I think there a few slightly misunderstandings about how the Orion Drive works, as described in the video. Your typical fission reaction produces about 5% of the energy in the form of neutrons and gamma rays, and 95% of the energy is released in the form of those two charged nuclei fragments when the atom splits. So most of the energy is almost immediately absorbed by the bomb itself, which then heats up to incredible temperatures, in the range of millions of degrees. When things get this hot, they produce massive amounts of x-rays. The bombs used by Orion drives are euphemistically called pulse units. And they have a special design. It contain components to reflect and absorb the x-ray flash, just before they themselves get blown up, and they redirect and focus the energy into a solid flat plate of tungsten, which absorbs the x-rays and is used as propellant. IIRC, over 80% of the bomb's energy is absorbed and redirected into a narrow cone, and thus accelerating a cone of vaporized tungsten plasma that is focused straight on the pusher plate. The pulse units are essentially nuclear shaped charges, they are not omnidirectional. That beam of tungsten plasma is relatively cold, in the range of 100,000 degrees centigrade. The plasma is hitting the pusher plate at like 150 kilometers per second. And kinda like a hammer striking the anvil, really. It strikes the pusher plate, pushing it forward, which, through the action of shock absorbers push the rest of the ship, at a survivable acceleration. And the plasma doesn't completely vaporize the pusher plate because the interaction between the mildly hot plasma and the plate is really short and not much heat can be transfered between the two. Oil would also be sprayed on the surface of the plate before each detonation, to provide a buffer to significantly reduce the rate of ablation. The important thing, it's matter, hitting matter, that creates thrust, not the gamma flux from the bomb.
pero hay una forma de dirigir la detonación de la bomba, en este caso es necesario que sea de fusión ósea hidrogeno que de por si permite un impulso especifico MUY ALTO, la idea es hacer una detonación laser, seria un pulso laser disparado hacia la bomba, el pulso láser se enfocaría con una lente en un punto diminuto de esa manera hacemos que el hidrógeno alcance temperaturas suficientes para la fusión en una fracción de segundo, en este caso el cañón láser estaría detrás del lanzador de las bombas (entonces lo que uno realmente llamaría una bomba sería simplemente un pequeño tanque lleno de hidrógeno líquido, entonces el verdadero nombre sería carga explosiva ya que el detonador, el láser es parte del motor) por lo que en sí mismo le daría una seguridad inherente al motor, y cómo dirigimos la explosión, el tanque de hidrógeno líquido tendría forma de cono (la punta apuntaría hacia nada , la parte más gruesa hacia la placa) con un agujero en el medio que sería donde el láser pasaría hasta llegar a la punta del cono y haciendo que la detonación vaya desde la punta hacia la parte más gruesa generando un efecto de propulsión dirigiendo la detonación hacia la placa propulsora, alrededor del 80% de la fuerza de detonación estaría dirigida hacia la placa dándole una eficiencia muy alta además de una seguridad que (en mi opinión) seria mayor que la de un cohete químico que tiene el combustible y el oxidante prácticamente juntos mientras que mi versión Orión solo tiene tanques en forma de cono llenos de HL , que si se rompe no pasaría nada
I've heard a few others say they got the impression I was treating Orion principally as a photon rocket, so I am wondering if on some bad phrasing or editing that got unclear [so much got chopped], and at least one of those bits was more on why antimatter drives are essentially photon rockets or how Orion works well in conjunction with laser pushers from home, but I thought I was pretty clear about explaining what photon rockets were and what the main original Orion system was not, though again the focus for today was on new approaches folks suggest and why or when they would or wouldn't work.
@@isaacarthurSFIA The USA did some research and the USSR worked on development nuclear reactor jet/rocket engine for long range bombers. I am in favor of high density thermite for engine fuel. Iron, oxygen, and zinc is easier to process and access in space then uranium is to process.
I always loved the idea of project Orion. We have a bunch of nukes we can just use to fly to another world. A good use of a powerful weapon. Not a lot of sci-fi stories use it. Of course in a story of humans coming to an alien planet and in conflict with the dominant species, having one of them say "they have a human bomb from your engine" would be pretty terrifying assuming you could understand them.
I can’t wait for this! I have dreamt about the possibilities abandoned in the Orion nuclear spacecraft project for decades, and loved when Neal Stephenson used the method to move his multiverse-traveling ship. The Pusher Plate; Jules Verne first thought of one when he shot the members of the Baltimore Gun Club to the moon through a cannon!
It's some 10+ years since I read Anathem, but wasn't the ship pyramid shaped as well? Would love to see the tinfoil hat people try to process that sight...
might be an attractive option if we clutter up space too much and need to blast a hole through the debris, people would be less touchy about nukes in space
We had a nuclear powered plane over 50 years ago and our largest subs have all been nuclear powered for years. Logic says we should have nuclear powered spaceships. Maybe we do....
@@friendlyone2706 Lol, cool idea for fiction but very unlikely since any orbital launch is not exactly a quiet affair and even the most cutting edge experimental reactor designs would require rockets in the super heavy category (ala Saturn V) to deploy. I'm comfortable asserting that the closest to nuclear powered spacecraft we've ever gotten is RTG powered probes. The only way to covertly pull off something like this is to launch it piece meal on the back of many otherwise normal launches and assemble it in orbit but such a craft would be enormous and easily visible from the ground. It would also require sending the fissionable material in one of those missions, an incredibly risky affair both ecologically and politically that would violate international treaties and embolden every other side to begin to openly experiment with their own atomic powered craft.
Took my girlfriend home yesterday and brought her back at 2am last night just so we could watch this come out together 💕 thank you so much for your wonderful channel, Isaac.
Wow! I love my wife of over 25 years dearly. But the idea that she would ever show even the slightest interest in such things is beyond impossible to hope for! Cherish this one Matthew, I guarantee you won't find another like her.
@@charlesjmouse man, I think I’m gonna marry her - it’s been 3 years and she’s the love of my life. I just don’t know how to ask her 😂😂 I’ve never done this before!
Issac, I'm 20 minutes in, and it seems like you're unaware that Project Orion developed nuclear shaped charges. Yes, we've had the ability to direct the output of nuclear bombs in particular directions since the 1960's. I think this is covered in Freeman Dyson's son's books. (If you know how a hydrogen bomb works, and how shaped charges work, it's easy to see the basic principle of how this is done.) Parts of this are still classified, but it was crucial to increasing the efficiency of Project Orion drives.
Ah, _this_ . I was quite disappointed he didn't mention the shaped charge pulse units intended to go with the dual-shock pusher plate design shown in most animations. Little nuke in a DU casing to reflect x-rays, hole in the top leading to a conical channel of beryllium oxide to turn the x-rays to heat, and a disk of tungsten atop to be converted into a disk extremely angry rapidly moving tungsten gas aimed for the pusher plate, allowing nearly 85% of the blast energy to be used for propulsion. Sadly, this omission also denied us a brief aside on the related Casaba Howitzer shaped nuclear charge weapon system, which focuses a blast similarly but with a much longer focal length and no beryllium oxide or tungsten to temper the atomic inferno, resulting in a kilometers-long spear of nuclear fire and the early sci-fi "particle lance" family of weaponry.
@@Archgeek0 Issac could probably do an entire episode on the effect of the existence of such weapons on Sci-fi movie plots! It basically invalidates most Kaiju.
Too much got cut from the script in its gajillion iterations I think, its probably why I was openly bemoaning it in the coda when we cut stuff all the time and I normally don't feel a need to dwell on it at the end of the episode. I kinda felt like the discussion of project Excalibur gets to nuclear shaped charges well enough though, this is what a bomb-pumped laser typically is. I'm not quite sure how explicit mention of vaporizing material got left out as part of the core design but but we definitely do discuss vaporizing material off that pusher plate for added push.
@@isaacarthurSFIA "I kinda felt like the discussion of project Excalibur gets to nuclear shaped charges well enough though, this is what a bomb-pumped laser typically is." -- True. But the impact of those words on those to whom the concept is completely new is awesome in that literal sense: "Nuclear shaped charges!" I'm sure another warfare related episode will come up though.
@@stcredzero :) Probably true, they do sound cool. I think I suggested their use for search and rescue before but if not, there's always another episode another day
Since you are doing Orion drive, please do a deep dive into Zubrin's Nuclear Salt Water Rocket. You could also interview Zubrin, he is quite reachable for interviews. He is both a Nuclear and Aerospace engineer. 👍
Currently the foreseeable engineering challenges for NSW seems to be harder than Orion, mainly on how the hell are we supposed to safely contain the nuclear chain reaction, because unlike Orion which has the pulse unit exploding outside the ship, all proposed NSW designs have the reaction occurs INSIDE the engine reaction chamber, and that will bring us back to the problems nuclear thermal propulsions have, which is melting (or in this case, exploding) engine.
@@lazyremnant380 Absolutely agrees with you there, but hey, that's for Scientist and Elon's legion of engineers to solve. I won't detonate my brain over that. 😄 Maybe Zubrin has matured his design, who knows. That's why an interview would be a good thing.
Just remember what Carl Sagan said (in the after-show "update" segment of the DVD version of the original Cosmos series): "That same rocket and nuclear and computer technology that sends our ship past the farthest known planet can also be used to destroy our global civilization. Exactly the same technology can be used for good and for evil."
Dr Theodore Taylor worked on the Manhattan project, and at Los Alamos after the war. He designed both the smallest yield and the smallest physical package bombs. He joined Orion at General Atomics, and helped bring Freeman Dyson in. He later because a staunch anti nuclear-weapons activist, since he knew very well how easy it would be for someone to get the knowledge and means to make one. He said that Orion is the hope in the bottom of the Pandora's box which nuclear energy is. Under all the weapons and horrible stuff. In this case atomic explosives, the very same application of technology that fried cities can help serve and save us.
About fusion: there is the idea of making (essentially an entirely scalable) "gun type" fusion bomb (voitenko compressor- light gas gun- DT fuel) which could end up being just in the kg of tnt range
Oh god small pure fusion bombs would be so terrifying. Anyone with water could manufacture nukes of highly customizable yield... they would be nigh-impossible to prevent the proliferation of. Which means interesting plot device for a political thriller!
@@Blaze6108 Don't forget that any one who can build big things in space, and certainly anyone mining NEAs or the Moon, has access to perfectly horrendous city-killing weapons. There's no practical defense, nothing on the planet is safe, and it's completely non-radioactive. I'd say that artificial meteorites are the number 1 contender for the "Great Filter" in the Drake Equation. It becomes available while a species is still new to space travel, so they probably still have lots of bad ideas around. Is it too far out to imagine a scenario where it's somebody's holy duty, or alternately a completely reasoned rationale, for effectively sterilizing the home planet?
Listening to this, I can't help but think back to the Niven / Pournelle book Footfall. The idea of an orion powered space battleship launching from Earth was awesome.
if icould id pay for you to do a vid on the "Nuclear lightbulb" a sealed system nuclear rocket, only found a few slivers myself but would love to see a fellow rocket lovers view on modernization of it. "Percussive maintenance" is my fave next to "if brute force isnt working, not using enough"
Hey Isaac, why not make an episode on radiators of the future? I read a book called saturn run a while back, and the main ship in it uses a magneticly guided liquid metal sheet flung through open space at high velocity and recollected to cool its molten salt nuclear reactor. James Webb’s sun Shield has sheets with geometries that bounce infrared light emitted by the layers out the sides to help passive cooling. You manage to bring up black holes in every episode (not that I’m complaining), why not try and shove the energy down one of those? Or for that matter while I’m on that thought experiment could gravity itself be used to assist in excess entropy dissipation in a spacecraft? What if its a war vessel and wants to be discreet about it, laser emission might help then.
Gorgeous artwork at 10:52 showing eight craft with 10m plates. Who drafted it? The closeups of the Orbital Test and Orbital Battleship show design features for atmospheric flight.
We look back at the ancient Greeks who had the basics of steam technology understood (the Aeolipile) but they never did anything with it because of many factors mostly cultural. I get the feeling that Orion is our era's Aeolipile, a technology that in the future humans will look back at us and wonder (like we do with the ancient Greeks) why no one bothered it implementing this technology when it is so obviously a great benefit to civilization.
They also figured out not only that the Earth was round, but the precise diameter (down to a few kilometers anyway) of the equator. And an ancient shipwreck actually had this amazing geared calculator device that we think was like a clockwork astrolabe or similar navigation device, a millennia and a half before the Renaissance navigation boom. The steam engine you mentioned? They didn't just have the engine part, they had every other component needed for a steam powered locomotive too. There was even an experimental railroad where this one peninsula took weeks to sail around but they figured out if they dragged the ships on shore, put them on a track and had mules pull it overland and to the other coast, the time was cut down to like a few days not weeks. Had they slapped one of the Aeolipiles they used as toys on the front, we would have called it a railroad. Never did anything with those technologies either. The Roman empire also did such massive scale hydraulic mining (which wouldn't be done again until the 1800s) that ice cores found in Greenland show the Roman mines in Iberia were producing amounts of lead that wouldn't be matched until the industrial revolution. There were several key peices of technology that all were "almost but not quite" invented and would have been critical in pushing the Industrial revolution a thousand years early. Unfortunately, the Roman Empire relied mainly on the Greeks for their R and D. There's a joke in philosophy that every ideology or philosophy that's existed has just been a response or rebuttal to Plato and he's either loved or hated by people in that field of study. For a Science and History guy like myself, if I had to pick one person responsible for delaying the scientific progress of humanity, it'd be Plato. May the bastard rot in his cave of shadows.
@@Lusa_Iceheart I think the biggest difference between Roman times and the times of industrial revolution was population density. When you have high enough population density and urbanisation you get enough brilliant people that can communicate and work together to create new technology and implement it at scale, also big population density drives the need for more resources, more efficiency. Its like the natives of Americas - they knew the concept of the wheel but they never made carriages because there just wasnt enough pressure from population density to increase efficiency, wasnt enough trade, which is also a big motivating factor.
@@georgewashington1621 Population density in Rome and the Greek cities was certainly dense enough, in fact Rome was the first city to have a population of over a million people, wouldn't be another to do that till London in the 1800s. Greek cities were similarly dense, having recovered in population under the stability of Rome. Obviously the Peloponnesian war and later Successor wars greatly dropped the population, but by the first century Greece was back in full swing. The Nile Delta was similarly dense and stable, hell, even Mesopotamia had a high density still. Population densities decreased after the fall of the Roman empire b/c it took a massive imperial bureaucracy to maintain a city like that, after it fell things were FORCED to be more rural and less dense. Rome itself imported grain from the Nile, olive oil from Iberia, livestock from Illyria, it was the first consumer city in the world. There's this one dig site in Rome that's effectively a hill, but it's entirely a pile of broken amphora shards. A literal mountain of just pottery, nothing else, right in the middle of the modern city. The population density, trade and imperial government apparatus was all there. Same as it was with Britain in the 1800s, a dense city of consumers that built a militarized empire almost solely to funnel trade goods to the capital city and maintain an ever increasing standard of living. Also, you might want to double check that fact on the Natives of the Americas not having dense populations, the Aztecs, Mayans, Inca and the recent discoveries of massive civilizations in Amazon basin might beg to differ on having cities. North American natives had cities too, there's a well known site in what is now Oklahoma that famously was visited by Conquistadors, they dragged a freaking cannon with them from New Spain thousands of miles away and shelled the city (tho it's likely the diseases they brought with them are what really destroyed the city). People always seem to forget the Spanish did the VAST majority of the genociding in the New World and what they didn't do the germs they brought did 95% of the remainder of the work. By the time America was founded, there was hardly any Native Americans left, the population had already been decimated. Estimates peg it around 95% gone within a decade of contact. Entire cities in the Amazon were wiped out and consumed by the jungle before Europeans ever made it that far inland, we're just recently finding massive city sites now in Brazil as a side effect of mass clear cutting but also LIDAR searches of the jungles. Anyway, there was a fuck load more humans in the Americas that didn't get recorded b/c they were wiped out so fast and modern archology is only just now finding evidence of.
That's Post-Columbian natives. Earlier their population was much greater and they had interconnected commerce over several hundreds of km, and many great engineering works that only great numbers over a long time, with great apparent will, could scatter all across both continents. Early explorers could not set foot on land anywhere, without immediately being in someone's back yard. Sail up and down the coasts for days, and never be out of sight of somebody's smoke. What were great impenetrable forests to later settlers, were to the first explorers nearly continuously inhabited, tended, husbanded for crops and tools & materials. Herds maintained and kept. The great horizon-spanning wilderness forests and bison herds, and the few wandering, warring, slaving people we found were the natural result of everything going wild after diseases (practically literally) decimated them. Early whites brought metal, dogs, horses, fabrics, and diseases along with guns. But still they show no apparent use of the wheel, or iron.
The issue why the Romans never did anything with the Aeolipile is more than cultural. To put it simply, it never had the same circumstances that Britain during the Industrial Revolution had, namely: 1) Availability of cheap fuel (coal became THE fuel of the steam engine being easily mined and available); 2) The lack of a consumer base that would require innovation for manufactured goods. 3) The lack of advanced metallurgy (brass is not cheap and Iron is not in its state to be used as well as the steel of the Industrial Revolution); 4) the lack of support for technological advancement (Roman high education is slanted heavily on logic and oration, in short it is geared towards making politicians, not engineers); and 5) interference from the powers to be. Roman history is full of emperors that suppress advancement because they "might" affect the delicate economic balance...
"If brute force isn't working, you aren't using enough of it" is such a good adage. I first heard it when playing Eve Online wow over a decade ago. Sheesh. So old. Ironically, one of the best adages applicable to the game is also why Eve Online became stale and also is why we don't live in a post nuclear war apocalypse! Fun!
0:10 "If a spaceship propelled by detonating nuclear bombs doesn't count, I don't know what would." Says the man who proposed a galactic scale megastructure powered by detonating supernovae.
Project Orion is the number 1 reason I’m confident in our ability to reach the stars… a propulsion system that can shove an interstellar-scale vessel up to a fraction of lightspeed, which has already undergone some testing and is considered proven- just too expensive to make right now unless it’s seriously needed. All the pieces for making an interstellar spaceship exist today. Also, I love the level of smugness in your voice as you brought up the 4 reasons to use nukes for search and rescue, and it made me remember the idea of also using hydrogen bombs to save the environment from “Climate Change Mitigation” 🤣
Isaac, you are one of the 3 channels I actually get excited about when I see a new video. Thank you so much for what you do. I don’t know what your production process is like but if other people are involved, thank you as well
I am compelled to be annoying by exclaiming “uranium salt rockets are a better concept than the pusher plate model” in the chat till the cows come home.
They are also a lot more uncertain. Orion was developed quite far, right up to the point where the next step would have been actual nuclear tests. There were computer simulations, scale model shock absorbers, high explosive generated plasma interaction tests, etc. All NSWR has is a very short paper by a person who is not a nuclear scientist. This doesn't mean it can't work, but the work to find that out has not been done yet. I know one nuclear researcher who thinks Zubrin was wrong about some things, but that the concept still shows promise and seems potentially viable, but requires more work.
You should do a video on the nuclear saltwater rocket! I absolutely love that concept and so far Scott Manley is the only channel I've seen really talk about it. I'm actually surprised you haven't mentioned it here even in passing. (so far as I'm aware)
In the 1980s, Carl Sagan, host of the original Cosmos, talked about this. Robert A. Heinlein also talked about it in his 1947 science fiction novel Rocket Ship Galileo which became the 1950 science fiction movie Destination Moon directed by George Pal.
If distance is not a concern (assume can reach any planet in 24 hr ) then which planet /moon is most comfortable for human .I mean required minimum life support ???
If we had the tech to reach any planet or moon in 24 hours, then it would definitely be Venus, since we would presumably _also_ have the tech to hang out in the upper atmosphere (where the temperature and pressure are much more conducive to human life than the surface). But honestly, as much as it sucks to say, *no* planet or moon in this solar system is anywhere even _remotely_ close to being "easy" for humans to live on besides earth. Every one of them will require us to dedicate the majority of the mission's technology, materials, and time to just keeping people alive and healthy. Everywhere besides earth is constantly trying to kill us in 100 different ways every second.
Certainly none within our solar system, not in their current states at least. The 2 most likely candidates, at least in the relatively near-term future, would have to be the moon, and Mars, in that order. The moon holds promise purely based on its proximity to Earth, but unless we bring fully self-contained habitats it is completely inhospitable to human life. It completely lacks an atmosphere, meaning there is absolutely no breathable air or protection from cosmic radiation. Theres also no water and virtually no geological activity. Mars is more promising due to the fact that it has an atmosphere, albeit a much thinner one than ours. Temperatures are also much more manageable than those found on the moon, and water is present at least in frozen form. This makes Mars a possible candidate for eventual terraforming, but in the initial stages of habitation we would also require enclosed habitats just like with the moon. The fact is that as far as we know, Earth is the only planet capable of naturally supporting human life
who knows, we can replicate everything cept gravity, and we don't know how much we need, maybe the moons is enough or maybe even Venus's is not enough to aviod medical problems. If you need 1g then lowest gravity would be best as it would be easier to build big spinning structures
I really like Orion. The name that is. It’s the name of one of the few human-constellations, it’s a god related to water, it’s this whole nuclear ship and it’s an accurate latinisation of my name.
Have you looked at Von Neuman probes from an engineering perspective? What components are required and what work do we need to begin to create them? Some, like automated asteroid mining, might get done soon.
When getting into conversations about how we need less nukes and all that, I bring up the orion project to let them know that there is a legitimate reason why we need them.
In some ways, I was very lucky to have been born in the 1950s. I do at times, wish I had been born early enough to have been a "mountain man," or late enough to colonize other planets.
An Isaac Arthur video is just what I needed today, and especially one kicking off the new year by discussing using nuclear bombs as propulsion - you know, relatively small-scale stuff
Aside from carrying Space Shuttles, and the Battleship turrets (1500+ tons and 50 crew each, plus the magazines). It's nice to see S.F. that sticks to understandable rules and assumptions of 'tech, and makes good aliens too.
Have you ever considered making a funny compilation book or video titled "the first rule of war" where you put together all the different first rules? ♥️
See "Medusa". They plan is to use tensile cables to pull the payload, and toss the bombs forward, to a giant parachute ahead of the ship that catches the plasma. The cables take hours to stretch and bungee back & forth. Note also that a magnetic sail could be used to catch the plasma, which can make your "pusher plate" immaterial, and tens of km across. Totally shield the ship from Solar flares and the bombs, though they'd be detonating at least a few km away. This has been suggested at what we were seeing as Oumuamua apparently did a perihelion pass propulsive maneuver past the Sun.
You have a great new year too! From your description of playing D&D with your DoD buddies almost sounds like you served with some of my friends, as most of them were really into it too!
What about smallest possible nuclear detonations at the front of the ship, where blast goes into circular mass accelerator accelerating small mass objects to desired speed so that they can be released in controlled manner to slow down or accelerate the ship? Probably will need multiple circular accelerators to compensate inertia pulling the ship to the rotation direction
That would be really hard. At small masses of plutonium or uranium it is extremely hard to start a nuclear reaction and it is unlikely to reach reaction sustainablity. The minimum mass needed for a real nuclear explosion called critical mass and for uranium it is about 47 kg and for plutonium it is about 10.
I told a friend that I'd want to bring in a ranger (I meant a half-elf). (He'd been Army, I was N.G.) He said that he'd dimension-warp me in from a drop bringing supplies and "military consulting" help to some rebels in some brush war. I had a couple of duffle bags of stuff, several magazines for my M-4, with M-203. We worked out what Claymores and grenades would be like. I had zero armor and a bayonet & karate for hand-hand. Over a couple of days, I did a lot with a usual D&D party who didn't quite know what the DM was doing any more than I did. After 2 days against orcs, bandits and bugbears (he rolled for me and told me that I'd pissed myself first time seeing them) I had to tell them that I didn't know how they could keep going and never get hit. I was on my last legs, many bandages and much of my first aid supplies gone, needing a few weeks at least to recover. (Magical healing? What's that? Superstition and witch doctors?)
Instead of ejecting hot matter to generate propulsive force, with more heat leading to higher propulsive efficiency, I wonder if it could ever be possible to convert that matter into exotic heavy quarks and then eject those quarks (or utilize the energy they emit when they decay). Since some of those quarks become 600-2000 times heavier than a normal 'up' quark it may be one way of compounding the momentum attained when ejecting matter for propulsive purposes.
I think it won't work the way you suppose. Using a massive reaction mass will increase your instantaneous thrust but require _much_ more energy for the same overall delta-V. Photon (massless) rockets are the most efficient. Since KE required goes with the square of the velocity, and the thrust is the momentum which is linear with velocity, your energy requirements go up with the square of the thrust. It doesn't matter if you're using a kg of gold, a kg of feathers, or a kg of heavy quarks; ejecting reaction mass gives thrust based on that amount of mass and its velocity. Using heavier particles instead of atoms doesn't "compound the momentum" in any manner.
7:00 however yo ualso have to conisder that high energy densities mean less mass but also less efficiency roughly speaking 100 times the energy density means 10 times the specific impulse and 10 times the propulsion/fuel consumption ratio although the exponentiality of the rocket equation makes evene asligh increase in specific impulse have a huge impact on actual fuel needed in most cases
Hey, run the numbers with a 10 Gigawatt nuclear plant just heating water to the ~1900C we can manage materials for. A 10 GW plant with pure fissile is looking about 5 m^3 (assuming the water takes the power away) and perhaps 40 tons. Teakettle SSTO, unless I am mistaken.
@@TokyoTrainStyle sorry my apologies I misspelled the name of the concept. What I meant to say was magnetic reconnenation thruster.. Or the Ibrahimi drive. I hope that helps.
Issac not sure if you have done an episode on a recently published engine process called muon catalyzed fusion engine. Would love your opinion on it if you haven’t done one or if so would love to listen to it.
Where can we find the chart shown at 11:00? Also mad kudos for mentioning Stanislaw Ulam, a Polish American who worked on the H-bomb, among other things - I never thought I'd see his name connected to space sciences! Also, I don't think the fact that we found peaceful and useful uses for nukes precludes using them for nefarious purposes - or using useful purposes as excuses, simply - saying that it's for propulsion while in reality it is weaponized.
I read the caption 'battleship' and instantly thought of the Archangel Mike... "God was knocking, and he wanted in bad!" 'Footfal', Larry Niven and the late Jerry Pournelle
It was one of my favorite parts of Marko Kloos's Frontlines novels when they started using Project Orion-style propulsion (though for a slightly different purpose, not to be too spoilery) and I recognized it. Also I want to recommend those novels for anyone into fairly hard military sci-fi (harder on the military than it is on the science, but the science is still at least on the firmer side from space opera [Alcubierre drives and gravity generators exist, but are never explained, for example]).
I kinda love the old Orion concepts, and wonder if there might actually be a few here and there already. Lotsa dark dollars and projects running around out there.
If a ship like this was setting off to mars or whereever from L.E.O could people on the ground see it? Like would people see flashes in the sky as the bombs do off? what is the luminosity of a nuke that you would use for this?
18:13 happy time handling Cf-252 at that quantiy needed for a critical mass ... that isotope is used for its high spontaneous fission rate ...definitly not the stuff you want to make a nuclear bomb with
The "Heinlein kinda predicted the fission bomb," remark kind of reminded me of how I though that H. G. Wells kinda predicted the laser with his Martian Heat Ray from "War of the Worlds." Thoughts?
If you want a space missile that is fast and agile (able to accelerate to avoid flak), nuclear pulse propulsion seems perfect, but you also ideally want to be a small target too. What's the smallest orion engine you can create? Does being single use allow you to skip the spring on the pusher plate?
The orion drive becomes extremely inefficient at small sizes, the smallest practical size is about 10 meters in diamater. But, a missile wont need to evade flak with this technology. A derivative of the orion drive is the "casaba howitzer", a nuclear weapon where the energy of the nuke is focused into a shaped charge that accelerates a relativistic plasma beam towards the target. Such a weapon could obliterate enemy space ships from thousands of kilometers away in the blink of an eye with a warhead the size of an artillery shell.
Were did the thumbnail art come from? I read in the description that you credited it to Jakub Grygier, but I couldn't fin it on his site, and I wanted to get a closer look at the art because it looks pretty cool.
I read there is a pellet beam propulsion drives being developed. We need a multinational manhattan project for orion. The videos on propulsion drives are always great to watch.
Isaac: Are there any kinds of star, perhaps ones close to others that would be of interest for colonising, that would be suitable for large-scale atmospheric braking? In Clarke's 2010, Jupiter is used for atmospheric braking, and would do a much better job than Earth. What about a red giant, or a brown dwarf? Any possibilities there? I am thinking of the problem of reducing the fuel usage required in decelerating a ship on arrival near its destination, especially a ship sent by laser blast, to a system that has not been colonised, and cannot therefore provide a laser blast for braking arriving ships. Another possibility would be sending freight in advance, at much lower speeds, freight which would contain equipment for setting up automated factories capable of providing not just habitats for colonists when they arrive, but also to provide laser systems for decelerating arriving ships.
Look into electric or magnetic breaking, or the concept of the Bussard ramjet. Any of the concepts that ultimately failed as a propulsion system because the friction is higher than the thrust will in fact still be useful as a _brake_ .
Imagine a mega-structure scale frisbee spinning to create artificial gravity on the edge, and with the bottom (concave) side painted with a radioactive mix that is in a controlled release state. The outbound radiation provides thrust. The inbound radiation is captured to provide house energy (and/or produce more radioactive paint). - The main efficiency problem is that the outbound radiation is omnidirectional while we would prefer that it be unidirectional. We can tweak the design by adding a skirt or magnetic coil around the edge to redirect some of the radially directed ions. - Recall that temperature is a statistical concept that averages the kinetic energy in a gas T = k * sum( m v^2 ) / n :: where 'n' is the number of particles in the gas. However, if you add in big-N 'N' to include the number of atoms in the heated structure, T can be reduced to below the structural damage point if N is orders of magnitude larger than n. (n
from what I remember the avurage square kilometer of territory on earths serface not the serface of the atmosphere that's pluss 30+ percent, receaves the equivalent of a 1 kiloton nuclear bombs worth of energy
"If brute force isn't working, you aren't using enough of it" is my favorite quote ever
overkill is underrated.
@@harmonyspaceagency1743 I'll have to steal that line :)
@@isaacarthurSFIA you're welcome to it
That's the first rule of brute force.
Can brute force be used to draw a perfect circle?
I think there a few slightly misunderstandings about how the Orion Drive works, as described in the video.
Your typical fission reaction produces about 5% of the energy in the form of neutrons and gamma rays, and 95% of the energy is released in the form of those two charged nuclei fragments when the atom splits. So most of the energy is almost immediately absorbed by the bomb itself, which then heats up to incredible temperatures, in the range of millions of degrees. When things get this hot, they produce massive amounts of x-rays.
The bombs used by Orion drives are euphemistically called pulse units. And they have a special design. It contain components to reflect and absorb the x-ray flash, just before they themselves get blown up, and they redirect and focus the energy into a solid flat plate of tungsten, which absorbs the x-rays and is used as propellant. IIRC, over 80% of the bomb's energy is absorbed and redirected into a narrow cone, and thus accelerating a cone of vaporized tungsten plasma that is focused straight on the pusher plate. The pulse units are essentially nuclear shaped charges, they are not omnidirectional.
That beam of tungsten plasma is relatively cold, in the range of 100,000 degrees centigrade. The plasma is hitting the pusher plate at like 150 kilometers per second. And kinda like a hammer striking the anvil, really. It strikes the pusher plate, pushing it forward, which, through the action of shock absorbers push the rest of the ship, at a survivable acceleration. And the plasma doesn't completely vaporize the pusher plate because the interaction between the mildly hot plasma and the plate is really short and not much heat can be transfered between the two. Oil would also be sprayed on the surface of the plate before each detonation, to provide a buffer to significantly reduce the rate of ablation.
The important thing, it's matter, hitting matter, that creates thrust, not the gamma flux from the bomb.
Compared to temperatures achieved when the bomb detonates, yah I suppose 100k C is relatively cold.
pero hay una forma de dirigir la detonación de la bomba, en este caso es necesario que sea de fusión ósea hidrogeno que de por si permite un impulso especifico MUY ALTO, la idea es hacer una detonación laser, seria un pulso laser disparado hacia la bomba, el pulso láser se enfocaría con una lente en un punto diminuto de esa manera hacemos que el hidrógeno alcance temperaturas suficientes para la fusión en una fracción de segundo, en este caso el cañón láser estaría detrás del lanzador de las bombas (entonces lo que uno realmente llamaría una bomba sería simplemente un pequeño tanque lleno de hidrógeno líquido, entonces el verdadero nombre sería carga explosiva ya que el detonador, el láser es parte del motor) por lo que en sí mismo le daría una seguridad inherente al motor, y cómo dirigimos la explosión, el tanque de hidrógeno líquido tendría forma de cono (la punta apuntaría hacia nada , la parte más gruesa hacia la placa) con un agujero en el medio que sería donde el láser pasaría hasta llegar a la punta del cono y haciendo que la detonación vaya desde la punta hacia la parte más gruesa generando un efecto de propulsión dirigiendo la detonación hacia la placa propulsora, alrededor del 80% de la fuerza de detonación estaría dirigida hacia la placa dándole una eficiencia muy alta además de una seguridad que (en mi opinión) seria mayor que la de un cohete químico que tiene el combustible y el oxidante prácticamente juntos mientras que mi versión Orión solo tiene tanques en forma de cono llenos de HL , que si se rompe no pasaría nada
well, that fixes what i thought of as a glaring inefficiency - thanks
I've heard a few others say they got the impression I was treating Orion principally as a photon rocket, so I am wondering if on some bad phrasing or editing that got unclear [so much got chopped], and at least one of those bits was more on why antimatter drives are essentially photon rockets or how Orion works well in conjunction with laser pushers from home, but I thought I was pretty clear about explaining what photon rockets were and what the main original Orion system was not, though again the focus for today was on new approaches folks suggest and why or when they would or wouldn't work.
@@isaacarthurSFIA The USA did some research and the USSR worked on development nuclear reactor jet/rocket engine for long range bombers. I am in favor of high density thermite for engine fuel. Iron, oxygen, and zinc is easier to process and access in space then uranium is to process.
I have lived the idea of Orion since I read Footfall. Thanks Issac!!
@Isaac Arthur
I am glad to see someone who looks at Project Orion with rationality - instead of the usual knee-jerk fear of "nukes."
I always loved the idea of project Orion. We have a bunch of nukes we can just use to fly to another world. A good use of a powerful weapon. Not a lot of sci-fi stories use it. Of course in a story of humans coming to an alien planet and in conflict with the dominant species, having one of them say "they have a human bomb from your engine" would be pretty terrifying assuming you could understand them.
Would be a nice peaceful way to get rid of the those thousands of old cold war nukes.
Wow it’s 8 seasons already: I think I’ve been watching for 6 years. Thanks for so many years of great educational content!
I can’t wait for this! I have dreamt about the possibilities abandoned in the Orion nuclear spacecraft project for decades, and loved when Neal Stephenson used the method to move his multiverse-traveling ship. The Pusher Plate; Jules Verne first thought of one when he shot the members of the Baltimore Gun Club to the moon through a cannon!
It's some 10+ years since I read Anathem, but wasn't the ship pyramid shaped as well? Would love to see the tinfoil hat people try to process that sight...
might be an attractive option if we clutter up space too much and need to blast a hole through the debris, people would be less touchy about nukes in space
We had a nuclear powered plane over 50 years ago and our largest subs have all been nuclear powered for years. Logic says we should have nuclear powered spaceships.
Maybe we do....
@@friendlyone2706 Twilight zone theme plays
@@friendlyone2706 Lol, cool idea for fiction but very unlikely since any orbital launch is not exactly a quiet affair and even the most cutting edge experimental reactor designs would require rockets in the super heavy category (ala Saturn V) to deploy. I'm comfortable asserting that the closest to nuclear powered spacecraft we've ever gotten is RTG powered probes.
The only way to covertly pull off something like this is to launch it piece meal on the back of many otherwise normal launches and assemble it in orbit but such a craft would be enormous and easily visible from the ground. It would also require sending the fissionable material in one of those missions, an incredibly risky affair both ecologically and politically that would violate international treaties and embolden every other side to begin to openly experiment with their own atomic powered craft.
Took my girlfriend home yesterday and brought her back at 2am last night just so we could watch this come out together 💕 thank you so much for your wonderful channel, Isaac.
Relationship goals!
Wow!
I love my wife of over 25 years dearly. But the idea that she would ever show even the slightest interest in such things is beyond impossible to hope for! Cherish this one Matthew, I guarantee you won't find another like her.
@@charlesjmouse man, I think I’m gonna marry her - it’s been 3 years and she’s the love of my life. I just don’t know how to ask her 😂😂 I’ve never done this before!
@@matthewthomson6466 you got this, man! You know her best, so I'm sure you think of a good way
@@charlesjmouse (also if you *do* wanna try getting your wife into it, SEA documentaries as we fell asleep was my gateway drug >:D)
Issac, I'm 20 minutes in, and it seems like you're unaware that Project Orion developed nuclear shaped charges. Yes, we've had the ability to direct the output of nuclear bombs in particular directions since the 1960's. I think this is covered in Freeman Dyson's son's books. (If you know how a hydrogen bomb works, and how shaped charges work, it's easy to see the basic principle of how this is done.) Parts of this are still classified, but it was crucial to increasing the efficiency of Project Orion drives.
Ah, _this_ . I was quite disappointed he didn't mention the shaped charge pulse units intended to go with the dual-shock pusher plate design shown in most animations. Little nuke in a DU casing to reflect x-rays, hole in the top leading to a conical channel of beryllium oxide to turn the x-rays to heat, and a disk of tungsten atop to be converted into a disk extremely angry rapidly moving tungsten gas aimed for the pusher plate, allowing nearly 85% of the blast energy to be used for propulsion.
Sadly, this omission also denied us a brief aside on the related Casaba Howitzer shaped nuclear charge weapon system, which focuses a blast similarly but with a much longer focal length and no beryllium oxide or tungsten to temper the atomic inferno, resulting in a kilometers-long spear of nuclear fire and the early sci-fi "particle lance" family of weaponry.
@@Archgeek0 Issac could probably do an entire episode on the effect of the existence of such weapons on Sci-fi movie plots! It basically invalidates most Kaiju.
Too much got cut from the script in its gajillion iterations I think, its probably why I was openly bemoaning it in the coda when we cut stuff all the time and I normally don't feel a need to dwell on it at the end of the episode. I kinda felt like the discussion of project Excalibur gets to nuclear shaped charges well enough though, this is what a bomb-pumped laser typically is. I'm not quite sure how explicit mention of vaporizing material got left out as part of the core design but but we definitely do discuss vaporizing material off that pusher plate for added push.
@@isaacarthurSFIA "I kinda felt like the discussion of project Excalibur gets to nuclear shaped charges well enough though, this is what a bomb-pumped laser typically is." -- True. But the impact of those words on those to whom the concept is completely new is awesome in that literal sense: "Nuclear shaped charges!" I'm sure another warfare related episode will come up though.
@@stcredzero :) Probably true, they do sound cool. I think I suggested their use for search and rescue before but if not, there's always another episode another day
Since you are doing Orion drive, please do a deep dive into Zubrin's Nuclear Salt Water Rocket.
You could also interview Zubrin, he is quite reachable for interviews.
He is both a Nuclear and Aerospace engineer. 👍
I'd love to see IA do some interviews with other smart people!
Please do!
Yeah that'd be great, I thinkn the NSW rocket has merit for real life spaceships, especially considering the distances involved.
Currently the foreseeable engineering challenges for NSW seems to be harder than Orion, mainly on how the hell are we supposed to safely contain the nuclear chain reaction, because unlike Orion which has the pulse unit exploding outside the ship, all proposed NSW designs have the reaction occurs INSIDE the engine reaction chamber, and that will bring us back to the problems nuclear thermal propulsions have, which is melting (or in this case, exploding) engine.
@@lazyremnant380 Absolutely agrees with you there, but hey, that's for Scientist and Elon's legion of engineers to solve. I won't detonate my brain over that. 😄
Maybe Zubrin has matured his design, who knows. That's why an interview would be a good thing.
Just remember what Carl Sagan said (in the after-show "update" segment of the DVD version of the original Cosmos series): "That same rocket and nuclear and computer technology that sends our ship past the farthest known planet can also be used to destroy our global civilization. Exactly the same technology can be used for good and for evil."
Dr Theodore Taylor worked on the Manhattan project, and at Los Alamos after the war. He designed both the smallest yield and the smallest physical package bombs.
He joined Orion at General Atomics, and helped bring Freeman Dyson in.
He later because a staunch anti nuclear-weapons activist, since he knew very well how easy it would be for someone to get the knowledge and means to make one.
He said that Orion is the hope in the bottom of the Pandora's box which nuclear energy is. Under all the weapons and horrible stuff.
In this case atomic explosives, the very same application of technology that fried cities can help serve and save us.
About fusion: there is the idea of making (essentially an entirely scalable) "gun type" fusion bomb (voitenko compressor- light gas gun- DT fuel) which could end up being just in the kg of tnt range
Oh, so long as it's 'just' in the kilogramme range!
Oh god small pure fusion bombs would be so terrifying. Anyone with water could manufacture nukes of highly customizable yield... they would be nigh-impossible to prevent the proliferation of.
Which means interesting plot device for a political thriller!
@@Blaze6108
Don't forget that any one who can build big things in space, and certainly anyone mining NEAs or the Moon, has access to perfectly horrendous city-killing weapons. There's no practical defense, nothing on the planet is safe, and it's completely non-radioactive.
I'd say that artificial meteorites are the number 1 contender for the "Great Filter" in the Drake Equation. It becomes available while a species is still new to space travel, so they probably still have lots of bad ideas around.
Is it too far out to imagine a scenario where it's somebody's holy duty, or alternately a completely reasoned rationale, for effectively sterilizing the home planet?
Freeman Dyson will one day be remembered the same way the Wright brothers are
Crazy good video Issac. I'm hype for this and I really hope I can live to see it happen :)
can I just say, I love that small grin at 6:50 when saying how little energy was used in the apollo mission compared to the hydrogen bomb.
I absolutely love getting notifications from your channel. Thank you once again for making ArThursday the best day of the week.
If you write a story with aliens and such, an Orion ship just seems like a quintessentially "human" thing for traveling.
We're really kicking this new season off with a bang!
Looking forward to see what new first rules of warfare we come up with
The first rule of warfare is that there is only the first rule. If you have something as the second rule you are clearly doing it wrong
What an opening line. With a start like that, we're in for a good episode.
overkill is underrated
2:00
also, most combustion fuels have these values listed withut takign the mass of hte oxygen needed into account
Listening to this, I can't help but think back to the Niven / Pournelle book Footfall. The idea of an orion powered space battleship launching from Earth was awesome.
oh i have to reread that soon, childhood memories....
Footfall, Lucifer's Hammer and Mote in God's Eye
Didn't they have brute force X-ray lasers as well?
@@dr.christophermeyer479 If my memory serves, yes as well as cannons from an Iowa class battleship and some shuttles strapped on.
Professor Dyson is the Yoda of this channel because (1) impressive ears, and (2) So many Good Ideas.
if icould id pay for you to do a vid on the "Nuclear lightbulb" a sealed system nuclear rocket, only found a few slivers myself but would love to see a fellow rocket lovers view on modernization of it.
"Percussive maintenance" is my fave next to "if brute force isnt working, not using enough"
Just so you know; channels like these are only thing keeping me from total misanthropy.
👽👍
This episode makes me wanna play KSP 2 even more
Comments that age like milk XD
Hey Isaac, why not make an episode on radiators of the future? I read a book called saturn run a while back, and the main ship in it uses a magneticly guided liquid metal sheet flung through open space at high velocity and recollected to cool its molten salt nuclear reactor. James Webb’s sun Shield has sheets with geometries that bounce infrared light emitted by the layers out the sides to help passive cooling. You manage to bring up black holes in every episode (not that I’m complaining), why not try and shove the energy down one of those? Or for that matter while I’m on that thought experiment could gravity itself be used to assist in excess entropy dissipation in a spacecraft? What if its a war vessel and wants to be discreet about it, laser emission might help then.
BTW, Wikipedia has a page called "Liquid droplet radiator".. sounds a little similar to that first idea.
Gorgeous artwork at 10:52 showing eight craft with 10m plates. Who drafted it? The closeups of the Orbital Test and Orbital Battleship show design features for atmospheric flight.
We look back at the ancient Greeks who had the basics of steam technology understood (the Aeolipile) but they never did anything with it because of many factors mostly cultural. I get the feeling that Orion is our era's Aeolipile, a technology that in the future humans will look back at us and wonder (like we do with the ancient Greeks) why no one bothered it implementing this technology when it is so obviously a great benefit to civilization.
They also figured out not only that the Earth was round, but the precise diameter (down to a few kilometers anyway) of the equator. And an ancient shipwreck actually had this amazing geared calculator device that we think was like a clockwork astrolabe or similar navigation device, a millennia and a half before the Renaissance navigation boom. The steam engine you mentioned? They didn't just have the engine part, they had every other component needed for a steam powered locomotive too. There was even an experimental railroad where this one peninsula took weeks to sail around but they figured out if they dragged the ships on shore, put them on a track and had mules pull it overland and to the other coast, the time was cut down to like a few days not weeks. Had they slapped one of the Aeolipiles they used as toys on the front, we would have called it a railroad. Never did anything with those technologies either.
The Roman empire also did such massive scale hydraulic mining (which wouldn't be done again until the 1800s) that ice cores found in Greenland show the Roman mines in Iberia were producing amounts of lead that wouldn't be matched until the industrial revolution. There were several key peices of technology that all were "almost but not quite" invented and would have been critical in pushing the Industrial revolution a thousand years early. Unfortunately, the Roman Empire relied mainly on the Greeks for their R and D.
There's a joke in philosophy that every ideology or philosophy that's existed has just been a response or rebuttal to Plato and he's either loved or hated by people in that field of study. For a Science and History guy like myself, if I had to pick one person responsible for delaying the scientific progress of humanity, it'd be Plato. May the bastard rot in his cave of shadows.
@@Lusa_Iceheart I think the biggest difference between Roman times and the times of industrial revolution was population density. When you have high enough population density and urbanisation you get enough brilliant people that can communicate and work together to create new technology and implement it at scale, also big population density drives the need for more resources, more efficiency. Its like the natives of Americas - they knew the concept of the wheel but they never made carriages because there just wasnt enough pressure from population density to increase efficiency, wasnt enough trade, which is also a big motivating factor.
@@georgewashington1621 Population density in Rome and the Greek cities was certainly dense enough, in fact Rome was the first city to have a population of over a million people, wouldn't be another to do that till London in the 1800s. Greek cities were similarly dense, having recovered in population under the stability of Rome. Obviously the Peloponnesian war and later Successor wars greatly dropped the population, but by the first century Greece was back in full swing. The Nile Delta was similarly dense and stable, hell, even Mesopotamia had a high density still. Population densities decreased after the fall of the Roman empire b/c it took a massive imperial bureaucracy to maintain a city like that, after it fell things were FORCED to be more rural and less dense. Rome itself imported grain from the Nile, olive oil from Iberia, livestock from Illyria, it was the first consumer city in the world. There's this one dig site in Rome that's effectively a hill, but it's entirely a pile of broken amphora shards. A literal mountain of just pottery, nothing else, right in the middle of the modern city. The population density, trade and imperial government apparatus was all there. Same as it was with Britain in the 1800s, a dense city of consumers that built a militarized empire almost solely to funnel trade goods to the capital city and maintain an ever increasing standard of living.
Also, you might want to double check that fact on the Natives of the Americas not having dense populations, the Aztecs, Mayans, Inca and the recent discoveries of massive civilizations in Amazon basin might beg to differ on having cities. North American natives had cities too, there's a well known site in what is now Oklahoma that famously was visited by Conquistadors, they dragged a freaking cannon with them from New Spain thousands of miles away and shelled the city (tho it's likely the diseases they brought with them are what really destroyed the city). People always seem to forget the Spanish did the VAST majority of the genociding in the New World and what they didn't do the germs they brought did 95% of the remainder of the work. By the time America was founded, there was hardly any Native Americans left, the population had already been decimated. Estimates peg it around 95% gone within a decade of contact. Entire cities in the Amazon were wiped out and consumed by the jungle before Europeans ever made it that far inland, we're just recently finding massive city sites now in Brazil as a side effect of mass clear cutting but also LIDAR searches of the jungles. Anyway, there was a fuck load more humans in the Americas that didn't get recorded b/c they were wiped out so fast and modern archology is only just now finding evidence of.
That's Post-Columbian natives.
Earlier their population was much greater and they had interconnected commerce over several hundreds of km, and many great engineering works that only great numbers over a long time, with great apparent will, could scatter all across both continents.
Early explorers could not set foot on land anywhere, without immediately being in someone's back yard. Sail up and down the coasts for days, and never be out of sight of somebody's smoke.
What were great impenetrable forests to later settlers, were to the first explorers nearly continuously inhabited, tended, husbanded for crops and tools & materials. Herds maintained and kept.
The great horizon-spanning wilderness forests and bison herds, and the few wandering, warring, slaving people we found were the natural result of everything going wild after diseases (practically literally) decimated them. Early whites brought metal, dogs, horses, fabrics, and diseases along with guns.
But still they show no apparent use of the wheel, or iron.
The issue why the Romans never did anything with the Aeolipile is more than cultural. To put it simply, it never had the same circumstances that Britain during the Industrial Revolution had, namely:
1) Availability of cheap fuel (coal became THE fuel of the steam engine being easily mined and available);
2) The lack of a consumer base that would require innovation for manufactured goods.
3) The lack of advanced metallurgy (brass is not cheap and Iron is not in its state to be used as well as the steel of the Industrial Revolution);
4) the lack of support for technological advancement (Roman high education is slanted heavily on logic and oration, in short it is geared towards making politicians, not engineers); and
5) interference from the powers to be. Roman history is full of emperors that suppress advancement because they "might" affect the delicate economic balance...
"If brute force isn't working, you aren't using enough of it" is such a good adage. I first heard it when playing Eve Online wow over a decade ago. Sheesh. So old. Ironically, one of the best adages applicable to the game is also why Eve Online became stale and also is why we don't live in a post nuclear war apocalypse!
Fun!
0:10 "If a spaceship propelled by detonating nuclear bombs doesn't count, I don't know what would." Says the man who proposed a galactic scale megastructure powered by detonating supernovae.
Project Orion is the number 1 reason I’m confident in our ability to reach the stars… a propulsion system that can shove an interstellar-scale vessel up to a fraction of lightspeed, which has already undergone some testing and is considered proven- just too expensive to make right now unless it’s seriously needed. All the pieces for making an interstellar spaceship exist today.
Also, I love the level of smugness in your voice as you brought up the 4 reasons to use nukes for search and rescue, and it made me remember the idea of also using hydrogen bombs to save the environment from “Climate Change Mitigation” 🤣
Isaac, you are one of the 3 channels I actually get excited about when I see a new video. Thank you so much for what you do. I don’t know what your production process is like but if other people are involved, thank you as well
Are the other 2 space related, if so any recommendations?
I am compelled to be annoying by exclaiming “uranium salt rockets are a better concept than the pusher plate model” in the chat till the cows come home.
They are also a lot more uncertain. Orion was developed quite far, right up to the point where the next step would have been actual nuclear tests. There were computer simulations, scale model shock absorbers, high explosive generated plasma interaction tests, etc. All NSWR has is a very short paper by a person who is not a nuclear scientist. This doesn't mean it can't work, but the work to find that out has not been done yet. I know one nuclear researcher who thinks Zubrin was wrong about some things, but that the concept still shows promise and seems potentially viable, but requires more work.
Only 6000 likes? This is my all time favorite space craft propulsion system.
You should do a video on the nuclear saltwater rocket! I absolutely love that concept and so far Scott Manley is the only channel I've seen really talk about it. I'm actually surprised you haven't mentioned it here even in passing. (so far as I'm aware)
In the 1980s, Carl Sagan, host of the original Cosmos, talked about this. Robert A. Heinlein also talked about it in his 1947 science fiction novel Rocket Ship Galileo which became the 1950 science fiction movie Destination Moon directed by George Pal.
If distance is not a concern (assume can reach any planet in 24 hr ) then which planet /moon is most comfortable for human .I mean required minimum life support ???
Moon, mars and maybe some Jupiter moon
Upper atmosphere of Venus.
Gravity and atmosphere pressure are near earth condition.
It just that acid atmosphere stuff tho. ☠️
If we had the tech to reach any planet or moon in 24 hours, then it would definitely be Venus, since we would presumably _also_ have the tech to hang out in the upper atmosphere (where the temperature and pressure are much more conducive to human life than the surface).
But honestly, as much as it sucks to say, *no* planet or moon in this solar system is anywhere even _remotely_ close to being "easy" for humans to live on besides earth. Every one of them will require us to dedicate the majority of the mission's technology, materials, and time to just keeping people alive and healthy.
Everywhere besides earth is constantly trying to kill us in 100 different ways every second.
Certainly none within our solar system, not in their current states at least. The 2 most likely candidates, at least in the relatively near-term future, would have to be the moon, and Mars, in that order. The moon holds promise purely based on its proximity to Earth, but unless we bring fully self-contained habitats it is completely inhospitable to human life. It completely lacks an atmosphere, meaning there is absolutely no breathable air or protection from cosmic radiation. Theres also no water and virtually no geological activity. Mars is more promising due to the fact that it has an atmosphere, albeit a much thinner one than ours. Temperatures are also much more manageable than those found on the moon, and water is present at least in frozen form. This makes Mars a possible candidate for eventual terraforming, but in the initial stages of habitation we would also require enclosed habitats just like with the moon.
The fact is that as far as we know, Earth is the only planet capable of naturally supporting human life
who knows, we can replicate everything cept gravity, and we don't know how much we need, maybe the moons is enough or maybe even Venus's is not enough to aviod medical problems. If you need 1g then lowest gravity would be best as it would be easier to build big spinning structures
Orion drives are just the thing if you're facing an invasion of miniature space elephants.
RIP Freeman Dyson. Thanks for the Orion concept
I really like Orion. The name that is.
It’s the name of one of the few human-constellations, it’s a god related to water, it’s this whole nuclear ship and it’s an accurate latinisation of my name.
Have you looked at Von Neuman probes from an engineering perspective? What components are required and what work do we need to begin to create them? Some, like automated asteroid mining, might get done soon.
It's crazy to think that the technology that nearly destroyed us is so necessary if we want to get to the stars in a timely fashion.
It would be so much more controversial if future humans came up with gravity devices!
The Orion Project is legit some planet evacuation type stuff xD
Planet evacuation? With this tech we don't need to evacuate shit! Lol
Nice to see KSP
When getting into conversations about how we need less nukes and all that, I bring up the orion project to let them know that there is a legitimate reason why we need them.
how i learned to stop worrying and love project orion
In some ways, I was very lucky to have been born in the 1950s. I do at times, wish I had been born early enough to have been a "mountain man," or late enough to colonize other planets.
An Isaac Arthur video is just what I needed today, and especially one kicking off the new year by discussing using nuclear bombs as propulsion - you know, relatively small-scale stuff
I loved the Orion warship in Larry Niven's "Footfall". Was one of the first really great Science Fiction novels I read.
“God was knocking, and he wanted in bad.”
@@Shaun_Jones
WHAM
WHAM
WHAM
quiet
I love that book. Just read it last year.
Aside from carrying Space Shuttles, and the Battleship turrets (1500+ tons and 50 crew each, plus the magazines).
It's nice to see S.F. that sticks to understandable rules and assumptions of 'tech, and makes good aliens too.
Have you ever considered making a funny compilation book or video titled "the first rule of war" where you put together all the different first rules?
♥️
With the shock absorbers moving forward after each thrust, these ships would be moving similar to giant Atomic Exploding Jellyfish.
Band name!
See "Medusa". They plan is to use tensile cables to pull the payload, and toss the bombs forward, to a giant parachute ahead of the ship that catches the plasma. The cables take hours to stretch and bungee back & forth.
Note also that a magnetic sail could be used to catch the plasma, which can make your "pusher plate" immaterial, and tens of km across.
Totally shield the ship from Solar flares and the bombs, though they'd be detonating at least a few km away.
This has been suggested at what we were seeing as Oumuamua apparently did a perihelion pass propulsive maneuver past the Sun.
You have a great new year too! From your description of playing D&D with your DoD buddies almost sounds like you served with some of my friends, as most of them were really into it too!
I’m working on my 2nd SciFi book 📖 now, got the 1st draft finished last night! World Anvil looks awesome 😃 Great episode, Isaac 👍🏽 Cheers!
Rocket-jumping to the stars. If all else fails, never underestimate the human ability to solve (or create) problems with massive explosions.
That closing line was extremely inspiring! Nice one, Isaac! :)
What about smallest possible nuclear detonations at the front of the ship, where blast goes into circular mass accelerator accelerating small mass objects to desired speed so that they can be released in controlled manner to slow down or accelerate the ship? Probably will need multiple circular accelerators to compensate inertia pulling the ship to the rotation direction
That would be really hard. At small masses of plutonium or uranium it is extremely hard to start a nuclear reaction and it is unlikely to reach reaction sustainablity. The minimum mass needed for a real nuclear explosion called critical mass and for uranium it is about 47 kg and for plutonium it is about 10.
I didn’t know you were an Army guy. A bunch of guys from my unit used to play D&D in our down time. 4th ID
I told a friend that I'd want to bring in a ranger (I meant a half-elf). (He'd been Army, I was N.G.)
He said that he'd dimension-warp me in from a drop bringing supplies and "military consulting" help to some rebels in some brush war. I had a couple of duffle bags of stuff, several magazines for my M-4, with M-203.
We worked out what Claymores and grenades would be like. I had zero armor and a bayonet & karate for hand-hand. Over a couple of days, I did a lot with a usual D&D party who didn't quite know what the DM was doing any more than I did.
After 2 days against orcs, bandits and bugbears (he rolled for me and told me that I'd pissed myself first time seeing them) I had to tell them that I didn't know how they could keep going and never get hit. I was on my last legs, many bandages and much of my first aid supplies gone, needing a few weeks at least to recover. (Magical healing? What's that? Superstition and witch doctors?)
8 seasons. You rock.
CANT STOP THE SIGNAL!
Project Orion is the most awesome ship we can currently build
Thanks for many years of amusement Isaac. Love listening to your brain tick
Instead of ejecting hot matter to generate propulsive force, with more heat leading to higher propulsive efficiency, I wonder if it could ever be possible to convert that matter into exotic heavy quarks and then eject those quarks (or utilize the energy they emit when they decay). Since some of those quarks become 600-2000 times heavier than a normal 'up' quark it may be one way of compounding the momentum attained when ejecting matter for propulsive purposes.
I think it won't work the way you suppose. Using a massive reaction mass will increase your instantaneous thrust but require _much_ more energy for the same overall delta-V. Photon (massless) rockets are the most efficient.
Since KE required goes with the square of the velocity, and the thrust is the momentum which is linear with velocity, your energy requirements go up with the square of the thrust.
It doesn't matter if you're using a kg of gold, a kg of feathers, or a kg of heavy quarks; ejecting reaction mass gives thrust based on that amount of mass and its velocity. Using heavier particles instead of atoms doesn't "compound the momentum" in any manner.
Nuclear pulse propulsion is the most Wile E. Coyote of all propulsion methods.
Gonna go ahead and prelike this and let it play on mute for the algorithm and come back to it after work 👍👍 10/10
Amazing Content, Daedalus is cool
7:00
however yo ualso have to conisder that high energy densities mean less mass but also less efficiency
roughly speaking 100 times the energy density means 10 times the specific impulse and 10 times the propulsion/fuel consumption ratio
although the exponentiality of the rocket equation makes evene asligh increase in specific impulse have a huge impact on actual fuel needed in most cases
Hey, run the numbers with a 10 Gigawatt nuclear plant just heating water to the ~1900C we can manage materials for. A 10 GW plant with pure fissile is looking about 5 m^3 (assuming the water takes the power away) and perhaps 40 tons. Teakettle SSTO, unless I am mistaken.
Isaac maybe you want to take a look at magnetic reconnenation rockets. It's a new concept but looks very promising.
I googled this but couldn't find that exact phrase, do you have any suggestions for where I could find out more?
@@TokyoTrainStyle sorry my apologies
I misspelled the name of the concept.
What I meant to say was magnetic reconnenation thruster.. Or the Ibrahimi drive.
I hope that helps.
Love this. I'm writing a series of novels on just this theme, blowing sh*t up with nukes to save worlds.
Issac not sure if you have done an episode on a recently published engine process called muon catalyzed fusion engine. Would love your opinion on it if you haven’t done one or if so would love to listen to it.
Where can we find the chart shown at 11:00? Also mad kudos for mentioning Stanislaw Ulam, a Polish American who worked on the H-bomb, among other things - I never thought I'd see his name connected to space sciences!
Also, I don't think the fact that we found peaceful and useful uses for nukes precludes using them for nefarious purposes - or using useful purposes as excuses, simply - saying that it's for propulsion while in reality it is weaponized.
Orion always struck me as a kind of cosmic mechanical inertial inchworm.
Thank you and the entire team once again. Congratulations to your friend. Best wishes all. These episodes are pure joy.
I read the caption 'battleship' and instantly thought of the Archangel Mike...
"God was knocking, and he wanted in bad!"
'Footfal', Larry Niven and the late Jerry Pournelle
Won't let me correct 'Footfall'
Wow I'm early, love you isaac ❤
It was one of my favorite parts of Marko Kloos's Frontlines novels when they started using Project Orion-style propulsion (though for a slightly different purpose, not to be too spoilery) and I recognized it. Also I want to recommend those novels for anyone into fairly hard military sci-fi (harder on the military than it is on the science, but the science is still at least on the firmer side from space opera [Alcubierre drives and gravity generators exist, but are never explained, for example]).
Ah what an explosives video to start the new year to. Informative as always Isaac.
I can literally listen to you for years non stop! XD thank you for your great content always!!
I kinda love the old Orion concepts, and wonder if there might actually be a few here and there already. Lotsa dark dollars and projects running around out there.
“I didnt come up with 1, I came up with 4!”
It’s not bragging if it’s true.
Awesome channel with awesome content and great quality 🌍💯
If a ship like this was setting off to mars or whereever from L.E.O could people on the ground see it? Like would people see flashes in the sky as the bombs do off? what is the luminosity of a nuke that you would use for this?
I appreciate your show good Sir. 🌌
18:13 happy time handling Cf-252 at that quantiy needed for a critical mass ... that isotope is used for its high spontaneous fission rate ...definitly not the stuff you want to make a nuclear bomb with
Nuclear battleship Micheal intensifies
My only issue with Orion is what brand of unobtainum they make the pusher plate out of? 🙃
The "Heinlein kinda predicted the fission bomb," remark kind of reminded me of how I though that H. G. Wells kinda predicted the laser with his Martian Heat Ray from "War of the Worlds." Thoughts?
If you want a space missile that is fast and agile (able to accelerate to avoid flak), nuclear pulse propulsion seems perfect, but you also ideally want to be a small target too. What's the smallest orion engine you can create? Does being single use allow you to skip the spring on the pusher plate?
The orion drive becomes extremely inefficient at small sizes, the smallest practical size is about 10 meters in diamater. But, a missile wont need to evade flak with this technology. A derivative of the orion drive is the "casaba howitzer", a nuclear weapon where the energy of the nuke is focused into a shaped charge that accelerates a relativistic plasma beam towards the target. Such a weapon could obliterate enemy space ships from thousands of kilometers away in the blink of an eye with a warhead the size of an artillery shell.
Happy Arthur's Day
Were did the thumbnail art come from? I read in the description that you credited it to Jakub Grygier, but I couldn't fin it on his site, and I wanted to get a closer look at the art because it looks pretty cool.
Great episode!
now i want a "californium dream" t-shirt 😎
that ship around 22:10 reminds me a lot of the MISC Odyssey's concept
Happy holidays isaac arthur
Great episode.
I read there is a pellet beam propulsion drives being developed. We need a multinational manhattan project for orion. The videos on propulsion drives are always great to watch.
Isaac: Are there any kinds of star, perhaps ones close to others that would be of interest for colonising, that would be suitable for large-scale atmospheric braking? In Clarke's 2010, Jupiter is used for atmospheric braking, and would do a much better job than Earth. What about a red giant, or a brown dwarf? Any possibilities there? I am thinking of the problem of reducing the fuel usage required in decelerating a ship on arrival near its destination, especially a ship sent by laser blast, to a system that has not been colonised, and cannot therefore provide a laser blast for braking arriving ships. Another possibility would be sending freight in advance, at much lower speeds, freight which would contain equipment for setting up automated factories capable of providing not just habitats for colonists when they arrive, but also to provide laser systems for decelerating arriving ships.
Look into electric or magnetic breaking, or the concept of the Bussard ramjet. Any of the concepts that ultimately failed as a propulsion system because the friction is higher than the thrust will in fact still be useful as a _brake_ .
Great video as always!!
Imagine a mega-structure scale frisbee spinning to create artificial gravity on the edge, and with the bottom (concave) side painted with a radioactive mix that is in a controlled release state. The outbound radiation provides thrust. The inbound radiation is captured to provide house energy (and/or produce more radioactive paint).
- The main efficiency problem is that the outbound radiation is omnidirectional while we would prefer that it be unidirectional. We can tweak the design by adding a skirt or magnetic coil around the edge to redirect some of the radially directed ions.
- Recall that temperature is a statistical concept that averages the kinetic energy in a gas T = k * sum( m v^2 ) / n :: where 'n' is the number of particles in the gas. However, if you add in big-N 'N' to include the number of atoms in the heated structure, T can be reduced to below the structural damage point if N is orders of magnitude larger than n. (n
from what I remember the avurage square kilometer of territory on earths serface not the serface of the atmosphere that's pluss 30+ percent, receaves the equivalent of a 1 kiloton nuclear bombs worth of energy