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'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.
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.
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
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.
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.
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.
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.
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!
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.
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.
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.
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. ;)
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.
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.
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?
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
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.
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
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.
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/
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.
but if you wanna stretch the definition - the falcon 9 is sortof a lifting body spaceplane - it doesn't have the most efficient wing design - as in none at all - but it uses lift from it's dcylindrical body to change it's reentry trajectory whcih is used both to save a bit of boostback fuel and to make course correctiosn / control the approach
same would apply to early spaceplanes and the technology to fix this would also fix it for rockets though it might be somewhat easier to fix for spaceplanes it mostly comes down to reliability again though
Both need pre-flight, rocket needs contruction and fuel a space plane needs jus fuel. The game changer however was the, not mentioned in this video for some reason... Pre-cooler that is the vital component.
@@mikewade777 that is just engineering details of individual vehicles, not a difference between concepts reusable rockets don't really need construction, they do need some logistics like payload loading and mating but spaceplanes would need the same
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!
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!
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!
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.
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.
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.
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?
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...
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.
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.
@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.
How is the fuel pressed into the burning chamber of the ram jet against the pressure if it has no moving parts? Actually, i don't even know how this works in normal jets
Yeah the thing that always used to puzzle me about how jet engines work was why does not all the combustion pressure just back up and spit out the mouth throwing the compressor blades in reverse. Guess the compressor blades must create a higher pressure than the combustion chamber while the the exhaust nozzle is wider and lower pressure with less turbines. In the ramjet it is the forward travel of the mach 3 or greater plane ramming and funneling air into the narrow intake creating high pressure while the large exhaust nozzle has a lower pressure.
@@MrMonkeybat That took a long time for me to figure out, too. Mainly because every explanation of jet engines skipped that part. But I still don't know about how the fuel isn't pushed back into the tank. And in rockets, that's basically the main source of complexity. There must be some kind of pump, but is it linked to the main shaft in jet engines? And without moving parts, is there an external pump in the ram jet? What powers it? A preburner as in rocket engines? Electric pumps with large batteries?
Generally most Gas turbine engine fuel systems feature a high pressure pump just before the fuel injectors, which is mechanically linked to one of the turbines main shafts via the engines auxiliary gearbox. Fuel flow is regulated by a rotating swash plate attached to the pump shaft which drives a set of pistons which push fuel into the injectors. The plate can have its angle changed which adjusts the rise and fall of the pistons, the larger the angle the bigger the movement hence more fuel heading for the engine. Hope that’s sort of clear- it’s been awhile since I studied aircraft tech and this method may have been superseded by more modern methods, but that’s how the old school mechanical pumps worked but I hope this gives you an idea.
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.
I have a hunch that using planes to get up into space is more energy efficient. Less power needed going up at an angle. Heck, why don't rockets with wings launch at say a 33 to 45 degree angle? Perhaps it would take longer, but use less total energy, and would exert less force on the occupants.
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.
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.)
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.
I love how a while back in life extension he mentioned how immortality would be incremental. I was born in 1994, and the possibility that I could one day tell a 25 year old person in the year 3019 "Immortality was a pipe dream when I was a kid" boggles my mind.
Lets say you want a 4 stage engine I can see how you can convert a ramjet into a scram jet and than by sealing the intake and injecting an oxidizer convert the same engine into a aerospace but I am wondering if it is possible to include the turbine and compressor assembly needed for low speed operation and somehow fold that assembly up or have some mechanism to remove it from the engine during switch over as I dont see how that assembly can be left in the engine at those high speeds without causing too much drag and damage to the fan blades.
*Another awesome video .* *I was wondering if you where going to mention Project pluto when you started talking about space plain using Atomic power .*
SSTO space planes have sort of fallen out of favor with SpaceX pushing reusable two-stage rockets, but I think a reusable rocket plane first stage in a two-stage set-up could still be very useful if you do in-air fueling before it ascends to a higher altitude and fires its rocket engines. You might be able to get a really good turnaround time, and your first stage could take off from a runway at an airport instead of having to launch from a platform or launch pad set at a distance from major cities.
Look up ESA's old Säenger concept. And BTW, vertically launching two-stage spaceplanes are also a thing, like the original Space Shuttle design - and they might even be more efficient than landing vertically.
8:08 scramjet means supersonic combustion ramjet, not supersonic compression ramjet. The big difference between a ramjet and a scramjet, is that for a ramjet air is decelerated to subsonic speeds in the engine before fuel is injected, while for a scramjet it is injected straight into a supersonic airstream.
The reference is to a Ted Talk about teaching Java Script. The talk was about futurism and was given by a man who, despite his many charitable works, and his many great ideas and innovations, he later turned out to be the leading suspect in a number of mass shootings.
Oh, and SkyLons $1,000 a pound projection didn't seem to include fixed over head and up front costs. Do those games and Shuttle was doing $1,000 a pound. Rockets are inefficient and costly per flight, especialy if you throw them away per flight, but even with that they don't contribute a significant fraction of the cost per flight, so it hardly maters.
14:35 bit disappointed you didn't go into the pre-cooler as this is THE key feature of the SABRE engine. It's the flux capacitor. Its what makes air breathing rocket engines possible.
Question, when talking about interstellar warfare you describe micro blackholes as poor weapons on their own because they would hit a planet and pass through it without interacting with anything. If that's the case, what makes them dangerous as a power source?
there really isn't much difference the line between reusable rockets and spaceplanes is very blurry, they share most advantages and disadvantages and it really comes down to the design in detail I personally think lifting body spaceplanes iwll be more useful in the future - they can be made more structurally reliable and more versatile than reusable rockets which is really not the highest priority right now but once we get reusability beyond 100 flights a piece this is gonna be quite important
Man the A&P requirements and FAR's are going to be gnarly for such craft though. Great episode as always Isaac, nothing quite like lunch time with a new episode.
As an A&P I can't wait for the FAA and Space force to merge creating the Federal Aviation Space Administration. The paperwork to return a spacecraft to service is going to be tremendous. "I got a nav light out" 4 mins to swap the bulb 35 mins to sign off the log book, gather the 8130, the space certificate of conformity, and get the inspector signature. Man, I hope I'm retired by then.
@@cannonfodder4376 I was thinking earlier about inspection schedules also, average owner probably isn't going to be okay with 100hr inspections costing 60K or more for approved FASA TSO/PMA space parts. I can just see the bill now. "Your reactor needed a new magnetic shield, that's 130K for parts and 15K for install."
@@commentguy4711 Lets hope automation will help lower inspection and part costs. But yup, the tolerances...PMA parts are going to be expensive as hell.
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.
Mmm, how many people you know with a Beechcraft airplane in their garage? Unless you have a ranch, I think you have to catch a robo-electric car to the local spaceport to spin up your spaceplane.
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.
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.
![Seungmin "그렇게, 천천히, 우리(As we are)" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/kAzmhLHePqU/mqdefault.jpg)
![Blox Fruits Dragon Rework Update [Full Stream]](http://i.ytimg.com/vi/EqDAp8udhm0/mqdefault.jpg)
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.
>got bored
>made dinner
>checks computer
>new arthurpisode
>perfect timing
Arthurpisode^^ I like that expression
Excellent.
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!!!!!!!!!!!!!!!!!!!!!!!!
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.
"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
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.
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.
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
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
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.
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.
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.
"...and I still am." Largest understatement on the entire channel.
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.
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!
Sweet.....space planes. IA never disappoints.
I now work Wed-Saturday. Arthursday is now my Saturday. What a time to be alive.
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.
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.
Oh my God! A SHORT SFIA with Isaac Arthur!
the booster ignited with the music at 2:41, hats off to the one that had that idea!
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.
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.
*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
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?
Its time i addmit what has long been unsaid. I'm addicted to your channel!
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. ;)
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.
Graduating high school today, great video
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.
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.
Your videos are amazing thanks for the content brother!
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?
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
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.
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
Been waiting for this one. Im a big fan Isaac! Keep up the good work.
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.
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.
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/
It is a joy to listen to Isaac Arthur talk about plausibilities of the future.
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.
but if you wanna stretch the definition - the falcon 9 is sortof a lifting body spaceplane - it doesn't have the most efficient wing design - as in none at all - but it uses lift from it's dcylindrical body to change it's reentry trajectory whcih is used both to save a bit of boostback fuel and to make course correctiosn / control the approach
Rockets don't have a 24 hour turn around.
same would apply to early spaceplanes
and the technology to fix this would also fix it for rockets though it might be somewhat easier to fix for spaceplanes
it mostly comes down to reliability again though
Both need pre-flight, rocket needs contruction and fuel a space plane needs jus fuel.
The game changer however was the, not mentioned in this video for some reason... Pre-cooler that is the vital component.
@@mikewade777 that is just engineering details of individual vehicles, not a difference between concepts
reusable rockets don't really need construction, they do need some logistics like payload loading and mating but spaceplanes would need the same
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!
Man it'd be awesome to go from your home straight into space for a cruise.
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!
Had an ortho appointment. This made up for it 10 fold
Zeppelin changing into a bombship might look like in sci-fi. Zeppelin elasticity can be used as a pusher plate.
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!
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.
"i was quite the sci fi junkie when i was a kid and i still am". what a great quote
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.
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.
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
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...
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
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.
Spaceplanes.
WHAT?
Spaceplanes..
SPACEPLANES!!!
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.
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.
@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.
We need a third stage guild navigator with the spice milange.
How is the fuel pressed into the burning chamber of the ram jet against the pressure if it has no moving parts?
Actually, i don't even know how this works in normal jets
Yeah the thing that always used to puzzle me about how jet engines work was why does not all the combustion pressure just back up and spit out the mouth throwing the compressor blades in reverse. Guess the compressor blades must create a higher pressure than the combustion chamber while the the exhaust nozzle is wider and lower pressure with less turbines. In the ramjet it is the forward travel of the mach 3 or greater plane ramming and funneling air into the narrow intake creating high pressure while the large exhaust nozzle has a lower pressure.
@@MrMonkeybat That took a long time for me to figure out, too. Mainly because every explanation of jet engines skipped that part.
But I still don't know about how the fuel isn't pushed back into the tank. And in rockets, that's basically the main source of complexity. There must be some kind of pump, but is it linked to the main shaft in jet engines? And without moving parts, is there an external pump in the ram jet? What powers it? A preburner as in rocket engines? Electric pumps with large batteries?
Generally most Gas turbine engine fuel systems feature a high pressure pump just before the fuel injectors, which is mechanically linked to one of the turbines main shafts via the engines auxiliary gearbox. Fuel flow is regulated by a rotating swash plate attached to the pump shaft which drives a set of pistons which push fuel into the injectors. The plate can have its angle changed which adjusts the rise and fall of the pistons, the larger the angle the bigger the movement hence more fuel heading for the engine.
Hope that’s sort of clear- it’s been awhile since I studied aircraft tech and this method may have been superseded by more modern methods, but that’s how the old school mechanical pumps worked but I hope this gives you an idea.
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.
I have a hunch that using planes to get up into space is more energy efficient. Less power needed going up at an angle. Heck, why don't rockets with wings launch at say a 33 to 45 degree angle? Perhaps it would take longer, but use less total energy, and would exert less force on the occupants.
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.
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.)
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 😂😂
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.
I love how a while back in life extension he mentioned how immortality would be incremental.
I was born in 1994, and the possibility that I could one day tell a 25 year old person in the year 3019 "Immortality was a pipe dream when I was a kid" boggles my mind.
The first part of the video is an excellent refresher on how jets work. Great video as always.
Lets say you want a 4 stage engine I can see how you can convert a ramjet into a scram jet and than by sealing the intake and injecting an oxidizer convert the same engine into a aerospace but I am wondering if it is possible to include the turbine and compressor assembly needed for low speed operation and somehow fold that assembly up or have some mechanism to remove it from the engine during switch over as I dont see how that assembly can be left in the engine at those high speeds without causing too much drag and damage to the fan blades.
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??
*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.
SSTO space planes have sort of fallen out of favor with SpaceX pushing reusable two-stage rockets, but I think a reusable rocket plane first stage in a two-stage set-up could still be very useful if you do in-air fueling before it ascends to a higher altitude and fires its rocket engines. You might be able to get a really good turnaround time, and your first stage could take off from a runway at an airport instead of having to launch from a platform or launch pad set at a distance from major cities.
What would be the point of in-air fueling ?
Look up ESA's old Säenger concept. And BTW, vertically launching two-stage spaceplanes are also a thing, like the original Space Shuttle design - and they might even be more efficient than landing vertically.
8:08 scramjet means supersonic combustion ramjet, not supersonic compression ramjet.
The big difference between a ramjet and a scramjet, is that for a ramjet air is decelerated to subsonic speeds in the engine before fuel is injected, while for a scramjet it is injected straight into a supersonic airstream.
When your Uber driver pulls up and you're standing there wondering "He's about to take me to mach 20...does this guy even know Java Script?"
What are you smoking... ? o.O
Or in javascript function(you, stuffToSmoke) { if stuffToSmoke === 'pot' return 'allright'; else return 'heh' }
The reference is to a Ted Talk about teaching Java Script. The talk was about futurism and was given by a man who, despite his many charitable works, and his many great ideas and innovations, he later turned out to be the leading suspect in a number of mass shootings.
I love Spaceplanes, way too much, thanks for the information Isaac, and the designs for the Spaceplanes as well
At 8:20, wow. I had no idea the speed of sound changed in such a counter intuitive way as you gain altitude toward the stratopause.
Oh, and SkyLons $1,000 a pound projection didn't seem to include fixed over head and up front costs. Do those games and Shuttle was doing $1,000 a pound. Rockets are inefficient and costly per flight, especialy if you throw them away per flight, but even with that they don't contribute a significant fraction of the cost per flight, so it hardly maters.
I'm about to gobble this knowledge faster than a tub of ice cream
14:35 bit disappointed you didn't go into the pre-cooler as this is THE key feature of the SABRE engine. It's the flux capacitor. Its what makes air breathing rocket engines possible.
Question, when talking about interstellar warfare you describe micro blackholes as poor weapons on their own because they would hit a planet and pass through it without interacting with anything. If that's the case, what makes them dangerous as a power source?
there really isn't much difference
the line between reusable rockets and spaceplanes is very blurry, they share most advantages and disadvantages and it really comes down to the design in detail
I personally think lifting body spaceplanes iwll be more useful in the future - they can be made more structurally reliable and more versatile than reusable rockets which is really not the highest priority right now but once we get reusability beyond 100 flights a piece this is gonna be quite important
Man the A&P requirements and FAR's are going to be gnarly for such craft though.
Great episode as always Isaac, nothing quite like lunch time with a new episode.
As an A&P I can't wait for the FAA and Space force to merge creating the Federal Aviation Space Administration. The paperwork to return a spacecraft to service is going to be tremendous. "I got a nav light out" 4 mins to swap the bulb 35 mins to sign off the log book, gather the 8130, the space certificate of conformity, and get the inspector signature. Man, I hope I'm retired by then.
@@commentguy4711Those log books are going to triple in size at a minimum.
@@cannonfodder4376 I was thinking earlier about inspection schedules also, average owner probably isn't going to be okay with 100hr inspections costing 60K or more for approved FASA TSO/PMA space parts. I can just see the bill now. "Your reactor needed a new magnetic shield, that's 130K for parts and 15K for install."
@@commentguy4711 Lets hope automation will help lower inspection and part costs. But yup, the tolerances...PMA parts are going to be expensive as hell.
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.
Mmm, how many people you know with a Beechcraft airplane in their garage? Unless you have a ranch, I think you have to catch a robo-electric car to the local spaceport to spin up your spaceplane.
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 excited for Clarke tech : Super powers .*
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.