Kerbal Space Program - 'Orion' Nuclear Pulse Rocket

[@ViperHeadshot]

"We're just killing velocity very carefully" he said, blowing up his 200th nuclear bomb.

[@ElijahWatkins-l3y]

Like what

[@ElijahWatkins-l3y]

Oh wait the entire solar system

[@SkyWKing]

When people hear of nuclear bombs, they immediately think of giant city-levelling fireballs and space-reaching mushroom clouds. That's why they fail to appreciate the beauty of this idea. The nukes used in the Orion rockets are actually of very low yield; they are in fact less powerful than suitcase nukes or nuclear artillery shells. The liquid fuel packed in N1 and Saturn V is equivalent to a tactical nuke (the N1 accident is the most powerful non-nuclear artificial explosion with a yield of nearly 7kt). An Orion uses less than that amount of energy since the fuel is much lighter, not to mention that the warheads are much more chemically stable than liquid fuel (as Scott Manley pointed out, nukes don't detonate simply from impact, random chemical explosion, or fire). Technically most of the hazard comes from the SRBs used to lift the vehicle to an altitude. I suppose with modern minituarized warheads and lightweight material a propelling pellet would only weigh half of the originally pellet proposed in 1950s, which was already very light. The only barrier to this idea is politics. It may generate too much acceleration for human, but would make nice efficient cargo delivery vehicle.

[@PuzzlingGoal]

Is it even possible to create small enough warheads for that? The smallest nuke ever still was 10 tons powerful (enough to destroy a building or two), and it was pushing the limits of critical mass for practical-to-use fissionable material way too much already.

[@spartanonxy]

Giannis Pantazis Practical yes that is the limit for fission the idea for the Orion's drive was a tiny atom bomb to make heat and pressure and then the rest hydrogen and helium for fusion.

[@mrchangcooler]

You think the smallest nuke is that small. The smallest nuclear bombs were in the orion project. Most of the plans are still classified by the US government to prevent terrorists from getting nuclear weapons.

[@spartanonxy]

Mr.chang cooler Well they were by size the smallest if you increase size you can use more advanced methods of ignition to scale the yield much better.

[@TheAmericanCatholic]

SUN SU You can use uranium 233 from thorium which has less dangerous waste projects

[@amperzand9162]

So, everyone does realize that that last craft was not only an Orion-powered plane, but an *Orion-powered biplane*?

[@squishybrick]

*drives an aircraft powered by nuclear explosions* "Fly safe~"

[@incognitoburrito6020]

I mean, we drive vehicles powered by carefully controlled constant explosions almost every day, so we're not really one to talk.

[@scottmanley]

Actually, I explained that in the video, the amount of fissionable material needed is almost identical for a small one vs a large one. There's a certain minimum size of fission warhead that's needed to get an explosion, but once you reach that limit you can use it to initiate a fusion payload so the extra energy comes with almost no increase in fallout.

[@spiderobot]

Hey Scott! Your video just got linked from Randall Munroe's XKCD "What If?".

[@karanbirbains9114]

+michael boullon Same here!

[@jensenmiller6410]

yup

[@benschwartz6473]

That's why im here

[@kaibutsu6100]

Same!

[@alexandreo.3083]

I got here from there

[@CrazyMinecrafter99]

whos here after orion drives were confirmed in the ksp 2 trailer?

[@jamesiguess2547]

Me

[@adamkollar2207]

*we*

[@tortellini6607]

that'd be me

[@SkyTheGoogleTranslateguy]

ME

[@ClarifyGS]

chat i dont think there will be orion drives...

[@soylentgreenb]

Scott Manley There's a "continuous" version of orion; the nuclear salt water rocket. Another interesting device of far more modest proportions was the nuclear ramjet (project pluto). Before the ICBM became a proven technology work was done on building an unshielded nuclear reactor, acting as the heat source for a ramjet. It was supposed to fly at mach 3 at low altitude, essentially without moving parts (except steering) and stay aloft for weeks. If called into action it was supposed to zig-zag across the USSR dropping bombs as it goes. They actually built and tested the nuclear ramjet portion; it was tested stationary on a rail that could be used to remotely move it into a shielded concrete building after firing (it would have been lethal to be anywhere near it when firing; it had no shielding). Coors (who are now mostly known for making beer) made the uranium-beryllium oxide fuel elements. They used miles of oil pipeline to store compressed air for the ramjet (it was a stationary test, so there was no ram-pressure to work with). It worked beautifully, but it was not followed up with a real flight test because the thought of flying the damned thing over continental US was too scary, in case it went off course and flew over a town or something.

[@tankmodeler]

>>but it was not followed up with a real flight test because the thought of flying the damned thing over continental US was too scary Scary, but not just because it was a flying unshielded nuclear reactor (as if that wasn't enough). Pluto's core continuously eroded and spit out minute particles of incredibly radioactive material, essentially poisoning anything it flew over. This was the actual reason the program was cancelled. There was no way to actually test it. Once it started to fly, all you were doing was poisoning more real estate, even if you are doing it over the ocean, the radioactive dust would stay in suspension in the oceans for thousands of years. Pluto was the ultimate doomsday weapon.

[@voxelsofsorrow]

It seems that Russia has announced it's building something akin to Project Pluto as a warhead delivery system, as if 2020 needed more horsemen of the apocalypse.

[@littlemikey46]

"Fly safe"... or as safe as you can fly while setting off thousands of nuclear explosions.

[@kellywilson-lawson1857]

Oh being safe isn't being fun

[@VenseyNess]

This is undoubtedly the most fanboy-induced moment I have ever achieved. from my favorite spinoff of my favorite webcomic, you sent me to my favorite youtube channel. I mean... WHAT!?!?

[@justmeitis1143]

Randall is love, Randall is life

[@nickf.8203]

Vensey Ness same here!

[@Apophis122]

Vensey Ness Same, though in full admission to my inner geek, I've already seen this movie.

[@Blackholefourspam]

Vensey Ness It's truly a beautiful thing.

[@TehFrenchy29]

+Vensey Ness Following the same process, I am now sitting at my computer giggling far more than most would likely consider reasonable for a 20 - something male (though those people are wrong, because enjoyment on the scale said process has given me is never unreasonable, and knows no conceptual barriers). And quite possibly the most fun a nuclear detonation (or series of them, in this case) can possibly be--powering a (semi-) fictional device, propelling a fictional airfcraft, flown by an enthusiastic Scottsman.

[@johnalogue9832]

Randall Munroe tied you for most Kerbal craft ever. Submarine with a GIANT heat shield on the front dropped into Jupiter.

[@SuperSMT]

*Jool Scott Manley , you must recreate Randall's Joolmarine!

[@Clem2TheClemening]

SuperSMT And launch it strutted to the back of the Orion Spaceplane

[@AniSky759]

These comments are pure gold. Too bad gold probably won't help you survive an atmospheric entry into Jupiter.

[@helioskitty9328]

+LukeDude759 It'll look really pretty if you're in a submarine falling behind it though.

[@johnalogue9832]

LukeDude759 Pretty sure gold is a pretty soft metal, but it would be melted butter entering Jupiter's atmosphere... Mmm...melted Jupiter gold butter....

[@MoonbeamPony]

*builds an airplane powered by nuclear explosions* "I'm Scott Manley, fly safe."

[@nightw4tchman]

I can't stop laughing at Scott's calm, and dare I say interesting, voice narrating over FREAKING NUCLEAR EXPLOSIONS taking place every few seconds. It's just so surreal. Love the work!

[@rein7046]

I feel like you were a bit too cautious with that landing. I mean, if that plate is able to absorb the force from a nuclear detonation then I don't think it should have too many problems absorbing the impact from a collision with the ground.

[@CrimsonGamer99]

I wonder how Danny could abuse this... ...evil grin...

[@aubreys.8308]

>:)

[@aubreys.8308]

LETS TELL HIM CrimsonGamer99 !

[@CrimsonGamer99]

Nelson Muller Nuclear Pulse in general!

[@crabgnome5388]

100 years from now people will look at this video, laugh, and get up from their quantum locked couches and tables to go grab a bag of popcorn from their pulse rocket powered microwaves. Of course people will still eat popcorn then. And watch youtube. Some things will never become obsolete.

[@theaveragepro1749]

Solid Banana You mean say 1 bowl of popcorn and watch as their supercooled conducter robot flies to them and gives them their 3D printed popcorn using nutrient packed organic matter covered in specifically grown bacteria to cause taste.

[@TCWordz]

+Solid Banana Just imagine the comments... "Oh, 1080p, we meet again!"

[@helioskitty9328]

+Tommy59375 "1080p? Was this filmed on a moldy piece of bread?"

[@KnowledgePerformance7]

Sounds like a Colin furze universe

[@spindash64]

except 4k is basically over the limit of what your eyes are capable of at best. yeah. granted, GM and implants and what not, but one step at a time, mate

[@CharTheDude]

Thanks for reminding me of this video, XKCD

[@scottmanley]

But didn't they later show that higher yield devices produced less fallout?

[@bergmanoswell879]

I've heard of disposable rocket motors, but disposable launch facilities and disposable CONTINENTS? Yup, that's the most Kerbal thing ever. Is there such a thing as a NERVA thruster in the game? Those were at the working prototype stage when the project was killed, and were cleaner in radioactivity terms than a sunny day in the tropics.

[@maxhess3151]

5:00 holy crap hes lighting up the dark side of kerbin like the midday sun

[@VanBurenOfficial]

8:18 We need to start building that NOW

[@430zack]

Yah probably will have more saftey features since when the idea was invented

[@Danbearpig]

Larry Niven used this idea for a spectacular scene in his science fiction book Footfall. So cool.

[@caav56]

WHAM WHAM WHAM quiet

[@orbemsolis]

When you've mastered astrophysics and start messing with nuclear bombs RETROGRADE HOHMANN TRANSFER

[@edwinrobert7192]

Underrated

[@KTheStruggler]

I FOUND IT! I used your video in a school project I did last year about Nuclear Pulse Propulsion. I later found a different video of yours quite recently and am surprised but not surprised at the same time that you made this video :D

[@Icy_vixen]

Why are we not funding this?!

[@Icy_vixen]

Don't forget there are also fusion bombs and fuel pellets with electric beams concepts for Orion since Fission is very inefficient and dirty like you described in the earlier Orion studies. However, we have not created controlled fusion energy with electron beams or anything else, but anything is possible.

[@wigster600]

***** You do realise that the amount of radiation this would make is rather..... pathetic compared to the radiation a space fairing ship would have to withstand in space.

[@Icy_vixen]

Are you suggesting ion engines and better nuclear chemical rockets?

[@kidlink4OoT]

Funding and research would have continued but the "Partial Nuclear Test Ban Treaty" banned testing nuclear detonations so the project had to be stopped. Honestly it was a stupid idea since this would have been an amazing way to get around the solar system.

[@wigster600]

I doubt the explosion would cause much of an issue, if the flash of the nuclear bomb is close enough to the earths atmisphere to tough it then it may be a problem, but if the flash has the void of space seperating itself and the earth, then the shockwave can't travel to the earth.

[@SteelxWolf]

I was doing my science homework after watching this

[@kermanguy1877]

"Well boys, we spent trillions of dollars on nukes, a couple billion on building a damn plane that could use it, and we destroyed the planet in the process. Good work, team!"

[@bradynowlan5917]

Actually, they predicted that getting a rocket to orbit would only create as much pollution as one of the early atomic bomb tests.

[@kermanguy1877]

Brady Nowlan Shut the fuck up. I'm fucking sick and tired of nobody on this fucking site understanding jokes.

[@GnanaPrakash86AP]

+Brady Nowlan Haha! I think he was referring to how mankind used nukes instead of how they should be used.

[@halowraith1]

+Kerman Guy there wont be a shortage of smartasses anytime soon - especially not on this side of youtube.

[@dreadpenguinlord340]

My absolute favorite space travel concept! Hilarious how the astronauts were terrified the entire time - though probably realistic.

[@Trinzilla]

10:13 As Scott said, there is inflation. Factor in said inflation and you get $2,608,342,348,911.97 USD.

[@CharTheDude]

+Trinzilla Still, that's only about 3.5% of the world's annual GDP. Hell, that's an eighth of the USA's GDP. Point is, if we humans decided we wanted to do it, it's totally possible.

[@MrLittlelawyer]

+Trinzilla That is for the most massive/fast of the crafts. Furthermore, think about mining and the possible returns of suddenly being able to send not just one or two astronauts, but entire crews of 500-100 people, scientists, engineers, technicians, soldiers, workers, etc into space, and not just them but their equipment/labs.

[@racer927]

Who else is still a little shocked that KSP 2 will actually have the Orion drive? I still remember seeing some pre-alpha gameplay and went "is that a freaking ORION DRIVE?!"

[@omnomnomnom2939]

your telling me to fly safe? im gonna say that to you scott

[@GuitarJammer]

This is a really outstanding video! I've been reading Project Orion by George Dyson (Freeman Dyson's son), and you've done a great job covering the history and design features of the project. Got to love KSP for making these kinds of creations possible! What a great game, and fantastic video and commentary!

[@jkholtgreve]

There’s a documentary based on that research if you poke around KZbin featuring interviews with all the principals who were alive 20 years ago. As fun as it is ultimately sad and infuriating to hear all these old men wax poetic about the math and engineering and imagination that went into it.

[@GuitarJammer]

@@jkholtgreve Thanks for thé recommendation, I found the doc. After 7 years I suppose I’m due to re-up my research on the project.

[@DoNeeh]

I seen this on the National Geographic Channel Documentary Evacuate Earth They used Orion project to make them speed up almost a light speed!

[@DoNeeh]

I like that channel

[@Shadow77999]

***** an i

[@msbuinov926]

***** Indeed

[@axtmann]

I based my design degree work on Project Orion! Thanks for making this video Scott. Lots of fun. The KSP community never ceases to impress.

[@ObadiahtheSlim]

That nuclear powered plane was anything but flying safe.

[@OrionSX]

There was a really good book titled "Footfall" in which a Project Orion spacecraft was built out of necessity, after a hostile alien incursion. Might have a look at it, if you're curious. They discuss some of the intricacies of the design in it, as well as turn it into an impromptu weapon.

[@nathanschubert3048]

We are XKCD. We are legion.

[@GelatinousSSnake]

I just love how the explosion flare lights an entire Kerbin hemisfere lol

[@StarmuteVII]

Knights of XKCD invade!

[@BosonCollider]

On a side note, the list of weapons that the USAF planned to stick on their "battleship Orion" version is quite surreal. Basically, enough nukes to vaporize a continent, six hypersonic landing boats, a bunch of Casaba-Howitzers(much stonger version of the propulsion charges, designed for attacking enemy Orions), a dozen of turrets capable of firing the nukes from low orbit into a suborbital trajtectory, and more stuff that still isn't declassified yet. Result: immediate cancellation by JFK.

[@Heiryuu]

i feel as if this is something that would have been a fallout technology

[@KertaDrake]

Considering the vending machine aspect, I'd fully expect Nuka-Cola labeling on the bomb launcher.

[@tog3334]

6:00 the looks on the crew's faces is priceless, like they realize just how nuts their ship is.

[@KertaDrake]

Complete with random flashes of light in the portraits that aren't even occurring in all of them with each explosion... It's like a nuclear rave in the cockpit!

[@zacksstuff]

I did some math, and it turns out that if you could constantly maintain 1 G thrust for a year, you would reach the speed of light.

[@d2factotum]

Problem is, as you get closer to lightspeed mass dilation means it takes more energy to go faster--you wouldn't be able to maintain 1G. It would actually require an infinite amount of energy to accelerate any object with mass to lightspeed, but you could get pretty darned close.

[@EpochSecutor]

I really, really love how you've chosen the Orion project..

[@shokteenik]

I always thought they'd fire up the nuclear pulse rocket in orbit, not use it for the initial launch. That's just crazy.

[@namewarvergeben]

They probably would, but this is a videogame ;)

[@novasolarius8763]

No, the Orion was actually meant as a launch system. The way Scott used it is basically the way it was planned to be used IRL.

[@kellywilson-lawson1857]

+Nova Solarius a different design of the Orion was meant to use nukes to get into orbit but the final design would use conventional rockets to get into orbit where it would then use the nukes

[@novasolarius8763]

kelly wilson whitehead Well, that's lame.

[@aajjeee]

this would be way to heavy to get to orbit and it being worth it

[@Sean_735]

"In the atmosphere" We're talking about detonating nukes hundreds of kilometers above the atmosphere...

[@MegaAwesomeNick]

I guess in the case of imminent total planetary annihilation it would be a good design dust off and send a city sized generation ship to the nearest stars thus preserving humanity. OR better, you can go the "Sunshine" route and take all of those valuable nuclear bombs and throw them into the sun because it might help. I still don't get that movie.

[@rockspoon6528]

Far better to secure the galaxy's future by nuking every launch sight, and confining our plague to earth.

[@mikeysgametime8914]

In sunshine they take the nukes to start an artificial self sustaining fusion reaction becuz the sun has stopped

[@LarsaXL]

I love the last part, that plane is epic, scary and impractical, but still cool.

[@vKILLZ0NEv]

Has that landing strip always been there!?!?

[@yobeefjerky42]

yes

[@jerrycan1756]

Scott, Scott... the "Most Kerbal Vehicle Ever" award is limited only by the modding community.

[@tardigradegaming2132]

Hey Scott do u really awnser questions! WOW! Subscribed & Liked

[@scottmanley]

Yes I answer questions.

[@tardigradegaming2132]

Whoa thanks man! Pewdiepie probably doesnt have time to awnser questions!

[@michaelpapadopoulos6054]

scott have you heard of vsauce?

[@shibaplays]

Tardi Grade Gaming He replies to comments

[@MrGewoonDaan]

I can't easily think of a more spectacular way to get rid of nuclear weapons than this right here, make it happen!

[@andrehenchenski2310]

xkcd.com mention this video on the "what if" section on a question about jupter and submarines. (Just in case no one told you yet)

[@wolfmannn2008]

The double wings thing was ingenious :) So creative, so smart, I was amazed!

[@加州猫主席]

Anyone come here from What If?

[@Lutranereis]

I independently came up with this idea when I was in high school. I was taking a calculus class and we were discussing parabolic disks and how every point on the disk would sent a signal back to a specific point. I was immediately struck with the thought of a pressure wave hitting one of these plates causing it to move in a single direction. It wasn't much of a jump from there to nuclear bomb powered ships. Story of my life -- I independently invent things decades too late.

[@Unclevertitle]

1/3 Kerbonaut approved!

[@ZarPof]

15:10 when you ran out of RCS, you could have transfered it. But either way, good science and history lesson. And the way you freeball your course corrections, no plotting with the auto targeting computers, is rather impressive.

[@lunafoxfire]

So what you're saying is that RIGHT NOW we have the technology to launch a rocket the size of a small city to 10% of the speed of light. WHY ARE WE NOT DOING THIS?! HOLY CRAP WE COULD BE AT PROXIMA CENTAURI WITHIN 50 YEARS (actually probably longer than that because you'd have to accelerate and then slow down again but still).

[@TheBalefire]

LydianLights Because it would cost several trillion dollars, and irradiate the planet when it left....

[@TheRambo010]

LydianLights u really did not got what happens whe you use this in the atmosphere? Its like, if u have a fallout in ur city, at next day, every single person is DEAD

[@IAmTehEllie]

TheBalefire meh, radiatiion makes things more interesting anyway i want 3 heads!!

[@jdlessl]

LydianLights Because "nukes are bad!". In truth, the environmental consequences aren't great, but then neither is burning the downright toxic crap that chemical rockets use. Or, for that matter, coal power plants, which release enough uranium into the air that the potential fissionable energy thereof actually exceeds the energy you get from burning the coal. The warheads used would not be big city-buster types, but much smaller, so EMPs would be much less of an issue.

[@jdlessl]

TheBalefire No, the whole point is that pulsedrives are insanely _cheap_ compared to chemical rockets. And no, if the 2000+ nuclear test bombs detonated since 1945 haven't irradiated the planet, then this wouldn't either.

[@adammullarkey4996]

"...no, the most Kerbal vehicle award goes-" KZbin: Screw you, have an ad!

[@giaxo1739]

Hi from xkcd!

[@tehlastcenturion]

as far as I can tell by the recourses about the project put on the internet, this was indeed meant as a means of interplanetary flight meant to get their more quickly so that the time spent in space would be minimal, and it seems a very efficient means of doing that!

[@whiterottenrabbit]

And the pilots only slightly broke the airplane :D

[@bevvox]

Come to think of it, maybe we should use a magnetic pillow instead of a physical "pusher plate" to absorb and translate the energy, plasma, kinetic, etc. Much like the designs for a room temperature thermonuclear fusion, with superfluidic, superconductive barriers to protect the actual device/generator/container...

[@georgeevans9044]

Hail xkcd! View count as of now: 264,442. Lets see what happens.

[@Ink_25]

above 400,000 views at the moment

[@DiverseGamingLeague]

I actually did my senior year research paper on orion rockets!!

[@Hunter-we8ve]

"Fly safe"

[@SINDRIKARL1]

Yeah, he once mentioned that he's pushing that phrase as a joke XD At least for that specific video.

[@bevvox]

Funny thing you've mentioned the 15g specifically, that was the required upper limit for passing centrifugal tests the Soviet cosmonauts, they were forced to endure said stress while continuing to function(as opposed to Apollo era's US astronauts 13gs), explains why there were so few space goers back then, among other things... Like their short lifespans... After all most of them weren't preparing for this their whole lives, at least not to that extent that is, granted they all had excessive military training, but even so... As things stand now, as far as I know, currently virtually nobody is being trained to that rigorous extent

[@kit0134]

XKCD sent me here o.o

[@DoRC]

Iike how the nukes going off automatically set all the Kerbals faces to terrified the whole time

[@PixelGarett]

This was acually invented to travel light years. The propulsion will get you going about lightspeed in space. It was invented as a resource for another planet to live on incase we needed it, but the nearest solar system is lightyears away. With this idea they could build a massive massive spaceship that could travel the 6 lightyears in 100 years. It was basically a whole community inside a massive spaceship. They would have babies in space which they would have been able to see the new planet they could live on but there parents could not. This was not a stupid idea. If NASA had the money, they would without a doubt build this.

[@Edgewalker001]

A generation style colony ship. Yeah, it's not a bad idea, but you once again run into the spam in a can problem. People do not take well to being stuck inside a giant tin can for a hundred years.

[@PixelGarett]

***** Yes, but also it was a last resort, they would have to deal with it. They cant get out of it even if they wanted to.

[@tankmodeler]

GarageGamer, I'm sorry, but it was never designed to travel light years. It was designed, from the start, as a way to push a lot of mass into orbit and then to rapidly explore the solar system, getting to Saturn in 2-3 months. Interstellar travel was never iamgined as the systems to survive that long were not within the scope of the program. There is a great history of the program written by Freeman Dyson's son 8-10 eyars ago.

[@PixelGarett]

tankmodeler Okay thanks for the info! I watched a documentry on it also where it would use the exact same concept of the engine and build a colony in space, off of that idea, it would go and travel one light year in 16 years or so and the full 6 light years to get to the next solar system or the next closest star to hopefully to find another habbital planet to stay on and repopulate to create a new world, The Documenty is called The Orion Effect Its pretty amazing the stuff they talk about and the animations they do in it.

[@General12th]

TheGarageGamer98 Although tankmodeler is right in that the original Project Orion was never intended for interstellar travel, more thoughts on the subject came in the following decades. Project Daedalus is one example, although it was planned as a rapid flyby. Project Longshot would achieve an actual orbit around Alpha Centauri using even less hypothetical technology. Project Icarus would also achieve orbit, but in less time and with an entirely different drive system (so I don't really know why I'm listing it as an example). All in all, it seems that nuclear pulse propulsion *could* be scaled up to provide interstellar travel to humans. There's not really a maximum yield of the bombs used or a maximum size of the ship, so at some point, manned interstellar trips would be achievable. Such journeys would take several decades, though, so it might be a lot easier to popsiclize the crew. That would save weight on food, water, and living space; not to mention the original crew would enjoy the fruits of their sacrifices. I don't predict there will be many (if any) interstellar missions, manned or otherwise, launched this century. There will probably be some launched next century. Given the rapid advancement of medical and life-extending technology, it's not unlikely that both you and I will live to see them.

[@thetau12]

Megaton - TNT equivalent is a method of quantifying the energy released in explosions.so eg power relesed (blow up) by. 1 megaton nuke = 1 million tons of TNT

[@sicus0]

The prototype video with chemical explosives, Scott mentioned, can be watched here: kzbin.info/www/bejne/q4Kmo4OEetiEl7s

[@SonakaG]

close to the ending of the video, right when he is flying towards the island, you can see the kerbal on the left panicking, the kerbal in the middle panicking, and the kerbal on the right COMPLETELY HAPPY with smiles. I WAS LAUGHING at the sight of this.

[@will2dye4]

xkcd brought me here :)

[@nathanjqn1]

The retraction is the explosive force which pushes the spacecraft. It's expansion is not enough to stop the spacecraft either. It works trust Mr. Manley. Mod's pretty fun too.

[@AluVixapede]

Project put-put \o/

[@CuzicanAerospace]

If nobody mentioned this yet--KSP forum user TiktaalikDreaming (AKA Dogmatic Pyrrhonist) has created more parts to go with Nyrath's Orion drive, and I believe has also retextured the drive to make it more stockalike. (The IVAs are really nice--they reminded me of the rocket interior scenes in *Destination Moon*.) forum.kerbalspaceprogram.com/threads/112077-TD-Industries-Orion-bits-Alpha

[@johncarter3728]

Lose the unbypassable advertisements, KZbin. Downvoted.

[@scottmanley]

+John Carter You aren't getting hit by that AdBlock bug are you?

[@maxzero9647]

+John Carter Have you tried AdBlock Edge? It's a pretty decent fork!

[@pmcburn1]

+John Carter yes. How dare people monetize their own content.

[@johncarter3728]

What other recourse is left? Don't allow KZbin to run advertisements on your channel, if downvotes are an issue. I'll not be subjected to an involuntary waste of my time.

[@pmcburn1]

+John Carter Then watch another channel. The author has the right to monetize his content. You have the right to piss off.

[@bevvox]

For finer maneuvers we can always use more standard rcs thrusters, deployed then necessary, internally hidden for protection while under full speed

[@Edgewalker001]

"Likes to think big" Yeah, for a guy that proposed using all the mass in a solar system to build a shell around the system primary and then harness all the energy generated. That may be the most appropriate statement ever. Even though he then came up with the idea of a satellite cloud that could do more or less the same thing with much less mass used. And then Larry Niven came up with the Ringworld idea which is kind of the best of both worlds, but would require even crazier materials to work.

[@WinchellChung]

Yes, you are correct. Throttle from 1% to 30% make detonation interval every 1.5 seconds. 30% to 60% is every 1 second. 60% to 100% is every 0.8 second. So the 3.5MN bomb detonated every 0.8 second is 3.5 / 0.8 = 4.4MN thrust

[@johnmothershead1690]

Larry Niven and Jerry Pournelle used this concept in their novel Footfall (Del Rey Books, 1985). The basic plot is the old, old sci-fi standard: aliens show up in a big ship and invade Earth and we humans band together to get rid of them. In this case we secretly build an Orion vehicle in Bellingham harbor, named "Michael", and launch it into orbit to attack the Fithp mother ship, complete with all four Space Shuttle Orbiters strapped on the outside, with ETs, plus numerous nuclear missles and particle beam weapons powered by the propulsion bombs.

[@jessemckeown5628]

I'm impressed by how the pulses visibly illuminate night side kerbin.

[@BobzeMovie]

sound can travel through any material. As long as there is something there, sound can move through it, not just oxygen. So in the cockpit there would be sound from it travelling through the metal in the ship and through the helmet then through the ears.

[@tardigradegaming2132]

Hey Scott! 0:55 Now there is no gravity in Kerbins atmosphere! Woaw!

[@WarDaft]

I don't know if this has been mentioned, but the largest designs for project Orion had spacecraft weighing TEN MILLION tonnes, not eight thousand. The largest class of aircraft carriers never even reached a hundred thousand tonnes. We're talking about a ship that could lift an aircraft carrier and a *berth for it to float in* into space, and then take it anywhere in the solar system in a reasonable amount of time (or to another star if everyone involved is reeeally patient), without this even being a significant portion of it's cargo weight limit.

[@AbazeStudio]

"them we'll trim the orbit using the smaller nukes" I find this sentence incredibly ironic

[@MechMan0124]

High velocity plasma hitting the pusher plate provides the thrust. The projects physicists had designed micro-warheads that would produce a cigar-shaped jet of plasma directed at the pusher plate and out the back. No need for air to propagate the energy. Check out the book on Amazon if you're interested, it's a great read: "Project Orion: The True Story of the Atomic Spaceship by George Dyson". It goes into quite a bit of detail on the physics.

[@WinchellChung]

Yes, that is true. The smaller devices are so inefficient that not all the fissionable material in the bomb is consumed. The other source of fallout is dirt from the ground that is neutron activated. Using a launch pad of armor plate coated with graphite eliminates that fallout.

[@MegaTNTCreeper]

Correct. Sound waves can be transmitted through any particles, and they would in fact travel better through the craft.

[@greenlight2k]

18:18 "I call Shenanigans!" XD ---- gotta love this guy ;)

[@albatrossboss]

Scott Manley How does it feel to get linked to from XKCD as the most Kerbal vehicle ever built?

[@KoobztheShawk]

Using an extra set of wings to permanently pitch it "up" Gimbal Lock eat your heart out.

[@MusicVideoFun]

funny thing is this concept of nuclear powered rockets by bombs was a idea revealed to government but the gov. decided to classify it then several years latter leave it due to the no nuclear bombs treaty thing

[@WinchellChung]

The USAF 10 meter Orion the mod is based on made artificial gravity by being a "tumbling pigeon", rotating end over end. But there was a design that had rotating arms, which folded down flat for periods of acceleration.

[@Mazzinwx]

Coming from 'what-if xkcd' :) The concept of Nuclear-bomb-propelled spacecraft reminds me of the one from Dan Simmons' Ilium-Olympos books

[@HiroNguy]

Dude this is Bad Ass! Love the rapid fire nuclear blasts!

[@LarryPhischman]

Apparently Dyson and his team figured out how to make a relatively clean nuclear warhead, with an unusually efficient fission primary.

[@Tulio509]

"Fly safe", he says. After this video, it's one of the strongest examples of "Do what I say, don't do what I do"