Spinlaunch... Can it succeed?

[CatalinaWOW]

SpaceX really is not revolutionary but some incremental improvement.  It reduce cost in large part by good execution instead of revolutionary technology.  I would have imagine they mind their operations like a hawk to ensure good execution.

Given Musk's Tesla model3 experience, I expected his operation(s) to be smoother than it seem so far.  The virus lock downs and panic that happened in the last couple of years may have been a factor.

SpaceX is a good thing for the industry.  I would not like to see it fail.

Really going to ignore the self-landing reusable booster thing as "not revolutionary"? The only other "reusable" rocketry was the space shuttle and that really isn't reusable in a meaningful way by both in time and cost.

The idea isn't revolutionary at all. SpaceX is just the most successful at making it work.

Reusable spacecraft go all the way back to 1962, when the reusable X-15 launched from a reusable B-52 and entered space, earning astronaut wings. An event that was repeated 12 times during the 199 flights of the program.

One of the gemini capsules flew twice.

You already mentioned the space shuttle.

There's the X-37, which you don't hear much about because it's military. They have two vehicles that have flown six long-term missions (the sixth is still in progress) since 2010.

Northrup Gumman Pegasus has put smaller payloads into low orbit from reusable carrier aircraft starting in 1990.

And of course Blue Origin and Virgin Galactic have both flown reusable vehicles now.

The whole idea of whether this is revolutionary requires some detail and explanation.

The idea of re-use is of course not revolutionary.  It has been applied in many applications since the stone ages.  The idea of re-usable spacecraft is also not revolutionary.  Science fiction has assumed them since the early days of the genera.  And of course as Nusa says, elements of space vehicles have been re-used for several decades now.

SpaceX does have the first re-usable booster (I don't count the X-33 as a booster, but it does count as a landing demonstrator.)  And for several reasons it does appear to be revolutionary.  There are several elements of how they did it that are either novel, or which had been discarded as impractical by prior explorers in this regime.  More importantly, they have taken over much of the launch market from legacy players, and appear to be making money at a much lower price point than the market previously supported.  The rush of the legacy players to adopt some form of booster re-use supports the idea that this is revolutionary, a sudden and major change in the way things are done.

If SpaceX succeeds with their Starship program, a totally re-usable space vehicle, I would again call that revolutionary.  Not because a totally re-usable space vehicle is a new idea.  For two reasons.  First, because it will again cause major changes in the space industry.  Second, because that capability will be achieved decades earlier than it likely would have been achieved by the legacy players in the market.

[CatalinaWOW]

The issue with spin launch is not whether the idea breaks physics or not.  It is clear to me that at least some variant of spin launch does not break physics.

I do question its economic viability.   It has only a couple of major advantages over other systems.  It keeps a large fraction of the launch machinery on the ground for re-use.  And it allows accumulation of launch energy over a long period of time from relatively simple energy sources.  But to achieve these it has to master difficult technology hurdles in several areas, and without benefit of prior art or transfer from other uses of similar technology.

Cannon launch approaches have a large body of prior art.  Rocket launches the same.  Aircraft launch the same.  I just don't see any cost advantage in the finished product large enough to overcome what I see as very large development costs.

[PlainName]

I wonder if some flavour of spinlaunch could feed into a railgun-type launcher. Winding up the speed to some value that isn't too onerous in centripetal force but enough to shorten the rail needed to reach a decent terminal speed magnetically (without the huge acceleration) could be a solution to two problems.

[jonovid]

I wonder if some flavour of spinlaunch could feed into a railgun-type launcher. Winding up the speed to some value that isn't too onerous in centripetal force but enough to shorten the rail needed to reach a decent terminal speed magnetically (without the huge acceleration) could be a solution to two problems.

something similar to the 1942 London gun V3 super cannon or maybe the 1989 Iraqi supergun Project Babylon

with some magical pixie dust almost anything is possible   

[DougSpindler]

I wonder if some flavour of spinlaunch could feed into a railgun-type launcher. Winding up the speed to some value that isn't too onerous in centripetal force but enough to shorten the rail needed to reach a decent terminal speed magnetically (without the huge acceleration) could be a solution to two problems.

something similar to the 1942 London gun V3 super cannon or maybe the 1989 Iraqi supergun Project Babylon

with some magical pixie dust almost anything is possible   

NASA has already evaluated it.  Yes it can be done, but the cost would  be significantly more for each launch.  Do you want to pay $10,000 per pound to get something in orbit or $100,000? 

[PlainName]

I wonder if some flavour of spinlaunch could feed into a railgun-type launcher. Winding up the speed to some value that isn't too onerous in centripetal force but enough to shorten the rail needed to reach a decent terminal speed magnetically (without the huge acceleration) could be a solution to two problems.

something similar to the 1942 London gun V3 super cannon or maybe the 1989 Iraqi supergun Project Babylon

with some magical pixie dust almost anything is possible   

No, those were classic guns, weren't they? And at 500ft long the barrel is kind of unwieldy. But if you could insert the load at, say, half the speed necessary to get it wherever, the barrel could be a lot shorter and the acceleration a lot lower. Obviously, you could then use an explosive charge to boost it, hence a railgun-type propulsion.

[DougSpindler]

I wonder if some flavour of spinlaunch could feed into a railgun-type launcher. Winding up the speed to some value that isn't too onerous in centripetal force but enough to shorten the rail needed to reach a decent terminal speed magnetically (without the huge acceleration) could be a solution to two problems.

something similar to the 1942 London gun V3 super cannon or maybe the 1989 Iraqi supergun Project Babylon

with some magical pixie dust almost anything is possible   

No, those were classic guns, weren't they? And at 500ft long the barrel is kind of unwieldy. But if you could insert the load at, say, half the speed necessary to get it wherever, the barrel could be a lot shorter and the acceleration a lot lower. Obviously, you could then use an explosive charge to boost it, hence a railgun-type propulsion.

NASA has evaluated the feasibility of a rail gun launch...  It is possible, but the cost per kg/pound is far more costly than launching with a traditional rocket.

[PlainName]

NASA has evaluated the feasibility of a rail gun launch..

Did you miss the part about loading it up with a payload already traveling at a significant velocity? I am pretty sure NASA didn't include that in their feasibility study.

Note that I am not suggesting it would work, be cool, cheap, whatever adjective you want to apply. I just think that the attitude shown would dismiss electric cars on the basis that someone once figured an extension lead wouldn't let it drive very far.

[DougSpindler]

NASA has evaluated the feasibility of a rail gun launch..

Did you miss the part about loading it up with a payload already traveling at a significant velocity? I am pretty sure NASA didn't include that in their feasibility study.

Note that I am not suggesting it would work, be cool, cheap, whatever adjective you want to apply. I just think that the attitude shown would dismiss electric cars on the basis that someone once figured an extension lead wouldn't let it drive very far.

Where is the energy going to come from to get the payload traveling at a significant velocity?  I have not seen the NASA study, but those folks are no dummies.  I would think someone would have considered that.

The history of the evolution of energy to power cars is an interesting one.  Well over 100 years ago it was steam or external combustion was the technology everyone thought would be powering cars.  At the time steam was a proven technology.  Then you had Edison and Baker who were making EV cars.  They were simple, low maintenance and had enough stored energy to get people around 60 miles.  ICE was the new comer and was smelly, smoky and high maintenance.  But due to the energy density of gas, and that gas was a waste product from cracking crude oil there were some advantages.  It took time but ICE was the choice of consumers because of Ford's low cost.

In 1923 electric vehicles were going to cars of the future.  Teals claimed have an all electric car which was powered by the resonating frequency of the universe. Under the hood were vacuum tubes and an it had an antenna tuned to the resonating frequency of the universe.  Like many claims Tesla made in latter life they were that...  just claims.  Like Elizabeth Holmes or Trevor Milton they were just after the fame and money BSing people.

[PlainName]

Where is the energy going to come from to get the payload traveling at a significant velocity?

The spinlauncher!

I wonder if some flavour of spinlaunch could feed into a railgun-type launcher. Winding up the speed to some value that isn't too onerous in centripetal force but enough to shorten the rail needed to reach a decent terminal speed magnetically (without the huge acceleration) could be a solution to two problems.

[DougSpindler]

Where is the energy going to come from to get the payload traveling at a significant velocity?

The spinlauncher!

I wonder if some flavour of spinlaunch could feed into a railgun-type launcher. Winding up the speed to some value that isn't too onerous in centripetal force but enough to shorten the rail needed to reach a decent terminal speed magnetically (without the huge acceleration) could be a solution to two problems.

Nothing new.....  something we have been doing for 60-70- years.  What you are talking about is a Synchrotrons but with a much greater mass.

[PlainName]

A synchrotron is like the spinlaucher in that it accelerates the particle in a circular path and then lets go at the right time. What I was suggesting was one of these feeding the particle into a railgun. So far as I know, that's not how a synchrotron is usually configured.

Nevertheless, if they did configure them like that AND they've been doing it since forever, I don't think that invalidates my suggestion because they sure ain't been doing it on the scale of putting an object into orbit.

I am wondering if I need to draw a picture since no-one appears to have understood what I was originally suggesting!

[Rick Law]

With the repeated comparison against acceleration force of bullets and other projectile at supersonic/hypersonic speed, I should also remind folks that in the case of spinning the g-force is lateral.

With a cannon/rail launched projectile, the tip of the the projectile is pointing in the same direction as acceleration.  The acceleration's "g-force" points at the opposite direction (Newton's 3rd Law), so the "g-force" is pointing at the bottom.  Say you have a PCB paced with bottom facing projectile's bottom, the entire PCB is subjected to exactly the same g-force.  So, a 1gm part will weight 11kg.  The PCB can be thick enough to hold the 11000x the weight.

With a spinning force launch, the centrifugal "g-force" is pointing away from the center of rotation - so the centrifugal  acceleration and the centrifugal  force are lateral - the force is towards the side of the rocket and not the bottom or top.  If you mount the PCB aligned with the bottom of the rocket, all the g-forces are lateral against that PCB.  That 1 gm part has 11kg pulling it sideways.  A regular PCB's solder pad will likely not hold up against 11kg force pulling that soldered part sideways.  The solder itself may not have enough cohesive force to hold itself together and the solder itself may break.  Moreover, one side of the PCB will be closer to the center of rotation than the other side.  So one side is being pull at a greater force than the other.  That force translate to a force stretching the PCB.  So, mechanical re-enforcement will be needed all over the place and with every payload for this lateral force.  Probably doable, but a huge and expensive job.  Probably more than the cost of a traditional rocket launching itself.

Even the rocket itself will be subjected to a bending force.  If you mount the middle, the two ends will bend outward.  If you mount the ends, the middle will bend outward.

You can get around them by mounting the rocket flat - that is the front end of the rocket pointing at the center of rotation.  Now the centrifugal g is pointing "down" toward the base of the rocket.  But with laying flat, now you end up with a different problem.  Your rocket will launch sideways, and your rocket will rotate end-to-end at launch because of the launch speed difference (front end vs tail end).

You can picture that rotation easily.  Think about holding a box with both hands each holding one side of the box.  Now you try to throw that box upward by moving your hands upward - except you move your left hand at twice the speed of the right.  Your box will end up rotating.

The bottom of the rocket will travel at (2*pi*radius*RPM).  The inside (top) will travel at (2*pi*(radius-X)*RPM) where X is the length of the rocket.  So the two will differ.  In the case of a vertical launch, the X is merely the diameter of the rocket is presumably small in comparison to the length of the rocket, so the rotation would be much more controllable.  When laying flat, X is the length of the rocket, now the speed delta is much bigger.  So your launched rocket is pointing sideways, and rotating end to end.  Again, correctable after launch but a much bigger problem than before.

* * *

So, as said by others before, at that spinning g-force, it is pretty much reduced to launching raw material only.

I have another potential use however.  Those who wants the ashes send into low-orbit space.  Cans of ashes can be nicely arranged to handle the g-force, and the occupant is no longer g-force sensitive anymore.  So, the family announces:  You can see grandpa's re-entry fire trail on January 1, at 10 pm.  Look up the eastern sky, and grandpa that fire trail you see is grandpa saying goodbye.

[DougSpindler]

A synchrotron is like the spinlaucher in that it accelerates the particle in a circular path and then lets go at the right time. What I was suggesting was one of these feeding the particle into a railgun. So far as I know, that's not how a synchrotron is usually configured.

Nevertheless, if they did configure them like that AND they've been doing it since forever, I don't think that invalidates my suggestion because they sure ain't been doing it on the scale of putting an object into orbit.

I am wondering if I need to draw a picture since no-one appears to have understood what I was originally suggesting!

You might, but I think what you are describing is a Bevatron.  It's a cyclotron coupled to a linear accelerator.  You'll have the same problems but with a much larger mass. 

[DougSpindler]

With the repeated comparison against acceleration force of bullets and other projectile at supersonic/hypersonic speed, I should also remind folks that in the case of spinning the g-force is lateral.

With a cannon/rail launched projectile, the tip of the the projectile is pointing in the same direction as acceleration.  The acceleration's "g-force" points at the opposite direction (Newton's 3rd Law), so the "g-force" is pointing at the bottom.  Say you have a PCB paced with bottom facing projectile's bottom, the entire PCB is subjected to exactly the same g-force.  So, a 1gm part will weight 11kg.  The PCB can be thick enough to hold the 11000x the weight.

With a spinning force launch, the centrifugal "g-force" is pointing away from the center of rotation - so the centrifugal  acceleration and the centrifugal  force are lateral - the force is towards the side of the rocket and not the bottom or top.  If you mount the PCB aligned with the bottom of the rocket, all the g-forces are lateral against that PCB.  That 1 gm part has 11kg pulling it sideways.  A regular PCB's solder pad will likely not hold up against 11kg force pulling that soldered part sideways.  The solder itself may not have enough cohesive force to hold itself together and the solder itself may break.  Moreover, one side of the PCB will be closer to the center of rotation than the other side.  So one side is being pull at a greater force than the other.  That force translate to a force stretching the PCB.  So, mechanical re-enforcement will be needed all over the place and with every payload for this lateral force.  Probably doable, but a huge and expensive job.  Probably more than the cost of a traditional rocket launching itself.

Even the rocket itself will be subjected to a bending force.  If you mount the middle, the two ends will bend outward.  If you mount the ends, the middle will bend outward.

You can get around them by mounting the rocket flat - that is the front end of the rocket pointing at the center of rotation.  Now the centrifugal g is pointing "down" toward the base of the rocket.  But with laying flat, now you end up with a different problem.  Your rocket will launch sideways, and your rocket will rotate end-to-end at launch because of the launch speed difference (front end vs tail end).

You can picture that rotation easily.  Think about holding a box with both hands each holding one side of the box.  Now you try to throw that box upward by moving your hands upward - except you move your left hand at twice the speed of the right.  Your box will end up rotating.

The bottom of the rocket will travel at (2*pi*radius*RPM).  The inside (top) will travel at (2*pi*(radius-X)*RPM) where X is the length of the rocket.  So the two will differ.  In the case of a vertical launch, the X is merely the diameter of the rocket is presumably small in comparison to the length of the rocket, so the rotation would be much more controllable.  When laying flat, X is the length of the rocket, now the speed delta is much bigger.  So your launched rocket is pointing sideways, and rotating end to end.  Again, correctable after launch but a much bigger problem than before.

* * *

So, as said by others before, at that spinning g-force, it is pretty much reduced to launching raw material only.

I have another potential use however.  Those who wants the ashes send into low-orbit space.  Cans of ashes can be nicely arranged to handle the g-force, and the occupant is no longer g-force sensitive anymore.  So, the family announces:  You can see grandpa's re-entry fire trail on January 1, at 10 pm.  Look up the eastern sky, and grandpa that fire trail you see is grandpa saying goodbye.

Nice explanation.  Mthybusters sort of did this with when firing a gun and spinning.  The myth questions is would the bullet travel straight from the gun?  Or would the path follow an arc trajectory.  Dustin on Smarter Everyday did something similar with spinning water jets.  The results were surprising.

[CatalinaWOW]

In some ways the spinlaunch environment may be more benign than the cannon.  Electronic have been surviving cannon launches since the 1940s (see the VT or proximity fuze).  Forces in a cannon launch are not purely longitudinal.  The projectile doesn't slide smoothly down the barrel.  It rattles, with lateral forces in the thousands of g's.  Many cannons are rifled leading to enormous torsional accelerations. But as noted previously, projectiles and measurement instruments routinely survive these environments.  Design for the spinlaunch is difficult, but not impossible.

[DougSpindler]

You know with VC giving out money so freely for technological ideas.  I'm wondering if I could get a VC to invest in satellite launch using the Hutchison Effect.   The Hutchison Effect is based on honest truthful research bases loosely on the laws of Physics.   

[T3sl4co1l]

With a cannon/rail launched projectile, the tip of the the projectile is pointing in the same direction as acceleration.  The acceleration's "g-force" points at the opposite direction (Newton's 3rd Law), so the "g-force" is pointing at the bottom.  Say you have a PCB paced with bottom facing projectile's bottom, the entire PCB is subjected to exactly the same g-force.  So, a 1gm part will weight 11kg.  The PCB can be thick enough to hold the 11000x the weight.

Right, you've proven that naked unsupported PCBs can't be launched.  So what?

As has been mentioned many times, artillery has done it for the better part of a century, even with much heavier and seemingly more fragile vacuum tube tech.  Silicon has it downright easy.   Just stuff it in potting for hydrodynamic support, buoyancy as it were, and use enough reinforcement to take up the remaining strain.  Not exactly trivial, but a solved problem to be sure.

Tim

[Rick Law]

With a cannon/rail launched projectile, the tip of the the projectile is pointing in the same direction as acceleration.  The acceleration's "g-force" points at the opposite direction (Newton's 3rd Law), so the "g-force" is pointing at the bottom.  Say you have a PCB paced with bottom facing projectile's bottom, the entire PCB is subjected to exactly the same g-force.  So, a 1gm part will weight 11kg.  The PCB can be thick enough to hold the 11000x the weight.

Right, you've proven that naked unsupported PCBs can't be launched.  So what?

As has been mentioned many times, artillery has done it for the better part of a century, even with much heavier and seemingly more fragile vacuum tube tech.  Silicon has it downright easy.   Just stuff it in potting for hydrodynamic support, buoyancy as it were, and use enough reinforcement to take up the remaining strain.  Not exactly trivial, but a solved problem to be sure.

Tim

There is a cost cap here.  If it cost less to launch it using a regular rocket than this new method is worthless.

The purpose is not to show unsupported PCB can or cannot be launched.  The intend is to show that something familiar (as least to us here) will have a lot of problem dealing with the G's, particularly when lateral.  One can of course harden and orient a PCB to make it 11,000g capable.  The cost and time of making the payload objects and all the components (mechanical or electronic) inside a payload object capable of dealing with the G's will be very high.  The time required (time is money) will also be very high.  This cost will make the spin solution while technically viable but financially difficult to accomplish - likely to the point of financially non-viable.

[Nusa]

Yet they're entitled to try. If you don't believe in it, don't invest your money or your time. Note that complaining about it in forums is investing time in the project.

[Bud]

They should make a scaled down version of this thing to throw grenades and sell it to the military    it is going to be a more realistic application 

[DougSpindler]

They should make a scaled down version of this thing to throw grenades and sell it to the military    it is going to be a more realistic application 

Wonder if that was tried during Word War I or II?  It would be like one of those baseball pitching machines where you l fill a basket with baseballs and they get thrown to a batter except with grenades.  Then, like now, I’m sure there was a reason why they used explosive charges and rocket propulsion system.   

[PlainName]

I’m sure there was a reason why they used explosive charges and rocket propulsion system.

Maybe because with those you load the barrel, hit the switch (or press the plunger, pull the trigger, etc) and off it goes. With a slingshot-type launcher you need some way of winding it up, so it's not plug'n'play (to mix metaphors). Also, it might be difficult to aim without some kind of automated release. Finally, a big dish is likely harder to hide and transport than a short barrel.

[DougSpindler]

I’m sure there was a reason why they used explosive charges and rocket propulsion system.

Maybe because with those you load the barrel, hit the switch (or press the plunger, pull the trigger, etc) and off it goes. With a slingshot-type launcher you need some way of winding it up, so it's not plug'n'play (to mix metaphors). Also, it might be difficult to aim without some kind of automated release. Finally, a big dish is likely harder to hide and transport than a short barrel.

I think you are correct.  Take a look at Katyusha/"Stalin's organ".  They could have used a spin-launch, but decided to go with a rocket launch. 

[PlainName]

I doubt if you could get half a dozen spinlaunchers on top of that truck, so if you only had one you wouldn't be able to fire them all off at once (or in quick succession).