To clarify for people, this isn't NASA endorsing the idea in as much as NASA just hands out small amounts of money to different ideas in many different science or engineering related spaces.

The fact of the matter is that this concept, if it works, will only launch as much payload into orbit as an Electron rocket (a very small launch vehicle), and would require payloads specially designed for the g-forces which would make them heavier. This launch concept has exchanged fuel mass for heat shield mass to allow it to survive after it leaves the spin system.

Now, one actual use case for this type of technology is if they were to build it on the moon, especially for launching things like mined resources off the surface. The launch forces would be lower as the speed requirements are lower and it would allow launching material with little to no fuel consumption as long as there is electrical power (of which there is near infinite amounts of because of the semi-constant sunlight).

One wonders how practical this would be given the huge G forces involved, especially so for large complex satellites.

However, electronics have been subjected to such high G forces as far back as WWII but on a much smaller scale when the proximity fuze was introduced towards the end of the War (one of its first uses was at the Battle of the Bulge, Patton waxed lyrically about its high effectiveness): https://en.wikipedia.org/wiki/Proximity_fuze

When I first heard about VT Fuzes years ago I didn't really believe it because it didn't use solid state devices, transistors etc. but rather a 'ruggedized' vacuum tube (this was several years before the transistor was invented in 1947). At the time I couldn't see how glass vacuum tubes could withstand ≈20,000Gs when fired out of a gun barrel but somehow they did.

Therefore, I'd imagine that upgrading to solid state devices would allow an even higher scaling in the G department (i.e.: relative to the VT Fuze), so it seems highly possible (perhaps the SpinLaunch idea actually originated from VT type Fuzes, I'd not be surprised).

Like many others I was very skeptical of SpinLaunch's claims. Even with their successful demo launch you wondered if you'd be able to build a viable payload (especially one with a rocket motor, not just solid state electronics).

Though if NASA have chosen to enter into a contract them that gives a big credibility boost. It'll be very interesting to see how it goes.

As Kerbal Space Program has taught me, it’s all very well reaching ballistic apogee but you need to apply thrust again at apogee to circularize orbit (raise your perigee to the same altitude as you are right now.) Otherwise you’ll just come straight back down again.

How can this device fling a functioning rocket motor into space?

If NASA had plans for a moon base, and also had plans to send things back from there, this might become an interesting launch capability - no atmosphere and lower escape velocity provides more flexibility. Run it with stored solar power and it’s self contained and needs no expendable supplies

The interesting thing about this technology, is that it's a way to bypass the rocket equation - in theory at least. There are a lot of practical objections, not the least of which is the fact that they've had to add so much heat shielding that it cancels out the gains of not needing to take so much propellant. But maybe they can work around that at some point.

The practical problems make me skeptical, but the potential advantages make me hopeful. To all the skeptics out there : remember that people were also skeptical when SpaceX said they wanted to land their rockets, yet here we are.

“People who say it cannot be done, should not interrupt those who are doing it.” - George Bernard Shaw

Reminds me of the centrifuges that people would build for Pumpkin Chunkin, a competitive pumpkin throwing contest from Delaware, USA.

https://www.youtube.com/watch?v=p2GeuWqNXWU

I don’t know how viable this is but there is something both visceral, simple, and super futuristic about this whole idea.

I don’t know why but I’m excited about this idea.

Its a collosally impractical idea for many reasons, but I'll give the simplest one

Whatever rotating mechanism (call it flywheel) they have needs to be charged up with rotational energy to launch. The amount of energy remaining in it after the projectile gets launched is the fraction M/(M+m) where M is the flywheel mass and m is the mass of the projectile.

Now you see the problem (if you have any physics instinct)

If you dont want a sudden shift in the center of rotation (going off balance) then you need the flywheel mass to be high. But the higher the flywheel mass, the more amount of energy left "wasted" as it spins to a halt in the de-evacuated atmosphere.

Bearings can handle some amount of jerking and some amount of imbalance in most applications. But here there is massive centrifugal pull of the imbalanced flywheel, the instantaneous jerk as the rotational center shifts after launch, shock wave of the instantaneous rushing in of air into the vacuum (speed of sound), the massive heating up of the whole structure, the precession that may be induced by turbulence etc.

This will most likely destroy the whole shebang in seconds, if not make it completely unusable a second time.

Slingshots work only because the sling has negligible mass compared to the stones that are launched.

This comic book idea dreamed by by some non-engineer is just going to eat up investor money and lots of precision machined equipment

Perhaps NASA is backing this because they think there’s a good chance that at some point the launch facility will experience a RUD and they really want to be there to watch.

Coolest part of this company is the founder is a (i think high school) drop out who read some physics books and thought "this should work." Have spent some time with Jonathan on MajikBus.co and I appreciate the way his mind works.

5000 mph = 134112 meters/m = 3557 rpm at 12m diameter

I guess that's not too bad, but still wonder how difficult it is to reliably achieve a precise launch angle?

Or are sensors so fast these days that this is easy? Maybe this is just a misplaced instinct from my subconscious fear of stuff hitting me in the head when kids inevitably start playing with centripetal motion using heavy objects.

Well, a low orbit is 18,000 miles per hour. This system wants to use 5000 miles per hour in their test of tech. That still leaves 13,000 miles per hour delta V, plus atmospheric drag will slow it until the rocket fires. Might be good to build this in Bhutan or another place with flat land over 12,000 feet high = far lower drag to launch. This is a test at 5000 = next 10,000 - how far can the strength of materials go when spinning at these rates? And if they can do both, spin at 10,000 mph+ as well as launch from Bhutan/Hawaii/Chile - it is worth exploring.

Here's video of a test launch from their website, if you're curious:

https://www.spinlaunch.com/suborbital

Everyone called me crazy when I said eventually we will start shipping things by dropping them from orbit.

This is the next step in my genius idea with 0 flaws or potential disasters

If they can get this working reliably on Earth then I would imagine it would work incredibly well in space. Could do (cargo) launches from the Moon to Earth with just energy from solar panels without any propellant. Probably would be the optimal way to put a ton of satellites in orbit of the Sun too for something like a Dyson Sphere.

I have to admit I know nothing of launching stuff into space. Whilst that's interesting my first thought on watching their video was comparing it to a railgun. No payload just a solid projectile at high speed. I don't know the viability of that but it seems like a logic other usecase.

Rather than a spin system with all that g force, i would have thought it more useful if an electric rail gun was used along a very long track in a helium filled tube that swept up a at a modest rate at the end to get the angle.

I've thought this through and I think the Gerald Bull supergun HARP/Project Babylon approach is more cost-effective.

8000km/hour is 2200m/s. Reaching 2200m/s at only 10000 gees takes 23 milliseconds, which is only 25 meters if you're traveling in a straight line. So you might be able to do this with, say, a 2-meter-diameter by 25-meter-long supergun, with a total volume of 79 cubic meters, which you might want to dig into the ground to reduce the risk of explosion. Accelerating a 200 kg launch vehicle at 10000 gees takes 20 meganewtons; over a 2-meter-diameter area that's about 6 megapascals of gas pressure, which is only 900 psi, eminently achievable with a light gas like hydrogen (the SHARP gun reached 3km/s). Then it's just a matter of timing the gas release through different ports as the launch vehicle moves through the barrel, a problem that's enormously easier now than in the 01960s with HARP or in 01918 when the Germans solved it for the Paris Gun.

The vehicle itself doesn't have to be 2 meters in diameter, and shouldn't be; an APDS-like approach with a lightweight sabot that fragments upon exit from the barrel gives your launch vehicle better power to penetrate the atmosphere.

Contrast that with a centrifugal launcher like the SpinLaunch design. For the centripetal acceleration to be only 10000 gees at 2200 m/s, the radius of the spinning arm needs to be 49 meters, which means its diameter is 98 meters, four times the length of the supergun. It's a building the size of a city block! But turned up on its side, vertically, so it's 40 stories tall. Its total cross-sectional area is 7700 square meters. You probably have to evacuate the interior so air resistance doesn't melt your rotor, since its outer edge is spinning at Mach 6.7. (This is the "300-foot diameter steel vacuum chamber" mentioned in the article). Even if you can make it only 100 mm thick over most of its area, it's 770 cubic meters, about an order of magnitude more volume than the supergun, and that entire huge area has to be leakproof, which makes it expensive (though admittedly it only has to withstand one atmosphere of pressure, not 60 like the supergun barrel).

From appearances their test launch facility is only about 7 stories tall, so only about 20 m, and they say they're only doing launches at about 450 m/s, which would work out to about 2000 gees by the same math. But it also looks like it's about 3 m thick, 30 times more volume (per unit area) than I described above: 20000 cubic meters at full scale.

The usual problem with centrifugal weapon systems doesn't apply here, though: you don't need to aim your launch vehicle precisely at a target to milliradian precision, you just need to hit the exit port instead of the solid launch-chamber wall. (The enormously larger radius also means you're spinning at many fewer radians per second.) And the free breaking length of carbon fiber is 400 km at one gee, and thus 40 m at 10,000 gees, and the outer part of the rotor can be thinner than the inner part, which is also under proportionally lower acceleration, and there are another half dozen materials with free breaking lengths over 150 km, so a 49 m rotor that spins at this speed is straightforwardly achievable. So I think the SpinLaunch approach will work if they spend enough money on it. I'm not a SneerClubber, I'm not here to sneer.

(Realistically the most likely way for centrifugal space launch to happen is that NASA will cut their funding before they can do their first launch, and ten years later China will build a working centrifugal launcher, because building new things is not really a thing people do in the US anymore.)

But if you're willing to evacuate 20000 cubic meters to launch your vehicle at 2200 m/s, you could drill your supergun barrel down through 6 km of rock, dropping the necessary acceleration to only 42 gees. That would enormously simplify the design of the launch vehicle, though it still wouldn't allow crewed spaceflight.

These definitely seem like they would be really good as like a return system from mars to earth… like factories ok mars could use this to probably launch materials back to earth

With these sorts of technologies I wonder if it just makes more sense to lay whatever needs to be paid to build a space elevator or equivalent and be done with it.

10,000Gs is probably too much for electronics, but fine for raw steel. Probably useful to have a low cost way of shooting a lot of working material into space.

> But the company says it'll be appropriate for smaller launch vehicles weighing up to about 440 lb (200 kg)

In this particular configuration, the rotational kinetic energy for a 200kg load would be massive and the current materials would not be able to withstand it and another issue would be the release timing through the opening, as seen on the video the margin of error would be so narrow that is likely not possible with the current technology. I hope I am proven wrong in my armchair assessment though.

Could we use this to launch radioactive waste into space at higher speeds than what’s needed to remain in orbit?

I was so badly hoping they were building a launch loop. Still giant centrifuges are always fun.

How many Starship launches does it take to get SpinLaunch to the moon, belt, etc.?

Neal Stephenson nods in approval.

I can only imagine what a spectacular show would it be if the load unclips at the wrong moment.

It's a scam!

https://www.youtube.com/watch?v=9ziGI0i9VbE

https://www.youtube.com/watch?v=ibSJ_yy96iE

There is a lot of skepticism around spinlaunch:

https://www.youtube.com/watch?v=9ziGI0i9VbE

https://www.youtube.com/watch?v=ibSJ_yy96iE