Why Is It So Hard to Build an ICBM?


There’s been a lot of talk, confusion and fear lately surrounding North Korea, and ICBMs or Intercontinental Ballistic Missiles. On an individual level, like there’s not a whole lot that I can do about North Korea but sometimes it helps to understand the things that we’re like kinda freaked out by, so we wanted to talk about how these weapons of mass destruction work, why they’re so difficult to engineer, and why they’re so dangerous Missiles are guided, rocket-propelled weapons and ICBMs are the longest-range missiles out there. They can travel at least 5,500 kilometers (about the distance between New York and London). Some designs can go twice as far or even farther. ICBMs can also carry warheads, the toxic or explosive stuff that makes them especially dangerous and a big concern these days is having an ICBM that carries nuclear warheads. Over the last few years North Korea has been testing missiles that can go farther and farther and on July 4th they launched their first test ICBM and they’ve already followed up with a second on July 28th. Experts say that, well, it doesn’t seem like they’ve completely figured out how to make functional ICBMs; they are getting closer. Now the US and Russia have had ICBMs since the late 1950s, but building them is really hard. It’s literally rocket science. At the core of the problem is a trade-off between mass and distance. If you want a missile to go really far, it’s easier if it weighs less, but you need fuel to propel it those long distances, and the warhead is pretty big too which means it kind of has to weigh a lot, so you need to engineer your way out of the problem and find a balance. That’s led weapons designers to build ICBMs with multiple stages instead of just one fuel tank and set of engines. They work a lot like the rockets we use to get the space. Missiles with multiple stages lift off of the blast from the main stage or booster. But, once that fuel is spent that part of the missile with the heaviest engines that produce the most thrust can be let go. The lower mass then makes it easier for the rest of the missile to accelerate and travel farther propelled by engines and fuel in higher stages. Multiple stages can really extend the missile’s range by gradually sloughing off some of the weight, but the nuclear warheads they’re designed to carry are still very heavy. They’re made out of enriched uranium or plutonium; some of the heaviest elements, so weapons engineers try to nuclear warheads as tiny as possible. We’re talking several hundred kilograms instead of a thousand That’s known as miniaturization. Less material usually means a smaller, lighter weapon, but there are ways to organize metals and other unstable materials to make the reactions extremely powerful. I’m not going to get into too much detail about this for obvious reasons, but one of the most space efficient designs is a thermonuclear weapon; one that uses a fission reaction and then triggers a secondary fusion reaction. Fission reactions release energy by splitting atoms, basically, neutrons it kicked out of the nucleus of an unstable atom hit another nuclei setting off a chain reaction that releases lots of heat and X-Rays. When you build your weapon the right way that release of energy can set off a secondary fusion reaction which releases energy by putting atoms together and producing more neutrons, and if there’s more uranium or plutonium wrapped around the fusion fuel the fusion reaction can trigger more fission, using up more material and releasing even more energy. The combination of fusion and fission makes a really powerful bomb Nuclear weapons are so destructive because messing with subatomic particles can unleash a lot more energy then just breaking chemical bonds like typical explosives do. More energy means more immediate destruction plus there’s the ionizing radiation that can damage tissue and cause radiation sickness. While the basics of designing a compact thermonuclear bomb have actually been well known for more than half a century, which is why I’m able to talk about it right now, putting all these engineering strategies into practice is a lot easier said than done. You have to make the materials and figure out how to trigger the fusion reaction and keep the chain reaction going through as much material as possible. And even if you stick with a simpler bomb that only uses fission you’d need to keep it tiny and keep those reactions going instead of just fizzling out. To make an ICBM you have to do all that and then send the missile into space and back. And another huge challenge for missile engineers is re-entry through the Earth’s atmosphere. Even though other ballistic missiles go into outer space, ICBMs have it the hardest because they’re traveling so fast when they’re coming back into Earth’s atmosphere, at more than 21,600 kilometers an hour, and when you re-enter the atmosphere that fast you generate lots of heat like even above the surface of the sun temperatures, it definitely melts metal, so without some kind of protection these missiles would just disintegrate before reaching the ground. One way to protect the warhead is to have a big, bulky re-entry vehicle that slows it down before it hits the lower denser parts of the atmosphere, Where the heating gets to be the most intense, but big and bulky feeds into the weight issue. We talked about before and it’s harder to hit a target with this slower type of design. Engineers can build heat shields that are relatively lightweight and are designed to break up during reentry These chunks carry away the superheated gases and heat from the surface of the missile, keeping things relatively cool, but this can also raise new challenges for getting the missile to where you want to go. It’s hard to use computer models to predict how an object might veer off course when pieces of it are burning off, especially because they can burn off unevenly, and that’s even harder for missiles like ICBMs that spend a lot of time in the atmosphere because tiny trajectory errors can get compounded over longer distances. So because ICBMs travel so far and fast, everything is harder. You need it to have powerful engines and survive the atmosphere, but you also need it to be as lightweight as possible, and of course you need to be able to aim the thing and modelling a missiles trajectory is its own huge challenge. It takes a lot of work and engineering and brainpower all for something incredibly dangerous that pretty much everyone agrees should never be used. To be clear, we’re pretty sure that North Korea doesn’t have working thermonuclear ICBMs yet, but they might someday. As more countries make destructive weapons, it’s easy to feel powerless or afraid but it can help to at least understand the technologies that humans are using to threaten each other, and we do have ways to protect ourselves against the threat of an ICBM which we will get into in a future episode in the meantime Don’t freak out too much, and thank you for watching this episode of Scishow News. If you’d like to see our other episodes about the science of nuclear weapons or if you’re interested in learning about more things in science, generally you can go to youtube.com/SciShow and subscribe

100 Replies to “Why Is It So Hard to Build an ICBM?”

  1. We had a distracting glitch in our last upload, so this is a re-upload from a few minutes ago. Thank you so much to those of you who pointed it out!

  2. Hank, you missed the bleeding obvious. One of the most difficult challenges is to build a nuke to withstand the G-Forces and vibrations of lift-off. Nukes are one of the most sophisticated, complicated and above all fragile inventions ever devised. It doesn't take much to make the weapon fail, that is why maintenance and servicing are of paramount importance and a constant drain on a nation's resources.

  3. KEEP YOUR HANDS STILL!!!!!!! Damn it's hard to watch your videos while you're gesticulating wildly like a wacky waving inflatable arm flailing tube man.

  4. Seems many people here are unaware of the fact that Hank is also a Chemistry PhD. if I remember correctly along with being the host, and #2 accelerate was misspelled in the graphic splash, just fyi.

  5. You only worry about dying while you are alive. Once you are dead, you don't worry anymore. Therefore, if you are currently worrying about dying, that means you are still alive. And if you are still alive, then you're not dead, so why are you worrying about it? You're alive… enjoy it… and stop worrying.

  6. Cause people are watching Uranus, ready to explore it at any signs of life….especially life coming from such ghastly places…..I mean gassy…

  7. My goodness it appears as if you are having a 6 minute seizure…PUT YOUR HANDS IN YOUR POCKETS AND PUT ON A NECK BRACE!!! Otherwise, great video.

  8. After this whole Jussie Smollett MAGA-Beatdown hoax. Who knows what's real? It could all be one giant hoax designed to scare the world into submission while making the global industrial military complex filthy rich.

  9. ICBM = I see a Bowel Movement coming. If someone fires an ICBM at you, then you are guaranteed to have a Bowel Movement. This is a known fact. An Inter Continental Bowel Movement. Guaranteed!

  10. How smart is a smart missile? Specifically the ones made to counter destructive ones. How are they made? Are they difficult to make?

  11. The easiest ICBM to build: a rock thrown across the Bosporus in Istanbul. It’s a missile, it’s ballistic, and it crosses a boundary between continents!

  12. Such impressive engineering devoted to something I pray is never used. Fortunately there are lots of good things that have come from the programs as well. Our space program is useless without the same technology.

  13. Americans have no moral right to lecture other countries about having nuclear weapons. Specially, when they are the only nation to have used it to kill women and children.

  14. oh crap! I guess I'll go back to throwing rocks, and find out if I can throw it farther than 550 cm or Twice or even FARTHER. don't worry I'll keep everyone updated on my new project.

  15. **In other news, Kim Jong Un has stated that North Korea has completed upgrades to their latest ICBM. He stated that a video from SciShow gave them the secret information necessary to complete the project…

  16. The dprk wouldn’t use them unless they are nuked or invaded first. It’s deterrence. They are vehemently anti imperialism, an unprovoked strike against another country would be a form of that

  17. You cannot talk about it for obvious reasons? You make it sound like you have a security clearance or some such.

  18. I KNOW THEIR ARE NO STUPID ?S BUT COME ON…. ANYTHING THAT TRAVELS BETWEEN WHOLE CONTINENTS WILL BE HARD TO UNDERSTAND….

  19. I bet it’s actually really easy to build one and they’re telling us it’s hard so that we don’t try to make one ourselves! 😆

  20. Scientists are capable in building icbms but a time isn't coming yet to find cure for deadly disease like cancer it's Shame.

  21. Yeah but why go thru all this trouble when they can easily smuggle them in and load them up in uhaul trucks?

    A missile has a return address, a nuclear uhaul ied doesn't.

  22. That's why it's best to build a thermonuclear bomb at the place you want to detonate it. Saves you building a ICBM.

  23. The redstone rocket has been around since the 1950's developed and built by Chrysler corporation this is a fact as these were the guys that built the saturn rocket that put a man on the moon . So this guy is not actually talking about the rocket but the bomb not really a true title of this video

  24. The day after November of 1983 the greatest television movie ever this movie saved the world from nuclear war god bless the day after you saved all of us thank you abc and the day after

  25. The Christian God Jesus is Satan the devil and he is not coming back… Christians worship Satan with a human sacrifice of Jesus to Satan… you've been deceived… repent accept Jahovah an do good works. In

  26. Modern nuclear warheads don't really weight that much. British nuclear warheads only weigh 164kg, and only 3kg of that is plutonium. In a complete weapon, you might have 10-15 kg of fissionable material. The weapon fuel mass is a tiny faction of the total missile mass.

  27. the fact that they're expensive and difficult to build has both positive and negative aspects to it
    the positive is that few people have them the negative is that the worst people have them
    No matter how bad it is Western science and technology can't be ignored because it can kill you and it makes you poor
    One may wish icbm's didn't exist but is nothing you can do about

  28. Although it's easy to buy into the demonization of North Korea, and there may be significant deficiencies in their government, one should be aware their belligerence has been cultivated by 70 years of sanctions and continuous threats. Western media tends to blame the NK government for starving citizens but western governments and the US puppet, the UN, are the ones preventing NK from buying foodstuffs. Many people failed to make the connection between NK threatening Guam last year. The US was flying nuclear capable bombers from Guam directly at NK several times a week. NK had to go into full response mode every time. The publicised "Live Fire Drills" are systematically destroying fish habitats to worsten the alleged food shortage. Another interesting thing is that when NK shot missiles over Japan, the Patriot missile batteries failed to do anything. This could lead one to assume the Patriot missiles around the 34 US military bases in Japan were tasked for offense instead of defence and could not be re-programmed in the time the NK missiles were in the air. I am not an apologist for N Korea, I am not a cheerleader for the west, I simply seem to get more information in my retirement location than western media exposes to their people.

  29. I suppose if anyone reading this comment wants an update on this situation. North Korea got stuck on the problem of making the nukes small enough, and making them survive reentry at the same time. They may have figured out the small enough nuke part by now, but probably not.

    They definitely didn't figure out reentry, they only managed to launch a few unsuccessful test payloads that didn't survive before running out of resources. They can no longer import any rocket fuel, and they don't have the infrastructure or resources to make their own, or to even make the things required to begin making their own. There is also no way to sneak in enough rocket fuel to do anything with, because they need such massive amounts there is so way they could sneak them in.

  30. I work with wifi system, I set up the college wireless network with authentication and monitoring and open source software. I also deal with unrealistic expectations from my users and bosses. Such as connecting 300 users in a small hall with 10 year old AP.

    I would like to know how others doing it. Especially the many difficulties I encountered along the way. Is anyone out there actually doing detailed traffic monitoring + data quota for wifi?

    Same if I encountered an intelligent being from another planet, I would love to know how did they do it too…not the wifi, I mean, do they build nukes to threaten each others, or is there some other more elegant ways. How do they deal with differences? How?

  31. The terminal guidance is the difficult part. As far as the nuke we, the Russians, and I'm sure many others make them for artillery that weigh just over 100 lbs.
    To just cause destruction just use powdered plutonium and spread it over whatever areas you wish to destroy life on

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