Can A Giant Potato Cannon Throw Things Into Space Cheaper Than Rockets? Longshot Think so!

LongShot space are a SF Bay Area company who have resurrected the hypersonic projectile launcher with an eye to scaling it up to the point it could launch payloads into space at a lower cost that traditional rockets. And while this lofty goal is a long way off, they do have a contract to build a launcher able to throw test payloads at mach 5 for the Department of Defense who want to test hypersonic payloads.
This is by no means a new idea, in fact I made a video about gun based launchers over a decade ago • Real World Kerbal Spac...
However a more scientific discussion is found in this paper:
"A comparison of distributed injection hypervelocity accelerators" A. J. Higgins
www.researchga...
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[@clayel1]

Scott Manley, the only person who can forget about an aerospace company inviting them for a personal tour and still getting to do it years later

[@psychopotato87]

I mean with that inbox he sure can be excused for missing that one

[@parveshkhatri1027]

I bet there are multiple emails from NASA too

[@andyspoo2]

They don't seem to have progressed much over 2 years. I don't think he missed much.

[@5nowChain5]

Bet theres one or two from SpaceX in there...😅

[@alphagt62]

In the book by Jules Verne, From the Earth to the Moon, they shot them up there in exactly the same way.

[@samsonsoturian6013]

I just love how brutally honest these guys are about the problems faced and odds of success.....

[@jacewhite8540]

But even if it doesn't work out it seems like a very worthwhile project to work on for a few years!

[@sandwich2473]

Honesty is a very rare thing in tech sadly Garners a lot of trust when people are actually open and honest though

[@fredrik-wendt]

Very refreshing!

[@NBSV1]

Much better than the spin launch people. Spin launch seems much more focused on marketing and getting money.

[@TastySlowCooker]

See: Black Box Thinking by Matthew Syed

[@GertvandenBerg]

I like the guy that showed you around, he seems to be realistic... Often the places have people doing marketing BS talking to external people....

[@r3dp9]

There's a general perception that honesty holds people back, but I hold the belief that it's a better policy in the long run. You generally get a better resume from failing the right way than 'succeeding' in burning all your bridges.

[@calvinnickel9995]

@r3dp9 The world runs on confidence. Fake it to make it is a real thing. That’s why you have Fortune 500 companies with more debt than assets and negative cash flow with high stock prices. That’s why you see an average looking guy with an insanely hot woman. That’s why most scams involve instilling confidence upon the victim (this is where con-artist comes from).

[@mathis8210]

He is more honest than others have been, but far from realistic. Even if they could make this thing reach orbital launch velocity it would be useless. Its in the lower atmosphere, where friction and compression heating will fuck all your shit up. Not to mention the intense shockwaves destroying everything around the launch. This thing exists to suckle money out of the government teets. But they obviously can't just say that outright.

[@GertvandenBerg]

@@mathis8210 I do think the hypersonic testing part of the company might be able to function.... Project HARP did reach space (179 km) with a gun-launched projectile in 1966... So that is possible... Whether something useful can survive being carried by such a projectile is likely another question (for orbit, it would likely need at least a rocket to get it out of a suborbital trajectory....)

[@MmMm-f2y7c]

100% a valid concept. Saddam Hussein had a Canadian inventor build something similar and was partially built before the invasion. It would have been able to launch Intercontinental ballistic payloads potentially smaller orbiting ones with the help of a booster rocket as part of the payload.

[@42grath]

Some of the best redesign and improvement comes from: "We did some analysis and realized we were just doing something dumb" lol great video, and really fascinating concepts they are working with!

[@svenjonsson9]

Good design is knowing you don't have all the answers yet, and that it is going to take hard work and experimentation to get there. I really admire these guys, and wish them all the best!

[@GetSmartish]

"Oh, yeah, we were being dumb" Truer words have never been spoken by authentic innovators. I worry when I don't hear some variant of that phrase frequently and fervently.

[@bradhoward9701]

The world is not changed by words like Eureka. It is changed by words like 'oh, im an idiot!'

[@Space_Parrot]

Think that fella who ran OceanGate said something similar...

[@glytchd]

Yeah like the cyber truck... I mean srsly how can you claim to know anything about manufacturing

[@virutech32]

​@@Space_Parrot I mean he didn't and always thought he was right which is why he's fish poop now

[@x--.]

yup, been there. done that. anyone who has ever had to really try to get something working, especially quickly, is going to know that phrase well.

[@Alienalloy]

no matter what people say, its guys like this with a passion that I'll always always admire.

[@DB-zp9un]

And even if they personally dont succeed, they probably lead the way for others to succeed..

[@oggyoggy1299]

Okay

[@InexcyeSolms-handle-is-taken]

The cargo container. The chicken wire. The long lean-to shack. I love these guys.

[@jakethesnake630]

Haha yeah I fell in love with this company as soon as he said he was setting off car alarms and moving the storage container haha...and the fact he looks like Brains from Thunderbirds. Love this.

[@nathansmith1085]

Yeah, they might as well build a sub lol

[@TheStormpilgrim]

I'm sure the first rocket setup was pretty janky, too.

[@emeraldoqrol1265]

Tony Stark was able to build this in a cave! With a box of scraps!

[@Redskies453]

Weapons grade tyvek shielding

[@innobius4898]

I remember a few years ago a system that utilized a light gas gun to propel a shaped projectile into a combustable mixture of gasses that already had a high detonation speed. The projectile then compressed the gasses against the wall of the barrel initiating detonation. Since the detonation was propagated by the projectile as the projectile sped up so did the blast wave. This further accelerated the projectile. The article i read claimed they were reaching speeds in excess of mach 7 with 10 theoretically possible, but impractical due to lack of entry velocity to the combustion barrel.

[@notknownguy]

What a fantastic startup!! I love how rustic and down to earth this company is I wish them an amazing venture

[@WilliamW2010]

"You can't do it in Kerbal Space Program" Not with that attitude

[@benn454]

It's been done in Satisfactory

[@grotebaby1827]

Mass drivers can actually fill a similar role

[@KaizokuSencho]

Yeah, you need an positive attitude, ie +0 degrees over the horizon to launch something like that.

[@samuraidriver4x4]

​@@benn454hypertube canon's ftw. 😊

[@heidelbergaren5054]

I see what you did there

[@rh9909]

15:10 I was expecting a "That's impossible", but instead got a "I don't know how to do that". And my respect to the man and his team goes 1000000%

[@absurdengineering]

If you had an electromagnetic actuator system, it can withdraw a sliding gate without breaking it at this timescale. First you use a cylindrical coil to bump the gate and unseat it, and very soon after you kick the linear actuator to pull the gate out. Then the gate has to be decelerated to a stop, also electromagnetically, lest it turn into non-reusable shrapnel. I’m not sure what the fatigue life of a gate would be, but probably more than 1 actuation, to say it won’t crack apart on first use 😂.

[@paulelephant9521]

Great catch and comment, sometimes the internet is good! Knowing that something is going to be difficult is a good skill to have in engineering! You don't want the task that you thought was going to cost you $X has already cost you $2X and you're still nowhere close!

[@JasminUwU]

​@@absurdengineering you're gonna need 200,000 G of constant acceleration, and reach a maximum velocity of 2 km/s

[@NoTraceFound]

@@JasminUwU You could technically split the sliding gate into several parts that overlap to seal, that way you split the mass into 3, 4 or however many times you want and the distance in half.

[@JasminUwU]

@@NoTraceFound unfortunately, 100,000 G of constant acceleration and a maximum speed of 1 km/s is not much more realistic

[@user-qf6yt3id3w]

These guys are very endearing. I like the way he's obviously very smart and self critical and the whole thing looks like it's being done on a complete shoestring budget.

[@pieppy6058]

They did the science before the marketing

[@actually5004]

It's not popular, giving money to people recreating Nazi super weapons like the Vergeltungswaffe 3.

[@scottwillis5434]

A few thoughts on burst discs: I think that can be done WAY faster than 30 seconds. 1. Think film projectors: they advance and clamp into place a strip of film at many frames per second. Do similar with burst-disc metal strip. 2. Forget hydraulics. Look at stamping presses: Spinning inertial disk, trigger a mechanism, it does a cycle of stamp-and-release. Just switch where the moving platen (or whatever the term is) stops: a choice of stopping clamped or unclamped. 3. Combine: stamping-press clamps up on the burst-disc strip. Fire. Stamping-press unclamps, advance the strip, clamp back up. Fire.

[@carpemkarzi]

I like the reasonably grounded philosophy. Not promising Mars in 5 years but storying with first principles and seeing how far they can take it. Wish them the best

[@WWeronko]

As a retired engineer who spent a good deal of time in defense, I have seen lots of fruity ideas. DoD is often mesmerized by what could be possible no matter how improbable. Longshot sounds like a kooky idea that might have some ultimate application on the Moon or asteroid mining. Like Spin Launch, accelerating technological things runs into the delicate nature of such objects. Your construction has to be rather robust to withstand acceleration that can reach hundreds of thousands of g's. It can be done. Smart artillery ammunition typically experiences acceleration forces of around 10,000 to 15,000 g's during firing. A railgun can accelerate projectiles to speeds between Mach 6 to Mach 8. The acceleration itself can reach hundreds of thousands to millions of g's. If you are sending raw material off the Moon, delicacy is not a major factor, However, telling a microsat manufacturer to ensure their satellite withstand a 10,000 to 15,000 g's acceleration might be a stretch.

[@john_in_phoenix]

Yes, but many artillery projectiles have programmable smart fuses that withstand the acceleration every day. Even the first smart fuse (WWII proximity fuse) managed with vacuum tubes.

[@mezu-e]

The spinlaunch guys seem convinced that a lot of components and materials are already suitable just untested because there hasn't been a reason to validate crazy Gs

[@WWeronko]

@@john_in_phoenix Indeed. How they do that puts significant restraints on what can be accomplished. The electronics and sensors inside smart munitions are built with reinforced components that can endure high acceleration. These include hardened circuit boards and shock-resistant materials that can absorb and dissipate energy from the intense forces. Sensitive electronics are typically encapsulated in shock-absorbing materials, such as rubber-like compounds or special polymers, which cushion them from the high acceleration forces. Moreover, smart munitions are designed with redundant systems. If one sensor or circuit fails due to stress, others can take over, ensuring the munition still functions as intended. There are many other design constraints used in smart munitions beyond the scope of this reply. As I said, it can be done for a single use / purpose munition but it puts huge constraints on a more complex satellite.

[@c6q3a24]

Did you watch the video? Peak acceleration in this system is roughly 150G. That's why the barrel is so long.

[@hamjudo]

Spinlaunch tested a lot of different electronics in traditional centrifuges. A stock iPhone can withstand thousands of g acceleration if it is lying flat. They need padded cases to survive off axis falls.

[@michaelhill6451]

Aside from the challenge of the very precise timing of the burst disks, I'd say the synchronization of the two burst disks on either side of the projectile is an issue. If one bursts and the other doesn't you are putting a lot of force on one side of the tail of the projectile and potentially causing it to dig into your barrel. This might result in the destruction of at least a portion of the barrel. You'll also have many burst disks involved which increases your probability of failure. In other words, the burst disks have to be extremely reliable.

[@natosaichek]

Totally. Burst disks are absolutely the biggest challenge and the thing that has to work correctly. Lots of work going into making them reliable.

[@blueskytoday2230]

Right. It's hard to know how badly off course the projectile is going to wonder with less than perfectly symmetric bursts but that alone is enough of a reason for me to think that this is a terrible idea.

[@natosaichek]

@@blueskytoday2230 Projectile is on rails that run the length of the system. It's not flying free in the barrel.

[@Nainara32]

Loud bangs aside, I don't think I'd want to own a house or work at an office within a few blocks downrange of this device.

[@fjsa_2471]

Having one burst disc instead of two opposite discs eliminates the problem. It would require changing the shape of the tail and looking into mass distribution within the tail, but I think technically it's a much easier solution. Also, the interaction of the released gas with the tail can be such that it causes payload to rotate. This would help with stabilizing trajectory while it travels within atmosphere.

[@r3dp9]

The cool thing about this kind of research, is they are sure to (and probably already have) solved engineering problems that will have many unexpected uses in the decades to come. When you shoot for the moon, you can hit pretty high even if you miss by a lot.

[@ChiefArug]

One of my favourite Māori whakataukī is "Whāia te iti kahurangi, ki te tuohu koe, me he maunga teitei", meaning "Aim for the sky so that if you miss you will hit a lofty mountain". Pretty much exactly what is happening here!

[@WestOfEarth]

I love the raw authenticity of this start up. People with a dream making it happen.

[@chadcrotts870]

I love content like this, showcasing humans pushing the limits of possibility!

[@kurttate9446]

Reminiscent of the German V-3 during WWII. They had a very long barrel with multiple charge chambers along its length to add additional propelling gas. The problem was the propelling gas leaking around the projectile and igniting downstream charges before the projectile passed that chamber.

[@nickl7488]

well, they didn't have computer controlled detonation back then

[@reneberthold334]

As i saw this the First thing was that this is a modern version of the V3. The germans back then are 70 years ahead of it’s time.

[@kurttate9446]

@@nickl7488 They didn’t have sufficient gas seal to keep the gases behind the projectile. I think the idea was to let the propelling gas ignite the propellant as the projectile passed the chamber.

[@davefb]

nah look just like some petrochemical pressure vessels ... honest..

[@marcinborkowicz2557]

I was about to mention V3 ballistic cannon. The same principle behind (actual physics) but the old technology.

[@solandri69]

There was someone trying to make the same thing in the 1990s-2000s. He wanted to build a gun with over a 1 km barrel, suspended in the ocean to minimize distortions by gravity. He had a 1+ hour lecture on KZbin going over a lot of the technical details and math, but I can't seem to find it anymore. It was a pitch to the USAF as a SBIR (which was eventually declined). One part I distinctly remember from the video was that they were having problems finding anyone able to manufacture electronics able to survive the g-forces the gun would generate. A friend working on a classified project (probably guided artillery shells) pulled him aside, told him to take some regular electronics, pot it in resin, and try firing it. He did, and lo and behold it survived just fine. Apparently modern electronics have been miniaturized to the point where high g-forces result in very little net force on the components.

[@vancemarin8022]

I think you are referring to Gerald Bull a Canadian who worked on the Harp project and then went on to a bigger gun but was assassinated by the Mossad.

[@thebigmacd]

​@@vancemarin8022 yeah, Israel wasn't too keen on Saddam's supergun.

[@solandri69]

@@vancemarin8022 No, Bull was assassinated in 1990. KZbin wasn't founded until 2005. It would've been quite an achievement for Bull to have uploaded a video to KZbin.

[@RCAvhstape]

In WWII the US figured out how to put tiny radar transceivers into anti-aircraft artillery shells, vacuum tube tech that could withstand the shock of being fired out of a gun barrel.

[@UCannotDefeatMyShmeat]

Ah so the Omega space gun in SOMA

[@RuralJuror420]

He literally brought you to the drawing board. This group of guys are passionate and knowledgeable and I’d probably have a 2 hour convo with them at a house party lol. I’m so excited that new space startups are starting to get the funding to get some proof of concepts, etc.

[@Skank_and_Gutterboy]

Being passionate and knowledgeable doesn't turn a bad idea into a good one. Seriously, this is the hyperloop of the space launch business. It's a terrible idea.

[@blinking_dodo]

@@Skank_and_Gutterboy Can you explain why? I think this one is better than the spinlaunch one to be honest.

[@kilianortmann9979]

@@Skank_and_Gutterboy Unlike the Hyperloop, they are developing new technology, like the super fast acting burst discs. It might not get them to space (and I think they are aware of that possibility), possibly staying with hypersonic testing or impactors but they'd like to get into space if at all possible.

[@natosaichek]

@thePronto Muzzle exit velocity is ~mach 25 (8.5 km/s) to get us to about 7.5 km/s at orbital altitude. We lose about a km/s in drag through the atmosphere.

[@natosaichek]

@theProntoMach is about 343m/s. 343 m/s * 25 = 8575. Check yo numbers

[@cncgeneral]

The problems they have to solve seem so clear and straightforward (fast valves, timing and projectile shape), it seems unlikely that the big weapons companies won't just solve them themselves

[@absurdengineering]

Big companies are often terribly inept at the simplest of things - not because they got a hard problem to solve engineering-wise, but because they treat their people in a way that makes whole teams mired in cellulose molasses and 50/50 hate going to work.

[@Basswire]

getting a 1 meter valve that can operate in 150 microseconds is not a straightforward problem, no big weapons company is solving that problem any time soon. Weapons companies are the potential customers of companies like this, them "solving" these problems will be by going to a company doing hypersonic ballistics testing like longshot.

[@badscrew4023]

Almost one million of unread emails? Scott you're my hero!!!

[@jacewhite8540]

Actually love this, it's not a bunch of silicon valley bros with big fancy facilities trying to do this to get venture capital to come in. It's literal garage inventors just for the love of space and engineering!

[@zedaprime]

If Scott Manley came to my office, I would act like I had too much caffeine too.

[@dougaltolan3017]

Yeah, if that's every day him, I'd have to ban coffee from the lab.

[@obsidianjane4413]

Esp. if he looks like he is about to punch you (holding the selfie stick).

[@natosaichek]

I was two cups of earl grey deep

[@heidisparklebottom]

I've been in this situation, someone important visiting, me excited and passionate and wanting to explain a thousand things a minute 😅 he's genuine af

[@whophd]

It was the other way around at the supersonic plane factory last week

[@798Muchoman]

Not at all what I expected from this. I figured they'd have a pie in the sky idea and plan, not a reasonable idea to test and good profit along the way. Cool stuff.

[@EShirako]

Yeah, this all seems very sensible so far! I'm a bit impressed.

[@chrimony]

@@EShirako Not really. As Scott mentions at the end, fuel is cheap compared to the hardware costs, and they aren't saving an amazing amount. As a practical way to launch satellites into space, it seems like an idea that looks better on paper than it does in reality.

[@Varadiio]

@@chrimony That's not what Scott meant. He was saying that despite Falcon 9 having a slightly better fuel weight to payload ratio, the common gases are much cheaper than the hardware part of the system. There's certainly a lot yet to test for durability, but right now the major consumable for Longshot is their burst discs. They've already considered reforging discs as a possible strategy. This will exceed even the best reusable rocket program in expenditure of hardware unless some other unforeseen cost is involved.

[@EShirako]

@@chrimony Hm, drat! I was hoping it could maybe eliminate an entire stage of rocket, maybe, but if they can't drop a whole STAGE to do that, yeah, the fuel savings alone would be 'visible' but not worthwhile. Even dropping the whole first stage of a rocket might not be worthwhile, but I suppose the math folks would need to look into the engineering and stuff to see if it is, but I had hoped that it might be!

[@mobiuscoreindustries]

If anything the military would always be interested. Their approach to system cost is just whatever and the ability to lob a projectile with terminal guidance across the planet for cheaper than an ICBM (and without the ambiguity of potential nuclear payload) is I think the exact kind of fringe weapon systems the USG is going to throw money on.

[@lossexe6331]

Love your videos. Im a long time viewer and I sincerely appreciate both ends of the spectrum, I regularly seek out your videos if I need help in ksp.

[@ZeroUm_]

2:40 I love that the speed of sound for Carbon Monoxide is undefined for imperial units

[@arnaudt3935]

Now you showed your mailbox, everyone who wrote you will now think it's better to send the message at least twice to get a chance to be read by you lol Thx a lot for your taste of sharing your knowledge Scott !

[@MrWhite2222]

Scott needs a secretary 😂

[@mbak7801]

Twice?? Nope. Send 400,000 and then there is a good chance it will be read. You will need to add random elements to prevent algorithmic filtering. There can be a whole project for "How To Contact Scott Manley". HTCSM.

[@jeffreypierson2064]

@@MrWhite2222 An intern is better...

[@theRPGmaster]

They already do that. I'm not an important person, and none of the companies I'm associated with are particularly well-known, but the spam still gets to me. They're absolutely wasting their time.

[@LoftBits]

Looks like fb would be a better bet 😂

[@Rubrickety]

I really love the extremely self-aware company name.

[@john_hind]

The thing I do not get with any of these ground level accelerator launch systems is what happens when the payload emerges at mach 25 into sea level air. The drag and heating would be phenomenal! And the amount of deceleration you'd get passing through the atmosphere would mean you had to be going even faster than that when you leave the accelerator!

[@wiregold8930]

Launch from say Atacama desert would almost be a necessity.

[@kayleigha4132]

Most all of them do not have their exit in sea level air. The accelerator is already 15km long in this case - why not push the end of the barrel vertically upwards a few kilometers (which you have to do anyway to get into an orbital trajectory)? Lots of them are concepted to be built against mountains for free structural support, for this reason.

[@SomeDudeInBaltimore]

@@kayleigha4132 Even at the altitude of Mt. Everest you still have like 95% of the way to go to space. The air is still relatively thick for hyper-sonic velocities at that altitude.

[@logicbuilder1204]

Hopefully your aimed slightly up so your spending very few time in the air

[@HypoceeYT]

Do ICBM Reentry Vehicles get down OK? It's the same problem in reverse. Basically if you make your thing dense and dartlike, maybe put some ablative stuff on the front, it's fine. You do have to tack on some more Machs for the drag, but the wonder of engineering is that ultimately big numbers are still just numbers.

[@MrGoesBoom]

The valve set up and the timing issues it faces reminds me a lot of coilguns and the issues they face. At any rate, even if it sounds silly, it's nice to see people trying to new ideas and pushing the engineering forward.

[@scottyallen7237]

I learned a lot from your video, much less violent environment inside the barrel than I expected. the dove tail projectile and radial gas injection was fascinating. One glossed over detail concerning the burst disk replacement is that the flowered disk may not be so easily removed without disk debris creating a FOD hazard for the next shot. It is a Longshot to get to Mach 25 in a vacuum, let alone designing a useful spacecraft that can withstand the 150g's AND not melt before leaving the discernable atmosphere - maybe this would be better suited for atmosphere-less applications like sending lunar samples back to Earth, or delivering ore from an asteroid mine.

[@Hykje]

A KZbin Video where somebody is drawing something on a whiteboard that makes sense -that's a big step for humanity.

[@jgedutis]

If you like white board science and math you should check out Engineering Explained on KZbin. That guys whiteboard kung fu is strong.

[@Hykje]

@@jgedutis When you see a guy on KZbin with a whiteboard it's usually somebody who wants to explain his brand-new conspiracy theory or why the Earth is flat.

[@alexplayslife7782]

if you like spooky stuff, windigoon does a lot of crazy shit on whiteboards that has around a 50/50 chance of either making sense or being the most deranged crazy thing you've ever heard.

[@robloggia]

The way he said oh when Scott mentioned the chance of fire gives me more confidence in his engineering experience than any official credentials he could produce.

[@haydenalbrey]

I cringed when Scott said that. Did he think these guys needed to be told about a fire risk?

[@literallyjustgrass]

​@@haydenalbreylooking at that setup with all the plywood, yes😂😂

[@Tuned_Rockets]

Died 1990. Born 2024. Welcome back Gerald Bull!

[@blahsomethingclever]

Just learned about the G Bull last week. What a fascinating life. Love his vision I'm 100pcnt with him.

[@jeffreywoodhead2682]

Those 16" Naval gun barrels are probably still somewhere in the Barbados jungle if anyone fancies resurrecting the HARP gun... 😊

[@matterwiz1689]

saddam hussein smiling upon san fransisco from up high

[@ezza2x899]

You can still spot the other Harp gun at the Yuma test range, it’s not as big but the barrels where next to it last time I looked

[@olpaint71]

@@jeffreywoodhead2682 There's probably some still at the Highwater Test Range in Quebec/Vermont, too, but I wasn't able to find a definitive answer on whether they've been scrapped after Space Research Corporation went under. There are relatively recent photos of the gun in Barbados on the internet.

[@chillmonkey6782]

That's a compliment when you reach out to a company, and they have already reached out to you

[@rdyer8764]

Cool! I was once part of an DARPA-funded, SBIR company doing research. It's fun environment to work in, as long as you're flexible when the $$$ eventually dry up.

[@jongmans38]

I am glad these guys still exist; I thought the entire world was going dumb....

[@beansdad70]

ACME Spud-Gun Launch-O-Matic. Wylie Coyote would be proud!

[@DrownedLamp9]

Okay but hear me out; Tater-inator by Doof(enshmirtz) Evil Inc.

[@ARandomTroll]

Backyard ballistics did a great video on the thermodynamic limit of gun velocities and propellants.

[@AdamMi1]

You could try to make something like a railgun.

[@nickl7488]

​@@AdamMi1very large emals, as seen in many sci fi

[@blueredbrick]

Great video as always. Rediscovery of earlier ideas is a good thing. Cheers.

[@awmperry]

So it’s essentially an evolution of Haskell’s multi-charge cannon and the V-3 at Mimoyecques? I also kind of appreciate that they’re developing it boffin-in-a-shed style with improvised kit; they’re making their funding go a long way rather than doing the classic tech startup thing of overspending on glitz.

[@JohnPowell6]

Hypersonic research tool? Definitely. Space launch platform? Doubtful.

[@thearpox7873]

Depends on if they can get large payloads to launch with this thing. Even cutting a couple km/s would be great if you still have a conventional rocket to do the rest.

[@minibeefcake]

It'd probably be great for sub-orbital weapon delivery system. I'm not sure how useful that really can be for launch anything meaningful to space. I find it really hard to envision this doing multi-ton payload to space.

[@r3dp9]

@@minibeefcake You don't always need a multiton payload. What if you want a small time sensitive payload that needs to go up inbetween scheduled rocket launches?

[@marcogenovesi8570]

not with this attitude

[@criticalevent]

@@thearpox7873 There's no if about it, you can't launch something into orbit on a ballistic trajectory, they have to be shooting a rocket down that tube.

[@nunogomes6011]

"The Moon is a Harsh Mistress" by Robert A. Heinlein. Railguns firing moon rocks.

[@ilmaio]

RAH's catapults were magnetic though, and operating in the vacuum.

[@beansdad70]

50K of those e-mails are probably related to his car’s extended warranty.

[@UncleKennysPlace]

Or some sort of, um, enhancement pills.

[@kieranmilner4208]

I’m pretty sure his rocket is in good condition considering his entire channel is about them

[@Psycorde]

Sirs redeem

[@InconsistentManner]

Nigerian prince wants to give you his fortune

[@addictedtofigbiscuits]

*planes :P

[@derekbridgerii2102]

It mimics the gas expansion in a gun barrel. Admittedly, thus is far more sophisticated. The control, and data collection is superb.

[@andymouse]

What an awesome bunch ! I wish them all the luck they need.

[@DaDudeb]

After a V2 kicked off the space age they are using the V3?

[@brucermarino]

Yes!

[@BSJinx]

But they could've had a V8!

[@marcogenovesi8570]

as usual, spicy german technology superiority is confirmed once again

[@DragonsAndDragons777]

​@@marcogenovesi8570Common German W

[@PaulKlinger]

17:22 "Small business, couple hundred million dollar market cap" 😂

[@c6q3a24]

Yes. You idiot. A small group of people with a small amount of money did a huge amount of work - and they have produced a company that could be worth many millions.

[@haxi52]

It almost sounds like he said "couple hundred billion dollar"..

[@ironcito1101]

It's like when Warren Buffett speaks of "tiny, tiny" amounts, like $10 million.

[@andrasbiro3007]

Today that's small. A well positioned startup could get billions easily. Like Rivian was valued at $80B at IPO, with not much to show.

[@danboy12342]

I assure "hypersonic weapons testing" will get them a few hundred million these days with a half assed tube and some big gas cylinders in the desert

[@benn454]

"Hey there, it's Josh. Welcome to Let's Game It Out!"

[@codder32]

I do miss the KSP videos. I was so hype about KSP 2, such a mess :( Kinda forgot about this channel for the past couple years and I have been watching a lot of your videos for a couple weeks, glad you're still putting out such interesting content !

[@I_Am_Empyrean]

If you know the speed at which an electrical signal travels through a wire, the speed at which the valve opens, and the speed of the projectile through any given segment, then you should be able to write a piece of software to perfectly time the opening of each valve.

[@gregclare]

Really interesting and detailed interview. But I can’t help thinking that “Longshot” is a really appropriate company name! But it’s always great to see people working on advancing solving the hard problems. Nothing is impossible, we just haven’t figured out how to do it yet.

[@johnhinkey5336]

As a UW Ram Accelerator alum, a co-PhD student of Andrew Higgins and having worked on other similar concepts for other start-ups I can say these guys have their work set out for them. Sure you can get a slug of something up to high speeds, BUT there are a lot of practical limitations (i.e., engineering challenges). Like scaling up in size (area vs. volume), aero heating, barrel wear/drag, g-hardening of a payload, needing a kick-stage for LEO injection, etc. all of which cut-away at the useful payload. Anyone need a consultant on this - drop me a note . . .

[@johnhinkey5336]

Oh, the what's old is new again technology - replaceable burst discs, side charges, projectiles on internal barrel rails, etc., etc.

[@dougaltolan3017]

What is "UW" and "alum" please. I got "Ram Accelerator", those are the easy bits😊

[@Shelleloch]

​@@dougaltolan3017I'm taking a guess at "University of Wisconsin former student" (alum is a shortening of alumnum/alumna).

[@jeffreypierson2064]

@@dougaltolan3017 University of Washington alumni... I would put in the website, but YT tends to censor links.

[@jeffreypierson2064]

@@Shelleloch You missed the paper that he showed was from a researcher at University of Washington.

[@michaelhill6451]

18:50 Yep. This is a much better idea than SpinLaunch. I would venture to say that SpinLaunch is just about the worst way I can think of launching a projectile from Earth. You have a projectile that has to withstand > 10,000 Gs of acceleration for an extended period of time vs 100s of Gs for a tiny fraction of the time. This also doesn't require a huge vacuum chamber, etc.,

[@glytchd]

Yeah like this is what tech allows us to do. Not cutting edge - by making practical simple ideas we simply couldn't implement in the past Information texhnology... too bad we let the commies take over the free world Guess that's the cost of free trade - the free world and China producing 300ppm co2 in less than 20yrs

[@theevilcottonball]

No the worst way is to tie a rocket to a helium balloon, then once it reached its final height go to the space elevator and bring it up to LEO (the counterweight of the space elevator is beyond GEO), then ignite the rocket to speed it up to orbital velocity while it is falling back to earth, then use a couple of skyhooks to save propellant. Now that we got the rocket into orbit but forgot the payload we accelerate the payload using a rocketsled bolted on the back of a large aircraft and hook it onto the orbital mass driver, detach and use steam powered thrusters to attach it to the rocket we shot into space earlier. From then on we use the rockets built-in fusion explosion motor to reach the target orbit.

[@matt1863]

But I want something that generates constant sonic booms and then hucks something into space.

[@thearpox7873]

@@theevilcottonball This is stupid. Just dig a tunnel into the base of the Mount Everest till you are directly under the peak, then turn the upper ~5 kilometers into a maglev rail for your rocket to accelerate. That way you both launch from the top of the highest mountain, bypassing the atmosphere, don't have to deal with the weather up top, AND can get to several km/s even before lighting the engines. See, pure simplicity.

[@theevilcottonball]

@@thearpox7873 The mount everest is covered in snow, so it has both weather and atmosphere. The biggest mountain is not Mount Everest it is Olympus Mons anyway, it has less atmosphere, less gravity and less of what we would describe as weather, so that would be the better location to launch rockets from.

[@wanfuse]

just a thought, dynamically change the slope of the back side of the projectile? and also behind shutters ( like camera shutter) or roll in coins into chamber, shutters likely better or layers of roll in coins along circumference, shortening closure distance to travel that is proportional to the count of roll in coins. Alternatively: This approach could work effectively for a projectile launcher. By injecting a low-viscosity liquid behind the gas, you're essentially creating a hybrid system that leverages the benefits of both incompressible liquids and compressible gases. The idea is to use the liquid as a force "amplifier" to push the compressible gas into a smaller, confined area, limiting how much gas needs to expand and increasing the pressure quickly. Mechanics of the System: Low-Viscosity Liquid Injection: You inject a super low-viscosity, non-compressible liquid behind the gas. This liquid quickly fills a portion of the tube behind the projectile, effectively isolating the compressible gas to a smaller volume. Since liquids are incompressible, they transfer force efficiently. By pushing the liquid into the system first, you reduce the overall space the gas needs to fill, meaning less gas is required to create high pressure behind the projectile. Compressible Gas Injection: Once the liquid has limited the gas volume, the gas injector pushes the gas into the confined space. Since the gas now occupies a smaller area, it compresses rapidly, building high pressure behind the projectile. Effect of the Gas: Gases store energy when compressed, and upon release, they expand rapidly, which creates a strong force. In this case, the gas doesn't need to fill the entire tube, only the space between the liquid and the projectile. This localized high-pressure gas can then push the projectile forward with significant force. Optimizing the Area to be Filled by Gas: By controlling the liquid's volume, you limit the amount of gas required for compression. You could even design a system with variable liquid and gas injection, allowing you to fine-tune the pressure and force exerted on the projectile. Key Advantages of This System: Efficient Pressure Build-Up: The liquid quickly reduces the space the gas needs to fill, allowing the gas to reach higher pressure levels more quickly. Controlled Expansion: The gas, when compressed in a smaller volume, exerts a stronger force over a shorter distance, which could increase the speed of the projectile. Lower Gas Consumption: By limiting the area the gas needs to fill, you reduce the amount of gas needed, making the system more efficient and reducing the wear on gas injectors. Liquid as a Safety Barrier: The incompressible liquid acts as a buffer, preventing rapid gas expansion in a larger area. This could also reduce the chance of gas leakage or uncontrolled expansion. Liquid Options: As mentioned earlier, a low-viscosity liquid like silicone oil, isopropanol, or a glycerin-water mix could work well. These are all non-compressible and flow easily, allowing quick injection behind the gas. Key Design Considerations: Injection Timing and Sequence: You'd need to precisely control the injection of the liquid and gas to ensure the system works efficiently. This might require a timing mechanism or pressure sensor to activate the gas injector after the liquid has filled the desired portion of the tube. Pressure Management: Since liquids can generate high force quickly, you may need pressure relief valves or other safety mechanisms to prevent overpressure in the system. Projectile Fit: The projectile needs to be tightly fitted in the tube to ensure that the pressure generated by the liquid and gas translates into forward motion rather than escaping around the edges. In summary, combining low-viscosity liquid injection with compressible gas injection is a clever approach to limiting gas volume, building higher pressure, and improving the force behind a projectile. This method takes advantage of the rapid pressure increase from gas compression while maintaining control and efficiency with liquid injection.

[@indigobluu]

Episodes like this teaches you to work on hard things no matter how absurd and not give up

[@chompchompnomnom4256]

Your invisible selfie stick makes it look like you're about to punch him 🤣

[@andreasu.3546]

10:28 Searched for this comment.

[@RLD_Media]

This is the kinda team that I would be head over heels excited to work with/for.

[@peterwoolliams1283]

Reminds one of Gerald bull and the V3. Clever idea, be interesting to see how fast it can go.

[@marcogenovesi8570]

the spicy germans are at it again

[@Luni_2000]

oh no, I haven't actually seen the video, I have just seen the thumbnail and thought: Oh another satisfactory video with a hypertube launcher. It took a second to see what it really was. And it's so fitting.

[@ssocar96]

I love how space gun concepts end up keeping the option open of the payload being a little rocket.

[@wally7856]

It has to shoot a rocket if it wants to stay in orbit and not fall back down. You can't throw something into orbit no matter how hard you try, it'll always come back to it's starting place and hit you in the head. You NEED a 2nd burn at apogee to circularize the orbit.

[@officermeowmeowfuzzyface4408]

As a ballistics guy, its common to see 3x speed of sound (556nato, 762nato, 50bmg, etc) then there are some like Win Short Mag that can do more than 3x. With sabots it can go 4-5x speed of sound (tanks etc).

[@camillovidani2586]

He means the speed of sound in the propellant gas, not in the air outside.

[@kahlzun]

I never understood how sabots made things go faster. Is it essentially just cause the projectile can be lighter?

[@officermeowmeowfuzzyface4408]

@@camillovidani2586 that's weird because the speed of sound is based on pressure, aren't pressures in the range of 60,000 psi? As the pressure increases, speed of sound increases. I think.

[@camillovidani2586]

@@officermeowmeowfuzzyface4408 The speed of sound depends mostly (for an ideal gas, entirely) on temperature and chemical composition. Pressure has a very minor effect.

[@officermeowmeowfuzzyface4408]

@@camillovidani2586 temperature and pressure are very closely related, you can't have one without the other. In the barrel your pressures will be 60kpsi and temperatures over 700C. Lead or lead alloys require a gas seal, which is either a copper jacket or a copper base, or the tail melts. Cold high pressure will increase pressure dramatically as temperature increases. Temperature and pressure are linked, that's why we have something called STP, Standard Temperature AND Pressure.

[@festerallday]

It's common for modern 'varmint rifles' to run 3000-4000 fps with 20"-24" barrels. The problem isn't getting to that speed. The problem is that anything that fast wears out the barrels very fast

[@nickl7488]

much less of a problem with smoothbore, you can even line the inside with tungsten 120mm smoothbore has several times better service life than 120mm rifle, even with higher velocity

[@WalksAlone]

This is a real “Geek-Meet-Nerding-Fest” 🤓😎 Absolutely love it!

[@dannymac6368]

Made me feel a bit better about my inbox. Thanks mate.

[@impguardwarhamer]

This interview certainly inspires a lot more confidence than their extremely amateurish social media posts

[@ccudmore]

Without watching the video, I dearly hope the answer is "Yes"

[@calloutman]

But we all know the answer is no.

[@virutech32]

​@@calloutman Well of course a potato wouldn't survive

[@Superkuh2]

It is no because there is no means or orbit circularization or raising perigee above the ground to achieve a real orbit.

[@toahero5925]

​​@@Superkuh2You could use drastically smaller rockets if they only needed to circularize their orbit. On the moon (or anywhere else with minimal atmosphere) it's an extremely valid option. Launching from Earth is a bit more of a question mark.

[@nomar5spaulding]

If it shoots hard enough, yes!

[@captainchaos3667]

At least there are proper nerds working on this; gives me confidence. 👍

[@ns219000]

You had me at "gas cylinder, but with a flange, for a bottom".

[@almicc]

I wonder if this idea has been tried: think of a long series of meshes split into two parts, a static part and a moving part. This can be whatever size and shape you need, however long to retain the pressure well. The moving part can be moved a very small distance to effectively make the structure transparent to gas. In one moment it's a long solid piece, the next moment after a very small movement, you have a large void that gas can travel through nearly unobstructed. I thought of how laminar flow is made with fountains, you have many small tubes that restrict how the water can travel, then at the end the all join together and you have a much larger void that the water can fill quickly.

[@pietrosigismondodelvalenti6371]

Thanks for making this video. So glad to see the idea I had when I was 10 years old is finally happening. Thanks for catching up, life has been lonely and uninspired without people to share our infinite potential with. Cough cough V3 cannon COUGH Wait until they realize the absurdity of the project is not the gun itself, but the safety features that prevent the gun from being dangerous. Creating acceleration without needing onboard fuel is incredibly useful for increasing cargo capacity. They're aiming for the Kármán Line, every little advancement they make is helpful.

[@booneylander]

While a rail gun is certainly no simple thing to build I feel like rapidly replacing 10 000 burst disks every launch is no small expense.

[@fakestory1753]

Yeah this is getting to a point where you need to open valve at many sonic speed. I was thinking they should just use rail gun, or at least use some sort of super heated gas. not only that, sealing a piston that travels km/s sounds like it is going to hurt barrel, though i don't know if that close contact is actually do any damage to barrel

[@DrewLSsix]

This is competing against current rocket technology that throws literal tons of hardware away with every launch and where reusable hardware exists theres weeks or months worth of refurbishing required AFTER recovering the parts which may be strewn across a hemisphere. The burst disc's and their related servicing are peanuts.

[@hinz1]

Rail erosion is killer, with millions of Amps and several 1000m/s. That phase velocity/wave surfing design here is actually quite smart, if it works And does not necessarily require burst discs, small powder charges might work just as well, might require longer tail, however.

[@inteallsviktigt]

@@fakestory1753well if we can use a normal gun barel for shooting thousands of rounds weighing thousands of pounds.

[@lithobreak3812]

burst disks are just sheet metal

[@Afifi96]

Litterally almost a million unread email, Scott Manley is a MANIAC

[@Green_Tea_Coffee]

And I thought my inbox was bad...

[@chippymm22]

I suppose he'd be even more or a maniac if he had read them

[@theevilcottonball]

1.) Write a bot to send 2 million mails to yourself. 2.) Claim you are more famous than Scott Manley 3.) ???? 4.) Profit

[@Xaqaria]

That company is clearly engineering led. I wish we advertised more examples like this: a group of engineers are building a business addressing problems the engineers want solved.

[@m420-nd1if]

lead*

[@Xaqaria]

@@m420-nd1if double check your references.

[@tyreni]

Easily the best comments section on youtube. Smart and down-to-earth people from all over the globe.

[@MikkoRantalainen]

Is there even a reasonable plan to have something else but burst plates to act as valves? For this short demonstration shot replacing 3 plates per launch doesn't seem that bad but if the final product is supposed to have hundreds or thousands of boost stations, you cannot keep replacing burst plates for every launch or it will be more expensive than rockets very soon. Especially with SpaceX constantly lowering the price of getting 1 kg to orbit. Update: I see you asked this very same thing around 14:38 - great job! If they go with that plan, they will require *a lot* of machinery to be built before they can start shooting stuff but assuming that they can rebuild the burst plates in automated manner (or otherwise cheap enough) you're absolutely correct that in the long run the amount of consumables per launch is the most important thing and here it appears that the amount of hydrogen + energy needed to compress it + amount of energy needed to manufacture the burst plates might be less than what SpaceX can do. Of course, if SpaceX can get their launch even cheaper per kilogram, then it might cause problems for this project. Is there even a rough estimate how much it would cost to build all the machinery with the whole track? Are we talking about SpaceX budget already?

[@alan2here]

The explosive compresses the hydrogen, the hydrogen fuses and fusion provides even more pressure and you have an H-Gun.

[@magnemoe1]

Nice now you have an fusion engine or better an power plant.

[@absurdengineering]

Yeah. And the projectile gets heavier down the barrel as it absorbs neutrons. Noice!

[@itsmesuryat7570]

Bruh

[@jajssblue]

Hopefully we can, at least, launch potatoes. Even if they end up fries 😂

[@MattSimmonsSysAdmin]

Man, pneumatics are so much more dangerous than basically every other propulsion source. Between that, the fact that burst discs are analog, the jerk subjected to the payload, and the payload mass limitations and need for a kick stage, this is a really complicated endeavor.

[@oznerol256]

More dangerous than super toxic propellants discussed in the "ignition" book? More dangerous than nuclear salt water rockets?

[@criticalevent]

@@oznerol256 More dangerous in that the government will allow you to work on these bombs in the middle of a city because they don't know any better.

[@jimsvideos7201]

I don’t know if it will work or not but I admire their style in finding that answer.

[@boelwerkr]

I'm sure they have thought about it. My thought about the valve problem was pulling out a valve plate really fast. Furthermore connecting all the valve plates of the booster stages to a long ribbon that then will be pulled through with the same speed of the projectile. The plate-ribbon displace only very litte air and therefore can be pulled very fast. the additional openings from the removed plates are also very small compared to the openings to the main chamber. The only real problem is to pull the pate-ribbon with mach 25 at the last stage.

[@petergerdes1094]

This seems awesome but it feels more like something that is useful for missle defense than for getting to space.

[@georgesmith4768]

🤫 Don’t tell the DoD (who is the primary funder) They would be devastated

[@mrpicky1868]

it's not for humans. it's for material

[@dougaltolan3017]

You want to aim a 15km gun?

[@MazeFrame]

Missile defense and getting into space have been the same thing ever since someone lit a tube pointed at the sky.

[@petergerdes1094]

@@mrpicky1868 Yes, I'm aware but air resistance goes up with v^2 while rockets get more efficient as they increase in size so I'm just not convinced that it will ever make sense to fling things very quickly to get into space from the earth.

[@Innerbrave]

That inbox screenshot lol. Thanks for being a cool science KZbinr Mr. Manley.

[@jeromethiel4323]

Sounds a lot like the German V3 weapon from WW2. One long barrel with multiple chambers off of the main barrel with additional charges. As the projectile traveled down the barrel additional charges were fired behind it. This kept the pressure up so that you could get a very high velocity at the muzzle. One of the main problems they had was timing (1940's tech), and the projectiles tended to fly apart after they left the barrel, due to the extreme velocity. In contrast with the V2, the V3 never worked, to my knowledge. But it was an interesting idea.

[@thomashemenway7384]

The Tallboy bombs collapsing the chamber probably had something to do with it not working :)

[@Ahtalon]

as far as i know the V3 facility got hit by an air raid and destroyed it early in development (brits didnt even knew it existed, only after the US captured the facility).

[@enscroggs]

It did work in combat, but only a half-size version (160 meters long) built in Germany and aimed at Luxembourg City, about 40 miles away. The Germans fired at least 183 shells from two Hochdruckpumpe guns. About 40 shells landed within the city, with several landing near General Patton's 3rd Amry HQ. Patton was convinced it was an assassination attempt, at least that is what he wrote to his wife. As it transpired the whole thing wasn't as effective as a medium-sized air raid by Ju-88 bombers.

[@jimtalbott9535]

@@enscroggsThough given the air superiority situation at the time (the Luftwaffe didn’t have it at all), this was much easier to pull off.

[@jimtalbott9535]

17:00 - So, would the use of a Tesla Valve next to the travel path before the projectile exits improve anything?…….

[@pauldunlop1660]

Orbital spud gun the sign of a well spent childhood, epic!😁😁😁

[@Martin-pb7ts]

This is really cool program but my first question is what happens to that projectile when it exits the pipe at a speed higher than escape velocity? It has to counter the earths drag and the loss of speed with no more acceleration (although they did mention including a rocket engine "maybe") once it leaves pipe. Can a useful payload withstand that shock which is essentially an impact. A rocket carries it's own propellant and spreads the acceleration of the payload over a much longer period. What speed does the projectile need to be travelling at when it exits the pipe and what is the size of the shock/impact against the atmosphere when it exits the pipe? Apart form that I agree - I think it is amazing that we have people like this team working on problems like this. I really admire their approach and their drive to keep going.

[@RealAndySkibba]

Scott always asking the right questions

[@Superkuh2]

He didn't ask how they intend to circularize the orbit so it actually orbits instead of just hitting the ground on first perigee.

[@jnawk83]

​@@Superkuh2small rocket on the back of the payload surely?

[@TheSnivilous]

I was hoping he'd ask about what speed and variables are they assuming to actually get something to orbit. What is the curve of how much mach they lose due to air resistance.

[@Superkuh2]

@@jnawk83 The volume of the projectile is so small that any rocket they develop that could fit and actually raise the perigee above the atmosphere would be better than any rocket that has ever been made by orders of magnitude. If they are capable of building the best rocket engine in the world in an impossibly tiny volume (no vacuum bell nozzle) then they should use that rocket technology to just launch from the ground.

[@natosaichek]

@@TheSnivilous we lose about a km/sec in the atmosphere, so we aim for muzzle speed of about 8.5 km/s

[@orionbarnes1733]

Weird question, but wouldn't this still be a sub-orbital trajectory, even if it did work? I thought entering orbit required a boost at (or near) apoapsis, something which a ground-based gun couldn't do. Granted, all I know about orbital mechanics is my many thousands of hours in KSP, which is good for the basics being drilled into my head, but I do admit that orbital precession and that sort of thing is foreign to me. Wouldn't it be necessary to have a rocket be included at least somewhere in the payload, for that final boost?

[@Dyson_Cyberdynesystems]

That's what I don't understand about these kinetic projects or space elevator concepts. You want delta V but it is very inefficient getting that in the atmosphere. And having altitude outside of significant atmosphere doesn't get you delta V. Only way this is useful is having a gun like this mounted on a space elevator.. Even on an air launcher platform you still need a stage on the projectile to attain a stable orbit.

[@dougaltolan3017]

Think if these systems as replacing only the first stage. The "projectile" is the entire second stage plus payload, which can do the orbit insertion burn.

[@michiganengineer8621]

Maybe not if the "muzzle velocity" was like 4 or 5 times orbital velocity. You'd need one hell of an ablative layer on the payload though, pretty sure it would look like a meteor in reverse!

[@dougaltolan3017]

@@michiganengineer8621 Orbits don't work that way... Unless you reach escape velocity, you will return to the surface at the same angle you left it (if air resistance is ignored) Orbits are eclipses, the fastest (and lowest) point is perigee, the highest (and slowest) is apogee. These projectile launch systems represent perigee, and after 1 orbit the payload will return to where it started from. What you need is a rocket burn at apogee to put you in a new orbit that dosent intersect the starting point.

[@michiganengineer8621]

@@dougaltolan3017 Thank you, I KNEW there was something wrong with my "logic"!

[@mumblingfree]

12:00 Rogue frame. You're welcome x

[@diditbreak]

Who is it? I can't quite grab it

[@mumblingfree]

@@diditbreak I think it's the fellow that explained everything to Scott but it's a distorted image

[@frostbot117]

I kinda want to buy kleenex now.

[@siztem]

Whew, i thought i was having a stroke

[@issssse]

Yes! After like 4 minutes of pausing, rewinding, pausing... I finally got it. And you won't believe your eyes when you see what it is...

[@johnb2219]

In America we run pipes full of oil across the country. You can run a longer pipe to reduce the thresholds and build up desired speeds at desired points. Currently trying to make it as small as possible go longer!!

[@Oldw00d]

that guy seems to know his stuff and is passionate with it I hope he does it

[@rogerc7960]

Navy once had an air cannon to launch sticks of dynamite. Launch a solid rocket second stage?

[@dreweab]

This is an old idea we sent a manhole cover into space years ago with a big gun. Just add nukes

[@zebo-the-fat]

Orion??

[@playgroundchooser]

I think this time they want to do it intentionally 😂😂

[@karl0ssus1]

​@@zebo-the-fatOperation Plumbbob. The "manhole cover" was a 1.5 tonne iron cap over a shaft with a nuclear bomb at the bottom. There was apparently a single frame of footage of the cap going skyward after the bomb went off, best estimates are it was doing several times escape velocity. Pretty likely that the frictional heating vaporised it and it never made space, but it's a fun joke.

[@alan2here]

What cut transitions are those in the video? Fast morphs?

[@guggol148]

could you maybe use a sort of reusable burst disc, with something like a star shaped series of cuts that create separate petals, all held together by a small burst ring (or even a wire clip?) at the center? That way you do not need to replace the entire 1m wide disc every time, just close it back up and replace the burst clip... which shouldn't be too hard to automatize...

[@denvera1g1]

With normal guns, there is a very tight gas seal, so tight it actually bends metals on the bullet as they pass thrrough the rifling, and bends the casing so that it also creates a nice tight seal. The problem is that with a longer barrel, you would need additional charges at regular intervals down the barrel, as well as delayed charges at all points to keep that pressure up. This is going to generate an enormous ammount of friction and heat on the projectile "What about a less tight fit" Well with a less tight fit you now get gasses escaping past the projectile now acting to slow the projectile down, which the the problem many of these 'hyperloop' projects face where much of the energy spent is still pushing air out of the way of the car, despite it being a 'vacuum' This isnt to say it cant be useful, but i feel like orbital velocities are unlikely, and a more reasonable approach is to launch a traditional rocket at say mach 2 from a 1 mile or shorter barrel Alternatively, you could take the approach of the first every object thought to be sent to space This used a nuclear powered gun to launch a 900KG "manhole cover" at an estimated 125 thousand miles per hour though most of it probably was vaporized by friction with the air before reaching space. I propose a cylindrical spitzer shaped plug rather than a flat cap