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Can something like SpinLaunch actually work?

It appears that Spinlaunch attempts to accelerate a capsule to very high speeds and then basically throw it into space.

A regular rocket is moving slowest where the atmosphere is thickest, but with SpinLaunch the capsule is moving fastest in the thickest part of the atmosphere. One would think that the amount of heating generated by friction with the air would be far more intense than what most spacecraft endure during ascent, or even reentry.

Also, one would expect quite rapid deceleration once the capsule starts moving through the atmosphere. It seems questionable that many payloads could handle those forces without being redesigned.

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    $\begingroup$ The acceleration during the spin launch will be much harder than the quite rapid deceleration through the atmosphere. Only special designed payloads will survive both. A lot of additional structural mass is necessary to handle these forces. A very heavy heatshield will be needed for the high speed in the densest part of the atmosphere. $\endgroup$
    – Uwe
    May 12, 2022 at 7:54
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    $\begingroup$ Scott Manley makes an interesting point on his YouTube channel in one of his comments on a Spin Launch video. He states that while this technology may be hampered on earth by the atmosphere, there's nothing in this technology preventing it from being deployed on the Moon or on Mars. So, if dense air is an obstacle, use it where there's no dense air. $\endgroup$
    – Dohn Joe
    May 12, 2022 at 8:30
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    $\begingroup$ I agree with the concerns raised in the question. A launcher that must reach its maximum velocity at liftoff seems highly impractical. $\endgroup$ May 12, 2022 at 12:35
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    $\begingroup$ @OrganicMarble it might actually be better if it had max velocity at liftoff. It actually gets released at around 2 km/s, delivering less delta-v than any first stage I know of. So it has the problems of withstanding extreme accelerations and hypersonic flight from sea level, but also requires a high-performance rocket stage (or more likely, two or more stages) that can survive those conditions and deliver the remaining 7-8 km/s required to reach orbit. $\endgroup$ May 12, 2022 at 13:15
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    $\begingroup$ @OrganicMarble the two aren't necessarily exclusive. But I'm reminded of interviews where Yaney basically said they were specifically hiring inexperienced people who wouldn't tell him it was a stupid way to do things. $\endgroup$ May 12, 2022 at 16:15

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Spin launch should work, but suffers from so many draw backs on Earth that it may well be impractical or limited to very niche or suborbital applications.

Huge accelerations will need to be applied which will make its use impossible for many cargos such as crews or anything remotely susceptible to being crushed (peak g load reported as 10,000g).

There are serious structural problems with spinning large objects to high speed which will restrict the scaling of this technology.

The initial launch does not provide sufficient velocity to escape Earth so it is effectively only a first stage device and leaving the Earth’s surface at such high velocity also creates a lot of frictional inefficiency requiring a heat shield as well as massive deceleration initially.

The concept might have more promise on the Moon or on Mars.

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  • $\begingroup$ re: huge accelerations, hardware wise they seem to be working on this issue with some success, though without many details. $\endgroup$ May 16, 2022 at 18:42
  • $\begingroup$ On the moon, if for no other reason that you get the vacuum for free. $\endgroup$ May 16, 2022 at 19:12
  • $\begingroup$ There's also the possibility on earth of launching from a platform suspended by helium balloons at an altitude of 30km, I even tried to suggest the idea to CNES but to no avail... $\endgroup$ Jan 25, 2023 at 10:21
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If your question is simply whether or not it will work, the answer is unequivocally yes. Their 1/3 scale test was fully successful and the science to back it up is there. As stated, it is a replacement for the first stage of launch only. The capsule is not only payload but is itself a second-stage rocket. This second stage will be doing almost all of the circularizing of the orbit. Peak velocity will not be on the ground but the final orbital velocity, just as with all other low-earth launch systems.

As a company, they are vetted as well. They have secured contracts with NASA as a payload launcher and were named a Top 100 Most Influential Companies of 2022 by Time Magazine. Whether that means as a business they will be economically successful is another story, but at the moment it seems they will at least be able to deliver on their promises.

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    $\begingroup$ "If your question is simply whether or not it will work, the answer is unequivocally yes." I don't feel you've supported this assertion very well. It's the engineering that's in question, not the science. $\endgroup$ May 19, 2022 at 0:11
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    $\begingroup$ Can a rocket stage of sufficient performance reach orbit if hurled off the ground at 2 km/s by a centrifuge? Sure. Can SpinLaunch engineer a rocket stage of sufficient performance to do so that actually survives the launch? That is far from certain. It has to do a lot more than just circularize the orbit, it has to provide 80% of the delta-v to reach orbit. That's difficult even if it didn't also have to be engineered to withstand tens of thousands of gravities in sideways acceleration and hypersonic flight at sea level. $\endgroup$ May 19, 2022 at 1:14
  • $\begingroup$ It depends on what he means by "work"! Can we throw something at high velocities? Yes. Can we get something in orbit without additional propulsion? Will it be possible to get something in orbit with additional propulsion? Probably. Will it be more efficient than a tradition boos stage? Maybe. Will it make economic sense on earth? I doubt it (but that lat one is just oppinon!) $\endgroup$
    – TrySCE2AUX
    May 19, 2022 at 12:37
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It depends on what you mean by the word "work"!

In some sense it already worked. They accelerated a projectile with a payload (a camera) to high speed and released it into the atmosphere. We can consider this as "works".

Can we get payloads without additional propulsion into orbit with this? No, definitely not! (But that's not the intention of SpinLaunch!)

The idea is to replace the first stage (or reduce its size). Can this goal be achieved? That's really hard to say! Even lifting a rocket to 30000 feet with an airplane does not seem to help that much that it gains a lot of traction (and believe me, if something makes economic sense, some customers will be "very quick" to choose a carrier that brings their payload to orbit the cheapest). So I'd say that on Earth with it's relatively deep gravity well and thick atmosphere, SpinLaunch will have a hard time competing with reusable launch systems.

I think it's a good thing that the possibilities are explored. And maybe, on day we'll use systems like that on the Moon, on Mars or on asteroids!

But I think on earth the additional mass needed to withstand the forces during spin up and afterwards the enormous dynamic forces created by drag in the dense atmosphere will just not outweigh the benefits of "electric initial boost".

But we will see, I hope, that I'm wrong.

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