I love reading about the declassified reports of SR71 pilots. More than a few times, it amounted to, "SAM launch detected. Accelerated to outrun missile. Success."
The one that I heard about was Malta receiving a distress call. The pilot stated that his craft was losing fuel and needed an emergency landing. When asked his ETA and current position, he replied fifteen minutes, arctic circle.
@@janbaer3241 yea that sounds 100% credible, it took sr-71 ~2 hours to fly across the atlantic (correct me if im wrong), and only 15 minutes to get from arctic circle to Malta? And having an emergency over arctic circle, they chose to fly all the way over to an island smack in the middle of mediterranean sea? 100% credible say i. Going from arctic to Malta you've got possibly Greenland and England, and surely whole of Europe to land on, but naa, they chose Malta because its sunny i guess
@@slevinchannel7589 The channel says that any spaceship that is able to do interstellar travel in anything like a human lifetime (in other words it's traveling between star systems at a significant fraction of light speed) can easily destroy a planet. This is true. Kinetic energy can absolutely be used to destroy planets. A single flower petal, if it was going fast enough, could blow up the earth.
@@slevinchannel7589 For example, a thousand kilograms traveling at half the speed of light would have a kinetic energy of 13 quintillion joules, around 60 times larger than Tsar bomb, the biggest nuclear bomb ever detonated. What u want for this is the relativistic kinetic energy formula, it's hard to type out here but a quick google search will show u what it is.
I was thinking of a beautiful bird of peace, flying into space...then stolen, and twisted to the purpose of war. EDIT: Since I guess this was too cryptic - ruclips.net/video/xcQHUMEGAoA/видео.html
@@Burkhart4192 Louis Blériot felt the same way about airplanes in general in their early days, but if a technology can be militarized to one's advantage, it will be... Welcome to history.
@@matthewblairrains6032 based on the actual science of it were probably not too far off that, check out iter. it will probably still take many years (possibly even decades) for it to reach the implementation stage though.
Mhm, Interesting, yes. 😀 YEEEE HA! 😄I do declare I am intrigued. Awesome in all senses of the word and much much more. Whéééhhee! I am pretty fortunate IMO to be quite a knowledgebase overall, not above average brain but more focused on these matters for 25 years c.a. Basically just for the simple sake of our dear common sense that Einstein said was our most valuable asset, be good at common sense that has its focus pointed to the common sense goal of as many as happy, free, able, cool, common sensed, rich, fun, responsible, wild, respectful etc etc as we possibly can in a common sense manner. Perhaps.. who can tell? Who can tell? 👼 DON'T PANIC 🐶
@@gumunduringigumundsson9344 Common sense is not scientific, that was the doom of Einstein interpretation of Quantum Entanglement he though it was non sense, he was wrong.
I mean, any founding that Skylon receives is because people (speak: Airbus) wants that SABRE. A dual-mode engine like that would allow people to build literal stratoliners which would bring great benefits in flight time and fuel efficiency, which are two of the biggest issues for airlines. And while it has a somewhat lower isp than turbofans, it also has a much higher twr than them, meaning you'd need less engines per plane.
I'd say the association of increased power and speed with the word turbo comes from the word turbo charger (used to increase the power of an internal combustion engine) rather than turbojet since they were in more common use.
@@stefanr8232 From what I know, they were called turbo superchargers before just being shortened to turbochargers. This was during the gap between WW1 and WW2 where they started seeing more widespread use in internal combustion engines. I'd say they were named such as they use a turbine to extract kinetic energy from the exhaust gas stream.
@stefanr8232 just in case you still care after four years, a turbocharger has a turbine pump inside. There's an episode of _Scrapheap Challenge_ where they built an afterburning turbojet out of a turbocharger.
A couple of quick comments about a great show, 1) Aerospike nozzles and there brethren (aka Annular Nozzles) include spike, aerospike, expansion deflection, horizontal flow, and reverse flow. They don't necessarily point the gasses better, they adjust to different atmospheric pressures, unlike conventional Bell and cone nozzles. eg they are more efficient at altitude or in space while they are still usable at sea level. The Isp efficiency of a given propellant/engine combo in a vacuum is mostly dependent on the area of the engine out the back, until #2 below happens. 2) The Gasses leaving a rocket engine can be quite cold, despite being created at or above the material limits of the combustion chamber. Seeing an RL-10 running in a vacuum chamber with ice falling off/out and water running out of the engine is quite a surprise. You just want that fluid or solid moving as fast as possible. 3) One really important aspect of space planes is the re-entry / return / landing. Rocketback, hoverslam, etc are really complicated and somewhat expensive. A human pilot can't really land a Falcon 9 and a lot of payload is lost for the extra propellants. Some time ago you pointed out that the materials in an (atomic) rocket are the major limiting factor in Isp. The old NERVA engines were inferior in Isp to common, off-the-shelf Resitojets with the same propellant. Most people miss that. I love my Thursday Video Treat. -Gar.
Breathtaking work as usual Isaac. Your productions are some of the few I can go back to time and again. Thank you for sharing your beautiful mind with us.
5:00 "turbo chargers" have been around for longer than jet engines. The first ones being used on coal furnaces to get greater heat for boilers and thus more power for steam engines.
I think it's time for Neil deGrasse Tyson to step aside as the preeminent science/space/ futurism communicator and let Isaac Arthur take his turn. I guarantee Isaac wouldn't interrupt his guests or panel the second they started speaking lol.
@Casanova Frankenstein...ok? Anyway, I've been and remain a huge NdGT fan. I've watched all of the star talk lives. A good amount of the radio shows, but they're not as good as the live stage panels. The show show on i think natgeo? Not my thing. Loved the cosmos reboot. I've seen dozens of his lectures and interviews. It's just that as time goes on it becomes more and more apparent that he has an issue with interrupting others. He's an excellent lecturer and direct solo communicator. He just is a bit overbearing in an interview setting.
A scramjet-ntr combo would be very good I think. A nuclear reactor heats the air in the scramjet instead of fuel, and when it reaches high altitude switches to ntr and flies to orbit Like a nuclear variant of the sabre engine concept. The only problem is the extreme heat the reactors are generating, and the whole engine can melt down
Isaac Arthur the phenomenon as the evisceration of most types of brainpoop. Cause sometimes, not often but sometimes it is best to make brain poop with the protection and safety of my personal golden humor as my old and sturdy glowing hot katana and grenade launcher that is goldplated.
A bit of a correction on the aerospike (at least if I'm remembering correctly). Bell-shaped nozzles do generally focus the exhaust, but that depends on the density of the air around the nozzle, meaning its efficiency depends on altitude. This is why some nozzles have controllable geometry. The aerospike is *technically* less efficient in a vacuum (or it might be just as efficient, but not more), but the design naturally uses the surrounding atmosphere to focus the exhaust, making it efficient at all altitudes.
Spaceplanes might be the perfect case for the use of nuclear fusion. Its power density is not good, so it may never provide the thrust-weight required to launch a rocket vertically, but a spaceplane has wings so it doesn't require high thrust. A rocket needs a TWR of 1.5, whereas, for example, a modern airliner has a TWR of just 0.2/0.3.
Issac previously mentioned tethers and rotavators. If rotavators were built you could use a ramjet PR precooled turbojet space plane that can't reach orbit, but can fly high and fast enough to hook up a descending space tether.
Oh man, I'm so pumped!! It's been such a crazy week I totally forgot it was Arthursday, and that this week's episode is about frickin' space planes! This day just got WAY better.
As someone who's working on what might turn out a paradigm shift in VTOL... I'm tempted to say that we'll never have SSTO below the level of something like an airliner. Because anything else is logistically unviable and unnecessary, unless you're talking direct electrical energy -> momentum drive. And, once you hit that point - already a big "if", since we do not know whether if it is indeed possible to achieve this effect - then you're going to be capable of building a space elevator or orbital ring/skyhook system, so you're jumping from the one solution to the next immediately. The problem is, as always, reaction mass and the material concerns surrounding the human form, since we're discussing this for personal transportation. We've got the powerplant tech since long ago. We can generate the necessary specific power. It's converting it into useful form that is difficult. However, even if I'm successful in my efforts and we can manage to squeeze a VTOL craft down to a personal helipod package weighing in like a light sports plane or slightly less, the reason it would be successful is precisely because we've got a ready travel medium for reaction mass which we can use a single efficient engine to drive. You win by being able to take advantage of the medium and any resistance for better energy transfer and lifting purposes. Probably, even in the far distant future where we are making the steps toward something like an efficient EI drive or fusion or MPD thrusters, their efficiency will likely be capped far lower than that of simply using atmosphere as a combined fuel source and reaction mass for a considerable time. And we must entertain the possibility that it may indeed be for _all_ time, and with such a difference in absolute efficiency as a result of physical constraints, that it will never make sense to use a one-drive solution for both in-planet and even borderline off-planet transportation.
@@musaran2 Don't be a doof. Of course I'm not expecting to do anything alone. And did I say I was? But an idea is an idea, and it works if it works. And I've already proven that it works in principle. Of course I can't knock a thousand a day out in my bloody garage. So I've brought my old man and a couple more guys on, and I am putting feelers out with manufacturers and sponsors. But because of the way of these things, and because I don't want to get flattened, I am playing it close to the chest. Come the worst, I'll just get hold of an engine and modify and then build something around it myself to pot around in alone. And then you can blame "angel investors" and the fucking salesman-driven car industry for the fact that you can't have nice things.
The sabre engine is also a ramjet of shorts in air breathing mode, some of the super hot air bipasses the precooler and get mixed with fuel in the champers around the center rocket engine.
Is there anything better than the smell of jet fuel in the morning? Coffee, maybe. Spresso (the ramjet version of coffee)? Yes. Chatting about the future of aviation and propulsion with knowledgeable people and Mr. Arthur's community of out of this world nerds? Of course!
@@AdrianoCasemiro Coffee and jet fuel are 2 of my favorites. The last airshow I got to attend had a demonstration of a US Navy F/A-18F. When they cranked the engines, everyone else complained about the noise and smell but I stood there and absorbed it all.
@@AdrianoCasemiro "And people complaining about them have no place anywhere near them. " Look man, I love jet engines and rocket engines, I love the technology that makes them tick, it's why I became a jet engine mechanic, but don't knock people who complain about them. For all you know, the people complaining are the ones who do HAVE to be near them. Spending 9-12 hours a day trying to talk over them on a flightline is headache inducing, and will cause permanent long term hearing loss, and JP-8 is the spawn of satan. Its fumes kill brain cells faster than any drug, it causes rashes, itchiness, swelling and allergic reactions if it comes anywhere close to your skin, it increases cancer risk, contact with it can cause tinnitus and hearing loss, and it can even make your bones "glow" in medical X-rays... And sometimes the job basically requires you get drenched in the stuff, which effing sucks. I remember getting it in my hair one time. 2 days later, a ton of my hair fell out, and most of the skin in my scalp died and flaked off. Even its aftermath, like carbon, will coke up components and cause them to fail. I can't tell you how many start fuel nozzels I've had to replace on APUs because the carbon immediately clogs them. If you're not used to it, and you get to go experience the smell, sound, and sight at an airshow, and it's a unique once in a lifetime experience for you, then fine, enjoy it. But trust me, it's not a "privilege" to be that close on a daily basis. At best, it's an annoying headache you eventually get used to, at worst it's a long term medical nightmare. Sometimes the job is cool, like seeing F-15s take off full afterburner in the dark... But then another 20 do it in 1 minute intervals while you're trying to carry on a conversation, and it gets old real quick.
Another problem with using fission (to some extent fission, depending on the fuels used) in aircraft or in launch roles is because of the heavy shielding they need to avoid irradiating the crew or ground support crew. For this reason (as well as other ~complicated~ ones related to propellant choice and the heat issues Isaac mentioned), nuclear rockets and jets tend to have rather poor thrust-to-weight ratios compared to chemical rockets, which cancels out some or in some cases all of the advantage of better specific impulse.
I can see the awesomeness now: Two people, Garry and Matt, are walking out to the Matt's garage. The lights automatically come on when the sensors detect them walking in. Matt's cockpit ladder deploys, and he climbs into the cockpit. As he closes it, they both activate their ends of the peer-to-peer direct-brain-enhanced conversation system to hear each other. Garry: "I see you're probably having fun in there." Matt: "That's likely." The garage door opens. With a thought that lasts only a second, Matt imagines lifting his right index finger, and the engines ignite. Garry: "Yep, you definitely are." Matt: "What?! I can't hear you!" Garry: "I said...YOU DEFINITELY ARE!" Matt just nods and checks the cockpit. As he does so, information about engine diagnostics flashes in his vision. All four engine modes are graphically projected to be in good condition. Matt: "I CAN'T HEAR YOU!" he replies, overexaggerating. Garry: "YEAH, SURE!" Matt: "I'M JUST MESSING WITH YOU!" He grins at Garry as hs pushes his left index finger forward, for real this time, and just for the fun of it, pushing him back in his seat. The engines push the spaceplane forward, and a few seconds later, Matt lifts off the runway gently. The landing gear retracts automatically, and he raises his right hand, his palm facing down, lifting the metal and graphene composite dart into the sky. That's just something I thought would be fun to write.
Considering the successful test of Reaction Engines precooler in the UK and US, even at supersonic conditions, I am convinced that the SABRE will be built. Its use as a hypersonic vehicle are numerous as is the lightweight precooler tech. Skylon was taken off their site but the engine is what makes the concept viable. There is a big point you forgot in your video. Oxygen is far heavier than hydrogen. That is where a lot of the extra delta v comes from, flying to mach 5.5 on atmospheric oxygen.
The trouble with scramjets is that the Mach number of the fluid to which you introduce heat matters a great deal. The higher the Mach number, the more total pressure is destroyed when heat is added. This concern dominates even the concerns of keeping the combustion chamber lit and that of getting the fuel to burn to relative completion before it is literally behind the aircraft. In practice, scramjets are expensive toys that will never really be useful, and certainly not beyond about Mach 15 or so; the entropic losses become too great, to say nothing of the extreme thermal environment to which the entire aircraft would be subjected.
upload.wikimedia.org/wikipedia/commons/a/ab/U.S._historical_fusion_budget_vs._1976_ERDA_plan.png Pretty much covers it. They knew back in '76 that Fusion was gonna be expensive. This whole 40years away thing happened only because nobody in politics had a clue....real dev cost is probably gonna be another 5 times those estimates. But that would still be cheap compared to G20 military spending, so, easy.
Oh, and don't forget the XS-P or Phantom Express quick turn around reusable booster. That and a streached X-37 would give you a two stage to orbit spaceplane, or just consider the X-37 variant the space plane, and that could fit in a garage. ;)
I'm so intrigued, I have never heard this type of speech before. Is it a dialect? I love these videos, somehow makes my hopes for the future bigger! Thanks for it all!
As always, very good video, but I can actually comment something useful for once. I wanted to give a small correction that ramjets can operate from about mach 0.5, depending on how the intake geometry is optimized. Although it isn't overly hard to vary the intake geometry to optimize the ramjet for different speeds on the fly, in fact Airbus already has a patent on it, and they aren't the only ones who do. So it is in fact possible to get up to speed using a propeller (although I guess you are right as a turboprop would be most practical for this) and then turn the ramjet on at around 300-350 mph. Of course you'd have to come up with a mechanism to fold the propellers away, but I've had a few ideas on how that could be done. This way you could make the takeoff and landing fully electric too, so not even that environmentally unfriendly.
one of the advantages of the skylon design claimed for it by its developers is in terms of reliability. rocket launches obviously do have a very high failure rate, compared to other forms of transport, and i think this alone makes things like skylon an interesting proposition, if they can dramatically improve on that
I love this. So practical and inginuitive. Efficient Space planes would definitely reduce the launch cost and would reduce the risk of crash landing dramatically
Hey Isaac, I was listening to one of your older videos the other day (Impact of fusion because I wanted my son to understand how big a game changer that would be) and noted with delight that you are really improving on that speech impediment. Keep working at it! Sending you good wishes!
Isaac, could you utilize the high speed exhaust of a turbojet to feed that ramjet the 400mph intake it needs to get it off the ground? Like a tiny but powerful turbojet that isn’t powerful enough to get it off the ground but is powerful enough to fire up the ramjet and then the turbojet retracts into the body of the plane when sufficient airspeed is attained and then the cone assembly can also change geometry to switch to scram operation, and then maybe a way to to change the body of the engine so that it can achieve shcram operation?
It is thrilling to see Branson climb another rung of the orbital ladder. After the Challenger shuttle crash my mentor Bill Mouton and I explored space-launches, rethought limitations, and saw Chuck Yeager's X-1A space-plane as touchstone for a safer, cheaper, and saner way. For two years we applied ourselves to pitching and educating the Shuttle Launcher concept, but NASA remained in shock, catatonic, and our ideas lay fallow for a generation. Memes evolve. Today we see Virgin Galactic as a sleek iPad-style design in modern aerodynamics & composites applied to Von Braun inspiration and Allen's Vulcan Stratolaunch the direct industrial-scale successor to Mouton's "Deuce Goose". These prove our design goals; the catamaran safely pops-up and away before ignition, dramatically lower fuel-loads save money + environment impacts… we even foresaw landing spacecraft at municipal airports, as Heinlein intended. www.formandfunction.com/
Reaction Engines SABRE engine’s problem is works at specific size and geometry (big) which means that it’s difficult to build a small demonstrator. The Skylon spaceplane is the size it it’s to hold the fuel. So happens at that configuration the payload to LEO works out about 15-tons. I hope it flies someday, but I”m doubtful.
It won't. Right from planning phase they use bleeding edge tech yet are at the edge of operability, so any of those pesky real-world complications will kill it. SSTO is a bad idea, won't happen with chemical energy.
It is unusual to see one of these videos covering something that we could see in the near future, rather than centuries from now. Keep up the good work!
Your definition of specific impulse is a little inaccurate. Isp is just the exhaust velocity divided by gravitational acceleration at Earth's surface. So really it's just a measurement of exhaust velocity, which tells us how efficient it is. The reason for dividing it by gravity is to give everyone a common unit of measurement, since we all use seconds, but still some of us might use feet instead of meters. Also the measurement in seconds is nice and small, usually around 390 or somewhere around there. It's cleaner than 370,000 m/s. Just keep in mind a gallon of hydrogen and million gallons of hydrogen both have the same Isp in the same engine. So it says nothing about how long it could hover before running out of fuel.
@@musaran2 In order to hover something it has to generate a certain amount of thrust, which is mass flow times exhaust velocity. Some ion engines have Isp in the thousands of seconds but wouldn't hover at all since they generate very small thrust. I do see your point though, but I wouldn't put it the way Isaac said it. It's a little confusing. It leads people to believe that if a rockets engine has an Isp of 400 seconds then that's how long the engines burn, but that all depends on how much fuel there is.
@Isaac Arthur great video! I love spaceplanes and SSTOs and I definitely like this. I was wondering what would happen if the inside of a scramjet was lined with insulating stuff, like wood ash.
That would mean extensive refurbishment after each use, entirely defeating the point of spaceplanes. Honestly, unless you switch to laserlaunch (partially) reusable twin stage to orbit is likely to remain king for quite a while IMO.
For some reason, talking about multi-mode engines that could become anything from a turbofan to an aerospike made me think of the transformium from the fifth(?) Transformers movie. Spaceplanes would be a _much_ better use of that technology than speakers or whatever they were doing.
Isaac your series is absolutely great! I cant believe I haven't heard of it sooner! This should definitely be a series on Netflix or science channel. You have done an amazing job, keep it up!
I really enjoyed being able to see some of the specific engineering tech/challenges behind space planes in this video, something you can't normally do with the more futuristic videos.
KSP already proves that SSTO's aren't the most efficient route at this moment with our current technology. It's much easier to invest in reusable rockets. Yet the Skylon has still been my favorite reaction engine. The things a beast!
....your basing your opinion of real life, from a game. A. Game. A bug ridden game. It does not, and can not prove -anything-. The closest you can get is Realism Overhaul and it does get damn close, but its not perfect and there are still a good number of bugs. Basing assumptions about what is possible in the real world on a fucking game and then trying to argue that point with a futurist content creator of Arthur's caliber is so far beyond excusable ignorance.. I wont go so far as to call you stupid, but this opinion at least in so far as how you justify it, is incredibly stupid.
The original concept for the space shuttle was for a space plane. The X-15 was on that road. The space shuttle doesn't know whether it's a rocket or a plane. Too many engineers with their pet designs. Surprised it worked so well.
Originally, the Space Shuttle had a two-stage fully-reusable winged flyback design, but that was too expensive to develop on NASA's shoestring budget after Apollo had ended. #FundNASA
Would you be able to make a space plane that kept oxidizer on board instead of fuel, and fly it on a moon like titan? OR magnesium fuel that could burn using a co2 atmosphere like Venus or mars?
Axel I feel like it would work well titan, coupled with its super low gravity, and dense atmosphere... did you see the wickman mars space plane concept?
What is wrong with using the energy derived from the Barium->Irridium->Beryllium conversion as a "fuel source?" Kind and Respectful Regards, Isaac, Uyraell, New Zealand.
I am thinking that one of those dual mode ram/scramjets would work well with a skyhook, no reason that you couldn't make the launch runway a maglev skid or something. I am thinking along the lines of a perhaps around 10 km 1000km/h maglev track built for 1g acceleration. Kinda long for this purpose but my idea in making it this long is that at 1g it takes around 2km to get up to 1000km/h which then gives you 6 km (~20 seconds) to get a confirmation of positive ignition on the ramjet and release the craft before you have to have the automated abort system reverse the drive current for a 1g abort deceleration. Though I don't know how long ramjets take to start up but I'd assume it would be pretty quick as it doesn't have a giant turbine that needs to get up to speed first like a turbofan or similar. But this way you in theory can get away with just a single means of propulsion on board the craft and you are also making maximum use of fixed installations with offboard power supplies to maximise the portion of the vehicle mass you can devote to useful payload. We already have demonstrated maglev systems at speeds or around 650 km/h (400 mi/h) as it is and speeds of up to 1000 km/h even without needing to resort to using reduced pressure have been proposed so should be doable. Also 10 km for the launch track doesn't seem that bad hell we already have atmospheric aircraft that need dedicated 3 km runs to take off with full load, yeah you are not exactly going to fit this thing in the middle of downtown but it's not much worse than dealing with the construction of a commercial airport or similar.
For a reusable craft.. How about a *Matrioshka Railgun?* You have the first railgun being fairly long but not that much. 500M or less. After the length of the ctaft. That eccelarates it between mach 1.5 to 2.5. Then every second a shell discharge a supper capacitor and accelerate the remaining craft at abit more than a G. Twenty five such shells.. While they will have to be picked up.. Will be each much smaller and lighter(?). Also. It would be easy to make the internal side have *feathers* a texture designed to to use liquid dynamics to slowdown. So it doesn't kill people. Also. Doesn't turnout as disposable. And here. Fuel waight is out of the picture.
*Another awesome video .* *I was wondering if you where going to mention Project pluto when you started talking about space plain using Atomic power .*
My father worked at UTC in Sunnyvale calculating thrust yields of various fuels for a booster intended to get a Shuttle competitor design working. I don't recall specifics (I was 6) but he always wanted this other thing to get a chance. I have heard of one such competitor referred to as Pegasus, but have no idea if that's the one my dad worked on.
If Moore's Law had applied to space technology, you could today buy a rocket to the moon that used 1 gallon of gasoline, weighed half a ton, and it would cost $25.
I’d love to know how RUclips’s algorithm doesn’t realize that SFIA is my favourite channel! I never miss an episode, am subscribed, and occasionally comment, but always have to search for it for the channel...
Not spaceplane related, but why aren't turbojets and ramjets used for first stages in multistage rockets? You can get about 15% of your escape velocity from turbojet/ramjet stages that don't need oxidizer. They're probably unpleasantly expensive for disposable first stages because of the turbine, but we're recovering first stages now.
it's a shame the other content on nebula from you and other creators I love is behind a paywall that I can't really afford to climb (especially since the AI safety video is on an interesting topic, anyone reading this should check out Robert Miles btw) but it's good that there is a place for new different kinds of content to be shared without needing to tick all the yt boxes
It's unfortunately one of those tradeoffs... Part of what makes youtube so finicky is that RUclips itself is beholden to what advertisers feel comfortable placing ads on. Since the content has to be paid for one way or another, it's either a paywall, or ads... Both have their pros and cons... I guess if you thought it out really carefully you might be able to devise another method, but it'd be tricky to get it right...
Super lightweight ultra strong material,( yet to be invented ) large saucer shaped outer shell filled with helium, inner compartment for passengers, just float off into space and apply thrusters when required
😀 The Venturestar!!!!🤗 I wish they had gone through with it. I did a highschool report on the X-33 prototype. It was a history class 😂 I had some nerve doing a future space plane as a history report but the teacher wouldn't let me do a report on the Luftwaffe🤷♂️.
Among other basic inaccuracies in this video, the purpose of high-bypass turbofans is not cooling, it is to increase thrust by moving a larger volume of air. F = MA.
There was a time when it was believed that everyone was going to have a personal aircraft in their driveway by 1960. In reality we still fly multimillion dollar machines from multimillion dollar facilities, even a privet aircraft needs a special facility and thousands to operate.
SSTO and space planes are missing a piece of tech not invented yet. Like computers in the early 1900s using springs and gears, it was the invention of the transistor and the microprocessor that made it practical. It maybe a new for of propulsion or energy source. I only know we're missing something.
Being able to do a Phase conversion versus a Stage break separation, is key to SSTOL, engines that can start out into basic jet-to-ramjet & scramjet to *ram-rocket* before full rocket thrust. "Ram-rocket" meaning a ramjet head having rear/back mounted hidden rocket boosters surround of it, offering gas/thrust flares as substitute atmosphere where the blade purpulstion gathers & then stresses to create momentum with the fuel atmosphere. Simulating troposphere level flights while your actually in near flughtvrise stage of exo orbit velocity park altitude.
An interesting engine idea I had is to have the bypass passages in the center of the engine. The turbine part would then be a ring on the outer perimeter. Thus the center tube could be made to function as a scramjet, and some sliding sleeves on the outer ring could seal off the turbine portion when not used. Another interesting idea is to get rid of the laminar drag boundary on the aircraft itself. I was thinking along the lines of supercavitation, or doing some other means to eliminate fluid friction on the external surfaces. (Maybe using a film of superfluid?) Now you're not wasting energy pushing and compressing a wall of air into the shockwave that only serves to make a sonic boom. (Without the shockwave, you're only displacing the volume of the aircraft itself, instead of this huge additional area around it.) If this could be figured out, propulsion would be much simpler and the overall aircraft would be way more efficient. (UFO reports say they go supersonic with no supersonic boom, so I was thinking of how to do this with technology that we already know.)
One thing I rarely get to see talked about as a potential rocket fuel is Metastable Helium. As far as I know as a concept it is perfectly viable and in no way science fiction. However to my knowledge there is no reliable method to fashion it, and in it's pure state would have a life time measured in hours at most before it releases it's stored energy. If it is viable it does have some of the same drawbacks mentioned for Metallic hydrogen or other more volatile and high energy fuels. It's basically using helium to store vast quantities of energy (needing a high energy production facility too, most likely meaning the fuel will be rather expensive anyway), but this also means it is releasing vast quantities of energy when used. Having it around would not be quite as bad as having an atomic bomb in the garage, but way worse than any chemical explosive. There has been the talk of He-IVa, which (to my limited knowledge) is the proposed bonding of two metastable helium atoms and two normal helium atoms. MS helium would make a rocket (or pulse engine more likely) with an ISP of around 4000, almost ten times that of the best current chemical rockets. He-IVa would half that to maybe 2000 but be more stable for long lasting storage... presuming the stuff is stable enough to not explode if shaken. Supposedly He-IVa is far more stable, with a figure of years for it's life span being one I've seen quoted. One other prospect is to use it as a fuel source for a more conventional rocket, say take a NERVA style nuclear rocket, remove the atomic core and instead fire pellets of He-IVa into the stream to heat the reaction mass. Not as efficient as a nuke in the core fuel, but would get similar ISPs (somewhere between 500 and 1000) and relatively high thrust. It also has the advantage that, unlike the NERVA, you don't care if the 'core' of the exhaust melts... because it is an explosion and is going out with the exhaust anyway. So you could push higher core temperatures than a typical Fission Thermal rocket engine. However, I have great difficulty in finding much hard data on Metastable helium and if anyone has actually produced any. Is it really practical? Is it only likely to be produced once we get a more energy efficient society? i.e. when fusion happens (if it happens). Plus there is even less talk of the He-IVa variant. I'm still not sure if that is even theoretically possible beyond a pure thought experiment. Anyone know any more on this than me?
I love reading about the declassified reports of SR71 pilots. More than a few times, it amounted to, "SAM launch detected. Accelerated to outrun missile. Success."
The one that I heard about was Malta receiving a distress call. The pilot stated that his craft was losing fuel and needed an emergency landing. When asked his ETA and current position, he replied fifteen minutes, arctic circle.
@@janbaer3241 yea that sounds 100% credible, it took sr-71 ~2 hours to fly across the atlantic (correct me if im wrong), and only 15 minutes to get from arctic circle to Malta? And having an emergency over arctic circle, they chose to fly all the way over to an island smack in the middle of mediterranean sea? 100% credible say i.
Going from arctic to Malta you've got possibly Greenland and England, and surely whole of Europe to land on, but naa, they chose Malta because its sunny i guess
@@janbaer3241 bro to go that far (~3400 km) in 15 minutes he would have to be going at over mach 11. That's not possible.
@@slevinchannel7589 The channel says that any spaceship that is able to do interstellar travel in anything like a human lifetime (in other words it's traveling between star systems at a significant fraction of light speed) can easily destroy a planet. This is true. Kinetic energy can absolutely be used to destroy planets. A single flower petal, if it was going fast enough, could blow up the earth.
@@slevinchannel7589 For example, a thousand kilograms traveling at half the speed of light would have a kinetic energy of 13 quintillion joules, around 60 times larger than Tsar bomb, the biggest nuclear bomb ever detonated.
What u want for this is the relativistic kinetic energy formula, it's hard to type out here but a quick google search will show u what it is.
"Heres to a future with wookie friends and spaceplanes in shoddy hangers"
Cheers!
I was thinking of a beautiful bird of peace, flying into space...then stolen, and twisted to the purpose of war.
EDIT: Since I guess this was too cryptic - ruclips.net/video/xcQHUMEGAoA/видео.html
Burkhart 4192 hawks prey on serpents. long live the feathered serpent lol
And becoming a bus driver for a Mary sue! :D
TheTwilitHero meh who needs a storyline when you can fuck up star wars, still getting paid, amiright
@@Burkhart4192 Louis Blériot felt the same way about airplanes in general in their early days, but if a technology can be militarized to one's advantage, it will be...
Welcome to history.
Miniaturized fusion would be such a huge revolution, allowing the co construction of everything from garage sized spaceships to iron suits.
You sly bastard:D
first we would have to invent fusion
@@matthewblairrains6032 we have
@@spawnof200 yes but making it a practical power source ?
@@matthewblairrains6032 based on the actual science of it were probably not too far off that, check out iter. it will probably still take many years (possibly even decades) for it to reach the implementation stage though.
I'm not the first to say it, but these near-future videos are some of my favorites. Thank you as always Isaac!
Yeh, moving stars is pretty awesome and all. But near future stuff and getting into the possibilities of it, are much more interesting.
Mhm, Interesting, yes.
😀 YEEEE HA! 😄I do declare I am intrigued. Awesome in all senses of the word and much much more. Whéééhhee! I am pretty fortunate IMO to be quite a knowledgebase overall, not above average brain but more focused on these matters for 25 years c.a. Basically just for the simple sake of our dear common sense that Einstein said was our most valuable asset, be good at common sense that has its focus pointed to the common sense goal of as many as happy, free, able, cool, common sensed, rich, fun, responsible, wild, respectful etc etc as we possibly can in a common sense manner. Perhaps.. who can tell? Who can tell?
👼 DON'T PANIC 🐶
@@gumunduringigumundsson9344 wut...
@@gumunduringigumundsson9344 Common sense is not scientific, that was the doom of Einstein interpretation of Quantum Entanglement he though it was non sense, he was wrong.
Oh right, I just remembered that today is Arthursday... I thought it was Sunday...
Arthursday is the best day!
This threw me through a loop, because tomorrow is Sunday lol
You're always a welcome breath of optimism and wonder. Thank you for doing what you do =)
And you know, it'll probably be even better than this
@@ofthecaribbean It usually is isn't it? Great time to be alive!
I dunno what you FUCKTARDS are talking about. There is no hope in this shit world, ONLY DISPAIR!!!!!!!!!!!!!!!!!!!!!!!!
5:03 Note the logo on the plane; Imagine Issac getting THAT successful that he can fly to symposia on his own fleet 😀
We need to build up his reputation to a point where this actually happens. He definitely deserves it for all that he has done for this community
>got bored
>made dinner
>checks computer
>new arthurpisode
>perfect timing
Arthurpisode^^ I like that expression
Excellent.
upward bound (my favorite opening music)!
So good.
I mean, any founding that Skylon receives is because people (speak: Airbus) wants that SABRE. A dual-mode engine like that would allow people to build literal stratoliners which would bring great benefits in flight time and fuel efficiency, which are two of the biggest issues for airlines. And while it has a somewhat lower isp than turbofans, it also has a much higher twr than them, meaning you'd need less engines per plane.
I'd say the association of increased power and speed with the word turbo comes from the word turbo charger (used to increase the power of an internal combustion engine) rather than turbojet since they were in more common use.
I thought the auto industry called it a turbo charger in order to take advantage of the association.
@@stefanr8232 From what I know, they were called turbo superchargers before just being shortened to turbochargers. This was during the gap between WW1 and WW2 where they started seeing more widespread use in internal combustion engines. I'd say they were named such as they use a turbine to extract kinetic energy from the exhaust gas stream.
@stefanr8232 just in case you still care after four years, a turbocharger has a turbine pump inside. There's an episode of _Scrapheap Challenge_ where they built an afterburning turbojet out of a turbocharger.
A couple of quick comments about a great show,
1) Aerospike nozzles and there brethren (aka Annular Nozzles) include spike, aerospike, expansion deflection, horizontal flow, and reverse flow. They don't necessarily point the gasses better, they adjust to different atmospheric pressures, unlike conventional Bell and cone nozzles. eg they are more efficient at altitude or in space while they are still usable at sea level. The Isp efficiency of a given propellant/engine combo in a vacuum is mostly dependent on the area of the engine out the back, until #2 below happens.
2) The Gasses leaving a rocket engine can be quite cold, despite being created at or above the material limits of the combustion chamber. Seeing an RL-10 running in a vacuum chamber with ice
falling off/out and water running out of the engine is quite a surprise. You just want that fluid or solid moving as fast as possible.
3) One really important aspect of space planes is the re-entry / return / landing. Rocketback, hoverslam, etc are really complicated and somewhat expensive. A human pilot can't really land
a Falcon 9 and a lot of payload is lost for the extra propellants.
Some time ago you pointed out that the materials in an (atomic) rocket are the major limiting factor in Isp. The old NERVA engines were inferior in Isp to common, off-the-shelf Resitojets with the same propellant. Most people miss that.
I love my Thursday Video Treat.
-Gar.
Nothing quite like waking up to an Issac Arthur episode
Or at the afternoon at the end of the day on the other side of World.
Breathtaking work as usual Isaac. Your productions are some of the few I can go back to time and again. Thank you for sharing your beautiful mind with us.
5:00 "turbo chargers" have been around for longer than jet engines.
The first ones being used on coal furnaces to get greater heat for boilers and thus more power for steam engines.
I think it's time for Neil deGrasse Tyson to step aside as the preeminent science/space/ futurism communicator and let Isaac Arthur take his turn.
I guarantee Isaac wouldn't interrupt his guests or panel the second they started speaking lol.
Tyson is overrated. Kind of a tool.
@Casanova Frankenstein lol. Dude, you can say something about a black man without it having anything at all to do with him being black.
@Casanova Frankenstein...ok? Anyway, I've been and remain a huge NdGT fan. I've watched all of the star talk lives. A good amount of the radio shows, but they're not as good as the live stage panels. The show show on i think natgeo? Not my thing. Loved the cosmos reboot. I've seen dozens of his lectures and interviews.
It's just that as time goes on it becomes more and more apparent that he has an issue with interrupting others.
He's an excellent lecturer and direct solo communicator. He just is a bit overbearing in an interview setting.
A scramjet-ntr combo would be very good I think. A nuclear reactor heats the air in the scramjet instead of fuel, and when it reaches high altitude switches to ntr and flies to orbit
Like a nuclear variant of the sabre engine concept. The only problem is the extreme heat the reactors are generating, and the whole engine can melt down
"I was an avid space junky when I was young, and I still am" I would have never guessed that, sir.
"I used to love space. I still do, but I used to too." - Issac Hedberg.
@@bigoljoe1829 LOL, top notch reference.
Yeah I think he's kinda old too.
☜☆☞♪ ♬ ヾ(´︶`♡)ﾉ ♬ ♪◌⑅●♡⋆♡LOVE♡⋆♡●⑅◌ๆ
Issac turning my day around right off the bat today, it's a good day!
Isaac Arthur the phenomenon as the evisceration of most types of brainpoop. Cause sometimes, not often but sometimes it is best to make brain poop with the protection and safety of my personal golden humor as my old and sturdy glowing hot katana and grenade launcher that is goldplated.
A bit of a correction on the aerospike (at least if I'm remembering correctly). Bell-shaped nozzles do generally focus the exhaust, but that depends on the density of the air around the nozzle, meaning its efficiency depends on altitude. This is why some nozzles have controllable geometry. The aerospike is *technically* less efficient in a vacuum (or it might be just as efficient, but not more), but the design naturally uses the surrounding atmosphere to focus the exhaust, making it efficient at all altitudes.
Just signed up for your Patreon. AMAZING content man.
Wow, it is plane to see, this is an real uplifting topic!
Marlon lacert Have you ever been up on a spaceship? (repeat that question really fast!) (up on. = "a pun") Obviously, I like your kind of humor.
Sweet.....space planes. IA never disappoints.
Spaceplanes might be the perfect case for the use of nuclear fusion. Its power density is not good, so it may never provide the thrust-weight required to launch a rocket vertically, but a spaceplane has wings so it doesn't require high thrust. A rocket needs a TWR of 1.5, whereas, for example, a modern airliner has a TWR of just 0.2/0.3.
So… a spaceplane’s at around 0.7?
Issac previously mentioned tethers and rotavators.
If rotavators were built you could use a ramjet PR precooled turbojet space plane that can't reach orbit, but can fly high and fast enough to hook up a descending space tether.
the booster ignited with the music at 2:41, hats off to the one that had that idea!
Oh man, I'm so pumped!! It's been such a crazy week I totally forgot it was Arthursday, and that this week's episode is about frickin' space planes! This day just got WAY better.
"...and I still am." Largest understatement on the entire channel.
As someone who's working on what might turn out a paradigm shift in VTOL... I'm tempted to say that we'll never have SSTO below the level of something like an airliner. Because anything else is logistically unviable and unnecessary, unless you're talking direct electrical energy -> momentum drive. And, once you hit that point - already a big "if", since we do not know whether if it is indeed possible to achieve this effect - then you're going to be capable of building a space elevator or orbital ring/skyhook system, so you're jumping from the one solution to the next immediately.
The problem is, as always, reaction mass and the material concerns surrounding the human form, since we're discussing this for personal transportation. We've got the powerplant tech since long ago. We can generate the necessary specific power. It's converting it into useful form that is difficult. However, even if I'm successful in my efforts and we can manage to squeeze a VTOL craft down to a personal helipod package weighing in like a light sports plane or slightly less, the reason it would be successful is precisely because we've got a ready travel medium for reaction mass which we can use a single efficient engine to drive. You win by being able to take advantage of the medium and any resistance for better energy transfer and lifting purposes.
Probably, even in the far distant future where we are making the steps toward something like an efficient EI drive or fusion or MPD thrusters, their efficiency will likely be capped far lower than that of simply using atmosphere as a combined fuel source and reaction mass for a considerable time. And we must entertain the possibility that it may indeed be for _all_ time, and with such a difference in absolute efficiency as a result of physical constraints, that it will never make sense to use a one-drive solution for both in-planet and even borderline off-planet transportation.
K man
"if I'm successful"
Wait, what ? You hope to achieve a "paradigm shift" alone ?
Er.... good luck. You gonna need it.
@@musaran2 Don't be a doof. Of course I'm not expecting to do anything alone. And did I say I was?
But an idea is an idea, and it works if it works. And I've already proven that it works in principle. Of course I can't knock a thousand a day out in my bloody garage. So I've brought my old man and a couple more guys on, and I am putting feelers out with manufacturers and sponsors. But because of the way of these things, and because I don't want to get flattened, I am playing it close to the chest.
Come the worst, I'll just get hold of an engine and modify and then build something around it myself to pot around in alone. And then you can blame "angel investors" and the fucking salesman-driven car industry for the fact that you can't have nice things.
Oh my God! A SHORT SFIA with Isaac Arthur!
Its time i addmit what has long been unsaid. I'm addicted to your channel!
The sabre engine is also a ramjet of shorts in air breathing mode, some of the super hot air bipasses the precooler and get mixed with fuel in the champers around the center rocket engine.
*50 years later
Kid: MOM can I go out with friends tonight?
Mom: Sure but not too far!
*Flies to mars
Earth to mars far? Pfffh. Nah, mercury to oort cloud is a little far.
100 years later
Kid:- mom can I go out with my friends
Mom:- sure but not too far
* Flies to the Andromeda galaxy
Your videos are amazing thanks for the content brother!
Anytime you want to talk jets, ramjets, etc., I'm your girl.
Is there anything better than the smell of jet fuel in the morning? Coffee, maybe. Spresso (the ramjet version of coffee)? Yes. Chatting about the future of aviation and propulsion with knowledgeable people and Mr. Arthur's community of out of this world nerds? Of course!
@@AdrianoCasemiro Coffee and jet fuel are 2 of my favorites. The last airshow I got to attend had a demonstration of a US Navy F/A-18F. When they cranked the engines, everyone else complained about the noise and smell but I stood there and absorbed it all.
@@anna-elizabeth Those things are very loud. And awesome. And people complaining about them have no place anywhere near them.
@@AdrianoCasemiro Right? It was a privilege to be that close.
@@AdrianoCasemiro "And people complaining about them have no place anywhere near them.
"
Look man, I love jet engines and rocket engines, I love the technology that makes them tick, it's why I became a jet engine mechanic, but don't knock people who complain about them. For all you know, the people complaining are the ones who do HAVE to be near them. Spending 9-12 hours a day trying to talk over them on a flightline is headache inducing, and will cause permanent long term hearing loss, and JP-8 is the spawn of satan. Its fumes kill brain cells faster than any drug, it causes rashes, itchiness, swelling and allergic reactions if it comes anywhere close to your skin, it increases cancer risk, contact with it can cause tinnitus and hearing loss, and it can even make your bones "glow" in medical X-rays... And sometimes the job basically requires you get drenched in the stuff, which effing sucks. I remember getting it in my hair one time. 2 days later, a ton of my hair fell out, and most of the skin in my scalp died and flaked off. Even its aftermath, like carbon, will coke up components and cause them to fail. I can't tell you how many start fuel nozzels I've had to replace on APUs because the carbon immediately clogs them.
If you're not used to it, and you get to go experience the smell, sound, and sight at an airshow, and it's a unique once in a lifetime experience for you, then fine, enjoy it. But trust me, it's not a "privilege" to be that close on a daily basis. At best, it's an annoying headache you eventually get used to, at worst it's a long term medical nightmare.
Sometimes the job is cool, like seeing F-15s take off full afterburner in the dark... But then another 20 do it in 1 minute intervals while you're trying to carry on a conversation, and it gets old real quick.
I now work Wed-Saturday. Arthursday is now my Saturday. What a time to be alive.
Been waiting for this one. Im a big fan Isaac! Keep up the good work.
Hello State Farm? I need to update my policy. My neighbor has installed a black hole powered BBQ Grill/Pizza oven.
Thanks for that!
Lol.
Another problem with using fission (to some extent fission, depending on the fuels used) in aircraft or in launch roles is because of the heavy shielding they need to avoid irradiating the crew or ground support crew. For this reason (as well as other ~complicated~ ones related to propellant choice and the heat issues Isaac mentioned), nuclear rockets and jets tend to have rather poor thrust-to-weight ratios compared to chemical rockets, which cancels out some or in some cases all of the advantage of better specific impulse.
Graduating high school today, great video
I can see the awesomeness now:
Two people, Garry and Matt, are walking out to the Matt's garage. The lights automatically come on when the sensors detect them walking in. Matt's cockpit ladder deploys, and he climbs into the cockpit. As he closes it, they both activate their ends of the peer-to-peer direct-brain-enhanced conversation system to hear each other.
Garry: "I see you're probably having fun in there."
Matt: "That's likely."
The garage door opens. With a thought that lasts only a second, Matt imagines lifting his right index finger, and the engines ignite.
Garry: "Yep, you definitely are."
Matt: "What?! I can't hear you!"
Garry: "I said...YOU DEFINITELY ARE!"
Matt just nods and checks the cockpit. As he does so, information about engine diagnostics flashes in his vision. All four engine modes are graphically projected to be in good condition.
Matt: "I CAN'T HEAR YOU!" he replies, overexaggerating.
Garry: "YEAH, SURE!"
Matt: "I'M JUST MESSING WITH YOU!"
He grins at Garry as hs pushes his left index finger forward, for real this time, and just for the fun of it, pushing him back in his seat. The engines push the spaceplane forward, and a few seconds later, Matt lifts off the runway gently. The landing gear retracts automatically, and he raises his right hand, his palm facing down, lifting the metal and graphene composite dart into the sky.
That's just something I thought would be fun to write.
please do a video on how housing would be given in a post-scarcity economy
You'll probably need to clarify the topic a bit, though that's kinda the Arcologies, Ecumenopolises, and Virtual Worlds episodes.
I like the idea. But I'd like to say that this topic needs to be approached carefully given that it meshes with many political issues.
Considering the successful test of Reaction Engines precooler in the UK and US, even at supersonic conditions, I am convinced that the SABRE will be built. Its use as a hypersonic vehicle are numerous as is the lightweight precooler tech. Skylon was taken off their site but the engine is what makes the concept viable. There is a big point you forgot in your video. Oxygen is far heavier than hydrogen. That is where a lot of the extra delta v comes from, flying to mach 5.5 on atmospheric oxygen.
The trouble with scramjets is that the Mach number of the fluid to which you introduce heat matters a great deal. The higher the Mach number, the more total pressure is destroyed when heat is added. This concern dominates even the concerns of keeping the combustion chamber lit and that of getting the fuel to burn to relative completion before it is literally behind the aircraft. In practice, scramjets are expensive toys that will never really be useful, and certainly not beyond about Mach 15 or so; the entropic losses become too great, to say nothing of the extreme thermal environment to which the entire aircraft would be subjected.
Spaceplanes.
WHAT?
Spaceplanes..
SPACEPLANES!!!
No amount is too much to invest into fusion energy.
Give me a tenner and I'll think about fusion.
upload.wikimedia.org/wikipedia/commons/a/ab/U.S._historical_fusion_budget_vs._1976_ERDA_plan.png
Pretty much covers it. They knew back in '76 that Fusion was gonna be expensive. This whole 40years away thing happened only because nobody in politics had a clue....real dev cost is probably gonna be another 5 times those estimates. But that would still be cheap compared to G20 military spending, so, easy.
Oh, and don't forget the XS-P or Phantom Express quick turn around reusable booster. That and a streached X-37 would give you a two stage to orbit spaceplane, or just consider the X-37 variant the space plane, and that could fit in a garage. ;)
I'm so intrigued, I have never heard this type of speech before. Is it a dialect? I love these videos, somehow makes my hopes for the future bigger! Thanks for it all!
As always, very good video, but I can actually comment something useful for once. I wanted to give a small correction that ramjets can operate from about mach 0.5, depending on how the intake geometry is optimized. Although it isn't overly hard to vary the intake geometry to optimize the ramjet for different speeds on the fly, in fact Airbus already has a patent on it, and they aren't the only ones who do. So it is in fact possible to get up to speed using a propeller (although I guess you are right as a turboprop would be most practical for this) and then turn the ramjet on at around 300-350 mph. Of course you'd have to come up with a mechanism to fold the propellers away, but I've had a few ideas on how that could be done. This way you could make the takeoff and landing fully electric too, so not even that environmentally unfriendly.
one of the advantages of the skylon design claimed for it by its developers is in terms of reliability. rocket launches obviously do have a very high failure rate, compared to other forms of transport, and i think this alone makes things like skylon an interesting proposition, if they can dramatically improve on that
3:34 dude in the trench coat wasn’t scared at all while the guy next to him about tripped over his own self trying to get away 😂😂
I love this. So practical and inginuitive. Efficient Space planes would definitely reduce the launch cost and would reduce the risk of crash landing dramatically
Hey Isaac, I was listening to one of your older videos the other day (Impact of fusion because I wanted my son to understand how big a game changer that would be) and noted with delight that you are really improving on that speech impediment. Keep working at it! Sending you good wishes!
Isaac, could you utilize the high speed exhaust of a turbojet to feed that ramjet the 400mph intake it needs to get it off the ground? Like a tiny but powerful turbojet that isn’t powerful enough to get it off the ground but is powerful enough to fire up the ramjet and then the turbojet retracts into the body of the plane when sufficient airspeed is attained and then the cone assembly can also change geometry to switch to scram operation, and then maybe a way to to change the body of the engine so that it can achieve shcram operation?
Zeppelin changing into a bombship might look like in sci-fi. Zeppelin elasticity can be used as a pusher plate.
It is thrilling to see Branson climb another rung of the orbital ladder. After the Challenger shuttle crash my mentor Bill Mouton and I explored space-launches, rethought limitations, and saw Chuck Yeager's X-1A space-plane as touchstone for a safer, cheaper, and saner way. For two years we applied ourselves to pitching and educating the Shuttle Launcher concept, but NASA remained in shock, catatonic, and our ideas lay fallow for a generation.
Memes evolve. Today we see Virgin Galactic as a sleek iPad-style design in modern aerodynamics & composites applied to Von Braun inspiration and Allen's Vulcan Stratolaunch the direct industrial-scale successor to Mouton's "Deuce Goose". These prove our design goals; the catamaran safely pops-up and away before ignition, dramatically lower fuel-loads save money + environment impacts… we even foresaw landing spacecraft at municipal airports, as Heinlein intended.
www.formandfunction.com/
Man it'd be awesome to go from your home straight into space for a cruise.
It is a joy to listen to Isaac Arthur talk about plausibilities of the future.
Reaction Engines SABRE engine’s problem is works at specific size and geometry (big) which means that it’s difficult to build a small demonstrator. The Skylon spaceplane is the size it it’s to hold the fuel. So happens at that configuration the payload to LEO works out about 15-tons. I hope it flies someday, but I”m doubtful.
It won't. Right from planning phase they use bleeding edge tech yet are at the edge of operability, so any of those pesky real-world complications will kill it.
SSTO is a bad idea, won't happen with chemical energy.
It is unusual to see one of these videos covering something that we could see in the near future, rather than centuries from now. Keep up the good work!
Your definition of specific impulse is a little inaccurate. Isp is just the exhaust velocity divided by gravitational acceleration at Earth's surface. So really it's just a measurement of exhaust velocity, which tells us how efficient it is. The reason for dividing it by gravity is to give everyone a common unit of measurement, since we all use seconds, but still some of us might use feet instead of meters. Also the measurement in seconds is nice and small, usually around 390 or somewhere around there. It's cleaner than 370,000 m/s.
Just keep in mind a gallon of hydrogen and million gallons of hydrogen both have the same Isp in the same engine. So it says nothing about how long it could hover before running out of fuel.
Yes it does : hovering a million gallons will use fuel much faster.
Doubling the tank requires to double the burn rate, so it evens out.
@@musaran2 In order to hover something it has to generate a certain amount of thrust, which is mass flow times exhaust velocity. Some ion engines have Isp in the thousands of seconds but wouldn't hover at all since they generate very small thrust. I do see your point though, but I wouldn't put it the way Isaac said it. It's a little confusing. It leads people to believe that if a rockets engine has an Isp of 400 seconds then that's how long the engines burn, but that all depends on how much fuel there is.
@Isaac Arthur great video! I love spaceplanes and SSTOs and I definitely like this. I was wondering what would happen if the inside of a scramjet was lined with insulating stuff, like wood ash.
That would mean extensive refurbishment after each use, entirely defeating the point of spaceplanes. Honestly, unless you switch to laserlaunch (partially) reusable twin stage to orbit is likely to remain king for quite a while IMO.
For some reason, talking about multi-mode engines that could become anything from a turbofan to an aerospike made me think of the transformium from the fifth(?) Transformers movie. Spaceplanes would be a _much_ better use of that technology than speakers or whatever they were doing.
An interesting idea would be a sled to get a ram jet up to speed so it can operate without it's own turbines. This would keep its weight down.
Isaac your series is absolutely great! I cant believe I haven't heard of it sooner! This should definitely be a series on Netflix or science channel. You have done an amazing job, keep it up!
Had an ortho appointment. This made up for it 10 fold
I really enjoyed being able to see some of the specific engineering tech/challenges behind space planes in this video, something you can't normally do with the more futuristic videos.
KSP already proves that SSTO's aren't the most efficient route at this moment with our current technology. It's much easier to invest in reusable rockets. Yet the Skylon has still been my favorite reaction engine. The things a beast!
....your basing your opinion of real life, from a game. A. Game.
A bug ridden game. It does not, and can not prove -anything-.
The closest you can get is Realism Overhaul and it does get damn close, but its not perfect and there are still a good number of bugs.
Basing assumptions about what is possible in the real world on a fucking game and then trying to argue that point with a futurist content creator of Arthur's caliber is so far beyond excusable ignorance..
I wont go so far as to call you stupid, but this opinion at least in so far as how you justify it, is incredibly stupid.
The original concept for the space shuttle was for a space plane. The X-15 was on that road. The space shuttle doesn't know whether it's a rocket or a plane. Too many engineers with their pet designs. Surprised it worked so well.
Originally, the Space Shuttle had a two-stage fully-reusable winged flyback design, but that was too expensive to develop on NASA's shoestring budget after Apollo had ended. #FundNASA
Would you be able to make a space plane that kept oxidizer on board instead of fuel, and fly it on a moon like titan?
OR magnesium fuel that could burn using a co2 atmosphere like Venus or mars?
The Titan idea sounds feasible at face value, and a quick search returns a paper on using magnesium as a fuel on Mars, but I don't have access to it.
Axel I feel like it would work well titan, coupled with its super low gravity, and dense atmosphere... did you see the wickman mars space plane concept?
Axel www.wickmanspacecraft.com/marsjet.html
What is wrong with using the energy derived from the Barium->Irridium->Beryllium conversion as a "fuel source?"
Kind and Respectful Regards, Isaac, Uyraell, New Zealand.
I wonder if there'll ever be a guardians of the Galaxy kind of situation with just random people having spaceplanes and spaceships
"If you had a black light, it would look like a Jackson Pollack painting in here."
piratings fun
We need a third stage guild navigator with the spice milange.
I am thinking that one of those dual mode ram/scramjets would work well with a skyhook, no reason that you couldn't make the launch runway a maglev skid or something. I am thinking along the lines of a perhaps around 10 km 1000km/h maglev track built for 1g acceleration. Kinda long for this purpose but my idea in making it this long is that at 1g it takes around 2km to get up to 1000km/h which then gives you 6 km (~20 seconds) to get a confirmation of positive ignition on the ramjet and release the craft before you have to have the automated abort system reverse the drive current for a 1g abort deceleration. Though I don't know how long ramjets take to start up but I'd assume it would be pretty quick as it doesn't have a giant turbine that needs to get up to speed first like a turbofan or similar. But this way you in theory can get away with just a single means of propulsion on board the craft and you are also making maximum use of fixed installations with offboard power supplies to maximise the portion of the vehicle mass you can devote to useful payload.
We already have demonstrated maglev systems at speeds or around 650 km/h (400 mi/h) as it is and speeds of up to 1000 km/h even without needing to resort to using reduced pressure have been proposed so should be doable. Also 10 km for the launch track doesn't seem that bad hell we already have atmospheric aircraft that need dedicated 3 km runs to take off with full load, yeah you are not exactly going to fit this thing in the middle of downtown but it's not much worse than dealing with the construction of a commercial airport or similar.
"i was quite the sci fi junkie when i was a kid and i still am". what a great quote
For a reusable craft..
How about a *Matrioshka Railgun?*
You have the first railgun being fairly long but not that much.
500M or less. After the length of the ctaft.
That eccelarates it between mach 1.5 to 2.5. Then every second a shell discharge a supper capacitor and accelerate the remaining craft at abit more than a G.
Twenty five such shells..
While they will have to be picked up..
Will be each much smaller and lighter(?).
Also. It would be easy to make the internal side have *feathers* a texture designed to to use liquid dynamics to slowdown.
So it doesn't kill people.
Also. Doesn't turnout as disposable.
And here. Fuel waight is out of the picture.
The first part of the video is an excellent refresher on how jets work. Great video as always.
*Another awesome video .*
*I was wondering if you where going to mention Project pluto when you started talking about space plain using Atomic power .*
Project Pluto, for those times nuking your enemies won't irradiate them enough.
Are you gonna do a video on super strong materials
Search Isaac Arthur Metamaterials
My father worked at UTC in Sunnyvale calculating thrust yields of various fuels for a booster intended to get a Shuttle competitor design working. I don't recall specifics (I was 6) but he always wanted this other thing to get a chance. I have heard of one such competitor referred to as Pegasus, but have no idea if that's the one my dad worked on.
In the 1980s I thought we could be more high tech spacecraft wise than we are. Harder than we first thought.
If Moore's Law had applied to space technology, you could today buy a rocket to the moon that used 1 gallon of gasoline, weighed half a ton, and it would cost $25.
I'll be honest with you, I mostly watch your videos because of this epic intro you have and then can't stop till the end...
Came for the intro, stayed for the content??
Fly there from your driveway? Energy costs MONEY, and it takes a LOT of energy to lift to orbit. Even low earth orbit.
Just need to neutralize the inertia - temporarily.
Temporarily because it comes in handy sometimes.
I love Spaceplanes, way too much, thanks for the information Isaac, and the designs for the Spaceplanes as well
I’d love to know how RUclips’s algorithm doesn’t realize that SFIA is my favourite channel! I never miss an episode, am subscribed, and occasionally comment, but always have to search for it for the channel...
Not spaceplane related, but why aren't turbojets and ramjets used for first stages in multistage rockets? You can get about 15% of your escape velocity from turbojet/ramjet stages that don't need oxidizer. They're probably unpleasantly expensive for disposable first stages because of the turbine, but we're recovering first stages now.
it's a shame the other content on nebula from you and other creators I love is behind a paywall that I can't really afford to climb (especially since the AI safety video is on an interesting topic, anyone reading this should check out Robert Miles btw) but it's good that there is a place for new different kinds of content to be shared without needing to tick all the yt boxes
It's unfortunately one of those tradeoffs...
Part of what makes youtube so finicky is that RUclips itself is beholden to what advertisers feel comfortable placing ads on.
Since the content has to be paid for one way or another, it's either a paywall, or ads...
Both have their pros and cons...
I guess if you thought it out really carefully you might be able to devise another method, but it'd be tricky to get it right...
Super lightweight ultra strong material,( yet to be invented ) large saucer shaped outer shell filled with helium, inner compartment for passengers, just float off into space and apply thrusters when required
*I'm excited for Clarke tech : Super powers .*
😀 The Venturestar!!!!🤗
I wish they had gone through with it. I did a highschool report on the X-33 prototype. It was a history class 😂 I had some nerve doing a future space plane as a history report but the teacher wouldn't let me do a report on the Luftwaffe🤷♂️.
In your defense: The history of technology is actually more important than the history of anything else. So ... Right On!
Damn it the Upward Bound intro really gets me going
Sergey Cheremisinov - Sirius. It's on Spotify, too.
@@Gaehhn thanks
Among other basic inaccuracies in this video, the purpose of high-bypass turbofans is not cooling, it is to increase thrust by moving a larger volume of air. F = MA.
I'm about to gobble this knowledge faster than a tub of ice cream
There was a time when it was believed that everyone was going to have a personal aircraft in their driveway by 1960. In reality we still fly multimillion dollar machines from multimillion dollar facilities, even a privet aircraft needs a special facility and thousands to operate.
Icon5 will disagree with you. All you need is a dock on a lake by your house.
Arthursday is pay day for me. I also get my paycheck on thursdays
SSTO and space planes are missing a piece of tech not invented yet.
Like computers in the early 1900s using springs and gears, it was the invention of the transistor and the microprocessor that made it practical. It maybe a new for of propulsion or energy source. I only know we're missing something.
Being able to do a Phase conversion versus a Stage break separation, is key to SSTOL, engines that can start out into basic jet-to-ramjet & scramjet to *ram-rocket* before full rocket thrust.
"Ram-rocket" meaning a ramjet head having rear/back mounted hidden rocket boosters surround of it, offering gas/thrust flares as substitute atmosphere where the blade purpulstion gathers & then stresses to create momentum with the fuel atmosphere.
Simulating troposphere level flights while your actually in near flughtvrise stage of exo orbit velocity park altitude.
An interesting engine idea I had is to have the bypass passages in the center of the engine. The turbine part would then be a ring on the outer perimeter. Thus the center tube could be made to function as a scramjet, and some sliding sleeves on the outer ring could seal off the turbine portion when not used.
Another interesting idea is to get rid of the laminar drag boundary on the aircraft itself. I was thinking along the lines of supercavitation, or doing some other means to eliminate fluid friction on the external surfaces. (Maybe using a film of superfluid?) Now you're not wasting energy pushing and compressing a wall of air into the shockwave that only serves to make a sonic boom. (Without the shockwave, you're only displacing the volume of the aircraft itself, instead of this huge additional area around it.) If this could be figured out, propulsion would be much simpler and the overall aircraft would be way more efficient. (UFO reports say they go supersonic with no supersonic boom, so I was thinking of how to do this with technology that we already know.)
One thing I rarely get to see talked about as a potential rocket fuel is Metastable Helium. As far as I know as a concept it is perfectly viable and in no way science fiction. However to my knowledge there is no reliable method to fashion it, and in it's pure state would have a life time measured in hours at most before it releases it's stored energy. If it is viable it does have some of the same drawbacks mentioned for Metallic hydrogen or other more volatile and high energy fuels. It's basically using helium to store vast quantities of energy (needing a high energy production facility too, most likely meaning the fuel will be rather expensive anyway), but this also means it is releasing vast quantities of energy when used. Having it around would not be quite as bad as having an atomic bomb in the garage, but way worse than any chemical explosive.
There has been the talk of He-IVa, which (to my limited knowledge) is the proposed bonding of two metastable helium atoms and two normal helium atoms. MS helium would make a rocket (or pulse engine more likely) with an ISP of around 4000, almost ten times that of the best current chemical rockets. He-IVa would half that to maybe 2000 but be more stable for long lasting storage... presuming the stuff is stable enough to not explode if shaken. Supposedly He-IVa is far more stable, with a figure of years for it's life span being one I've seen quoted. One other prospect is to use it as a fuel source for a more conventional rocket, say take a NERVA style nuclear rocket, remove the atomic core and instead fire pellets of He-IVa into the stream to heat the reaction mass. Not as efficient as a nuke in the core fuel, but would get similar ISPs (somewhere between 500 and 1000) and relatively high thrust. It also has the advantage that, unlike the NERVA, you don't care if the 'core' of the exhaust melts... because it is an explosion and is going out with the exhaust anyway. So you could push higher core temperatures than a typical Fission Thermal rocket engine.
However, I have great difficulty in finding much hard data on Metastable helium and if anyone has actually produced any. Is it really practical? Is it only likely to be produced once we get a more energy efficient society? i.e. when fusion happens (if it happens). Plus there is even less talk of the He-IVa variant. I'm still not sure if that is even theoretically possible beyond a pure thought experiment.
Anyone know any more on this than me?
Great video! Thank you sir.