Human Mars exploration with nuclear propulsion is inevitable!
this video is supported by brilliant hey hey marcus house with you here now i've been wanting to make this video for many months so i'm really excited to finally be publishing this one today we are talking about spacex's hints at using nuclear propulsion along with nasa's artemis plans which also mention nuclear propulsion as well do they both plan to invest heavily in such things that remains to be seen but you might be surprised at the colossal difference that it would make compared to the chemical engines currently in use other high efficient methods of propulsion like ion drives are becoming much more common for long duration missions and we can even compare all this with some more futuristic options i think you are really going to love this one so believe it or not there are some pretty interesting technologies which would make travel to mars and beyond much more efficient now i'm not referring to all of the careless drivel about alien anti-gravity technology that governments have supposedly reverse engineered we have already got some game-changing propulsion systems on the table that have not only been tested in the lab but have already been used as crucial components in some of the most impressive missions of recent years so first just to set the standard let's just quickly run through the leaders in chemical propulsion before we dive into these more efficient engines spacex chose liquid methane and oxygen for starship this is a popular rocket propulsion mixture which will also be utilized by other massive players in the industry including united launch alliance with vulcan centaur and blue origins new glenn both of which will be driven by blue origins be4 engine so why use methane instead of hydrogen considering that hydrogen is well much more efficient it's because methane's boiling point is negative 161.6 degrees c and it is much more dense than hydrogen making it a lot less tricky to handle as well comparatively hydrogen must be kept at the incredibly cold temperature of negative 253 degrees c and requires extremely complex infrastructure to actively call it additionally hydrogen is bulky and it takes up considerable volume so you don't get a lot of fuel in the space that you need to store it when you factor all this in even though methane is less efficient it is much easier to work with and it's loads cleaner than rp1 which is what we see fly on say falcon 9. specific impulse or isp is the measurement that we use to determine how efficient a rocket engine is if you want a deeper explanation on isp and how all those numbers work check out the video right here because this is not the video to dive into that to cut a very long story short the faster that we can spit the exhaust out the more efficient our engine is going to be for now we are going to just keep these numbers based in a vacuum just because that is faster and easier for the purpose of this video as well we are concentrating on a vehicle that can be used as a transfer vehicle through a vacuum anyway so let's just run with that spacex's raptor engine is estimated to be at an isp just above 360 seconds or so based on these old numbers it may get a little more efficient than that but probably not by a great deal comparatively one of my all-time favorite engines the rl10 running off the more efficient but troublesome hydrogen gives us an isp slightly over 465 seconds now to easily demonstrate just how much difference this makes alone i've got a theoretical vehicle here that weighs 10 metric tons total and half of this mass is propellant so 5 tons here we are sitting in low earth orbit and we are going to see how much we can accelerate our vehicle in this example using methane as our fuel we can accelerate away until we hit 2447 meters per second in relative velocity that is what we call the delta v or the change in velocity available to us with the more troublesome hydrogen and oxygen propellant we can get our ship up to a much higher velocity at 3160 meters per second that is quite a big difference isn't it and this is really just an isp increase a little over 100 seconds the problem is the faster that you want to go the more propellant that you need and it becomes increasingly monstrous to land useful payloads on the moon mars or even further now we may not have access to an anti-gravity drive but what interesting options are out there first let's talk about nuclear spacex's president gwen shotwell not long ago mentioned that human mars exploration and nuclear propulsion systems are inevitable now that was an interesting point as i don't believe that we've heard anyone at spacex talk about efforts to develop a nuclear thermal rocket in-house i do vaguely recall her a few years ago mentioning that it was difficult to acquire nuclear materials for testing but since then nothing could spacex nasa or both be seriously working towards this technology we also see nasa mention wanting to include a nuclear propulsion subscale demo around the time of the artemis-8 mission nuclear thermal propulsion can still provide quite high thrust but it has a much higher efficiency if a mars transfer vehicle is propelled with this technology it makes a colossal difference it works by transferring heat from a nuclear reactor directly to a gaseous hydrogen propellant that super heats the hydrogen up over 2200 degrees c expanding it greatly and ejecting it at a massive velocity let's use our same test vehicle propelled in this way the specific impulse essentially is doubled here at over 840 seconds in a vacuum in fact some research even suggests that it could be as high as 900 seconds with some more refinement so with this we have a new delta v over 5700 meters per second at theoretical limits it almost doubles the delta v of the hydrogen oxygen engine so this is obviously advantageous isn't it nasa seriously looking into this though or is this just a pipe dream well it is indeed serious nasa is leading the effort working with the department of energy to advance this technology having already selected three companies to produce conceptual reactor designs for future missions designs for a nuclear thermal propulsion system which would use low enriched uranium fuel now keep in mind that the base technology isn't new nirva was a nuclear thermal rocket engine program that ran for almost 20 years and it was very successful sadly it never had a chance to fly in space after nixon killed the program in 1973. the engine was even deemed ready to integrate into a spacecraft so why did it get cancelled well environmental concerns were won but of course we can safeguard these concerns with the current technology people are not hugely fond of nuclear material being launched on rockets so the regulations and the protection systems needed there can't be understated then of course after the apollo missions political interest in the manned missions to mars sadly died the advantages of this are clear though you can get to the moon or mars and back with lower overall weight larger payloads and shorter travel time as well these are the colossal advantages of nuclear propulsion so who were the three companies selected for this bwx technologies in virginia partnering with lockheed martin ultra safe nuclear technologies of seattle partnering with a bunch of other companies including blue origin then we have general atomics electromagnetic systems in san diego they are partnered up with x-energy and aerojet rocketdyne so the great advantage to all this technology is that it can branch off in many interesting places nasa is also working toward a fission surface power system for use on the moon and mars as a source of power for the bases one example is work already done on a 10 kilowatt nuclear power generation unit this is the kilo power reactor using sterling technology or krusty for short hey hey oh man so many people tell me that my intro has been stolen off crusty of the clown so nasa's fission surface power project expands on these efforts aiming to upgrade the idea to one that can provide four times that power at least 40 kilowatts that is enough to continually run 30 households all of this technology is critical in my opinion and another interesting spin-off to this is for nuclear electric propulsion options not the same thing as nuclear thermal propulsion and i'll dive into that shortly so what could be a better option than nuclear after all if we don't need to launch radioactive material into space that would be better right well what if we could use water as propellant no i'm not talking about this crazy thing and i also don't mean converting it to hydrogen and oxygen and using it as already described instead i'm talking about just using water vapor introducing the microwave electro thermal or met thruster although this can use a variety of different gases using water vapor has been shown to give incredibly amazing performance in this paper it was claimed to have a specific impulse greater than 800 seconds yes that is almost the same as the nuclear thermal propulsion that we've just talked about okay great problem solved then right we can launch massive amounts of water to orbit with a huge vehicle-like starship water can be used for life support for shielding the crew from radiation and now even for propulsion the best thing no dangerous chemicals or radioactivity well just hang on a minute because there is a long way to go here the demonstrated matte thruster uses intense microwaves to superheat the water vapor or gas creating a hot plasma reaching about half the temperature of the sun's surface as far as i could find these tests have operated using up to 50 kilowatts of power yep it takes a lot of power and it provides quite low thrust currently companies like momentous space plan to continue innovating this technology initially created for small satellites they actually aim to make platforms to allow them to refill existing satellites and help them continue operation once again using water as the propellant in fact you may recall the vigoroid spacecraft launched on spacex's falcon 9 rocket on may 25th this year along with many other customers on the transporter 5 mission sadly due to the vehicle experiencing issues with the solar panels it has not been a fully successful mission although they did manage to deploy two of their customers satellites they had a lot of trouble on that first mission so yes they are planning more flights soon and it will be interesting to watch that technology evolve although the vigorous vehicle supporting up to 750 kilograms with up to two kilometers per second of delta v is the first step deep space vehicles are proposed such as fervorite claiming to support 20 metric tons with up to seven kilometers per second of delta v now that is obviously way down the track but long term this kind of technology could be incorporated to mine water from asteroids along with other precious metals so these engines are low thrust but with a lot of mission time who knows what goals could be accomplished sure it's unlikely to be used on crew missions but as supporting vehicles that is where the benefits lie with this type of technology so from an efficiency point of view it's very very hard to beat ion propulsion now honestly i could make a complete video just about this alone as there is just so much great content and history on all of this these are again very low thrust but extremely efficient methods of propelling a vehicle how efficient well typically these inject exhausted velocities anywhere between get this 20 to 50 kilometers per second yes per second that provides a specific impulse between say 2 000 and thousand seconds compared to anything discussed so far yep that is a lot more so let's go back to our experimental vehicle here with an isp of say 2 500 seconds just as an example this provides a velocity change potential of almost 17 kilometers per second now this is all stuff that exists right now you can even look at many small spacecraft out there whether it be something like starlink powered with krypton as its propellant or xenons such as what is used on the deep space 1 or dawn space probes this is out there now being used in many ways on small and large satellites and uncrewed emissions the technology here gets even crazier too with experimental thrusters such as the variable specific impulse magnetoplasma rocket yep you've probably heard that name before this takes it to the next level again using radio waves to ionize and heat propellant form a plasma and then vastly accelerate it using a magnetic field the specific impulse potential is claimed to be anything from 3000 seconds to 10 000 seconds and the thrust available could make it possible to propel vehicles large enough to support crew using our test vehicle again with a specific impulse of 10 000 yep that almost looks ridiculous it comes out to almost 68 000 meters per second that is 68 kilometers or a little over 42 miles every second now i shouldn't get too carried away here should i because we are a long way from this essentially because the power requirements are just staggering for a large vehicle such as a crude vehicle many even suggest you would need up above 200 megawatts of power requiring a colossal reactor then with all of that you are going to be generating ridiculous waste heat enough to require radiators at a size that could comfortably cover the size of a football field we just don't have that technology yet yet being the key word here because it is conceivable that one day we will and with specific impulse like this we could cut back a six-month trip to mars down to just a little over a month absolutely no problem vehicles such as ares 3 as shown in the martian start to look a lot more practical at this stage so this is of course where we round back to nuclear electric propulsion rather than using a nuclear reactor for propulsion such as the already mentioned nerva engine nuclear electric propulsion is simply using the generated electricity derived from a nuclear reactor to power higher efficiency engines such as ion engines or met thrusters nuclear electric propulsion continues to build on their existing work maturing the solar electric propulsion thrusters and systems for artemis alongside that the development of fission power for the lunar surface now what about even further down the track what if we could finally create stable fusion reactors okay yes i know fusion has got a bad reputation for always being 20 years away government-led research has been trying to crack this for what seems like forever every estimate seems to indicate another 20 years before the timeline is then extended again by 20 years so why even talk about this well what i think is interesting as of just recently is that the private sector is now beginning to throw colossal assets at this problem more on that in just a moment but real quick a huge thanks to brilliant today for sponsoring this video if you are looking for a great way to engage your mind and develop problem solving skills brilliant is for you they have loads of courses that combine storytelling with interactive challenges placed throughout the lessons if you are interested in topics like today's video you can get stuck right into this course here to form a solid understanding of the rocket equation this classical mechanics course will kick off at the ground level with wonderfully detailed and interactive components throughout start off understanding the basics of matter in motion and before you know it you'll have progressed right up to the rocket equation and be understanding at a deeper level how thrust in one direction causes that equal and opposite reaction you can also learn all about newton's law of gravity and crack open the universe and the consequences that spring from it brilliance thought-provoking math science and computer science content helps guide you through complex concepts breaking them up into smaller understandable chunks you'll start by having fun with the hands-on course components and before you know it you'll be amazed at what you've learned thank you very much to brilliant for their support of my channel here and if you would like to help support me and you'd like to give it a try go to brilliant.org marcus house the first 200 people will get 20 off the first year of brilliant premium the link is in the description below so yes nuclear fusion technology right now i think is more exciting than it has ever appeared private companies are now collectively throwing billions into this new technology and tackling it in a very different way in fact commercial solutions may not be as far away as you think loads of private companies such as general fusion creating very different designs to the typical tokamak style reactor such as that by jet which i'm sure that you're probably more familiar with this one is more like a fusion version of a diesel engine there is just such huge money invested in this project alone by big contributors such as jeff bezos this project alone i think is quite exciting because they are aiming to break new ground within months from now another interesting one is first light effusion claiming to approach the problem in a simpler more energy efficient way and with less risk as well this inertial fusion is a pulsed process where a small amount of fuel is injected and then hit with a high velocity projectile instead the best thing about most of this potential fusion technology is that it really requires no radioactive material now assuming humans made on earth are capable of utilizing fusion not only for power generation but also for direct propulsion what sort of efficiencies are we talking there well direct fusion drive research such as that done at princeton's plasma physics laboratory among others suggest that the efficiency could be up there with a specific impulse above 10 000 seconds similar to the magneto plasma rocket that we've just talked about but with much more power and thrust to harness fusion reactors could also power the vehicle itself so that could be quite the ultimate propulsion power source that is of course until someone manages to create a warp drive probably forever impossible and hey we've got to do more than just scratch the surface of the space-time continuum for that one a topic to fill an entire video on its own i'm sure so yes the investment going on right now within the private sectors is quite promising but of course the main hurdle right now is mass to orbit that we are going to continue to do with chemical propulsion at least for quite some time into the future there is really nothing else that provides that huge thrust needed to escape earth's gravity elon musk's goal of future reusability is step one and this changes everything alone think of the space inside starship that could be used for lifting reactor equipment into orbit even think of the other massive telescopes that we could launch that don't need to be folded up like the james webb space telescope in fact just thinking about that maybe making a video on that point alone could be interesting is that something that you would like me to explore maybe often your opinions are better than mine in that regard anyway once mass is placed into a stable orbit high efficiency and lower thrust options can be put to work on much larger vehicles options that are only just being invented or maybe being brought back from history what do you think are we likely to see the industry shift to nuclear fission for power generation and propulsion in space or are we destined to use chemical propulsion for decades to come let me know what you think and thanks a heap for supporting what i do here if i've just earned your subscription a huge welcome to you so grateful to all of you amazing patrons and youtube members right here you blow my mind every week if you love what the team and i do here and would like to help out the patreon link is right there and likewise if you need some new merch loads of options here just for you if you enjoyed this video here are some other deeper dive ones if you haven't seen them yet have an amazing week and i'll see you all in the next video
2022-08-24 21:29
