunity there is for low-earth orbit.

[SiliconWizard]

They have launched $80 million into orbit.

[DougSpindler]

Appears we aren't even close in coming to a consensus on this issue.

I say let's see if enough money is thrown at Spinlaunch if they can do it. It would be nice if we could get a poll to see how many of us think they will succeed.

The one I've been waiting for is liquid metal batteries.  If I recall correctly they were to hit the market in 2018/2019 timeframe.

I just noticed, MIT Professor Donald Sadoway has won the 2022 European Inventor Award, in the category for Non-European Patent Office Countries, for his work on liquid metal batteries that could enable the long-term storage of renewable energy.

I see there using the word "could" indicating there are issues which still need to be resolved.  Not saying this stuff is easy, but like Spinlanuch their are a lot of technical issues which still need to be solved.

[PlainName]

I say let's see if enough money is thrown at Spinlaunch if they can do it.

Are you sure you're speaking for yourself? Most of your posts are pushing the "it can't work" line.

[twospoons]

Big problem with the railgun approach is the power requirement.

The 300m railgun mentioned above would have to apply 1.8GW to a 200kg projectile to reach 2222m/s. With typical efficiencies being 10-50% that means a power source capable of somewhere between 3.6GW and 18GW, and energy storage between 1GJ and 5GJ.  Not trivial.
Making the railgun  longer reduces the power requirement, but the energy storage remains (or more likely gets worse).

[PlainName]

Would that be a real issue? I mean, if you have 100-300m in which to place your batteries or whatever, it's just repeating the first few yards (sorry for the mixed measures!) a few times. Not like you have to cram it all into a torus or something. Also you can trickle charge for as long as you like, so you're not going to made the local grid sag as you press the switch.

[Marco]

The 300m railgun mentioned above would have to apply 1.8GW to a 200kg projectile to reach 2222m/s. With typical efficiencies being 10-50% that means a power source capable of somewhere between 3.6GW and 18GW, and energy storage between 1GJ and 5GJ.  Not trivial.
Making the railgun  longer reduces the power requirement, but the energy storage remains (or more likely gets worse).

This maybe the one time flywheel storage makes sense. Bigger problem with railguns seems to be that the rails burn up during launch.

Hydrogen light gas guns don't quite have the power density of railguns, but they seem a bit more durable.

[DougSpindler]

I say let's see if enough money is thrown at Spinlaunch if they can do it.

Are you sure you're speaking for yourself? Most of your posts are pushing the "it can't work" line.

I'm not a physicist, only took a couple of classes in college. Sure looks to me like they intended on breaking several laws of physics and people who know more about physics see to agree with me.  And you have Thunderf00t who knows more about this stuff, who pointed out several many other issues.

We've had spin launchers for decades, called clay target launchers or skeet throwers.  If it would have been easy and cost effective someone would have built a Spinlancher years ago, but they didn't.

You have people like Elizabeth Holmes who believe anything is possible if enough money is thrown at it and you ignore the science and what the top researchers in that subject area tell you.

If someone has billions to spend on it, let them, it employee people.  I suspect several of the people at Spinlaunch know it can't be done and are happy to take a paycheck from some money guy who never took or failed a physics class.

We seem to have taught a generation All Things Are Possible If You Only Believe.  Which I think stems from
Mark 9:23 — "All things are possible for the one who believes.”

[fourfathom]

We seem to have taught a generation All Things Are Possible If You Only Believe.  Which I think stems from
Mark 9:23 — "All things are possible for the one who believes.”

I'm pretty sure it goes back further than that -- it's just basic human nature.  Some of us have learned that this isn't *exactly* true, but with the proper motivation most people can believe pretty much anything.  And we have a long history of trying to do the "impossible" (actually, merely very difficult), and succeeding, or at least finding something valuable in the process.

FWIW, I think Spinlaunch will ultimately be a sad failure, for the reasons explained here.  We may learn something useful from it, but it will be a very expensive lesson.

[wraper]

I'm not a physicist, only took a couple of classes in college. Sure looks to me like they intended on breaking several laws of physics and people who know more about physics see to agree with me.  And you have Thunderf00t who knows more about this stuff, who pointed out several many other issues.

We've had spin launchers for decades, called clay target launchers or skeet throwers.  If it would have been easy and cost effective someone would have built a Spinlancher years ago, but they didn't.

You have people like Elizabeth Holmes who believe anything is possible if enough money is thrown at it and you ignore the science and what the top researchers in that subject area tell you.

If someone has billions to spend on it, let them, it employee people.  I suspect several of the people at Spinlaunch know it can't be done and are happy to take a paycheck from some money guy who never took or failed a physics class.

We seem to have taught a generation All Things Are Possible If You Only Believe.  Which I think stems from
Mark 9:23 — "All things are possible for the one who believes.”

It does not break any laws of physics. Actually its principle of operation is pretty dumb. The questionable part is practicality, not if it can be built as such.

[DougSpindler]

I'm not a physicist, only took a couple of classes in college. Sure looks to me like they intended on breaking several laws of physics and people who know more about physics see to agree with me.  And you have Thunderf00t who knows more about this stuff, who pointed out several many other issues.

We've had spin launchers for decades, called clay target launchers or skeet throwers.  If it would have been easy and cost effective someone would have built a Spinlancher years ago, but they didn't.

You have people like Elizabeth Holmes who believe anything is possible if enough money is thrown at it and you ignore the science and what the top researchers in that subject area tell you.

If someone has billions to spend on it, let them, it employee people.  I suspect several of the people at Spinlaunch know it can't be done and are happy to take a paycheck from some money guy who never took or failed a physics class.

We seem to have taught a generation All Things Are Possible If You Only Believe.  Which I think stems from
Mark 9:23 — "All things are possible for the one who believes.”

It does not break any laws of physics. Actually its principle of operation is pretty dumb. The questionable part is practicality, not if it can be built as such.

I will disagree.  As several people have posted the laws of physics do apply including the ones the engineers at Spinlaunch overlook and are breaking.