Nuclear Thermal Rockets in Sci-Fi Spacecraft

#TheSojourn Season Two, Volume One - OUT NOW!
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Spacedock delves into nuclear thermal rockets in sci-fi spacecraft design.
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[@Spacedock]

#TheSojourn Season Two, Volume One - OUT NOW! www.thesojournaudiodrama.com/s02v01

[@TheArklyte]

Question: let's say you get an approval to make Voyager 2.0 with modern tech and mass budget of 5k tons(spread over modules of 200 ton max and yes, you need to include fuel into those 5k), what would it look like? Acceleration with NTER, sustained thrust with ions? What would be the equipment and tasks given to it? Let's say that 12 of them would be launched in 3D sphere pattern in all directions using gravity maneuvers around the Sun after they accelerate to a certain point and that a decade later a second set would be launched.

[@ericmadsen7470]

Thanks for the Nuclear science lesson.

[@silverjohn6037]

Has the channel ever done a video on the Aldrin Cycler concept?

[@DrBunnyMedicinal]

The two best bits: "spicy mode" and the X Files epilogue. 😆👏

[@A.Hanson]

I wish it were possible to actually buy Sojourn. I would love to have it on CD but I'm not spending real money to download something off the internet.

[@warmachine5835]

11:45 Jeb is just Built Different.

[@quentinking4351]

Literally, since he (and Val) are the only Kerbals with "Badass" checked as true.

[@electricminecrafter]

bro can survive 20,000 kelvin exaust but not a 10^2 meter fall

[@MrGhjkl63]

He vibin

[@Reoh0z]

Jeb survived a 74km space walk to reach the rescue vehicle. The rescue vehicle burned up on re-entry killing all aboard. I should have tried the 11km space walk but I thought I had enough fuel to do a better job. I did not, on either account.

[@stephen1r2]

Jeb is the Incredible Kulk. ...all of those Gamma Rays

[@Croz89]

I have a feeling "decommissioning" is probably going to involve dumping the whole reactor and engine assembly in a graveyard orbit and forgetting about it.

[@raverdeath100]

Jupiter's radiation belts would be a good place.

[@Croz89]

@@raverdeath100 May as well just lob it into the planet itself if you have the delta v to spare.

[@leon-ks9yn]

it would be cool to see what happens if we throw it to the sun

[@Croz89]

@@leon-ks9yn Pretty much nothing.

[@StrangeGamer859]

@@Croz89 And it takes a lot of delta-V to do it

[@ashero2092]

All my hundreds of hours playing Terra Invicta and staring at Drive charts paid off, because I've recognized every drive/fission type reactor.

[@chemplay866]

Do you prefer the good guys, the genocide guys, the nerds, the wallace breen wannabe, the conspiracy theorist pro-alien lady, the coward that wants to leave, or the capitalists?

[@TheArklyte]

The amount of sadness when the tech rolls end up not giving you either of final drives...

[@hunterpdx7061]

That's what I noticed too!

[@sonwig5186]

Should I give Terra Invicta another shot? The spaceship kind of stuff looks great but the grand strategy sucks so bad, I just wish I was playing a country rather than an organisation with no real power and not much agency.

[@ASlickNamedPimpback]

@@sonwig5186 if youve got the time to spare...

[@dariorthan8059]

Jeb has survived extra-vehicular reentry do you really think he gives a shit about such lowly things as nuclear exhaust?

[@fireshredder24]

NTR exhaust is moving way faster than Jeb upon re-entry. With an ISP of 800 seconds in vacuum, the LV-N Nerv puts out almost 8 km/s of exhaust velocity (though of course it's a vacuum engine and doesn't work at all at sea level). While your typical Kerbin re-entry is less than 4 km/s. (Which results in 4x the impact energy of each particle compared to Kerbin re-entry)

[@ThePCguy17]

@@fireshredder24 He has also, at times, used rocket exhaust as a stepstool to jump off of in order to perform a return journey from the mun to Kerbin...with no protective equipment save his space-suit and personal maneuvering thrusters. Something tells me this man is invincible, unless the Kraken has been recently summoned.

[@kludgedude]

Flying steam kettle

[@johnnydarling8021]

Henya the Space Poilet

[@granienasniadanie8322]

You really think only, because your in space means you can escape the steam engine?

[@aland7236]

Honestly dihydrogen monoxide must be the most versatile compound in the universe. That or humanity just seems to find a way to shoehorn it into the plan.

[@Talon19]

It always comes back to steam!

[@jon9021]

Let’s hope it doesn’t whistle!

[@knickohr01]

I just love how many KSP clips there are in this video

[@MrQuantumInc]

The NTR is the most popular rocket as it has double the efficiency but also decent thrust. The game illustrates its advantages pretty well.

[@UNSCPILOT]

Makes me wish KSP 2 hadn't been abandoned so early in it's development

[@jimmymcgoochie5363]

Worth mentioning: liquid hydrogen also has the twin benefits of being a) really cold (to cool the really hot rocket engine) and b) a nuclear moderator to boost the reaction rate in the reactor. More hydrogen flow = more reaction and also more cooling, which balances out to make it nice and throttleable with almost no changes to the reactor settings so more hydrogen in = more thrust out.

[@MrNicoJac]

Wut. But..... you literally just said.... Okay, so what happens when you want to decrease engine thrust? You decrease the hydrogen. This decreases the cooling. On an engine that's still Hella hot. Doesn't this Idea simply lead to an engine that can only ever go harder or stay the same, but can never be turned off?? 👀

[@man-from-2058]

​​@@MrNicoJacthe hydrogen also acts as a moderater which increases the rate of fissions, so decreasing the hydrogen along with inserting control rods would shutdown the reactor. Water would be an even better moderater than hydrogen.

[@hlynkacg9529]

​@MrNicoJac you shut down the reactor before you shut off the propellant flow.

[@annoyed707]

@@MrNicoJac Who would ever want to decrease thrust when you are destined for Infinity and Beyond!

[@MrNicoJac]

@@annoyed707 Hahaha Yeah, why stop at a place you can colonize (or at least refuel), if you could just zoom ever faster through sheer nothingness 😂

[@davidcolby167]

Fun fact: I've been writing a D&D in space setting whose entire premise is that it has a "standard fantasy" world that is forced into space due to a planetary catastrophe that destroys the biosphere - but they find a totally, 100% realistic solar system. Like, the most livable planet after their now destroyed home is a Martian icebox. After barely surviving in orbit for centuries using magic and advancing technology, someone invents a nuclear thermal rocket, combines it with the Decanter of Endless Water magical item, and boom, they have ships that can get just about anywhere. So, it's...a bit like the Expanse meets D&D!

[@weiwenng8096]

"Nonstop Chernobyl. Weapons-grade uranium." - Scott on the NSWR.

[@CTXSLPR]

Not a neutron moderator prison, it's a neutron poison or absorber prison. A moderator would just make things worse as it would push your neutron temperature down and make fission more likely.

[@derekp2674]

Well spotted - thanks.

[@hoojiwana]

You're right! - hoojiwana from Spacedock

[@TheTrueAdept]

If my time playing CoaDE is any indication, designing an NTR of any kind is a balancing act of immense proportions.

[@caliperstorm8343]

@@TheTrueAdept That’s only a problem if you’re doing it manually, like you have to in CoaDE. In real engineering you’d write a program in MATLAB or something to vary the inputs automatically and find the best configuration. Basically the same thing you do for interplanetary transfers with porkchop plots.

[@derekp2674]

@@TheTrueAdept In the 1950s, thermal reactors for nuclear powered aircraft were researched. The work I've read about used Beryllium Oxide moderation and then used atmospheric air as the coolant and propulsion gas. At least one episode of Gerry Anderson's Thunderbirds features a nuclear powered airliner.

[@DoubleG-l3b]

my favourite real life nuclear method of space travel was the early plans to drop nuclear bombs under a craft with a massive lead shield to the craft would ''bounce'' up off the ground then ''bounce'' further up on top more and more small nuclear bombs detonated under it. its insane to think it was genuinely considered as a form of early ascension into orbit

[@Techno_Idioto]

They did an episode on the Orion Drive, go check it out!

[@RorikH]

Ah yes, the "Morph Ball Bomb" technique.

[@carloshenriquezimmer7543]

basically a "DRY" nuclear salt water rocket

[@GabbieTheFox]

Oh god. Not Project Orion again. XD

[@TheWarmachine375]

In Universal Century of Mobile Suit Gundam, the nuclear thermal rockets were fueled by Minovsky Fusion Reactor filled with Helium-3 that produced Minovsky Particles which disrupts communication and scrambled targeting systems.

[@crashstudi0s]

Sounds cool, but whats that minovsky particle?

[@AngemonOfLight]

@@crashstudi0sA fictional particle in the Gundam series. Generated by fusion reactors in the series, the M-particles had new several side effects and applications. The most notable is the jamming of telecommunications.

[@federationprime]

@@AngemonOfLightthus, the return to mk1 human eyeball combat distances we see in early UC

[@Kestrel-ws3cg]

⁠@@AngemonOfLightThe M-particle has a side effect of existing being an EM field and the denser the M-particle is in an area the stronger the em field gets to a point where the only method of comms is light signals or more commonly laser comms

[@lancerhalsey4816]

Actually the main puropse of Minovsky Particle is to act as a fusion booster, like a muon that won't fizzle out instantly. The "Fuck your EW capacity" is mainly a side effect.

[@Garwinium]

1:26 *HANK! DON’T ABBREVIATE NUCLEAR THERMAL ROCKET ENGINE! HANK!*

[@matthewconnor5483]

NSWR is my favorite idea for a nuclear rocket and seems like the perfect concept for a deep space vehicle.

[@rfletch62]

The nuke / salt water rocket sounds like the Queller drive from "Space 1999". So bad it's inventor had to go into hiding like a war criminal.

[@RorikH]

No no, nothing so fanciful. It's more like riding a plume of Godzilla's breath.

[@torg2126]

And it's a reasionable torch drive, so we can get to interesting places within human liftime, instead of tortus lifetimes.

[@UGNAvalon]

@RorikH Thanks for reminding me of that one time Godzilla flew backwards using his own atomic breath as propulsion. 😂

[@realitypoet]

Another advantage of having a fission reactor onboard is you can use the high energy photons to recrystalize your dilithium!

[@Inglonias]

There's a plan to fly one of these pretty soon! It's a mission called DRACO: Demonstration Rocket for Agile Cislunar Operations

[@ComradePhoenix]

This was literally shown in the video.

[@ckl9390]

Ah, the snazzy acronym. The most important part of any space program, project, or mission. Because, otherwise, the "important" people who only ever read the cover letter won't sign off on the funding.

[@corporategunner5972]

Boy, I sure like this concept of NTR. I heard Japan likes to use them in their manga. Lemme just che-

[@the-letter_s]

reminds me of CBT. Cognitive Behavioural Therapy.

[@jacobbronsky464]

Play Rings of Saturn people. It's basically Nuclear Thermal Propulsion: the game.

[@jexiagalleta4712]

looking for this comment praise the round one

[@gorzonthechampion6784]

Please make a video covering the Honorverse.

[@nicholaswalsh4462]

I SECOND THE MOTION! Let it now be put to the question.

[@9Firedrake9]

It would be extremely cool

[@whitenekoknight6035]

Super Please!

[@zeux5583]

​@@nicholaswalsh4462 i third this motion!

[@greenhomes8843]

Fantastic idea

[@Attaxalotl]

I'm so glad you mentioned the NSWR; it's the Casaba-Howitzer of engines!

[@anonymouse...]

I will be stationed in a space warship one day mark my words

[@nobody8717]

i'm not sure that putting a corpse on a ship counts as "being stationed" on it.

[@remliqa]

Is that reference I missed? I doubt anyone alive today will ever be in a space warship at any time in the future.

[@MichaelWinter-ss6lx]

I sense a change in the near future. L👀k how well China is doing. India now taking consequances out of NASA's unreliability. But you just can't leave the paranoid Americans out of the equation. And ESA still pretending Europe the 51st state; not sure if even will be remembered by privat space corporations. Very much can happen within only 30 years. In two years we will see at least two nuke motor demonstrations in orbit. That will be the starting point. 400 years till we are ready for the stars. 🚀🏴‍☠️🎸

[@CodyLundberg]

If I don't die fighting pirates in the asteroid belt while filled with pig organs, was life really worth living?

[@martinjrgensen8234]

The pathfinder shuttle is fantastic

[@akiramasashi9317]

1:14 actual video start.

[@jaredray7034]

I don’t know about you guys, but if you’re already risking your neck by going into space, flying between planets, and using the nuclear propulsion, you might as well embrace the cool factor of riding a CONTINUOUS NUCLEAR EXPLOSION.

[@casbot71]

Ah footage from the movie *Lifeforce.* My mother thought it was classic British sci fi like Dr Who or Quartermass so _she took me to see it at the cinema_ when I was 13... For those that haven't seen it the lead *Space Vampire* is played by a _18 year old French actress_ who was *fully nude* for 90% of her screen time (the other 10% was in see through robes that hid very little). And a lot of it was full frontal. So while watching the film I was hugging my knees to my chest, but not out of fear. The McDonalds afterwards was eaten in silence. There exists levels of awkwardness you cannot even comprehend.

[@chid2196]

man I would so love a sojourn tabletop ship game.

[@bjboss1119]

I'm still waiting on a Battleship game that's more like Flames of war or WH40K in gameplay style, rather than alphabet practice.

[@intrynzyk]

NTR lol Yes, I'm 12 But also, it does kind of annoy and baffle me that we are willing to take massive risks with other technologies with no concern about what they might do to society or the environment, but nuclear power is apparently just off the table.

[@carboneagle]

Big green doesn't want competition.

[@HobnailJohn]

The nuclear salt water engine has to be one of my favorite insane but still theoretically possible engine designs.

[@DX47-h3z]

"to stop it from going Spicy Mode" Interesting choice of words.

[@salixalba6536]

NTR means something else entirely to the internet

[@HitodamaKyrie]

Power up the Cuck Drive.

[@ButterflyD3fect]

I... should probably not google it I presume.

[@playyourturntodieatvgperson]

one time i was talking on discord about nuclear thermal rockets then someone said WHY DID YOU HAVE TO BRING CUCKOLDING IN JAPAN INTO THIS and thats how i learned of the other meaning

[@tomoe6108]

"Nuclear Thermal Rockets (NTR) are an incredible technology which bypasses one of the fundamental rules of the universe. To learn more, search 'NTR Rule 34'"

[@SportyMabamba]

Welcome to all the members of Today’s 10,000 who are finding out about the Japanese kind of NTR for the first time 🎉

[@Versudan]

Technically, you could decommission nuclear engines in a "special facility" known as the Sun. Just pointing out the option there. 😅

[@RorikH]

I think per the laws of orbital momentum it's actually easier to hurl them all the way out of the solar system than into the sun.

[@Versudan]

@@RorikH That also works.

[@RorikH]

@@Versudan And if it doesn't, then at least it's far enough away that it's not your problem anymore.

[@The_Viscount]

I am so happy you mentioned Nuclear Salt Water rockets. I love the nutty things.

[@dangernoodle235]

Modded Kerbal Space Program my beloved

[@FergorH]

I'm surprised Gundam didn't show up at all in this video in particular when compared to all the others where we got clips from the franchise, since 90% of the Mobile Suits (Mechs) and the ships use thermonuclear rocket engines as their main method of propulsion.

[@jessicam.4061]

I know the MS-09 Dom uses thermonuclear JET engines, but I was under the impression that most mobile suits and ships used some kind of conventional liquid propellant? Given most settings feature some kind of nuclear fusion powerplants, surely they're some kind of electrothermal or electromagnetic rocket instead? It seems incredibly wasteful to rig up a fission engine (or five), go to the trouble of providing adequate shielding and heat dissipation when... You can just use the onboard power source instead. It WOULD go towards explaining the absolutely massive propellant tanks on the Rewloola class, on the other hand.

[@FergorH]

@@jessicam.4061 They do use liquid propellant, mostly hear it is hydrogen, but I could swear I read somewhere they used propane or something similar, can't remember where, but hydrogen makes more sense anyways. Either way, it is still thermonuclear rockets, that's what's written in a all the lore books, they already got all that heat from the fusion reactor, might as well use it. Though I wouldn't rule out some magnetic confinement from the nozzles, especially on the later generation MS.

[@padawanmage71]

I remember the 'Queller Drive' from Space: 1999. It somehow achieved high speeds by spewing out 'fast neutrons' out the back, so it does sound like something similar to a nuclear rocket.

[@jonskowitz]

I think the Salt-water rocket is the only option where refuelling operations and storage are more terrifying than the rocket itself 🤣

[@schadowsshade7870]

Yes YEEEES I Need This Video! Let me consuuuuuume it 😲

[@SpottedHares]

Theirs something missed about the advantages of high temperature. using the far more abutment and stable U238 as fuel. At very high temperature the neutrons have so much more energy that when they are absorbed by the U238 they undergo fission rather then the normal 239 decay chain. you can kind of get around the radioactive and unstable fuel and since U238 is so good at absorbing neutrons at lower energy levels it helps keep they pesky partials under control.

[@mickeyhage]

The Nuclear Salt Water Rockets is my favorite.

[@mahatmarandy5977]

I have always wondered if the additional weight of the reactor core and such shielding as you have offsets the advantage of not having to have an oxidant. I suppose there is some combination of elements where you would definitely get more than enough power to offset that, but from what I know of the NERVA test, I am under the impression they did not reach that point. Another concern I have always had is that the NERVAs were always kept in an excited state, just barely shy of melting down. That’s not a huge problem when you’ve got just one engine, but if you’ve got three of them strapped together like in all of the early NERVA mars rocket designs, the neutrons escaping from each individuals stage are gonna hit the Coors from the other two stages because as you pointed out, there’s really only shielding on the front end, not on the sides. So I have always wondered if having clusters bundled together like that would automatically make them meltdown. Which obviously is not the same as if nuclear reactor melts down on earth, I’m not nearly as dangerous, they are in space after all, but I still wonder. On the bright side, though, getting rid of irradiated spent nuclear thermal engines is really not a problem. Just hook up a new fuel tank to them, and let them use whatever is left of their core to propel the dangerous engine off into interstellar space. Cake!

[@electricminecrafter]

moral of the story... jeb is invincible

[@SomeoneNamedTygget]

Funny that the thumbnail for this video about nuclear thermal rockets is of a spacecraft with methalox engines. Funnier still that there were two other spacecraft in the season of television that spacecraft is from and both of those other spacecraft used nuclear thermal rockets.

[@Imaboss8ball]

What show

[@SomeoneNamedTygget]

@@Imaboss8ball Pheonix from For All Mankind

[@hmr200subs]

Has the thumbnail changed? It's Nuclear Pathfinder currently

[@peteradvisers2684]

All my homies hate antinuclear NIMBY, they robbed us of the spicy rockets.

[@chrisbingley]

They robbed us of a lot of things.

[@enisra_bowman]

how about that: you convince them to build a nuclear storage facility under your houses and you can get your spicy rocket

[@peteradvisers2684]

@@enisra_bowman I would absolutely be okay with that. I’m an engineer too so I got to work near home.

[@deanlawson6880]

Wow! What a great video on the various and sundry different varieties of Nuclear Thermal propulsion systems! I completely agree that these are the near-term next step as we advance out of chemical propulsion to something faster and better to get us around our Solar System. I continue to believe that a little longer term solution is the Pulsar Fusion developed Fusion Plasma Torch drive - This will be an awesome propulsion system until we can someday advance to using antimatter based propulsion like our favorite Sci-Fi series uses!!

[@joaomiguelmoreira6363]

Hell yeah, the all and be all of my Duna trips

[@ruedigerleibrandt8394]

That Kerbals face expression is priceless!

[@excell211]

Thermonuclear propulsion makes me wonder why they don't use Laser Propulsion, you use the nuclear reactor to power up the laser to accelerate the gas thermally. This way you can use it in atmosphere and in space as a evaporative cooling and propulsion hybrid. Guys, I meant an electric laser powered by a nuclear reactor, not a laser directy powered by the radiation/explosion.

[@MrNicoJac]

Correct me if I'm wrong, but: When doing anything nuclear, you're essentially _also_ yeeting out the "laser" parts. If you're using a laser, that mass/energy remains unused. So that's why the laser is less efficient, and therefore not used. (also, when talking about nuclear, a little mass "evaporating" yield a LOT of energy, and that's a dynamic you're not tapping into with a laser) Keen to read your thoughts about all the above :)

[@Tuning3434]

more mass, more energy conversion steps, less efficiency. Sure, going nuclear is prob. best to run the lasers on, but chemical rockets have the advantage that they do no need a laser to do the explody and acceleration bit by explody heating. It would make the nuclear rocket part considerably worse, and I wonder how much efficiency gain is achievable considering how much thrust become a factor in draggy atmosphere.

[@henryfleischer404]

That kind of propulsion would require very large radiators.

[@goiterlanternbase]

Laser suck in energy efficiency. Even LED emitters suck against any steam engine.

[@Talon19]

@@goiterlanternbase Why does it always come back to steam!??

[@johnathan651]

Ironically, I think nuclear-thermal rockets are the coolest idea for an interplanetary vessel we could actually build today (technology-wise). The engines they tested worked, it was nuclear test bans that got in the way.

[@ConnorAustin]

It’s nice to see someone covering these in a non sarcastic manner or a mocking tone

[@lurkingllama8364]

Hearing you guys mention the Nuclear Lightbulb made me smile. Like for you!

[@NestorKYAT]

Ha, just finished watching For All Mankind less than a week ago. It was nice to see the thumbnail

[@philrm99]

Excellent explanation.

[@Eragon7331]

Not needing to shield space is only valid for empty space. If you have these things running in the upper atmosphere, you're probably going to wipe out quite a few satellites. On the bright side, we would be able to have polar lights over Central Europe once again. You lose some, you win some. 🤷‍♂

[@nobody8717]

it's less about the lights from the satellites, and more about the fact that you cannot walk 30 feet without a streetlamp. try going to the wh keck observatory sometime, and you'll instantly see the difference.

[@Zacho5]

The inverse square law means the unshielded reactor wont effect stuff past like 1km.

[@MichaelWinter-ss6lx]

Hey, children;•) must I remind you of the cosmic radiation? A dirty little fission reactor is nothing. And still it needs more protection against Coronal Mass Ejection. And NO: a mask will do no good.

[@lordilluminati5836]

Love the everspace music. Use more of it in the fiture too!

[@ludflight]

There’s a game called Retrograde Legends that has NTRs and orbital mechanics. It’s not out yet but its pretty cool

[@ckl9390]

The Radio Isotope Rocket (3:20) may be adequately suited to a long-haul engine that is meant to run continuously, such as a colony ship to a nearby system or placing more massive assets in the outer solar system. It is made-to-order, bolted onto a ready-to-go payload before it gets too hot, and when it runs out and is just warm instead of hot it can become a thermal generator for the ship or station. An afterburner could also be used in this one, similar to the liquid oxygen injection for the hotter engines, except the liquid oxygen isn't just heavier mass particles to heat up and propel but to get some bonus chemical energy for thrust from burning the hydrogen.

[@saturnv2419]

Chernobyl really changed our perception of nuclear energy that would take decades to recover.

[@byron2FZ]

A video on the concerns of Damage Control aboard a spacebound ship or station could be cool

[@MrChupacabra555]

As stupid (and Fun, in a 'turn your brain off' kind of way 😅)as "Life Force" was, I did love that 'long range space shuttle' sequence at the beginning, both the shuttle itself, and the 'Giger-esque' Alien Spaceship in the comet.

[@TheTrueAdept]

The thing about hydrogen is that it's a horrid propellant. You're better off using methane or decade than hydrogen if you're stuck using solid-core NTRs. If you're using gas-core NTRs (or better yet, fusion or antimatter rockets), then water is your best bet.

[@danwall3102]

Depends on whether you're going for higher thrust or higher efficiency... For high thrust, you're correct.

[@TheTrueAdept]

@@danwall3102 for a combat ship? High thrust is a must.

[@danwall3102]

@@TheTrueAdept True.

[@byron2FZ]

It would be cool to see a video on methods of surviving the extreme acceleration that some of the propulsion methods you have talked about would cause.

[@taiko1237]

Minor correction - we definitely don't have the technology to build most sorts of gascore nuclear thermal rocket. Certainly not a nuclear lightbulb. But yes, solid and maybe liquid core NTRs are fairly doable and (iirc) NASA actually wants to test a solid core in space by 2030.

[@Perrirodan1]

Why, what is the issue about maintaining some kind of vortex it easy no? lol If the vortex is off, just a little meltdown

[@taiko1237]

@@Perrirodan1 The vortex method probably doesn't work all that well iirc. As for 'just a little meltdown', more like 'all that extremely expensive nuclear fuel flies out the nozzle or melts the reactor walls and you're shit out of luck'.

[@Perrirodan1]

@taiko1237 And everyone will glow a bit, actually they exhaust super radioactive material constantly, I'm not sure those can be made safe ever, a shadow shield wouldn't be enough what material will resist the corrosion and radiation?

[@taiko1237]

@@Perrirodan1 Shadow shield would work fine, so long as you were behind the shadow and it was thick enough, and interplanetary space is empty enough that the radioactive exhaust wouldn't be a massive problem (although using an open cycle gas core near anything you didn't want getting irradiated would be just as bad of an idea as doing that with any nuclear rocket). The main problem with gas cores is confinement.

[@Vinemaple]

More than i currently wanted to know about nuclear rockets that aren't Project ORION, but I will definitely need all this info someday if I ever go back to hard SF fiction! I'm also amused to know that Professor Calculus's moon rocket could actually have been built.

[@tymek200101]

decomissioning: yeet it into a

[@nobody8717]

if you want to pay enough to push that engine 18-30km/s in the opposite direction of your craft, feel free. and that's just to deorbit it from near earth. I'd rather just drop it and use that same amount of fuel to go to jupiter, or uranus.

[@Bean-boi]

SPACEDOCK! MAKE A VIDEO ABOUT TORCH DRIVES OR SPACE TETHERS, AND MY LIFE IS YOURS!

[@jacobwei]

The last one is literally the same concept as regular rockets but difference is that if it go boom (which it is much more likely to) it just becomes a nuke. Though the high thrust and efficiency is perfect for military use

[@petersmythe6462]

Endurance matters a lot better because you're either gonna be missile jousting or missile slinging from standoff range and either way you need to be getting kilometers per second burns to actually defeat missiles.

[@einknxck4277]

We need to see a full on space battle of the sojourn

[@viktoriaalden3452]

I love the pathfinder from FAM, but lighting the nerva up in atmosphere is just insane. And it's especially weird because it does have two more engines that looks kinda like OMS pods. Wouldn't it make more sense to use those for atmospheric flight, and the nerva for orbital burns?

[@SpottedHares]

Maybe putting things that don't need to be protected from radiation like extra flue storage in bwetween you and the rocket would save on some mass, though the effeteness dose drop off as fuel is burned.

[@dsmiley53]

Hey for future content, the game Delta-V Rings of Saturn also uses nuclear thermal rockets for an Expanse-like near-future setting.

[@smimoma5930]

I'm pretty sure the spacecraft in the Thumbnail is powered by Methane engines in the show Edit: It's fixed now🙂

[@bigsarge2085]

Interesting!

[@the_kraken6549]

This vaguely resembles an open-cycle thermal management system in the sense that it’s putting heat into a liquid & then chucking it overboard. It’s just optimized for thrust instead.

[@theworkshopwhisperer.5902]

What about project orion aka the atomic pogo stick? While not technically a thermal rocket it is still atomic propulsion in space and should have gotten an honourable mention. (Spacedock already did a video on this if you're interested.)

[@cookiejarvis3856]

I would love seeing the different types of fusion engines or fusion reactors. Terra-Invicta has many engine and reactor types.

[@50043211]

This all sounds like to have a rendezvous with death.

[@britishneko3906]

so an NTER is basically a nuclear powered water steam railgun.... I love it

[@Alexandragon1]

Thx for the video!

[@ssdrbx6180]

another trade-off alternative is to use hydrazine/anomia/High-test peroxide as fuel instead, it halves the isp but x10 the thrust, also much more dense than hydrogen and doesn't need sophisticated fuel cooling system which can reduce dry mass

[@StupitVoltMain]

We are leaving Kerbin with that one 🗣️

[@casualsleepingdragon8501]

It would be interesting if you could induce trust wiþout need an exhaust.

[@bmouch1018]

Each video from Spacedock has me thinking they need to start using visuals from Children of a Dead Earth in their technical videos because NTRs are the main engine choice for warships in that game and you find pretty quick that methane is the most optimal fuel for a warship using NTRs made with present tech.

[@Jacen32272]

I would think the solution to engines producing radioactive exhaust would be simple: use chemical rockets to get into space and nuclear ones facing away from Earth once out there. This would have the radioactive materials moving away from the crew at all times while providing extended thrust towards the target destination.

[@TheSaneHatter]

One sub-topic worth addressing is how many of these designs are dependent on today's conventional, uranium-/plutonium-based fission (with its long history, but also its ties to the making of weapons), and how many could be sued with the newer, supposedly cleaner, thorium-based technologies that have been proposed. The choice could mean that space travel could well decided the future of nuclear power, depending on which is favored.

[@ComradePhoenix]

2:25 You know, I woke up this morning, never thinking I'd see such a cursed nuclear space shuttle design. And now here we are. Why? How? WHY?!

[@OpreanMircea]

I love this subject

[@sim.frischh9781]

"NTR" is a REALLY bad abreviation for the Nuclear Thermal Rocket... there is already another meaning for that.

[@thatnbaguy6473]

me when ksp mentioned :3

[@fjvmunsterman]

There is actually a more recent re-design of Zubrin's Nuclear Salt Water Rocket, namely the Lithium Salt Water Rocket (also known as the Lithium-6 deuteride rocket) by a friend of Zubrin called William Mook. It has most of the positives, but none of the negatives. A trip to the moon would take about 2 hours and 45 minutes, a trip to Mars just over 3 days, and a trip to Jupiter would take just over 7 days ! Plus, with the speeds a spacecraft reaches with this engine, would give it an onboard artificial gravity of between 0,45 g, all the way up to 1 g (not unlike what we saw in The Expanse tv series !) As the saying would go:"now we're getting somewhere !" Someone call Elon Musk ?

[@NonsenseFabricator]

11:45 - Conan O'Brien on Hot Ones

[@Allan_aka_RocKITEman]

Great video...👍

[@adamshafeeq8685]

Can you do a video on designations in sci-fi? This is something that has been confusing me for a while. Anytime i watch anything explaining ships, weapons, vehicles, etc, the one question that comes to mind is "wtf do any of those numbers and letters even mean?"

[@LikeTheBuffalo]

Kerbal Prime has been found! All Glory to Kerbal Prime!

[@TheArklyte]

Question: let's say you get an approval to make Voyager 2.0 with modern tech and mass budget of 5k tons(spread over modules of 200 ton max and yes, you need to include fuel into those 5k), what would it look like? Acceleration with NTER, sustained thrust with ions? What would be the equipment and tasks given to it? Let's say that 12 of them would be launched in 3D sphere pattern in all directions using gravity maneuvers around the Sun after they accelerate to a certain point and that a decade later a second set would be launched.

[@DecidedlyNinja]

Probably nuclear-electric propulsion. If you're going that far, you have plenty of time to accelerate so low thrust is less of a problem. I wonder what scientists would do with the payload capacity of even one 5,000 ton probe. That's worth a lot of instruments..

[@TheArklyte]

@@DecidedlyNinja that's why I was asking as it's more of a question what one would do with that. And mind you, majority of mass likely would be fuel and support systems.

[@adken77]

I will forever be disappointed that the nuclear salt water rocket isn't called the Chernobyl Drive

[@kkrolik2106]

I like NSWR perfect for deep space ships only restriction cannot go to orbit any object that human wants walk on ;) Also need to keep in mind that engine plume do not get in direction such object. Can be safely use inside Solar system due solar wind will blow out plumes outside.

[@HappilyHomicidalHooligan]

10:50 Wait, [insert Hypersonic Record Scratch here] WHAT??? Someone actually figured out how to make a SANE, Controllable Orion Drive??? More importantly, one we might actually be able to build with current Technology??? Holy 💩!!! 😄😁😆😅😂🤣