I understand the desire, and the two-stage designs for shuttle would likely have been superior to the actual design. Probably double the cost, however. I'm not convinced that the weight of the airframe, wings, and landing gear are going to be worth it.
@@EagerSpace>>> I have read there was a potential issue with the original straight-wing orbiter TSTO shuttle design by Max Faget. The straight-wing orbiter would have difficulty shedding all the reentry heat. Although I have worked in aircraft maintenance, I am NOT an aeronautical engineer. So I do not know if this heating problem was a valid concern or not. I read the USAF had a greater cross-range re-entry glide requirement than a straight-wing orbiter could provide, hence the choice of the Space Shuttles we got.
The Indian space agency has a prototype of exactly that. It's called the RLV-TD and, as I understand it, it will be a space shuttle on a first stage reusable like super heavy.
The original shuttle proposal was actually closer to Dream Chaser, with a smaller space plane atop a conventional rocket. Then the military got involved and it morphed into the expensive mess it ended up as.
@@jbullforg The X-37B is functionally similar to DreamChaser in it's unmanned configuration, and it's already flying. Neither are 'Spaceplanes' in the context of this video however, which is really talking about 'Winged launch vehicles'.
@@EagerSpace Your argument is this video is false with fasle premies. Trasnforming engine has been designed which makes first stage spaceplanes possibility, its currently being built and worked on in private sector.
@@finalfrontier001 There have been transformative ideas in spaceplane engine design for decades; you've got your ramjet, scramjet, aerospike, various unholy mergers of jet and rocket, and even nuclear rockets (for atmospheric phases of flight too!). I remember in 5th grade being super enamored with the X-30 and coming up with my own variant, the "X-56" (at that time the most recent "X" plane was X-55)... I would love to be wrong, but with everything I've learned since then, I can't help but feel SSTOs like X-30 are fundamentally economically unviable.
Spaceplane and SSTO (single stage to orbit) are not synonymous. We have at least two operational spaceplanes today, the X-37 and the SpaceShipTwo, with Dreamchaser probably joining them in less than a year. And historically we've had many more, such as the X-15, Buran and of course the Space Shuttle.
YES, thank you for this, this video is interesting but the amalgamation of spaceplane and SSTO particularily annoyed me. I mean one of the most iconic spaceplanes out there, the Orion, from 2001, is the 2nd stage of a TSTO, with it's first stage being a massive upscaled verion of it. BTW, Technically there are 3 operational spaceplanes, as the Chinese have an analogue to the X37B, the CSSHQ, which has flown twice and is currently in space on it's third mission. (but i wouldn't really count spaceship 2 as is has absolutely no control of itself when outside the atmosphere, contrary to the others, which means it barely qualifies as a spaceplane)
@soleenzo893 Yeah, my bad, I forgot about China. I am, however, fairly certain that SpaceShipTwo does have a reaction control system to control its orientation while in space.
@@plainText384 oh you're right, forgot it had RCS. then it barely qualifies as a spaceplane (by a hair lol compared to the ones that actually go to orbit)
And perhaps with a high-ISP engine in the atmosphere, but you have to carry those wings all the way to orbit and protect them on reentry. Since so much of the launch profile is out of the atmosphere I think you generally lose on the tradeoff.
@@EagerSpace well, in an ssto you also ahve to carry the engines you need on liftoff all the way into orbit and with the vehicle burnign fuel and getting lighter those enignes are argubaly not needed for most of the flight you can basically save like 70% of your thrust with wigns that can produce 100% of your weight in lift so for hte tradoef to be worth it wings that can generate a certain amount of lift have to be less than 70% the mass of an engine that produces the smae force in thrust - i nthat case it would cancel out and yo ucould basically ignore the wigns in the clacualtion and just swithc engines out for htem later unfortuantely thats really ahrd to esitmate because the lfit/weight ratio of wings depends on the overall size of hte vehicle, the wing design, the materials used and so on to an insane amount and htere's little eaisly available information on it like there is on rocket engiens where oftne oyu can simply look up their thrust to weight ratio for smaller vehicels this could be a worthwhile tradeof, for a hypoethetical winged sls core probably not so much because larger strucutres are generally less structurally weight efficient although hten yo uget into hypothetical scenarios like putting fuel tnaks into the wigns so they have to take less of the structural load and the weight of the thermal protection system dependso n the wings surface area more than their structural carrying capacity whcih means hte faster your vehicle takes off the lower its mass fraction because yo ucan have a higher wing loading
Regarding booster recovery: I was honored to meet Francis M. Rogallo about four different times at events hosted by *KITTY HAWK KITES* in the North Carolina Outer Banks in the latter 1990s. {I moved to N.E. NC in 1995, and Kite Flying is one of my hobbies.} Based on what I heard Mr. Rogallo say, and with access to the early internet, I became aware there were proposals to recover spent rocket boosters -- including the SATURN V FIRST STAGE -- by having them glide to runway landings using Rogallo Flexwings/Parawings. {There was also research into recovering manned Gemini & Apollo capsules to avoid splashdowns, but due to the goal of getting to the Moon _"Before this decade is out"_ recovering manned capsules this way was abandoned.} I am still somewhat surprised, although knowing how government works also not surprised, that this was never implemented at all.
I thought that the supposed principle behind the spaceplane as a concept was that "flying" up to altitude on wing lift is a lower delta-v launch profile than a typical gravity turn, and that's why they all have big heavy wings and lifting bodies. How that plays out in reality I don't know, but it feels like it should have been worth a mention, especially as it obviously requires much less initial thrust to weight.
yeah, following a constant dynamic pressure path up to orbital velocities would allow a lower thrust flight to orbit, and with the increased specific impulse of using airbreathing engines (which will be able to use the air given the constant dynamic pressure) the mass fraction is way lower and more practical. I think I ran some maths on a craft I was crappily designing and it was as good as fuel making up only 50% of the gross mass on the runway, and payload being around 10%. This was with multi-mode turbo-scramjets that varied geometry of the intake to ensure the best flow, a nuclear thermal orbital insertion engine, liquid hydrogen fuel and a waverider airframe design. of course there was a big problem with actually trying to figure out a trajectory and the fact the craft needed quite a lot of engines relatively speaking, as scramjets have terrible thrust to weight ratios (like barely 2, relative to their engine mass let alone the rest of the craft) and quite a lot of thrust is needed to accelerate whilst climbing - I think it was around 0.6 or so, so 30% of the spaceplane would have to be ramjet. a 10% dry weight sans engines would be a bit of a reach; at about the point I came to that number I gave up lol.
@@PearbabyREAL Great work! Boeing TAV TSTO was absolutely viable with no advances in technology in 1985, no scramjets needed. X-33 could have been suborbital with aluminum tanks. We have rockets using composite tanks today. I think some of the folks in the comment section might be onto something.
@@AnthonyDDean honestly the design I've ended up settling on (for now whilst I expand it into something more fleshed out) is something Skylon-looking but with a better delta wing-waverider setup, and only mach 6 turboramjets, as opposed to variable geometry scramjets. The scramjets are just too much extra mass for the amount of thrust they produce, and I figured out that it'd just be less hassle to light up a rocket at Mach 6/30km up rather than trying to eek out anything airbreathing. All the airbreathing I was hoping would be possible was more desperately clinging to different envelopes that only barely overlapped i.e. how scramjets are just barely viable at around Mach 10, which is when magnetohydrodynamic bypass becomes barely viable - and trying to patchwork 5 (turbine, ram, scram, MHD-slowed air for ram, vacuum rocket) different engine modes together is getting a bit overly complex. Even just 2km/s initial velocity is a huge weight saving for a rocket: an 10 ton dry vehicle needs nearly 120 tons of propellant (350 isp assumed) for 8.6km/s of delta V - 6.6 only needs about 60 tons, a literal halving (not even taking into account the increased isp from starting in a near-vacuum, and to a lesser extent the extra height above Earth). Sure, a 3 mode (turbine, ram, rocket) would have a worse propellant mass fraction than the 5 mode spaceplane, but it would simply be a lot less of a hassle and a lot easier to keep running safely in the harsh environments of hypersonic flight, reentry and low Earth orbit. 5 mode had a propellant mass fraction from my working out of about 50%, whereas 3 mode is closer to 65%. 5 mode also spent long times lingering, accelerating whilst not building any altitude, and my analysis of the atmospheric flight probably underestimated the amount of fuel wasted to gravity and air drag. I think this is very much possible and within modern tech's capabilities - aerodynamic flight up to Mach 6 is difficult, but not the damn near impossibility of trying to fly Mach 12+. The main legal/moral problem is the rocket powerplant; I'm running the assumptions optimistically based on random quotes of articles I need to probably reread lol that seemed to have a good TWR for a modern nuclear thermal rocket pegged at around 7, whereas NERVA didn't even crack 2. I'm also assuming that the exhaust isn't going to be too bad for the environment - it is just hydrogen of course, but better to be safe than sorry. Composite tanks are exciting, and something that's strong enough and light enough to both hold a massive central hydrogen tank as well as handle the transonic max-Q regime force-wise is going to be great. Highly innovative materials and tech on the inside, dumb but robust titanium skin. Just titanium or stainless steel might actually be good enough (at the very least minimisation of heavy ceramics is likely possible), because you could take a far shallower reentry path that minimises heat with the higher surface area-mass ratio of an empty spaceplane. Now this design seems a bit more solid than a pipe dream It'll be interesting to work on everything else that's necessary - the specifics of the nuclear reactor, the variable geometry wings transitioning from delta to waverider, the cooling system (definitely a big one). Good task to chip away designing at for years while I work and try to get enough money together to be able to head to uni for aerospace/start a business.
@@PearbabyREAL I remember reading a sci fi story where the featured space plane had both a SABRE and SCRAMJET. The SCRAMJET wasnt strong enough to propel the space plane alone, but it allowed to run the SABRE at less thrust and therefore lower the oxidizer requirement. Would a setup like that actually have a better LEO payload mass? I personally doubt it, but didnt run the numbers.
One advantage of spaceplanes is that Thrust to Weight Ratio is less important than Lift to Drag, meaning that very efficient engines that have a lower thrust to weight ratio can be used to offset the added weight. Airplanes can have a t/w ratio of 0.2.
That's true, but most of the time getting to orbit is spent outside the atmosphere, where the wings are just extra weight. I do think there may be a place for two stage spaceplanes, with a winged booster. I have a video on Dawn Aerospace's project to do that.
I demand they repeal this law and it’s equation. California is just the place for such political vision and action! If we can manage global weather, then the rocket equation doesn’t stand a chance.
Check out the presentation about Rotational Detonation Engines and the proposed Cochrane Exploration spaceplane that starts 1hr into video z_06OhH6Hj0 titled "APEC 7/8: Warp-Drives, Detonation Engine & TR-3B". Sooner or later someone will find the funding for some kind of runway-to-orbit spaceplane like these.
I've spent a little time looking at rotational detonation rocket engines. The ones that I found have low thrust and unimpressive specific impulse, but that might change in the future.
9:50 not sure if thats a fair assumption because yo ucan at the same tiem downgrade the stage from ahving to support two solid rocket boosters on the side - at least structurally it alreayd has to support a total twr greater than 1
Beamed power using the atmosphere as reaction mass could make things more viable, though, that is arguably a 2 stage rocket anyways, just, one of the stages is staying on the ground
Also spaceplane does not need to have additional weight penalty vs rocket. Just a fuselage geometry for lifting body lift for take off and light weight simple struts instead of heavy wheels. The main advantage of the VTOL space plane is to have rocket motors just with 25% of the lift to weight ratio (instead of rocket 120%). And also to use air breathing simple rocket motors (like e.g. Meteor missile) to reduce the required oxidiser weight by 75%.
You get higher efficiency and lift in the atmosphere with wings, but then you have to carry those engines and wings with you all the way to orbit, and you spend a lot more of your time out of the atmosphere during launch. If you can build a light hypersonic air-breathing engine it gets more interesting but nobody has gotten there.
@@EagerSpace again the space plane does not have to be SSTO. You can use your single stage space plane only to like 70km altitude for breath air engine operation and then lunch the 2nd stage to actual orbit. The only issue is the gravity and atmospheric drag. But you do not need to carry all the 1st stage oxidiser (which is 80% of the propellent weight). And your 1st stage has 5times less engine weight/numbers. Lifting body is the same weight as normal rockets as the wing is the fuselage. Also for the rocket reuse the space plane does not need to waste 5/10% of the propellent for landing as it would land horizontally as a glider (e.g. space shuttle).
Repeal the rocket equation was originated from the Good-Luck-With-That Dept. Anyway, nice short presentation explaining why we don't have single stage to orbit rockets. Dale Myers associate administrator or acting deputy administrator of NASA in 1970 when companies presenting ideas for the Space Shuttle. He immediately dismissed SSTO concept which saved much time. Fast forward to the X33 Venturestar with hope it would be a SSTO but had developmental problems of could it even fly to Utah from Calif before becoming too expensive. Some reason people thought they can overcome the Rocket Equation. The real downside was loss of testing aerospike engines and thermal projection systems for real even if suborbital flight.
I don't think you ever overcome the rocket equation, you just use the ramjet equation in the first stage aerodynamic trajectory, and switch to the rocket equation like Dr. Heiser stated. Polaris is using an aerospike and ceramic TPS is not required for a glider with a more shallow trajectory like Star Raker - both Star Raker and X-33 only required metallic TPS. The moment you go cone, lifting body, or brick (Shuttle), you need heavy TPS. Dr. Paul Czysz referenced a water-wicking titanium honeycomb TPS that was demonstrated to be viable in testing. The water-wicking TPS would have given more than several tons in payload capacity and weeks faster turnaround time. NASA Langley High L/D (John Becker) demonstrated theoretically that a Mach 18 vehicle could circle the Earth using outward centrifugal force from Earth's center as an accessory to atmospheric lift. HyperSoar demonstrated theoretically that skipping off the upper atmosphere would enable a Mach 10 vehicle to arrive at any point on Earth in an hour. The problem we had was groupthink and politics. Engineers always come up with solutions, and bean counters always find a way to pull us back to the lowest hanging fruit. We got to the Moon because it was the hard thing to do. We use rockets because its the easier thing to do.
@@AnthonyDDean Interesting discussion on metallic TPS or heavy TPS. It is a waste of time of solutions overcoming the rocket equation, you mention we use rockets because it is the easiest where other concepts will need more engineering (and expense)?
Yep. They'd be better off just admitting that they need two stages and fully committing to it, which lets you balance the mass ratio properly to get the full benefit. I.E something like the SpaceLiner: en.wikipedia.org/wiki/SpaceLiner
Yes. It's similar to air launch - like Pegasus or Virgin Orbit - but without the simplicity. The idea is that you have big tanks on the rocket sled that feed both the rocket sled and the spaceplane during that period so that the spaceplane hits the end of the sled track with full tanks and engines at full thrust.
@@EagerSpace Asparagus staging too? It will increase the performance, sure, but given how SpaceX abandoned it for Falcon Heavy I'm not so sure Radian can pull it off.
Thank you for including Reaction Engines concepts (led by the visionary Sir Alan Bond) - the engine design is gaining interest both by ESA and abroad. There must be another way gain to economical access to space - even Musk's Falcons have a finite life !
I never got Radians plan of using a rocket sled for takeoff, one of the advantages of a HTHL spaceplane would be the ability to launch from somewhat modified airports without a need for extensive ground infrastructure... I'm a bit skeptical about the various plans for SSTO spaceplanes. A lot of companies get around this by making the spaceplane the first stage and then getting the satellite to orbit on an expendable second stage, but what I'd personally like to see happen would be an HTHL with flyback boosters to actually get the spaceplane itself into orbit. Structurally challenging, I know...
Flyback boosters in a plane seems to be logistically difficult in terms of wingspan. It would be a little like the triamese shuttle concept but flattened out.
@@EagerSpace Absolutely, the boosters would either need a short wingspan or some sort of foldable wings. Alternatively, perhaps it would be doable to have the boosters land vertically like the F9 first stage, then they wouldn't need wings at all.
I have a question about the X37b. How many models are there , ty4sharing rocket launches are cool stuff, and Victor S, from Austria, invented an engine that is powering u.s.tech🤔
Eager Space worked at a large redmond software company when XBox was released. Played lots of CE multiplayer in conference rooms. Play a bunch up through 5.
It's the same issue with faster-than-light drives. We'd all love to have them because they allow so much fun in science fiction, but AFAWCT, physics hates us.
Acutally a rocket sled looks like a first stage which just remains close to the ground. Maybe the ground effect can be exploided. There are currently two stage spaceplane developments and I think it's some kind of fair to think of an assisted SSTO as basically a two stage spaceplane with second stage recovery. A rocket sleds limit so far is about 2.5 km/s or Mach 8.5. Maybe that can even be increased.
Hmm... 1) Where are you going to build a launch track? 2) How many Gs will you be pulling to get that speed? 3) How do you keep your vehicle from melting at that speed in atmosphere? 4) How do you mitigate the sonic effects.
@@EagerSpace Of course questions. As for the launch track I thought of exploiting the ground effect -- in other words a plane that can't really fly. Gs can be high if its only cargo. The sonic effects will be there and I'd say one needs to stay below Mach 3 so that things stay "cool". I suppose wings and gliding might save probably 300 m/s.
The USAF and DARPA looked at a two stage spaceplane were the stages launched separately. The first stage is a tanker. The second would take off lightly loaded with fuel and meet the tanker fuel up and head for LEO. If workable imo this would be ideal as a crew transfer taxi. But not a cargo vehicle.
The design brief for the 2CV did specify it should be able to drive in a field and not break eggs caried inside, so i think we can considered it ISN't restricted to roads. also the "roads" it drove over in the post war period were barely roads lol.
As impossible as it sounds: a SABRE is less "complex" and built simpler then a SCRAMJET. Yes, a SCRAMJET wouldnt have moving parts, but the required materials and the engineering behind the aerodynamics and combustion stability are ALOT more complex then a SABRE. For an example: the needed materials would make a SCRAMJET only have a crappy 2 to 1 thrust ratio. SABRE achieves a 5 to 1 ratio, because the stresses of the parts involved are so far lower, that they can use cheaper and way lighter materials. That said, I wonder if a combination of the two systems would work. I remember reading a scifi story a long time ago, where they used space plane that featured a SABRE and SCRAMJET combo. The SABRE would accelerate the plane to Mach 4, where the SCRAMJET would start helping up to Mach 20, so that the SABRE can throttle down and consume less oxidizer.
Any ideas on the feasibility of the Boeing X-37 sent out of spinlaunch? Also, a video talking Spinlaunch versus a standard sled would be interesting. (Just subscribed because I love your sense of humor and approach to delving into details…. Thanks for what you do!)
I did a video on spinlaunch. The feasibility of the X-37 on spinlaunch is zero. a) It's not a second stage and spinlaunch requires a second stage to get to orbit. b) Any payload on spinlaunch has to take 10,000 gs. I would be surprised if the X-37 is rated for higher than 15 gs, and it could be less.
I probably won’t receive an answer but worth a shot. What is your opinion on using an engine like Sabre as a first stage engine on a traditional rocket while leaving the 2nd stage and its engine as a traditional stage? The first stage can take a higher mass penalty and the 2nd stage will travel through almost no useful atmosphere, even if we stage early like spacex and blue do. Thank you and have a great day.
Two stages obviously makes things a lot easier and there have been designs like that in the past but nobody has built them. I think the problem is that you are talking about a very sophisticated and very big hypersonic vehicle that you have to design and build that competes with a simple dumb booster, and since SpaceX figured out how to reuse those, much of your theoretical advantage goes away. I'm generally not a fan of technology that hasn't actually been built. A ton of people have looked at sabre and passed on it. If it is workable, I think aiming at very high speed transport or hypersonics for military applications would be a good niche for it.
A plane that flys so high then rocket engines kick in to push it out the atmosphere would be cool but its the rocket equation all over again plus other stuff
Space plane does not mean it has to be SSTO. It could be 2 stages with 2nd stage being also, but smaller space plane. Or it could be disposable 2nd stage like e.g. Neutron rocket.
@@EagerSpace Obv this is all hypothetical, but a SSTO with advanced ramjets/scramjets capable of around Mach 6-7 and nuclear engines both fueled by liquid methane and utilizing a waverider design to maximize supersonic L/D should very much be possible given enough R/D. Obviously it will take a lot of money and ingenuity to achieve, but i personally think it can be done.
This is an interesting video but your title is misleading and not a good representation of your subect. You've amalgamated a Spaceplane and an SSTO. Those are 2 different and completely unrelated concepts. There have been concepts for non spaceplane shaped SSTOs and for non SSTO Spaceplanes (Space Shuttle, Buran, X37B, Chinese GSSHQ?). You've made a video that adresses why we don't have SSTOS and you've explained why very well: The rocket equation is a harsh mistress. If you wanted to make a video about where all the spaceplanes are you should have looked at the other main reason why spaceplanes have been made: Their advantages in reuse, Crossrange during reentry and precision landing, among other things. I think you should revisit this video with 2 separate ones: one about SSTOs in General and one about spaceplanes in general (with a section about SSTO spaceplanes if you like).
Yes. I limited the topic because putting together SSTO spaceplanes and winged orbital vehicles like shuttle, buran, x37b, dream chaser tends to make people confused.
@@EagerSpace i understand but in the end treating ssto and spaceplane as synonyms is just lore confusing i find. each concept is pretty different to the other. here you clearly focus on SSTOs and Spaceplane SSTOs, i think the title isn't adequat, but also some of the points in the video are incomplete by bot adressing the wider appications of both concepts.
for a plane to go to orbit you need: reacción engine like the ones on fiter planes,bigger wings so you can get more fuel and no much heat on reentry, landing gears will have to be light so take of will be with only a 10% of fuel the rest will be transfer in mid air ,aereal refuling is a prove TEC,and allow to take dowble the fuel that will be possible on take of because you will be traveling at tou times the speed, rockets need push at least a porcent more than the weight of the rocket the plane can do the same with one fith of the trust,so 2 engine instead of 10 and will be at least 10to 15 km higher, afterburner will be a great,is like a rocket that don't need oxigen and can go up to 30 km, that is a great head star.
Neither Lockheed Martin nor McDonnel Douglas were interested in funding development using their own money, and that's been an ongoing pattern with SSTO designs. The DC-Y might have been an interesting vehicle, but I don't think they would ever have gotten to the orbital version.
LOL. This is hilarious. No admission that Musk lied about inventing the concept and a deranged brattiness that you've been denied something. MuskCult is so lost.
IIRC, it was originally an air force X project and then taken over by NASA. Pournelle stated in his blog that they protected their cash cow the space shuttle by letting it fail.
Not everyone wants to do this for fame and subs. Some people just like sharing ideas and if people want to listen and watch and share with their friends that's well and good and if not so be it.
Unfortunately the audience for this type of stuff is pretty niche so while people like us find it great, other people might have a lower attention span
I've played around with hashtags and from what I can tell it doesn't make a difference. If you have suggestions for any of these, please let me know. I know very little about SEO.
I think I may already have had my 15 minutes of fame and I'm not interested in changing how I do things (much) to pull in more subs and views, but I'd be happier to reach more people.
would it be worthwhile for space x to divide the goals of going to mars from a single starship to.. lets say 3 different ships with 3 different purposes. 1 ship would go to LEO only, another ship would go from LEO to LMO only. And the last ship would go from LMO to Mars. Mars can easily have SSTOs in my opinion.
NASA tends to go with the highly optimized approach, and they end up with very functional spacecraft that are painfully expensive. Right now, starship is at the other end, a generic craft that can do a bunch of things less efficiently but at a lower cost. I do expect to see specific starship versions but they won't be that different from the base one, at least initially.
I thought the whole point of space plane is to use atmosphere for both oxidizer mass and reaction mass to push off against. The equation you're using is more applicable for a SSTO rocket than a SSTO space plane imho. In the atmospheric flight portion of the launch, space plane would benefit from air breathing mode, regular GE F404 engine has equivalent ISP of 2070, far above any rocket engine but of course, only operable within atmosphere. There is also the additional lift from wing, equating rocket lift to wing lift is not exactly equatable, since if you can get a lot more lift from a propeller thrust when an aircraft is fly horizontally than if you just point the propeller up and trying to use that thrust directly for hover. Mostly due to the fact kinetic energy scale with velocity square while momentum scale with velocity. So for the same energy input, you'll get a lot more thrust by accelerating a lot of air mass slowly than a little bit of air extremely fast. This effect is also why high bypass engine is significantly more fuel efficient than low bypass engine. A better comparison or analysis would be to take an aircraft fuel/payload performance metric with a rocket's performance metric, and just assume dead weight in each stage. The equation might still yield that it's better to have separate stage. But I think this way of analysis give a more accurate analysis for the atmospheric portion of the launch. Since a large portion of the launch is in the atmosphere. Ignore aircraft's effect and assume it behave like a rocket is doing a deservice to the space plane design. Then there is re-entry part of the launch, technically heat shielding needed if you descend too quickly. But if a space plane that glide down slowly, then you need less shielding. Granted, in high altitude flight, stall speed can get pretty close mach speed so it might be hard to maintain the correct sleep to glide down. But the point is if the space plane have sufficient lift over drag ratio, then the weight for heat shield can be reduce. I think space plane following more of a doctrine of inputting the required delta v slowly and remove that delta v slowly during re-entry. As compare to a rocket, which is optimize to get to space as soon as possible and out of atmosphere before building up delta v. I don't think analyzing a space plane like a rocket purely is entirely a fair comparison. Just as if you analyze a rocket like an aircraft, it'll look pretty bad as well.
When your spaceplane is in airbreathing mode, you have really high specific impulse and the lift from the wings, but the downside is that you are wasting energy on air friction which gets a lot worse as you fly faster and higher. You need to transition to rocket mode quickly and at that point you are just a very heavy rocket because of the weight of your wings and other plane stuff. The significant majority of the kinetic energy you need to get into orbit comes when you are out of atmosphere so your rocket performance is more important than your airplane performance, so the question is "can you get enough benefit out of starting as an airplane so that the vehicle can go SSTO once it gets out of the atmosphere?". The answer so far is a really clear "no". Trying to do a full analysis of airplane mode and rocket mode is a lot more complex than the approach I took and it would be very hard to present it in a way that is easy to understand. WRT heat shielding, you absolutely need to have it to survive reentry, where the air isn't dense enough to give you any lift but it is dense enough to give you a ton of heating.
Wow I like that physics hates humans idea, like if this was a rpg humans would be getting a negative bump to their chances of becoming spacefaring, if Earth was much heavier we'd probably evolve alright, bit stumpier fine, but right as the space race was beginning we'd be running tests on the best fuel possible and finding it required sci-fi levels of material tech to even get into orbit and completely give up on that part of the tech tree o.o
Or maybe like they'd settle for like, an eight stage rocket that puts a metal retroreflector pebble into orbit for a few hours and they track it and it takes their entire science budget to do so and they cheer and then space tick done
Japan Nitrogen's Noguchi of early 1940s Hamgyong Province was developing a rocket plane engine comprised of a Dewar of cryogenic liquified deuterium fuel connected to a beryllium alloy reaction chamber nozzle coiled in around electromagnet coils to focus cosmic ray muons while cryogenic fuel prevented exceeding of Curie Point. Therefore deuterated diborane fuel in Xcor's Lynx with a 9 volt battery powered electromagnet should be considered.
Patents of Mutsuro Bundo and Hector D"Auvergne could be improved with Robert L Morrison's patented lighter than air solids "SEAgel" or "biofoam" sealed in foil.
Can I petition you to add SSTO to the title? I didn't click on this video to see SSTO. By the way I have another question for you, some people claim that you can carry more payloads from LEO back to Earth using Spaceplane, is this true? Assuming that the accelerations cannot > 1.5g and the payload cannot be < 200t.
SSTO and space planes are not really the same thing at all. SSTO is a huge problem for engine design because you need to operate as an air breathing engine for as long as possible then switch to being a rocket engine when air gets too thin, anything else is just too heavy to be practical. Only one engine design ever got close to this but still never got anywhere. Space planes biggest problem is getting back from orbit in one piece because reusable heat shields are hard to do. The recent Starship flight 4 showed this well as we had video all the way down showing how brutal re-entry actually is.
Once again very good There are other factors like aerospikes to keep an engine optimized from sea level to vacuum like the venture star would’ve used, but I’ve heard that’s not worth it either. I think rockwell’s X-33 realistically could’ve worked Maybe the solution is a 2 stage full reuse space plane though
I talked about aerospikes in the rocket nozzle video I used. It's hard to come to a conclusion about the XRS-2200 - and the follow-on RS-2200 - because there are no published engine mass figures, but based on what I've seen it's not a game-changer.
Although this video has been nice and informative, it rather misses the mark with one important point: the question is, "why no space PLANES", not "why no SSTOs". One nice cheat offered by a space plane is that it does not need to LIFT all the mass at start. Unlike conventional rockets, it can begin with horizontal take-off acceleration. You have 2 components to the required delta V: horizontal and vertical. In conventional vertical launch rockets, any thrust insufficient to launch is wasted. In planes, however, can accumulate the horizontal delta V before adding in the horizontal once the overall mass is low enough. Another nice thing about planes is that they have wings. These have a considerable amount of surface area that can actually help to reduce reentry heating, decreasing the mass necessary for heat protection. These wings can also allow for aerodynamic reentry/landing, which decrease the required return fuel mass. Of course, actually dealing with PLANES adds a LOT of complexity that is difficult to cover, even with a much longer video. Oh, yeah, the benefits of airbreathing rockets deserve much more intensive treatment. Not to mention some of the other benefits, as well as some downsides, of aerodynamic forces in launch.
I talk about Dawn Aerospace in a different video; they have a spaceplane first stage architecture. Their plane is a rocketplane and I think that's likely to be the best approach.
Military tries to monopolize since even with my MIT work bureaucrats hysterical about "weapons proliferation" have Walter Pecked anyone who attempts to purchase isotopic fuels,
This video is actually wrong with fasle premise. Spaceplane does not exist cuz technology was not advanced enough to have transforming engines. Spaceplane Riker plan is under way currently is actually feasible.
Starship' 120 ton version doesn't work as an SSTO, but it might work as a single-stage suborbital space launch system. If SpaceX ever wanted to get into the suborbital tourist business, Starship-only launches could probably give them quite a ride.
@@EagerSpaceLOL. It doesn't work yet. And point to point is not possible at all. Thank you for revealing you're a member of the MuskCult and not a reliable source at all. Couldn't tell at first, you've all gotten a lot quieter as Musk's insanity was revealed.
The It wouldn't be Dragon. Do you understand: Dragon is the exact same concept as the Apollo system? Do you understand Musk is tricking you by calling different things "Starship" so you think it's a super ship that does everything? Do you even understand Musk lies about everything and he's a racist sociopath? No. By saying "Imagine if Dragon was .." you reveal your membership in the deranged MuskCult.
You have a great understanding of rocketry, but a little more focus on hypersonics is required here. You are talking rocket the whole time and giving very basic math. You can apply the same math to a spaceplane that takes off vertically. You cannot apply the same basic math to a spaceplane that takes off horizontally like NASA Langley/Marshall and Rockwell International Space Division designed Star Raker. Hypersonic vehicles designed by the Air Force Flight Dynamics Lab were capable of some pretty impressive things before the Space Shuttle was ever designed - an abortion learning to fly and a brick for reentry (we didn't want to weaponize space, so the least hypersonic and the least military looking plan won out.) 1) 9800 kms deltaV is the delta V requirement for a giant rocket, not a hypersonic vehicle coming from an aerodynamic trajectory. Orbital velocity is only 7800 kms, and a horizontal launch and partial aerodynamic trajectory is a completely different calculation from "me throw heavy rocket into sky" . 2) Hydrogen ISP (efficiency) does not relate to pure thrust - shown by very weak performance of pure hydrogen engines in autos. Hydrogen also makes the aerostructure extremely heavy because it requires four times more space than methane. It is also a nightmare waiting to happen (Hindenberg) in an aircraft. 3) You have the basic theory down, but engineering a hypersonic space plane requires a multi-disciplinary systems level engineering approach with a solid ideological goal that does not simply give in to groupthink or lowest hanging fruit. You didn't mention Star Raker or X-30 NASP, or the audience would notice and ask for a deeper thought process. Structure: engineering software is now capable of mass reduction (demonstrated by Czinger/Divergent and NASA Goddard), and additive manufacturing is now capable of part-count and fastener reduction (demonstrated by Relativity Space). Methane makes a smaller vehicle and provides THRUST, and SpaceX is proving out methane. Engines: rocket engines are now being 3d-printed (Hyperganic and Leap71). Rocket-based combined cycle engines like NASA's GTX (lighter and less complex than SABRE) would be a great for this application, as the compounding equation of heavy oxidizer sitting in a tank waiting to be launched with the "how to get your fuel, to get your fuel, to get your fuel" (why not just use aerodynamic lift for part of the trajectory?) launching dead weight vertically from a pad (that also restricts your number of locations). Dr. William Heiser stated that the most efficient way to get to space is an aerodynamic lift trajectory followed by a rocket boost to orbit. The problem with Stratolaunch and Virgin is that the launcher vehicle is subsonic. You need a multi-sonic vehicle to perform a TSTO to orbit. From a senior engineer who worked the project, Boeing's TAV was designed with no technological advancements to be more than viable in 1985 - that was nearly 40 years ago. Star Raker and X-30 were spent money on by governments and companies and worked on by engineers and scientists who were greater in their intellectual capacity than anyone in this generation. The tech wasn't there - the tech is now here, but that generation is no longer. Why do we not have hypersonic space planes that take off from the runway? Because we are not smart enough. Humanity has not advanced past being a warmongering species that cannot internationally collaborate on something of this magnitude - we were almost there with the Kholod scramjet collaboration, but the US government seems to have multiple personalities. The ideology here is that if we became smart enough to perform such a feat, the railroad to space would become a superhighway with no conversion of airport infrastructure required. Enter AI.
The point of the video was to do a quick analysis of what Dawn is doing and how it differs from other approaches, and the feedback I got directly from Dawn was quite positive. WRT spaceplanes in general, I have another video on that topic where I talk about the subject in more depth.
I have always hoped for something like the original shuttle proposals, a two stage design of a small spaceplane launching off a huge spaceplane.
I understand the desire, and the two-stage designs for shuttle would likely have been superior to the actual design. Probably double the cost, however.
I'm not convinced that the weight of the airframe, wings, and landing gear are going to be worth it.
@@EagerSpace>>> I have read there was a potential issue with the original straight-wing orbiter TSTO shuttle design by Max Faget. The straight-wing orbiter would have difficulty shedding all the reentry heat.
Although I have worked in aircraft maintenance, I am NOT an aeronautical engineer. So I do not know if this heating problem was a valid concern or not.
I read the USAF had a greater cross-range re-entry glide requirement than a straight-wing orbiter could provide, hence the choice of the Space Shuttles we got.
The Indian space agency has a prototype of exactly that. It's called the RLV-TD and, as I understand it, it will be a space shuttle on a first stage reusable like super heavy.
The original shuttle proposal was actually closer to Dream Chaser, with a smaller space plane atop a conventional rocket. Then the military got involved and it morphed into the expensive mess it ended up as.
We actually already have SSTO rockets, Apollo, Luna, OSIRIS, Hayabusa, and Chang'e
The problem is, earth sucks.
So to build an SSTO vehicle you would have to construct the vehicle out of Fullerene composite and power it with unobtaneum. Okay. Works for me.
Can I at least have a multi-stage spaceplane?
Sierra Space's Dream Chaser Spaceplane is designed to be launched on a first stage. It's a spaceplane version of a capsual.
@@jbullforg The X-37B is functionally similar to DreamChaser in it's unmanned configuration, and it's already flying.
Neither are 'Spaceplanes' in the context of this video however, which is really talking about 'Winged launch vehicles'.
You had shuttle...
@@EagerSpace Your argument is this video is false with fasle premies. Trasnforming engine has been designed which makes first stage spaceplanes possibility, its currently being built and worked on in private sector.
@@finalfrontier001 There have been transformative ideas in spaceplane engine design for decades; you've got your ramjet, scramjet, aerospike, various unholy mergers of jet and rocket, and even nuclear rockets (for atmospheric phases of flight too!). I remember in 5th grade being super enamored with the X-30 and coming up with my own variant, the "X-56" (at that time the most recent "X" plane was X-55)... I would love to be wrong, but with everything I've learned since then, I can't help but feel SSTOs like X-30 are fundamentally economically unviable.
Spaceplane and SSTO (single stage to orbit) are not synonymous. We have at least two operational spaceplanes today, the X-37 and the SpaceShipTwo, with Dreamchaser probably joining them in less than a year.
And historically we've had many more, such as the X-15, Buran and of course the Space Shuttle.
YES, thank you for this, this video is interesting but the amalgamation of spaceplane and SSTO particularily annoyed me. I mean one of the most iconic spaceplanes out there, the Orion, from 2001, is the 2nd stage of a TSTO, with it's first stage being a massive upscaled verion of it. BTW, Technically there are 3 operational spaceplanes, as the Chinese have an analogue to the X37B, the CSSHQ, which has flown twice and is currently in space on it's third mission. (but i wouldn't really count spaceship 2 as is has absolutely no control of itself when outside the atmosphere, contrary to the others, which means it barely qualifies as a spaceplane)
@soleenzo893 Yeah, my bad, I forgot about China. I am, however, fairly certain that SpaceShipTwo does have a reaction control system to control its orientation while in space.
@@plainText384 oh you're right, forgot it had RCS. then it barely qualifies as a spaceplane (by a hair lol compared to the ones that actually go to orbit)
I always liked the idea of a vertical maglev system providing the initial energy to launch an SSTO vehicle from a deep silo.
You might like this:
ua-cam.com/video/mjbuaY-psS0/v-deo.html
A bit like Buck Rogers.
There is a Seattle company, Radian, proposing the use of a rocket sled to give lift to a space plane. Could benefit from mag lev as well.
@@joeljong931 thankyou, I will keep an eye on them
Still, I can't wait to see the Deamchaser of sierra Nevada fly. Not all space planes are SSTO.
The trade-off between capsules and winged designs is interesting and I'm looking forward to it as well.
«Δ» is the capital of «δ» which is the lower case.
Wait we can petition to repeal physical laws?
Oh boy do I have a whole laundry list of issues to take to my local representative.
Not with that sort of attitude, no.
Fight the physics. I'm working against that quantum mechanics stuff as well...
@@EagerSpaceThese replies reveal all. "Not with that attitude" You mean Reality? MuskCult member.
@@java4653Take your meds, libtard
10:30
upside to wings is of course that they allow you to fly with a twr smaller than 1
And perhaps with a high-ISP engine in the atmosphere, but you have to carry those wings all the way to orbit and protect them on reentry.
Since so much of the launch profile is out of the atmosphere I think you generally lose on the tradeoff.
@@EagerSpace well, in an ssto you also ahve to carry the engines you need on liftoff all the way into orbit
and with the vehicle burnign fuel and getting lighter those enignes are argubaly not needed for most of the flight
you can basically save like 70% of your thrust with wigns that can produce 100% of your weight in lift so for hte tradoef to be worth it wings that can generate a certain amount of lift have to be less than 70% the mass of an engine that produces the smae force in thrust - i nthat case it would cancel out and yo ucould basically ignore the wigns in the clacualtion and just swithc engines out for htem later
unfortuantely thats really ahrd to esitmate because the lfit/weight ratio of wings depends on the overall size of hte vehicle, the wing design, the materials used and so on to an insane amount and htere's little eaisly available information on it like there is on rocket engiens where oftne oyu can simply look up their thrust to weight ratio
for smaller vehicels this could be a worthwhile tradeof, for a hypoethetical winged sls core probably not so much because larger strucutres are generally less structurally weight efficient
although hten yo uget into hypothetical scenarios like putting fuel tnaks into the wigns so they have to take less of the structural load
and the weight of the thermal protection system dependso n the wings surface area more than their structural carrying capacity whcih means hte faster your vehicle takes off the lower its mass fraction because yo ucan have a higher wing loading
Regarding booster recovery: I was honored to meet Francis M. Rogallo about four different times at events hosted by *KITTY HAWK KITES* in the North Carolina Outer Banks in the latter 1990s. {I moved to N.E. NC in 1995, and Kite Flying is one of my hobbies.}
Based on what I heard Mr. Rogallo say, and with access to the early internet, I became aware there were proposals to recover spent rocket boosters -- including the SATURN V FIRST STAGE -- by having them glide to runway landings using Rogallo Flexwings/Parawings. {There was also research into recovering manned Gemini & Apollo capsules to avoid splashdowns, but due to the goal of getting to the Moon _"Before this decade is out"_ recovering manned capsules this way was abandoned.}
I am still somewhat surprised, although knowing how government works also not surprised, that this was never implemented at all.
Interesting - thanks for sharing.
Great channel!
Thank you!
I thought that the supposed principle behind the spaceplane as a concept was that "flying" up to altitude on wing lift is a lower delta-v launch profile than a typical gravity turn, and that's why they all have big heavy wings and lifting bodies. How that plays out in reality I don't know, but it feels like it should have been worth a mention, especially as it obviously requires much less initial thrust to weight.
Exactly. HOTOL and the X-30 were intended to be operated out of extended runways.
yeah, following a constant dynamic pressure path up to orbital velocities would allow a lower thrust flight to orbit, and with the increased specific impulse of using airbreathing engines (which will be able to use the air given the constant dynamic pressure) the mass fraction is way lower and more practical.
I think I ran some maths on a craft I was crappily designing and it was as good as fuel making up only 50% of the gross mass on the runway, and payload being around 10%. This was with multi-mode turbo-scramjets that varied geometry of the intake to ensure the best flow, a nuclear thermal orbital insertion engine, liquid hydrogen fuel and a waverider airframe design.
of course there was a big problem with actually trying to figure out a trajectory and the fact the craft needed quite a lot of engines relatively speaking, as scramjets have terrible thrust to weight ratios (like barely 2, relative to their engine mass let alone the rest of the craft) and quite a lot of thrust is needed to accelerate whilst climbing - I think it was around 0.6 or so, so 30% of the spaceplane would have to be ramjet. a 10% dry weight sans engines would be a bit of a reach; at about the point I came to that number I gave up lol.
@@PearbabyREAL Great work! Boeing TAV TSTO was absolutely viable with no advances in technology in 1985, no scramjets needed. X-33 could have been suborbital with aluminum tanks. We have rockets using composite tanks today. I think some of the folks in the comment section might be onto something.
@@AnthonyDDean honestly the design I've ended up settling on (for now whilst I expand it into something more fleshed out) is something Skylon-looking but with a better delta wing-waverider setup, and only mach 6 turboramjets, as opposed to variable geometry scramjets.
The scramjets are just too much extra mass for the amount of thrust they produce, and I figured out that it'd just be less hassle to light up a rocket at Mach 6/30km up rather than trying to eek out anything airbreathing. All the airbreathing I was hoping would be possible was more desperately clinging to different envelopes that only barely overlapped i.e. how scramjets are just barely viable at around Mach 10, which is when magnetohydrodynamic bypass becomes barely viable - and trying to patchwork 5 (turbine, ram, scram, MHD-slowed air for ram, vacuum rocket) different engine modes together is getting a bit overly complex.
Even just 2km/s initial velocity is a huge weight saving for a rocket: an 10 ton dry vehicle needs nearly 120 tons of propellant (350 isp assumed) for 8.6km/s of delta V - 6.6 only needs about 60 tons, a literal halving (not even taking into account the increased isp from starting in a near-vacuum, and to a lesser extent the extra height above Earth).
Sure, a 3 mode (turbine, ram, rocket) would have a worse propellant mass fraction than the 5 mode spaceplane, but it would simply be a lot less of a hassle and a lot easier to keep running safely in the harsh environments of hypersonic flight, reentry and low Earth orbit. 5 mode had a propellant mass fraction from my working out of about 50%, whereas 3 mode is closer to 65%. 5 mode also spent long times lingering, accelerating whilst not building any altitude, and my analysis of the atmospheric flight probably underestimated the amount of fuel wasted to gravity and air drag.
I think this is very much possible and within modern tech's capabilities - aerodynamic flight up to Mach 6 is difficult, but not the damn near impossibility of trying to fly Mach 12+. The main legal/moral problem is the rocket powerplant; I'm running the assumptions optimistically based on random quotes of articles I need to probably reread lol that seemed to have a good TWR for a modern nuclear thermal rocket pegged at around 7, whereas NERVA didn't even crack 2. I'm also assuming that the exhaust isn't going to be too bad for the environment - it is just hydrogen of course, but better to be safe than sorry.
Composite tanks are exciting, and something that's strong enough and light enough to both hold a massive central hydrogen tank as well as handle the transonic max-Q regime force-wise is going to be great. Highly innovative materials and tech on the inside, dumb but robust titanium skin. Just titanium or stainless steel might actually be good enough (at the very least minimisation of heavy ceramics is likely possible), because you could take a far shallower reentry path that minimises heat with the higher surface area-mass ratio of an empty spaceplane.
Now this design seems a bit more solid than a pipe dream It'll be interesting to work on everything else that's necessary - the specifics of the nuclear reactor, the variable geometry wings transitioning from delta to waverider, the cooling system (definitely a big one). Good task to chip away designing at for years while I work and try to get enough money together to be able to head to uni for aerospace/start a business.
@@PearbabyREAL I remember reading a sci fi story where the featured space plane had both a SABRE and SCRAMJET. The SCRAMJET wasnt strong enough to propel the space plane alone, but it allowed to run the SABRE at less thrust and therefore lower the oxidizer requirement.
Would a setup like that actually have a better LEO payload mass? I personally doubt it, but didnt run the numbers.
One advantage of spaceplanes is that Thrust to Weight Ratio is less important than Lift to Drag, meaning that very efficient engines that have a lower thrust to weight ratio can be used to offset the added weight.
Airplanes can have a t/w ratio of 0.2.
That's true, but most of the time getting to orbit is spent outside the atmosphere, where the wings are just extra weight.
I do think there may be a place for two stage spaceplanes, with a winged booster. I have a video on Dawn Aerospace's project to do that.
Where can i sign that appeal. Ill bring all my friends to sign it aswell
I demand they repeal this law and it’s equation. California is just the place for such political vision and action! If we can manage global weather, then the rocket equation doesn’t stand a chance.
Check out the presentation about Rotational Detonation Engines and the proposed Cochrane Exploration spaceplane that starts 1hr into video z_06OhH6Hj0 titled "APEC 7/8: Warp-Drives, Detonation Engine & TR-3B". Sooner or later someone will find the funding for some kind of runway-to-orbit spaceplane like these.
I've spent a little time looking at rotational detonation rocket engines. The ones that I found have low thrust and unimpressive specific impulse, but that might change in the future.
13:36 fun tidbit: I believe modified rl10s have fired with “slush” LH2 since the 80s. Very fun way to add some performance.
9:50
not sure if thats a fair assumption because yo ucan at the same tiem downgrade the stage from ahving to support two solid rocket boosters on the side - at least structurally it alreayd has to support a total twr greater than 1
One explosion in 13 flights and they cancelled? SMH
Beamed power using the atmosphere as reaction mass could make things more viable, though, that is arguably a 2 stage rocket anyways, just, one of the stages is staying on the ground
Also spaceplane does not need to have additional weight penalty vs rocket. Just a fuselage geometry for lifting body lift for take off and light weight simple struts instead of heavy wheels. The main advantage of the VTOL space plane is to have rocket motors just with 25% of the lift to weight ratio (instead of rocket 120%). And also to use air breathing simple rocket motors (like e.g. Meteor missile) to reduce the required oxidiser weight by 75%.
You get higher efficiency and lift in the atmosphere with wings, but then you have to carry those engines and wings with you all the way to orbit, and you spend a lot more of your time out of the atmosphere during launch.
If you can build a light hypersonic air-breathing engine it gets more interesting but nobody has gotten there.
@@EagerSpace again the space plane does not have to be SSTO. You can use your single stage space plane only to like 70km altitude for breath air engine operation and then lunch the 2nd stage to actual orbit. The only issue is the gravity and atmospheric drag. But you do not need to carry all the 1st stage oxidiser (which is 80% of the propellent weight). And your 1st stage has 5times less engine weight/numbers. Lifting body is the same weight as normal rockets as the wing is the fuselage. Also for the rocket reuse the space plane does not need to waste 5/10% of the propellent for landing as it would land horizontally as a glider (e.g. space shuttle).
See my video on dawn aerospace
Repeal the rocket equation was originated from the Good-Luck-With-That Dept. Anyway, nice short presentation explaining why we don't have single stage to orbit rockets. Dale Myers associate administrator or acting deputy administrator of NASA in 1970 when companies presenting ideas for the Space Shuttle. He immediately dismissed SSTO concept which saved much time. Fast forward to the X33 Venturestar with hope it would be a SSTO but had developmental problems of could it even fly to Utah from Calif before becoming too expensive. Some reason people thought they can overcome the Rocket Equation. The real downside was loss of testing aerospike engines and thermal projection systems for real even if suborbital flight.
I don't think you ever overcome the rocket equation, you just use the ramjet equation in the first stage aerodynamic trajectory, and switch to the rocket equation like Dr. Heiser stated. Polaris is using an aerospike and ceramic TPS is not required for a glider with a more shallow trajectory like Star Raker - both Star Raker and X-33 only required metallic TPS. The moment you go cone, lifting body, or brick (Shuttle), you need heavy TPS. Dr. Paul Czysz referenced a water-wicking titanium honeycomb TPS that was demonstrated to be viable in testing. The water-wicking TPS would have given more than several tons in payload capacity and weeks faster turnaround time. NASA Langley High L/D (John Becker) demonstrated theoretically that a Mach 18 vehicle could circle the Earth using outward centrifugal force from Earth's center as an accessory to atmospheric lift. HyperSoar demonstrated theoretically that skipping off the upper atmosphere would enable a Mach 10 vehicle to arrive at any point on Earth in an hour. The problem we had was groupthink and politics. Engineers always come up with solutions, and bean counters always find a way to pull us back to the lowest hanging fruit. We got to the Moon because it was the hard thing to do. We use rockets because its the easier thing to do.
@@AnthonyDDean Interesting discussion on metallic TPS or heavy TPS. It is a waste of time of solutions overcoming the rocket equation, you mention we use rockets because it is the easiest where other concepts will need more engineering (and expense)?
Radian's sled launch is basically just a second stage without calling it a second stage lol.
Yep. They'd be better off just admitting that they need two stages and fully committing to it, which lets you balance the mass ratio properly to get the full benefit.
I.E something like the SpaceLiner: en.wikipedia.org/wiki/SpaceLiner
Yes. It's similar to air launch - like Pegasus or Virgin Orbit - but without the simplicity.
The idea is that you have big tanks on the rocket sled that feed both the rocket sled and the spaceplane during that period so that the spaceplane hits the end of the sled track with full tanks and engines at full thrust.
@@EagerSpace Asparagus staging too? It will increase the performance, sure, but given how SpaceX abandoned it for Falcon Heavy I'm not so sure Radian can pull it off.
Thank you for including Reaction Engines concepts (led by the visionary Sir Alan Bond) - the engine design is gaining interest both by ESA and abroad. There must be another way gain to economical access to space - even Musk's Falcons have a finite life !
I never got Radians plan of using a rocket sled for takeoff, one of the advantages of a HTHL spaceplane would be the ability to launch from somewhat modified airports without a need for extensive ground infrastructure...
I'm a bit skeptical about the various plans for SSTO spaceplanes. A lot of companies get around this by making the spaceplane the first stage and then getting the satellite to orbit on an expendable second stage, but what I'd personally like to see happen would be an HTHL with flyback boosters to actually get the spaceplane itself into orbit. Structurally challenging, I know...
Flyback boosters in a plane seems to be logistically difficult in terms of wingspan. It would be a little like the triamese shuttle concept but flattened out.
@@EagerSpace Absolutely, the boosters would either need a short wingspan or some sort of foldable wings. Alternatively, perhaps it would be doable to have the boosters land vertically like the F9 first stage, then they wouldn't need wings at all.
I have a question about the X37b. How many models are there , ty4sharing rocket launches are cool stuff, and Victor S, from Austria, invented an engine that is powering u.s.tech🤔
Eager Spaxe being a Halo fan is not something I saw coming
Eager Space worked at a large redmond software company when XBox was released. Played lots of CE multiplayer in conference rooms. Play a bunch up through 5.
Hahah physics hates hummans. It's a good summary of the situation.
It's the same issue with faster-than-light drives. We'd all love to have them because they allow so much fun in science fiction, but AFAWCT, physics hates us.
@@EagerSpace I Would GO FURTHER Than That & Say That The Universe HATES Humans AND Offers Humans NO HOPE ! ! !😭😭😭😭😭😭😭
@@EagerSpaceI REALLY LIKE Your Channel & It Is ONE Of THE BEST Out There ! ! !
Physics doesn’t hate humans, it’s the reason we have a universe in the first place.
Great video...👍
Repeal the rocket equation! (By living in space)
Acutally a rocket sled looks like a first stage which just remains close to the ground. Maybe the ground effect can be exploided. There are currently two stage spaceplane developments and I think it's some kind of fair to think of an assisted SSTO as basically a two stage spaceplane with second stage recovery. A rocket sleds limit so far is about 2.5 km/s or Mach 8.5. Maybe that can even be increased.
Hmm...
1) Where are you going to build a launch track?
2) How many Gs will you be pulling to get that speed?
3) How do you keep your vehicle from melting at that speed in atmosphere?
4) How do you mitigate the sonic effects.
@@EagerSpace Of course questions. As for the launch track I thought of exploiting the ground effect -- in other words a plane that can't really fly. Gs can be high if its only cargo. The sonic effects will be there and I'd say one needs to stay below Mach 3 so that things stay "cool". I suppose wings and gliding might save probably 300 m/s.
The USAF and DARPA looked at a two stage spaceplane were the stages launched separately. The first stage is a tanker. The second would take off lightly loaded with fuel and meet the tanker fuel up and head for LEO. If workable imo this would be ideal as a crew transfer taxi. But not a cargo vehicle.
Interesting. Do you happen to know what the project was called?
@@EagerSpace
Black Colt and Black Horse.
Although a 2CV is pretty awesome, it hasn't a range of 800+ km and it's restricted to roads
ua-cam.com/video/jt9g5e1kTig/v-deo.html
But I'm a bit biased as I used to own a DS19 Safari when I was young.
I stand corrected@@EagerSpace
The design brief for the 2CV did specify it should be able to drive in a field and not break eggs caried inside, so i think we can considered it ISN't restricted to roads. also the "roads" it drove over in the post war period were barely roads lol.
As impossible as it sounds: a SABRE is less "complex" and built simpler then a SCRAMJET. Yes, a SCRAMJET wouldnt have moving parts, but the required materials and the engineering behind the aerodynamics and combustion stability are ALOT more complex then a SABRE. For an example: the needed materials would make a SCRAMJET only have a crappy 2 to 1 thrust ratio. SABRE achieves a 5 to 1 ratio, because the stresses of the parts involved are so far lower, that they can use cheaper and way lighter materials.
That said, I wonder if a combination of the two systems would work. I remember reading a scifi story a long time ago, where they used space plane that featured a SABRE and SCRAMJET combo. The SABRE would accelerate the plane to Mach 4, where the SCRAMJET would start helping up to Mach 20, so that the SABRE can throttle down and consume less oxidizer.
I think that dual-engine designs are pretty universally going to fail because of the extra mass of carrying two engines.
Any ideas on the feasibility of the Boeing X-37 sent out of spinlaunch? Also, a video talking Spinlaunch versus a standard sled would be interesting.
(Just subscribed because I love your sense of humor and approach to delving into details…. Thanks for what you do!)
I did a video on spinlaunch.
The feasibility of the X-37 on spinlaunch is zero.
a) It's not a second stage and spinlaunch requires a second stage to get to orbit.
b) Any payload on spinlaunch has to take 10,000 gs. I would be surprised if the X-37 is rated for higher than 15 gs, and it could be less.
Thanks for the response, @@EagerSpace ! Just watched the spinlauinch video; thanks for being you.
For the X-37, it would not be _"SpinLaunch,"_ it would be _"Spin-RUD."_ 😉
I probably won’t receive an answer but worth a shot. What is your opinion on using an engine like Sabre as a first stage engine on a traditional rocket while leaving the 2nd stage and its engine as a traditional stage? The first stage can take a higher mass penalty and the 2nd stage will travel through almost no useful atmosphere, even if we stage early like spacex and blue do. Thank you and have a great day.
Two stages obviously makes things a lot easier and there have been designs like that in the past but nobody has built them.
I think the problem is that you are talking about a very sophisticated and very big hypersonic vehicle that you have to design and build that competes with a simple dumb booster, and since SpaceX figured out how to reuse those, much of your theoretical advantage goes away.
I'm generally not a fan of technology that hasn't actually been built. A ton of people have looked at sabre and passed on it. If it is workable, I think aiming at very high speed transport or hypersonics for military applications would be a good niche for it.
A plane that flys so high then rocket engines kick in to push it out the atmosphere would be cool but its the rocket equation all over again plus other stuff
Space plane does not mean it has to be SSTO. It could be 2 stages with 2nd stage being also, but smaller space plane. Or it could be disposable 2nd stage like e.g. Neutron rocket.
Yes. See my video on dawn aerospace who is working on a first stage space plane.
A nuclear powered SSTO is easily possible even with the technology available today.
Unless you are talking about Orion, I'm skeptical.
I did a whole series on nuclear engine designs.
@@EagerSpace Obv this is all hypothetical, but a SSTO with advanced ramjets/scramjets capable of around Mach 6-7 and nuclear engines both fueled by liquid methane and utilizing a waverider design to maximize supersonic L/D should very much be possible given enough R/D. Obviously it will take a lot of money and ingenuity to achieve, but i personally think it can be done.
This is an interesting video but your title is misleading and not a good representation of your subect. You've amalgamated a Spaceplane and an SSTO. Those are 2 different and completely unrelated concepts. There have been concepts for non spaceplane shaped SSTOs and for non SSTO Spaceplanes (Space Shuttle, Buran, X37B, Chinese GSSHQ?). You've made a video that adresses why we don't have SSTOS and you've explained why very well: The rocket equation is a harsh mistress. If you wanted to make a video about where all the spaceplanes are you should have looked at the other main reason why spaceplanes have been made: Their advantages in reuse, Crossrange during reentry and precision landing, among other things. I think you should revisit this video with 2 separate ones: one about SSTOs in General and one about spaceplanes in general (with a section about SSTO spaceplanes if you like).
Yes. I limited the topic because putting together SSTO spaceplanes and winged orbital vehicles like shuttle, buran, x37b, dream chaser tends to make people confused.
@@EagerSpace i understand but in the end treating ssto and spaceplane as synonyms is just lore confusing i find. each concept is pretty different to the other. here you clearly focus on SSTOs and Spaceplane SSTOs, i think the title isn't adequat, but also some of the points in the video are incomplete by bot adressing the wider appications of both concepts.
Unnecessary pedantry
for a plane to go to orbit you need: reacción engine like the ones on fiter planes,bigger wings so you can get more fuel and no much heat on reentry, landing gears will have to be light so take of will be with only a 10% of fuel the rest will be transfer in mid air ,aereal refuling is a prove TEC,and allow to take dowble the fuel that will be possible on take of because you will be traveling at tou times the speed, rockets need push at least a porcent more than the weight of the rocket the plane can do the same with one fith of the trust,so 2 engine instead of 10 and will be at least 10to 15 km higher, afterburner will be a great,is like a rocket that don't need oxigen and can go up to 30 km, that is a great head star.
I remember the DC X. If only it had been funded properly we might have been closer to cheap reusable launchers a lot sooner.
Neither Lockheed Martin nor McDonnel Douglas were interested in funding development using their own money, and that's been an ongoing pattern with SSTO designs.
The DC-Y might have been an interesting vehicle, but I don't think they would ever have gotten to the orbital version.
LOL. This is hilarious. No admission that Musk lied about inventing the concept and a deranged brattiness that you've been denied something. MuskCult is so lost.
IIRC, it was originally an air force X project and then taken over by NASA. Pournelle stated in his blog that they protected their cash cow the space shuttle by letting it fail.
another amazing video! great work
I love this channel ! why dont you have 300k subs ? Try seo, adding hashtags, discription, etc.
Not everyone wants to do this for fame and subs. Some people just like sharing ideas and if people want to listen and watch and share with their friends that's well and good and if not so be it.
@@rocdaroc more subs means more views. It seems like a hobby channel but explains complex stuff in plain english and clear accent
Unfortunately the audience for this type of stuff is pretty niche so while people like us find it great, other people might have a lower attention span
I've played around with hashtags and from what I can tell it doesn't make a difference. If you have suggestions for any of these, please let me know.
I know very little about SEO.
I think I may already have had my 15 minutes of fame and I'm not interested in changing how I do things (much) to pull in more subs and views, but I'd be happier to reach more people.
would it be worthwhile for space x to divide the goals of going to mars from a single starship to.. lets say 3 different ships with 3 different purposes. 1 ship would go to LEO only, another ship would go from LEO to LMO only. And the last ship would go from LMO to Mars.
Mars can easily have SSTOs in my opinion.
NASA tends to go with the highly optimized approach, and they end up with very functional spacecraft that are painfully expensive.
Right now, starship is at the other end, a generic craft that can do a bunch of things less efficiently but at a lower cost.
I do expect to see specific starship versions but they won't be that different from the base one, at least initially.
We just need way more efficient engines for sstos
I thought the whole point of space plane is to use atmosphere for both oxidizer mass and reaction mass to push off against. The equation you're using is more applicable for a SSTO rocket than a SSTO space plane imho. In the atmospheric flight portion of the launch, space plane would benefit from air breathing mode, regular GE F404 engine has equivalent ISP of 2070, far above any rocket engine but of course, only operable within atmosphere.
There is also the additional lift from wing, equating rocket lift to wing lift is not exactly equatable, since if you can get a lot more lift from a propeller thrust when an aircraft is fly horizontally than if you just point the propeller up and trying to use that thrust directly for hover. Mostly due to the fact kinetic energy scale with velocity square while momentum scale with velocity. So for the same energy input, you'll get a lot more thrust by accelerating a lot of air mass slowly than a little bit of air extremely fast. This effect is also why high bypass engine is significantly more fuel efficient than low bypass engine.
A better comparison or analysis would be to take an aircraft fuel/payload performance metric with a rocket's performance metric, and just assume dead weight in each stage. The equation might still yield that it's better to have separate stage. But I think this way of analysis give a more accurate analysis for the atmospheric portion of the launch. Since a large portion of the launch is in the atmosphere. Ignore aircraft's effect and assume it behave like a rocket is doing a deservice to the space plane design.
Then there is re-entry part of the launch, technically heat shielding needed if you descend too quickly. But if a space plane that glide down slowly, then you need less shielding. Granted, in high altitude flight, stall speed can get pretty close mach speed so it might be hard to maintain the correct sleep to glide down. But the point is if the space plane have sufficient lift over drag ratio, then the weight for heat shield can be reduce.
I think space plane following more of a doctrine of inputting the required delta v slowly and remove that delta v slowly during re-entry. As compare to a rocket, which is optimize to get to space as soon as possible and out of atmosphere before building up delta v. I don't think analyzing a space plane like a rocket purely is entirely a fair comparison. Just as if you analyze a rocket like an aircraft, it'll look pretty bad as well.
When your spaceplane is in airbreathing mode, you have really high specific impulse and the lift from the wings, but the downside is that you are wasting energy on air friction which gets a lot worse as you fly faster and higher. You need to transition to rocket mode quickly and at that point you are just a very heavy rocket because of the weight of your wings and other plane stuff.
The significant majority of the kinetic energy you need to get into orbit comes when you are out of atmosphere so your rocket performance is more important than your airplane performance, so the question is "can you get enough benefit out of starting as an airplane so that the vehicle can go SSTO once it gets out of the atmosphere?".
The answer so far is a really clear "no".
Trying to do a full analysis of airplane mode and rocket mode is a lot more complex than the approach I took and it would be very hard to present it in a way that is easy to understand.
WRT heat shielding, you absolutely need to have it to survive reentry, where the air isn't dense enough to give you any lift but it is dense enough to give you a ton of heating.
Wow I like that physics hates humans idea, like if this was a rpg humans would be getting a negative bump to their chances of becoming spacefaring, if Earth was much heavier we'd probably evolve alright, bit stumpier fine, but right as the space race was beginning we'd be running tests on the best fuel possible and finding it required sci-fi levels of material tech to even get into orbit and completely give up on that part of the tech tree o.o
Or maybe like they'd settle for like, an eight stage rocket that puts a metal retroreflector pebble into orbit for a few hours and they track it and it takes their entire science budget to do so and they cheer and then space tick done
Considering the space and atomic age were pretty coincident, I have a feeling the hypothetical high-g dwarves would find a way...
Spaceplanes will go extinct like the X-20 Dyna-Soar 🤣
Shhhh.... don't let the MuskCult know Reality exists.
Japan Nitrogen's Noguchi of early 1940s Hamgyong Province was developing a rocket plane engine comprised of a Dewar of cryogenic liquified deuterium fuel connected to a beryllium alloy reaction chamber nozzle coiled in around electromagnet coils to focus cosmic ray muons while cryogenic fuel prevented exceeding of Curie Point.
Therefore deuterated diborane fuel in Xcor's Lynx with a 9 volt battery powered electromagnet should be considered.
Patents of Mutsuro Bundo and Hector D"Auvergne could be improved with Robert L Morrison's patented lighter than air solids "SEAgel" or "biofoam" sealed in foil.
Can I petition you to add SSTO to the title? I didn't click on this video to see SSTO.
By the way I have another question for you, some people claim that you can carry more payloads from LEO back to Earth using Spaceplane, is this true? Assuming that the accelerations cannot > 1.5g and the payload cannot be < 200t.
I'd have to see the particulars of the two systems to have a real opinion. Seems hard to build something like shuttle with higher downs than starship.
SSTO and space planes are not really the same thing at all. SSTO is a huge problem for engine design because you need to operate as an air breathing engine for as long as possible then switch to being a rocket engine when air gets too thin, anything else is just too heavy to be practical. Only one engine design ever got close to this but still never got anywhere. Space planes biggest problem is getting back from orbit in one piece because reusable heat shields are hard to do. The recent Starship flight 4 showed this well as we had video all the way down showing how brutal re-entry actually is.
Once again very good
There are other factors like aerospikes to keep an engine optimized from sea level to vacuum like the venture star would’ve used, but I’ve heard that’s not worth it either. I think rockwell’s X-33 realistically could’ve worked
Maybe the solution is a 2 stage full reuse space plane though
I talked about aerospikes in the rocket nozzle video I used.
It's hard to come to a conclusion about the XRS-2200 - and the follow-on RS-2200 - because there are no published engine mass figures, but based on what I've seen it's not a game-changer.
Although this video has been nice and informative, it rather misses the mark with one important point: the question is, "why no space PLANES", not "why no SSTOs".
One nice cheat offered by a space plane is that it does not need to LIFT all the mass at start. Unlike conventional rockets, it can begin with horizontal take-off acceleration. You have 2 components to the required delta V: horizontal and vertical. In conventional vertical launch rockets, any thrust insufficient to launch is wasted. In planes, however, can accumulate the horizontal delta V before adding in the horizontal once the overall mass is low enough. Another nice thing about planes is that they have wings. These have a considerable amount of surface area that can actually help to reduce reentry heating, decreasing the mass necessary for heat protection. These wings can also allow for aerodynamic reentry/landing, which decrease the required return fuel mass.
Of course, actually dealing with PLANES adds a LOT of complexity that is difficult to cover, even with a much longer video.
Oh, yeah, the benefits of airbreathing rockets deserve much more intensive treatment. Not to mention some of the other benefits, as well as some downsides, of aerodynamic forces in launch.
I talk about Dawn Aerospace in a different video; they have a spaceplane first stage architecture. Their plane is a rocketplane and I think that's likely to be the best approach.
Military tries to monopolize since even with my MIT work bureaucrats hysterical about "weapons proliferation" have Walter Pecked anyone who attempts to purchase isotopic fuels,
Too bad we can't use stuff like pentaborane and chlorine trifluoride together. Chemistry is mean!
This video is actually wrong with fasle premise. Spaceplane does not exist cuz technology was not advanced enough to have transforming engines. Spaceplane Riker plan is under way currently is actually feasible.
Not sure what you mean by "spaceplane riker" - can you give me a link?
@@EagerSpace Spaceplane Star Raker. Technology is advanced enough to actually make space planes one stage possible.
Starship' 120 ton version doesn't work as an SSTO, but it might work as a single-stage suborbital space launch system. If SpaceX ever wanted to get into the suborbital tourist business, Starship-only launches could probably give them quite a ride.
It also works for point-to-point transportation, though there are many other issues with that.
@@EagerSpaceLOL. It doesn't work yet. And point to point is not possible at all. Thank you for revealing you're a member of the MuskCult and not a reliable source at all. Couldn't tell at first, you've all gotten a lot quieter as Musk's insanity was revealed.
Imagine if dragon was a space plane instead of a capsule.
The It wouldn't be Dragon. Do you understand:
Dragon is the exact same concept as the Apollo system? Do you understand Musk is tricking you by calling different things "Starship" so you think it's a super ship that does everything? Do you even understand Musk lies about everything and he's a racist sociopath? No. By saying "Imagine if Dragon was .." you reveal your membership in the deranged MuskCult.
You have a great understanding of rocketry, but a little more focus on hypersonics is required here. You are talking rocket the whole time and giving very basic math. You can apply the same math to a spaceplane that takes off vertically. You cannot apply the same basic math to a spaceplane that takes off horizontally like NASA Langley/Marshall and Rockwell International Space Division designed Star Raker. Hypersonic vehicles designed by the Air Force Flight Dynamics Lab were capable of some pretty impressive things before the Space Shuttle was ever designed - an abortion learning to fly and a brick for reentry (we didn't want to weaponize space, so the least hypersonic and the least military looking plan won out.) 1) 9800 kms deltaV is the delta V requirement for a giant rocket, not a hypersonic vehicle coming from an aerodynamic trajectory. Orbital velocity is only 7800 kms, and a horizontal launch and partial aerodynamic trajectory is a completely different calculation from "me throw heavy rocket into sky" . 2) Hydrogen ISP (efficiency) does not relate to pure thrust - shown by very weak performance of pure hydrogen engines in autos. Hydrogen also makes the aerostructure extremely heavy because it requires four times more space than methane. It is also a nightmare waiting to happen (Hindenberg) in an aircraft. 3) You have the basic theory down, but engineering a hypersonic space plane requires a multi-disciplinary systems level engineering approach with a solid ideological goal that does not simply give in to groupthink or lowest hanging fruit. You didn't mention Star Raker or X-30 NASP, or the audience would notice and ask for a deeper thought process.
Structure: engineering software is now capable of mass reduction (demonstrated by Czinger/Divergent and NASA Goddard), and additive manufacturing is now capable of part-count and fastener reduction (demonstrated by Relativity Space). Methane makes a smaller vehicle and provides THRUST, and SpaceX is proving out methane. Engines: rocket engines are now being 3d-printed (Hyperganic and Leap71). Rocket-based combined cycle engines like NASA's GTX (lighter and less complex than SABRE) would be a great for this application, as the compounding equation of heavy oxidizer sitting in a tank waiting to be launched with the "how to get your fuel, to get your fuel, to get your fuel" (why not just use aerodynamic lift for part of the trajectory?) launching dead weight vertically from a pad (that also restricts your number of locations). Dr. William Heiser stated that the most efficient way to get to space is an aerodynamic lift trajectory followed by a rocket boost to orbit. The problem with Stratolaunch and Virgin is that the launcher vehicle is subsonic. You need a multi-sonic vehicle to perform a TSTO to orbit. From a senior engineer who worked the project, Boeing's TAV was designed with no technological advancements to be more than viable in 1985 - that was nearly 40 years ago. Star Raker and X-30 were spent money on by governments and companies and worked on by engineers and scientists who were greater in their intellectual capacity than anyone in this generation. The tech wasn't there - the tech is now here, but that generation is no longer.
Why do we not have hypersonic space planes that take off from the runway? Because we are not smart enough. Humanity has not advanced past being a warmongering species that cannot internationally collaborate on something of this magnitude - we were almost there with the Kholod scramjet collaboration, but the US government seems to have multiple personalities. The ideology here is that if we became smart enough to perform such a feat, the railroad to space would become a superhighway with no conversion of airport infrastructure required. Enter AI.
The point of the video was to do a quick analysis of what Dawn is doing and how it differs from other approaches, and the feedback I got directly from Dawn was quite positive.
WRT spaceplanes in general, I have another video on that topic where I talk about the subject in more depth.