SpinLaunch: Giant catapult launching satellites | Hacker News Reader

SpinLaunch: Giant catapult launching satellites

thebrighterside.news

33 pointsDocFeind53 comments

The article is a bit fluffy and the headline completely misleading. It's proposed to get things to orbit by launching them up decently high and fast where the device then uses fuel to actually reach orbit.

Articles around SpinLaunch seem to be popping up lately which is a bit odd considering it's been ~2 years since they've done any testing and I've haven't seen any actual new announcements in these new articles yet.

Though, for what it's worth, replacing the first stage of a traditional rocket would still represent a dramatic reduction in fuel weight and perhaps also total launch costs.

You're kindasorta doing the equivalent of replacing an entire Falcon 9 with a relatively lightweight sabot. Either way the initial boost puts the orbital vehicle on a suborbital trajectory, so it needs to carry its own engine for the orbital insertion burn.

Agreed, with one nit: Initially you say first stage and later you say entire Falcon 9. Both approaches retain the 2nd stage rocket for orbital burn (separate from whatever propulsion the payload may have) so it's more equivalent to proposing replacement of just the first stage of the Falcon 9.

I don't really agree that the title is misleading. I would fully expect the launched satellite to need its own engine and fuel (if nothing else, you'll need orbital corrections).

This seems to replace the booster stage, which is still a pretty huge deal, and is also the largest expenditure of fuel.

> Articles around SpinLaunch seem to be popping up lately which is a bit odd considering it's been ~2 years since they've done any testing and I've haven't seen any actual new announcements in these new articles yet.

No argument here. Their website also seems to be about a year out of date (their "in the news" stops in late 2023).

It does replace the booster stage but it the 2nd stage isn't the satellite with its orbital corrections boosters to fine tune things, it's a rocket which provides 75% of the delta-v. The booster stage replacement doesn't even (propose to) get the 2nd stage to the Karman line without fuel, much less something to orbit without fuel like the title reads.

Replacing the booster stage is an interesting proposal, it's just not what the title conveys.

It's also strange because it's already well established that SpinLaunch is physically infeasible and borderline impossible to engineer, regardless of whether you have a 2nd stage. The article is written as if SpinLaunch has already been successfully tested for spaceflight, but it has not. No one should be promoting this scam.

You can build a "spin launcher" on the moon. Vacuum is a non issue there. A much bigger problem is that SpinLaunch does not have a design that is viable for the moon, because an optimal tether launcher uses kilometer long tethers to achieve the same velocity at low g forces.

The could be looking to be bought out by someone like Boeing or such so starting making more press releases?

Yep. Maybe they're having a, "we're not dead yet!" PR push.

That's what I was thinking, "we're not dead yet, and please someone buy us".

https://youtu.be/TGO4LtCctTk?t=22

Looks like a liquid-fuel rocket engine? Wow. That's got to be one heck of a hydraulic hammer when it hits 10,000g.

What kind of rocket engine have they designed that could survive this? Obviously it's not going to be a conventional turbopump; those things have micron tolerances, no way those could withstand 10,000g and still work. Probably they're doing some kind of pressure-fed engine (the fuel tanks held at high pressure, probably by compressed helium). They don't seem to publicly answer these questions, anywhere on their website? That's credibility-hurting.

There've been rocket engines built in the past that can survive low 100's of g's, at least. Those were exotic solid-fuel designs, intended as air-defense missiles.

https://en.wikipedia.org/wiki/Sprint_(missile)

Are they really actually claiming to have designed such a rocket engine?

Thanks for the Sprint info BTW, I had never heard of that.

I didn't see mentioned the size of payload compatible with this type of launch. I also didn't see anything about how loud it is, but I'd imagine it is quiet compared to a rocket launch. Would the payload be large enough to create a sonic boom on launch?

It's also just so much less dramatic visually compared to a rocket launch. It just feels anticlimactic. Still cool and interesting none-the-less.

It's more artillery than rocketry.

I'm not sure if this is reporting anything new?

I the 2022 test flights that the article mentions would have been from their smaller, vertical-throwing suborbital prototype. Last I saw they had kind of gone silent since 2023. The news page on their website [https://www.spinlaunch.com/in-the-news] hasn't posted any updates in almost a year.

I assume means they haven't successfully scaled up to the orbital launcher yet. Perhaps they're having trouble securing funding. Perhaps they're having trouble working out some engineering problems or securing a site for the facility. Or maybe things are just taking time. I'm guessing, though, that this is a situation where no news is definitely not good news.

Yeah wondering the same. I figure if they had anything new to show it would show up in their YouTube channel[0]. I can't even tell the difference between the Apr 2022 and Nov 2021 test launches as there isn't much detail provided.

[0] https://www.youtube.com/@spinlaunch6288/videos

Wow, I didn't realize they'd successfully put satellites in orbit already!

edit: turns out they haven't, the article is just poorly written.

They haven't, the title is just horrible.

They haven't. They have done scale model and simulations, but nothing actually to space.

Article from 2022 said they planned on having a real launch by 2026: https://www.space.com/spinlaunch-aces-10th-suborbital-test-l...

...however the company is struggling. No website updates in a long time, lots of C-suite staff changes.

Would love to see this work, but I think it's dead.

Oh, then these words in the article are, uh, poorly written:

> SpinLaunch has already conducted multiple successful tests with this technology. "This is not a rocket, and clearly our ability to perform in just 11 months this many tests and have them all function as planned, really is a testament to the nature of our technology," said Jonathan Yaney, founder and CEO of SpinLaunch, in a 2022 Space.com report after their 10th successful launch.

https://hn.algolia.com/?q=spinlaunch

As long as your satellite can withstand 10,000 Gs, spinlaunch will work great.

Founded in 2014, SpinLaunch has secured significant funding and has collaborated with major organizations like NASA, Airbus, and Cornell University, using their equipment in various tests. The technology has successfully withstood forces of up to 10,000 Gs, equivalent to 10,000 times Earth's gravitational pull, demonstrating its robustness.

Hopefully the minds behind it don't go the way of arty genius gone rogue Gerald Bull: "NARRATOR: To the end of his days, Bull was obsessed with what he saw as the injustice of his four‑month jail term."

https://www.pbs.org/wgbh/frontline/wgbh/pages/frontline/prog...

alot of the cost savings maybe shaved by needing to redesign the satallite to handle 10,000gs.

You gotta love how they just handwave away the fact that this is basically impossible with current technology. I guess payload design to such specs will be the customer's problem.

Not much space for anything hollow, or delicate, in those satellites.

How can this possibly work without at least some maneuvering rocket fuel? If the catapult is on the ground, any ballistic trajectory it can achieve intersects the ground. You can blast stuff into space, sure, but orbit? And the closer to a circular trajectory you get, the shallower the launch angle, and the more velocity-sapping atmosphere you have to plough through before you get to space.

I mentioned this elsewhere, but the aggressively simple answer is that it still works pretty much the same as current launch technology: the big huge rocket gets the payload onto an appropriately high suborbital trajectory, and then the payload use its own (much smaller) rocket to circularize the orbit. They're replacing the launch vehicle with a centrifuge, but otherwise the mission architecture remains broadly similar.

The launch vehicle only getting things onto a suborbital trajectory is a key reason why SpaceX recovering Falcon 9s is possible. They are not making a round trip around the planet before coming back, which would be necessary if it were actually doing orbital insertion too since the circularization burn happens a decent chunk of the way around the planet from the launch site. It would also be insanely wasteful; the fuel needed to get that whole giant chunk of steel up to orbital velocity would be vastly greater than the cost of just putting a small orbital maneuvering engine on the orbital vehicle so that it can finish the job for itself. And as an added bonus the spacecraft also gets to use that engine for general-purpose orbital maneuvering.

The Space Shuttle did something similar. Those huge main engines only got the orbiter onto a sub-orbital trajectory, too. They'd then jettison the external fuel tank while still on a sub-orbital trajectory (helpful for reducing how much space junk you produce), and use the OMS for orbital insertion. You really don't need such a big engine for this part of it, anyway. The SSME produced about 150x as much vacuum thrust as the OMS.

If you are on a sub-orbital trajectory, you have to do something more than “circularize” to get into any sort of orbit. How much more? Well, it depends on what your velocity is at the point where you fire the rocket. If your sub-orbital trajectory just makes it to about the von Kármán line with no more tangential speed than you had at ground level, you only have a fraction (~10%?) of the kinetic energy needed for an orbit. On the other hand, you cannot have anything approaching the minimum orbital speed while still in the atmosphere, as demonstrated by every satellite burning up on re-entry, but any unassisted catapult-launched object must have a higher speed at ground level than it will at altitude. The article’s claim, on a point that is fundamental to the concept, is misleading.

What about just launching up drones with big batteries to pretty respectable altitudes, that can then go e-refuel other drones?

Air power delivery has been a long little "wouldn't it be cool" notion for me. This just feels like it could be a good way to boost this idea, get it off the ground. Ok sorry about that.

The problem is they are using a catapult.... If they were using a trebuchet they would have no issues.

I think Newton is on the phone... Once the accelerating force is removed the object will go into an orbit that includes the point at which the force stops. This however is Earth

It doesn't remove fuel entirely, they still need an engine to circularize their orbit.

> The velocity boost provided by the accelerator's electric drive results in a 4x reduction in the fuel required to reach orbit, a 10x reduction in cost, and the ability to launch multiple times per day.

https://www.spinlaunch.com/orbital

Their promotional video shows this at around the 20s mark.

https://www.youtube.com/watch?v=TGO4LtCctTk

I think it's a cool idea. What increase in G's are we talking about launching things this way?

SpinLaunch: ~10000G

Rocket: ~5G

So roughly 3 orders of magnitude.

Wow are there issues with making things like chips that can even survive that? I remember when I was a scientist and 10,000g was some very high speed centrifuging that you better make sure everything like even glass and plastic can handle.

> SpinLaunch: ~10000G

I admit I was surprised people were able to build hardware that survived that.

They plan on launching a small 1st stage with the satellite. You need some delta-V to circularize & fine tune the orbit after the spin launch.

Time to break out Kerbal Space Program and see how well it works...

I believe all the payloads will have a small rocket on them to boost the periapsis up outside the earth

With enough force applied, the Earth will no longer be there when it comes back to that point.

Unless it reaches escape velocity (ie its never coming back) then it will always comeback to where it started from. The object is under the same gravitaional influences as the Earth

As others have pointed out, there is a rocket motor to put the payload into an orbit.

Next startup idea: have the satellite stay in place while we move the earth until satellite is at proper distance. We'll figure out details after IPO.

Thunderf00t made a great 2 part video series about Spin launch on YouTube, and how their science doesn't make sense. Busted!!

its just possible that something like this could be used to launch refined metals and or exotic compounds to an earth gravity capture from an asteroid or mini planetoid hairy scarry but launch the payloads with a heat shield ,directly into an aero brake splash down somewhere remote and recover the ingots

Isn´t this the entire plot of Heinlein's "The Moon is a Harsh Mistress" ?

There is a major difference though, in that book they use a long linear catapult. This helps keep the G force down (in fact it's low enough that humans can attempt to use the catapult to travel). Making a second stage for orbital maneuvering that can withstand that kind of acceleration is not particularly hard.

What spinlaunch is proposing is to use a fairly small circular catapult. The G force involved in that case is huge, something like 4 figures. We can make electronics that can survive that (although this is close to the upper limit), but can we make rocket engines and fuel tanks that sturdy? Personally I doubt it.

That was a linear driver on the moon. It's closer to The Man Who Sold The Moon, but that's also a linear driver up the side of a mountain on earth.

How fast is the payload when it leaves the launch tube?

2.1 km/s according to Wikipedia

I assume its a closed room because the acceleration isn't done in normal atmosphere - so you are going to literally explode out of this thing into normal air at 2100m/s?

Seems like a lot.

Seems like a lot, yet isn't no even close to the speed needed to yeet something into space.

Earth escape velocity is 11.1 km/s, which is Mach 32 at sea level. They have some more engineering to do, maybe even invent something better than carbon fibers.

Exactly. I don't think their scale demonstrator demonstrates much beyond the possibility of making a propulsion stage that survives the launch at 10000G's

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