One more reason why Super Heavy doesn't have a landing legs is a weight. SpaceX wants to keep as much stuff on Earth as possible to minimize Starship own weight and increase it's payload capabilities. It's complex and expensive to build Mechazilla, but Starship will pay it back on every next flight.
Not just the legs. Landing on legs requires a much more rigid body than hanging from the top. You can make a falling thin paper tube stop and hang from a pin holding it from above no matter how hard it hits the pin, while the same thin paper tube will likely crumple if you just drop it on the floor if it comes even a fraction of a degree off the vertical.
@@herbys68 I’d not thought of that additional reason for no legs before. But I’m also thinking are you right? My thought is that the booster would probably be strong enough to land anyway as it needs that strength during the lift off phase of flight. Although I guess maybe on liftoff more of the strength is produced from the pressure in the fuel tanks and there will be more fuel at take off of course! Just thinking out loud tbh
@@jamster2400 The 4 mm version maybe yes, maybe not, but as they try to shred weight and move to thinner sheet metal it will become more fragile, and there is simply no reason to make it sturdier than necesary. In other words, if it can withstand the landing forces, they can definitely go one level thinner with the sheet metal if they can forget about those forces. But there is another reason related to that: even if they make a rocket that is sturdy enough to survive a regular landing, there will be landings that are less than perfect, maybe one degree inclination, maybe coming a bit harder than expected. And such a landing would almost surely cause damage to the tanks like we saw with A 10, with catastrophic consequences to the booster and the landing infrastructure. They would have to make a much sturdier rocket to be able to survive such landing, and that would likely add significant weight. Hanging from the top means a slight variation in the angle or speed would not cause compressive forces, only pulling forces which the thin metal can handle much better.
Although from the data given in the simulation, with the booster hovering for 5s before being caught it now needs a lot more weight of fuel rather than doing a suicide burn. There must be a crossover point where it costs more in fuel weight to be caught like that than it does to simply use landing legs.
Disclaimer on top: Don't get me wrong, I am actually not against the tower-catching approach. It's an elegant way of getting around the big problems landing legs bring with them. I like playing devil's advocate and seeing what holes we can try to poke in the design and how we might fix/mitigate it. One big downside I can see is that, if the proverbial excrement hits the rotating aerodynamic surface, not just one ship is down for the count but all of your ships are now prevented from landing in that location for the foreseeable future. You could argue this is why you build more than just one tower and that is a viable risk-avoidance measure. Though you do still end up with the risk that an unforeseen design flaw causes a catastrophic failure, which in turn causes an investigation and *all* of your fleet to be grounded until the issue is resolved. This doesn't happen too often in the aviation industry but it is also certainly not unheard of, and I would imagine a major incident while Starship is operational would have similar consequences especially when there is a human cost. So, would multiple towers be enough? What would happen in the case of the eventual catastrophe that history teaches us *will* almost certainly happen no matter our intentions? Would that possibility lead to requirement for an escape system on human rated craft (or an alternative system designed solely to prevent RUDs on landing if that is more viable)?
You forgot the main reason for ditching the landing legs for a catching system: mass reduction. Truly stable legs, together with their housing and operational systems would weigh quite some tons. This is additional mass that in the end has to be cut from the payload..
exactly it would be far easier engineering a big sturdy and reliable retreival system on the ground it will not have to take the burden and beating of flight and renentry and there is no mass limitation to such a system while in the same time improving the reliability and payload of starship
@@marcopederzoli4939 He should work for SpaceX then. I do remember how all the people who had calculated that landing a rocket like the falcon planned to do was not feasible and how they saved SpaceX millions in useless r&d.
Meh... that's what I thought too before seeing the simulation. The 5-second hover should consume around 3 tons of fuel. That gets rid of most of the mass savings from removing the legs. After Musk released the simulation, I don't think mass reduction is an important decision factor anymore.
It was a simple typo. Wrong value copied in. Editing mistake. 5 Minutes after release (when I saw the first comment), I checked the video and started laughing! Honey, we created the lightest orbital-class booster stage in human history! Then, I edited the pinned comment to reflect it. I hope many see it! Thanks for bringing it up!
Soooo, I m pretty sure a Falcon 9 empty first stage doesn't weight close to 550kg (almost a four hundredth of a superheavy) but rather in the 25 ton range (an eight of a superheavy). I think you mistook the 550 ton fueled launch mass of the whole vehicle. Love the vids keep it up
550kg seemed unbelievably low to me too. I just searched for a minute, the weight of one single Merlin 1D Engine seems to be around 470kg! Empty weight of a whole Booster around 25t. just like you said :)
A note about grid fins. They only work when you have sufficient air flow through them so they aren't able to control the roll of the rocket during the last couple seconds of the landing. From that point on it's up to the engines to control roll or, if only a single engine is being used, the cold gas thrusters.
Going for *either* rapid reusability *or* full reusability is a bold move on SpaceX's part. Doing both at the same time is outright insane. If this works out and spaceflight becomes akin to regular flight, where you can just refuel a ship and reuse it at leas ta few times, it'll be a step forward like the first manned spaceflight or the moon landings. Maybe there is a not-so-distant future ahead where Starship-like vessels are used like airliners are today: In near constant service for several decades. Vacation on a space hotel suddenly doesn't look that far fetched, doesn't it?
It is utterly impossible to use rockets for transport around the globe. Anyone who disagrees is extremely ignorant of maths, physics, laws, and logic. Period.
@@ck_clemens_k Aircraft burn a carbon based fuel....and so, they do contribute to Global Warming...and any rocket that uses Kerosene for fuel also leaves the earth a little dirtier......but when burning Hydrogen/Lox or methane/ lox they are, environmentally clean burning!!!! The only pollution they create is sound and vibration pollution...please educate us how multiple flights would cause "environmental damage???"
SpaceX's crazy crazy capabilities notwithstanding, Mars as a planet I'm afraid is not that hospitable going by currently whatever much is known. So vacation on a space hotel does appear far fetched, i guess. That said, there could be other useful goodies in Mars that may be mined and brought to earth. So in that perspective it does make a lot of sense about this thrice a day launch cadence ..! Besides there's a whole new business i imagine SpaceX would get into soon. That of cleaning the LEO of space debris. When that becomes a busy biz, SpaceX might come up with circular launch towers with multiple chop sticks catching rockets, not SH boosters with collected garbage. If i run my wild imagination, they would build multiple Circular launch towers with multiple chop sticks in each of them...! LEO Space is already littered with so much debris, you only needed a viable clue how to grab them and dispose off. Once you do, there's so much money to be made, you would be out of breath for foreseeable future, leave alone Mars. they may even have few seats in those collection missions for those Space Vacationers. 😀 Imagine a bus load of people on Starship, vacationing on a garbage collection mission...! Returning with their own garbage collected from heavens😃 Drawing rooms adorned with Space Garbage will be a brag🤭 ...!
Much better for everything. Metals are much better under tensile than compressive forces. The dynamic forces acting on the structure on landing may be very significant, with a compressive force this may cause problems, but a tensile force will be no problem for a steel construction.
That will be quite the thing to see: Each SHB launched 3 times per day, with a stream of Starships, each one configured for its specific mission. At peak performance, it could look like massive, controlled chaos. Should be fun!
It looks like the axis are mislabeled at around 1:30, The spaceX charts show X as vertical, but you show Z as vertical in your overlay. You can tell that X is vertical because of the relatively huge accelerations in that axis. Loved the video! I'm super excited to see mechzilla actually catching rockets.
You have to scroll a long way down the comments to find yours, i thought more people would notice! You also see Y and Z labels to mark axes on rings and vehicles, so looks like they keep it consistent...
Good catch. Most rocket and plane simulation have x aligned with the centerline. It is also common to have different axis on a same project, one for the aerodynamic (x aligned toward the front) and one for the stacking x from nose to bottom.
Removing the legs is exactly the same as removing the seatbelts, airbags, and ABS from a car, and saying "This car is superior because it gets better fuel economy". It is technically correct, but it is also suicidally wrong.
@@Chris.Davies Should a leg fail on landing you would have the same result. If you have your landing gear on the ground it can always be serviced. you can not have a gear failure. I don't believe you have the correct line of thought on this. Though I fully understand what you mean.
@@Chris.Davies um - no. Space launch is all about getting payloads to orbit. By offloading systems from the booster to the launch mount system (e.g. landing catch mechanism, engine startup) you've made the booster both simpler and lighter which means that a greater percentage of fuel is used for payload and less is wasted by vehicle dry mass
@@Chris.Davies thats EXACTLY what they do for high performance cars! Do you think NASCAR drivers are blasting a stereo system in their sound dampened cars and watching a navigation system as they lap the track? NO! Those cars are stripped down...including no airbags and ABS systems in order to perform at the highest level. Do you think those are real headlights painted on a nascar body? 😂 They don’t need headlights, so they remove them for better performance. The cost/ton of payload to orbit is the most critical metric as to whether SpaceX is successful.
Can you tell me exactly how much mass to orbit capacity this adds? And why would they create a big dumb first stage if they plan on reusing it so much? It's contradictory to do the simple, cheap, and heavy thing for production but the complex, precise, weight-saving thing for maneuvers. "Yeah we put this meticulously crafted aerodynamic covering over this hummer running on a coal powered steam engine-- uh, for efficiency"
G'day, Yeah, and if it arrives sideways accross the Fueltank Farm, and blows Bocca Chica off the map...; Elon will be tarred and feathered and run out of Town on the Rails of his fraudulent HyperLoop. How reusable will it be, after the Choppy Stucks miss those TINY little load-beading Lugs, and tears the Grid Fins off...,? How well will it work after Thwaites Glacier goes "Plop !" and raises Sea Level by 3 ft ? Such is life, Have a good one... Stay safe. ;-p Ciao !
no, it won't. The only reason SpaceX is doing that is because otherwise Starship's payload mass requirement would not be achieved (no engineer would suggest such high complexity that could possibly destroy the booster if the project's requirements were already being met). Also, rocket structure is too damn fragil to fly again without a major maintenance and possible repairs, then the 24 turaround or even 3 flights a day with the same booster is just bulshit.
@@Chris.Davies yeah, and they said the electric light was impossible too, I'm sure. Ask Edison. And, closer to home, how many said Tesla couldn't make a practical electric car with "laptop batteries"?
I was totally right back in August when you asked about how mechazilla would catch the booster and I said "Maybe something like vice plates that track along the arms and close in on the hooks?” As for tiny movements to cushion the shock, this is F=ma deceleration basics. Tiny distances mean massive deceleration. A few centimeters of cushion might literally be millions of times less force.
There was a design someone posted a while back with four towers forming a square and steel wires strung between them that would contract and "lasso" the starship when it lands. This seemed much more practical than what they have chosen but it will still work I think.
Millions no, but hundreds yes. Sometimes even half the force is a big change between breaking and holding. 10cm of cushion means 20x less force than 0.5mm (just deflection of catch points), which for a booster is a LARGE reduction. Also, 10cm is on the small side, with such big arms, they could easily decelerate over 1 meter.
It's not much at all. Just a few centimeters in theory. That’s all that’s needed from 100 kilometers above the planet down to the resting position. If that last tiny bit is soft, it would work. Is that all it takes? What’s your thought? Edit: 550kg is NOT the weight of a Falcon 9 booster, that was a typo. The correct number would be 22,200 kg dry mass.
It's hard to be precise without firm numbers, but the cable supporting the catch arms should stretch appreciably as it is loaded by the weight of Super Heavy. My back-of-the-envelope calculation is 1 meter, but that could 0.1m to 10m based on accurate assumptions for the cable diameter and stiffness. Regardless, it'll provide some cushioning to the landing.
i have no doubt that would be sufficient! then add in a little flex from arms and a lil from the winch cable ! my biggest worry would be a catastrophic engine failure !
I really like it when you respond to your own show. The TH-cam algorithm should give you extra credit. Cute way to introduce sneak in the request for click and subscribe. Well done. me likeeeeeeeeeeee You know I ♥ your show.
Can't wait to see that beast slowly hover when landing. I think we will be all so satisfied when we see it approach Mechzilla and have a buttery soft landing.
Superheavy can be even more accurate with its angle, since the landing burn uses 3 engines which enables controll of roll axis additionally to the gridfins
Considering that SpaceX only accomplished getting 3 Raptors to finally work reliably ONCE to land the orbiter and how much the tightly packed plumbing of the 30 (or whatever it is now) Raptors at the base of the booster look like a cascading failure waiting to happen (N1), I hope they have great insurance on the incredibly expensive infrastructure at the launch site when they attempt to land (or even just launch) that booster. Yes, I know they plan to land (ditch) at sea at first.
Catching the rocket from the top will prevent the skin from buckling, due to compression. These rockets rely on the propellants pressure to prevent them from collapsing easily. If it lands on it's feet the compression of the skin could cause it to buckle. If they catch it from the top, the skin is only in TENSION. Even if it is a rough catch, the skin will easily withstand the tension.
On launch it is going to have 7500+ tons of thrust and a 1200t+ second stage, not sure what max q load is but this already has to take high compressive loads. It will still be pressurised on return, presumably?
Really cool videos always! Check some of mine out, if you have an opportunity. I am an aspiring astronaut and am trying to share my journey with as large an audience as possible.
@16:08 I think there is a bit of a typo regarding the weight of a Falcon 9. 550kg is less than the weight of a very small car. If it were so a single Merlin running at minimum thrust would accelerate the rocket at about 100G. I believe it is actually about 25 tons. The figure of 550kg would sound about right if it were referring to the mass of a single Merlin engine rather than the entire Falcon 9 first stage.
All of this is possible because each and every person that works at SpaceX are pioneers and visionaries with a singular goal in their mind. Anything is possible if we give constant collective effort. Respect to all of them who made this possible.
It's weird to me that most of the discussion re: landing legs seems to gloss over the fact that Starship will not have a landing system available on Mars. If it can't land on Mars, then the Starship project is Dead On Arrival™️. Starship will definitely need legs; there is no question.
Most likely a mars starship won't land on Earth. So the legs only need to support martian gravity and can be built much lighter. Similar to the lunar StarShip's legs (and that of the apollo landing) being rated for martian gravity only.
There will be many Starship variants. Those going to other worlds will need the ability to land without ground infrastructure - but far more common will be those going to Earth orbit and back (tankers, satellite launchers, etc), and those will always be returning to a properly-equipped landing site. Also, note that most of the discussion around landing legs so far is about SuperHeavy - not Starship.
currently, that's the case. legs or no legs. They have no way to lose enough speed after an interplanetary flight in an almost non-existing atmosphere. and I find it cute that they wanna test it all here on Earth, after only an orbital flight. They can demonstrate that they can land here. IF they can.
Very good episode, very well explained, amazing renderings. You're slowly becoming aware of how much Spacex is stirring up space travel if everything works out like this. They will literally be like they are from another planet for the competitors. The degree of reuse, of cost-efficiency, of frequency of starts, the mass that can be transported. It must be years before anyone can even come close.
Trailblazing and innovation are hard, but copying is easy. Many will simply copy what Musk/SpaceX have done, and govt space agencies will lead the way in doing that. Govts don't innovate as well as private companies do, but have the deep pockets to imitate or reverse-engineer a good idea, especially when it has strategic value.
@manofson I beg to disagree that copying is easy. SpaceX Falcon 9 has been launched over 100 times, yet the nearest would be "copy cat" Blue Origin is still stuck in suborbital fligts. Make no mistake, it aint about money because Jef Bezos has loads of that(maybe more than some state actors imho). The cutting edge technology and out of this world innovations at SpaceX, is the deal maker here.
@@odurthomasmande1723 - look at Chinese & Russian efforts, and you'll see that they're working on their own versions of Falcon9. They understand that such vehicles offer new strategic capabilities which are becoming important for the future. Satellites are very strategic - and nobody wants to be left behind.
Yea I made a German Chocolate cake I am going to put some icing on and eat it. yum Felix got his game on. Can't wait for what is coming up or going up as the case may be. Fire this puppy up please and thank you. Cake in the green room.
Thanks Felix! I wasn’t sure that you were going to explain the difference between the suicide burn and how starship and superheavy will be able to hover. It’s really a tremendous difference that a lot of people don’t get. Thanks!
I can't wait to witness this truly landmark achievement in technology as I am very sure that Space X will make it happen! Witnessing the amazing achievement of landing Falcon 9 boosters was something I jumped and cheered and brought my excitement back to space exploration!
Wow. The more you show the more I want to know, being the nerd I am this feeds my hunger for knowledge in Space X and I appreciate your channel while I work in the hospital.
When the question "why risk it?" Came up, I said out loud "because he can!!" And I keep thinking that fact is a large portion of his motivation in anything he does
A small correction for people wondering. In the SpaceX's simulation, the horizontal plane is the YZ plane. X-axis goes upwards through the booster. You can confirm by looking at the plots, where acceleration in the X-axis is proportional to the engines thrust and acceleration in Y and Z axes is negligible. You can also see green and blue lines coming from the booster in the horizontal plane perpendicular to each other. There is no red line as it is probably hidden in the booster model.
Really cool videos always! Check some of mine out, if you have an opportunity. I am an aspiring astronaut and am trying to share my journey with as large an audience as possible.
I’m certain they will eventually succeed, however, I don’t believe for a moment they’ll be able to rapidly refuel and relaunch the same booster and same starship immediately upon return and successful tower-catch or acquisition. Both rockets will need to cool down to ambient temperatures prior to refueling, and the main booster (BN#) will need to be fully refueled to maintain structural integrity prior to yet another starship again being stacked on top of it (it would collapse otherwise). If they go with a triple set of main boosters (BN#) and triple starships (i.e. two or three separate launch towers/pads) then rotate each launch within a few minutes or hours of each other, it’s far more likely to succeed. Otherwise, it’s not going to happen. In the end, I believe this is exactly what they’ll do, or possibly launch both tankers first, leave them in orbit for the refueling event, then launch the lunar starship last, then bring the empty tankers home, and finally, send the newly and fully refueled lunar version of starship off to its intended landing destination (Shackleton Crater?). This could work.
Super Heavy will need to be pressurized, but refueling isn't necessary to re-stack the Starship. This has already been done. In my opinion, the turn around time will certainly be shortened with time and confidence in the process and reliability of the systems. Getting it down to under 24 hours will be an amazing achievement, but it should be possible to reduce it from there. I agree with you about additional launch towers being needed. I seem to remember another tower planned at Boca Chica and of course there are the repurposed oil drilling platforms. It is a very exciting time for Space Enthusiasts! I love watching the progress and out-of-the-box thinking Space X is willing to try. It wasn't that long ago that we were rooting for Space X to successfully land the first Falcon 9 booster (and then on a drone ship at sea). That crazy idea has become routine.
Thanks for the uptade, appreciated ! I wonder how it is possible to catch a landing starship without damaging the heat shield with the arms ? Is there a way to catch it without touching the heat shield, or does SpaceX aims to make the tiles strong enough to survive that?
@@bkreativepainting7461 the first starships to land on other planets will have legs. Until they build these towers there. The starships intended to land on Mechazilla towers will not have legs.
Another superb presentation Felix and team. You consistently push our understanding forward. Wow. Now... a reflection on why SpaceX is so public about what they are doing. I suspect it is a combination of factors; some obvious, some less so. 1) They need massive enthusiasm for what they are doing because they are a disruptive company that threatens the rest of the industry with irrelevance if it doesn't step up to the plate 2) Since Musk's goal is to make the species multiplanetary AND he feels that there may only be a finite and shortish period to do so, he actually would want the rest of the industry to learn from what SpaceX is doing 3) The quality of your presentation today is an example of how being open about what they are doing in fact creates a huge basin of intelligent minds thinking about what they are doing and potentially pushing forward ideas that might be useful to SpaceX. Recall for instance how a comment by Everyday Astronaut in his interview with Musk caused the latter to stop, ponder, and integrate a change in how Starship is engineered. 4) So publicly being the coolest space company around will generate a constant stream of smart new hires who want to be part of what's happening. 5) SpaceX is so far ahead of all their competition that even if they "disclose" the new stuff they are trying to pull off, their competition can't really get more than the most general level understanding of what SpaceX is doing. As you pointed out "a hundred times more data is being collected and processed behind the scenes. All in all a net win for SpaceX with little downside that I can see.
Nice info. I would have love you had covered landing accuracy of the rocket which is the most vital part of the equation IMO. SpaceX seems highly confident they can achieve it. Interesting because we did not see that accuracy in any of the previous test flights.
Perhaps this talks more to the difference between ship and booster - so far we've seen low accuracy after ship flip to vertical, the presumption here is that the booster landing will be closer to a falcon 9 because of its almost identical approach. Share your interest around the ship though, perhaps need a lot more flip manoeuvre testing.
Falcon launches most often require a drone ship to recover the booster as the trajectory required for orbit takes the booster too far away from the launch pad for recovery there. With Starship, this will require return to launch pad for each launch. How will SpaceX accommodate this? The re-entry burn will require a huge amount of extra fuel (and weight) to return to the pad. This goes against their apparent goal of reducing weight and increasing mass to orbit efficiency. Would love to hear your thoughts and analysis on this in a future video.
This would hurt their range, but I'm pretty sure they plan on alleviating/solving that problem with two strategies. 1: Launch and Land in the ocean, which they are already working on (with the oil rigs they purchased). 2: Orbital Refueling and rapid launch cadence to do so.
@@Thorhian Neither of those scenarios are "return to original launch site" scenarios. The boosters don't reach orbit and thus can't refill in orbit to be able to "burn" back to the original launch site.
Now, I'm no expert, but SpaceX engineers and literal ROCKET SCIENTISTS are. I imagine they've either figured out a special point in flight which stage 1 boost back would be early enough to bring it back at a moderately low fuel cost or they simply won't use it for orbital missions. (Remember they also would like to use StarShip for inter-continental travel eventually but it isn't priority... so I'm left to assume the former.)
@@vpmcgeath Agreed... except it's not the cost which is the issue, it's the weight in fuel. Seems to me this will limit the potential range of trajectories, orbital options, and many other variables... Also, watching many of Elon's interviews and how he stresses simplicity, the best part is no part, etc etc. All which sounds wonderful. But the complexity, cost and sheer size of the infrastructure they are building... all to eliminate the weight of landing legs... seems illogical. The extra weight in Fuel to return the booster back to the pad, would likely be as much if not more than the landing legs... I know... they'll get it figured out... just seems to this mechazilla system doesn't fit into the "the best part is no part" philosophy...
Sure, they have already modelled the achievable payload, fuel, launch site and landing site configurations. They are working out the mechanical and construction details now, not wondering if boost back and return to base consumption will surprise them.
I wonder how much crosswind they will be able to handle on landing. I'm sure they can cancel it out with TVC, but not while also keeping the rocket perfectly vertical as shown here.
Felix, what about the blast from the landing rocket engine? As it would have to be close enough to the tower to be moved onto the booster would it not damage the booster or the tower it's self or the pad?
The OLM and its surroundings are designed to bear the brunt of 29 Raptors (33 next!). There will be a water deluge system too. Landing with 2 or 3 and 10-20m higher in the air will pale in comparison. The main difference will be to the top of the chopsticks which is why they will probably get metal shielding.
@Felix Have you/anyone seen anything current regarding the Crew Access ARM ? I'm curious on how it would be intergrated into the OLT and where, considering how the Catch Arms travel the towers structure (three sides are non usable, only leaving the rear of the structure for additional mounting.) At some point people will need to board Starship, and or load cargo, etc... This seems to be something not totaly clear right now, and the existing elevator doesn't seem capable of moving cargo, so it seems like that might be upgraded at some point, as it still looks like a construction grade elevator right now. Will there be other cranes or structures constructed alongside the towers ?? Likely the Crew Access arm will either attach on the rear of the tower and swing completely around, or possilby extend out of the back of the tower, and then move foreward through the center of the tower to make contact with Starship and or the cargo bay.. These are necessary items not officialy addressed yet. If they are going to go into regular launches later this year (or even intrernal SpaceX payload testing .) We should be seeing these topics addressed relatively soon, as that is more construction, and Elon doesnt like to waste time when he's ready to go.
I dont think theyll ever launch Crew from the current tower design but I think the crew arm could extend through the front side of the tower like these extendable laser swords do?
I would say the starship would be loaded inside one of the high bays and rolled to the site before being stacked. I doubt they will launch people from this site.
Felix, you and the WAI Crew outdid yourselves. Explaining the tradeoff for launching without legs covered a big question. It also shows SpaceX is thinking steps ahead, as we hoped. Great depth of story we can't get anywhere else. You guys Rock.
You forgot about the rocket equation. Not having legs, saves weight. This weight saves 10x the weight of fuel. This weight reduction saves fuel, and that weight saving adds more payload capacity to orbit.
Space travel and returning to Earth is in it's infancy . This would have been a cool addition to a Sci Fi movie 20 years ago . SpaceX will get this working
You missed the main reason why catching the booster mid-air is necessary: an empty booster doesn't have the internal pressure needed to provide structural rigidity. An empty booster has barely enough rigidity to stand upright, which is not enough to handle the impact of a landing without crumpling catastrophically. Hanging the booster from the top puts much less stress on the empty rocket body, same reason why Rocket Labs will be hanging their Neutron payloads from the top of the fairing. Making a rocket that's able to land on legs when empty would have required heavy reinforcement of the body, which would have added a lot of weight, much more than that of the legs themselves. The idea of the chopsticks most likely didn't come as an answer to the question "how can we save the weight of the legs" but to "how can we prevent the booster from crumpling from the forces of landing on is bottom".
about the precision in rotating the Super Heavy: yes, it has the same grid fins as the Falcon 9 (albeit much larger) but to my knowledge they are fixed
Watching this video makes me realize that SpaceX probably doesn't care too much about reducing the dry mass of their booster anymore. At a certain point, the raptors would need to throttle deeper to reduce mass unless SpaceX wants to start doing suicide burns into the tower.
Super heavy being able to hover and position itself gently is actually a major advantage over Falcon, which is forced to a suicide burn by too much thrust.
Those are not the main reasons for not wanting to use legs. The rocket equation shows that to carry essentially deaf weight to space and back would severely limit your payload to LEO. Remember legs capable of supporting superheavy would weigh tonnes, carrying that to space and back would decrease the payload capability by many times that weight.
Another highly technical explanation brought clearly and concisely. very appreciated especially with a lack of real-world landings to display at the moment. Thanks!
Thank you Felix, this appraisal and explanation of the catch operation /system was one of your finest works. Much appreciated, Thank you from Sydney/ Australia.
10:18 The dry mass of a Falcon 9 booster is 25,6t not 550kg please correct this or pin one of the various comments on this. It is hard enought to grasp the size of these things.
My theory is that the chopsticks will be elevated to MEET not to ARREST the fall at the very end. I.e, those bars primary task isn't as cusions (because lets face it, metal to metal does not cusion), but they act as potentometer, an actuator if you will, that gives feedback to the drawworks system. This way they can have instantaneous speed match sent to the drawworks, matching the analogue input of the "pedal bar" being pressed down by the booster as they connect. The booster will aim to keep itself hovering as best it can (if this means its slightly moving up or slightly moving down) does not matter IF the chopsticks are hoisting to meet them, rather than having the booster slam down into it. The thing you are talking about Felix, with the drawworks and load, you have to remember this is a 12 fall traveling block which means that the fast line tension at the drawwork is (under dynamic conditions) 32t if the block weight and hook load is 300t total. No problem making these type of movements with such a load, there's 6k hp that is PLENTY. I could do a drill line calculation if I wasn't on my phone :) ...but I'm quite sure it's plenty. I think this makes most sense to me, control system wise. We typically do operations on these oilrigs where we just incrementally nudge the drillstring up and down jsut by a few cm, so if you have the drill string/chopstick moving upwards, the inertia is already overcome and all you have to do is time it perfectly as you mate with the booster. You heard it here first folks ;)
Moving the whole assembly down as the booster arrives doesn't provide any damping, it just changes the delta-v required by changing the target speed. That's not to say they won't do it - but the reason why is different. They'll also need to provide damping separately. edit: The arms can move to provide damping - i mean the arms moving down before contact "to make it softer" doesn't provide damping. Cluches on draw works etc can help provide this though.
When SpaceX first announced that they will land the booster on legs in one piece, People did questioned the same " Why so?", "Why so much risk?", " It's not gonna work!"
Had some difficult times in my life at the end of 2021. Personal things I don't want to talk about. That's over now and rule number 1 is back. Try to improve on each episode! 😄
It really shows (content was really great then as well but recently its mind-blowing) happy to hear it is over. This is important work; if this project really takes of and takes us interplanetary this will be one of the best documentations how it happened.
You can notice in the simulation, the booster hover right above the chopsticks, to softly touch down on them. The chopsticks wont be moving down with the booster, to be a sort of suspension, it'll stay in place. This likely is to save it from unnecessary wear and tear
Very great short on how the chopsticks catch the fatty! It's going to be one of the biggest pillars of space exploration, ( if achieved?? Never stop making these videos. They make it easier for people getting into space exploration), easier to understand. I'm working on the first three of mine. Whish I had your help. Keep on keep'in on! ☘
One more reason why Super Heavy doesn't have a landing legs is a weight. SpaceX wants to keep as much stuff on Earth as possible to minimize Starship own weight and increase it's payload capabilities. It's complex and expensive to build Mechazilla, but Starship will pay it back on every next flight.
Not just the legs. Landing on legs requires a much more rigid body than hanging from the top. You can make a falling thin paper tube stop and hang from a pin holding it from above no matter how hard it hits the pin, while the same thin paper tube will likely crumple if you just drop it on the floor if it comes even a fraction of a degree off the vertical.
@@herbys68 I’d not thought of that additional reason for no legs before.
But I’m also thinking are you right?
My thought is that the booster would probably be strong enough to land anyway as it needs that strength during the lift off phase of flight.
Although I guess maybe on liftoff more of the strength is produced from the pressure in the fuel tanks and there will be more fuel at take off of course!
Just thinking out loud tbh
@@jamster2400 The 4 mm version maybe yes, maybe not, but as they try to shred weight and move to thinner sheet metal it will become more fragile, and there is simply no reason to make it sturdier than necesary. In other words, if it can withstand the landing forces, they can definitely go one level thinner with the sheet metal if they can forget about those forces.
But there is another reason related to that: even if they make a rocket that is sturdy enough to survive a regular landing, there will be landings that are less than perfect, maybe one degree inclination, maybe coming a bit harder than expected. And such a landing would almost surely cause damage to the tanks like we saw with A 10, with catastrophic consequences to the booster and the landing infrastructure. They would have to make a much sturdier rocket to be able to survive such landing, and that would likely add significant weight. Hanging from the top means a slight variation in the angle or speed would not cause compressive forces, only pulling forces which the thin metal can handle much better.
Although from the data given in the simulation, with the booster hovering for 5s before being caught it now needs a lot more weight of fuel rather than doing a suicide burn. There must be a crossover point where it costs more in fuel weight to be caught like that than it does to simply use landing legs.
Disclaimer on top: Don't get me wrong, I am actually not against the tower-catching approach. It's an elegant way of getting around the big problems landing legs bring with them. I like playing devil's advocate and seeing what holes we can try to poke in the design and how we might fix/mitigate it.
One big downside I can see is that, if the proverbial excrement hits the rotating aerodynamic surface, not just one ship is down for the count but all of your ships are now prevented from landing in that location for the foreseeable future. You could argue this is why you build more than just one tower and that is a viable risk-avoidance measure. Though you do still end up with the risk that an unforeseen design flaw causes a catastrophic failure, which in turn causes an investigation and *all* of your fleet to be grounded until the issue is resolved. This doesn't happen too often in the aviation industry but it is also certainly not unheard of, and I would imagine a major incident while Starship is operational would have similar consequences especially when there is a human cost.
So, would multiple towers be enough? What would happen in the case of the eventual catastrophe that history teaches us *will* almost certainly happen no matter our intentions? Would that possibility lead to requirement for an escape system on human rated craft (or an alternative system designed solely to prevent RUDs on landing if that is more viable)?
You forgot the main reason for ditching the landing legs for a catching system: mass reduction. Truly stable legs, together with their housing and operational systems would weigh quite some tons. This is additional mass that in the end has to be cut from the payload..
exactly it would be far easier engineering a big sturdy and reliable retreival system on the ground it will not have to take the burden and beating of flight and renentry and there is no mass limitation to such a system while in the same time improving the reliability and payload of starship
If it works - it will be even more entertaining than current landings. If it doesn't - I am sure they will find a way to strap legs on it.
somebody on Twitter made the calculations: the weight of the legs would be less than the weight of the extra fuel needed for landing
@@marcopederzoli4939 He should work for SpaceX then. I do remember how all the people who had calculated that landing a rocket like the falcon planned to do was not feasible and how they saved SpaceX millions in useless r&d.
Meh... that's what I thought too before seeing the simulation. The 5-second hover should consume around 3 tons of fuel. That gets rid of most of the mass savings from removing the legs. After Musk released the simulation, I don't think mass reduction is an important decision factor anymore.
It's not the fall that kills you, it's the sudden stop at the end
LOL! I love these episodes, thank you so much Felix & company!
. . . what I really appreciate is the diversity of YT channels to receive information and / or entertainment from . . .
A Falcon 9 booster has a dry mass of about 20 tons, not 0.55 tons as labeled in the video.
I thought 550kg seemed impossibly light for an empty falcon 9!
@@kyoteecasey I think they got it from the 550,000 kg full weight but mistook the American comma for a European comma. I thought the same as you!
25.6 tons dry mass + what ever is left in the tanks so ~26 - 27 tons.
It was a simple typo. Wrong value copied in. Editing mistake. 5 Minutes after release (when I saw the first comment), I checked the video and started laughing! Honey, we created the lightest orbital-class booster stage in human history! Then, I edited the pinned comment to reflect it. I hope many see it! Thanks for bringing it up!
@@robertvorster8933 its 22 tons empty ~1 ton propellant
Soooo, I m pretty sure a Falcon 9 empty first stage doesn't weight close to 550kg (almost a four hundredth of a superheavy) but rather in the 25 ton range (an eight of a superheavy). I think you mistook the 550 ton fueled launch mass of the whole vehicle. Love the vids keep it up
550kg seemed unbelievably low to me too. I just searched for a minute, the weight of one single Merlin 1D Engine seems to be around 470kg! Empty weight of a whole Booster around 25t. just like you said :)
Thank you for pointing this out, of course, this was a stupid typo!
I was also quite surprised about a falcon 9 first stage weighing half my tiny car 🤓
If the rocket weighed 500 kg you they would just carry it to the launchpad on foot
That makes sense as a brain fart anyone could have.
A note about grid fins. They only work when you have sufficient air flow through them so they aren't able to control the roll of the rocket during the last couple seconds of the landing. From that point on it's up to the engines to control roll or, if only a single engine is being used, the cold gas thrusters.
Going for *either* rapid reusability *or* full reusability is a bold move on SpaceX's part. Doing both at the same time is outright insane.
If this works out and spaceflight becomes akin to regular flight, where you can just refuel a ship and reuse it at leas ta few times, it'll be a step forward like the first manned spaceflight or the moon landings.
Maybe there is a not-so-distant future ahead where Starship-like vessels are used like airliners are today: In near constant service for several decades. Vacation on a space hotel suddenly doesn't look that far fetched, doesn't it?
So was thrust landing and reusing orbital class boosters; until it was done.
Elon has a habit of taking things that are certifiable insane, and making them surprisingly mundane. Gotta love it.
It is utterly impossible to use rockets for transport around the globe. Anyone who disagrees is extremely ignorant of maths, physics, laws, and logic. Period.
@@ck_clemens_k Aircraft burn a carbon based fuel....and so, they do contribute to Global Warming...and any rocket that uses Kerosene for fuel also leaves the earth a little dirtier......but when burning Hydrogen/Lox or methane/ lox they are, environmentally clean burning!!!! The only pollution they create is sound and vibration pollution...please educate us how multiple flights would cause "environmental damage???"
SpaceX's crazy crazy capabilities notwithstanding, Mars as a planet I'm afraid is not that hospitable going by currently whatever much is known. So vacation on a space hotel does appear far fetched, i guess.
That said, there could be other useful goodies in Mars that may be mined and brought to earth. So in that perspective it does make a lot of sense about this thrice a day launch cadence ..!
Besides there's a whole new business i imagine SpaceX would get into soon. That of cleaning the LEO of space debris. When that becomes a busy biz, SpaceX might come up with circular launch towers with multiple chop sticks catching rockets, not SH boosters with collected garbage. If i run my wild imagination, they would build multiple Circular launch towers with multiple chop sticks in each of them...!
LEO Space is already littered with so much debris, you only needed a viable clue how to grab them and dispose off. Once you do, there's so much money to be made, you would be out of breath for foreseeable future, leave alone Mars. they may even have few seats in those collection missions for those Space Vacationers. 😀
Imagine a bus load of people on Starship, vacationing on a garbage collection mission...! Returning with their own garbage collected from heavens😃 Drawing rooms adorned with Space Garbage will be a brag🤭 ...!
10:22 Falcon 9 booster dry mass 25,600 kg
8:42 "Sometimes it comes down to just a few centimeters"
That's what she said.
Which dimension, axial or diametrical ? -:)
Wait what?!? Falcon 9 booster weighs 550kg?!? Are you sure about that? That’s the same as like 6-7 people.
Nah, it's 25,600 kg
its about 20 tons
Maybe he meant 550,000g …. That sounds better? ;-)
Yeah, but only 3 Rosanne Barrs
I thought super heavy had fixed grid fins. How will they rotate the booster?
Thanks to the WAI team and all the 3D Creators featured in the episode, truly something to look forward to IRL 🚀
Amazing community! ❤️ Thank you for being a part of it, Sammy!!! Can't wait to see you again!
10:25 So I got a slightly different number of 25.6 tons for the first stage dry mass from SpaceFlight Insider....
I love that Dr. Strange is explaining SpaceX tech instead of the multiverse.
No legs also means no potential compression force on landing, only tension from the catch mounts. Presumably much better for the booster.
Much better for everything. Metals are much better under tensile than compressive forces. The dynamic forces acting on the structure on landing may be very significant, with a compressive force this may cause problems, but a tensile force will be no problem for a steel construction.
It does still get a heck lot of compression under launch though right?
@@danm6189 it's pressurised at launch, that provides a lot of rigidity.
@@jaqssmith1666 sure, and presumably on landing right?
Yes! Most definitely! Good point!
That will be quite the thing to see: Each SHB launched 3 times per day, with a stream of Starships, each one configured for its specific mission. At peak performance, it could look like massive, controlled chaos. Should be fun!
It looks like the axis are mislabeled at around 1:30, The spaceX charts show X as vertical, but you show Z as vertical in your overlay. You can tell that X is vertical because of the relatively huge accelerations in that axis. Loved the video! I'm super excited to see mechzilla actually catching rockets.
Indeed, they are probably using some standardized coordinate system convention from ISO 1151 (or DIN 9300 respectively)
Right. "Z" is vertical when a rocket is in the belly flop position... "X" is the centerline.
You have to scroll a long way down the comments to find yours, i thought more people would notice! You also see Y and Z labels to mark axes on rings and vehicles, so looks like they keep it consistent...
Good catch. Most rocket and plane simulation have x aligned with the centerline. It is also common to have different axis on a same project, one for the aerodynamic (x aligned toward the front) and one for the stacking x from nose to bottom.
Removing the legs also reduces the booster's weight which translates to greater payload to orbit capacity
Removing the legs is exactly the same as removing the seatbelts, airbags, and ABS from a car, and saying "This car is superior because it gets better fuel economy".
It is technically correct, but it is also suicidally wrong.
@@Chris.Davies Should a leg fail on landing you would have the same result. If you have your landing gear on the ground it can always be serviced. you can not have a gear failure. I don't believe you have the correct line of thought on this. Though I fully understand what you mean.
@@Chris.Davies um - no. Space launch is all about getting payloads to orbit. By offloading systems from the booster to the launch mount system (e.g. landing catch mechanism, engine startup) you've made the booster both simpler and lighter which means that a greater percentage of fuel is used for payload and less is wasted by vehicle dry mass
@@Chris.Davies thats EXACTLY what they do for high performance cars! Do you think NASCAR drivers are blasting a stereo system in their sound dampened cars and watching a navigation system as they lap the track? NO! Those cars are stripped down...including no airbags and ABS systems in order to perform at the highest level. Do you think those are real headlights painted on a nascar body? 😂 They don’t need headlights, so they remove them for better performance. The cost/ton of payload to orbit is the most critical metric as to whether SpaceX is successful.
Can you tell me exactly how much mass to orbit capacity this adds? And why would they create a big dumb first stage if they plan on reusing it so much? It's contradictory to do the simple, cheap, and heavy thing for production but the complex, precise, weight-saving thing for maneuvers.
"Yeah we put this meticulously crafted aerodynamic covering over this hummer running on a coal powered steam engine-- uh, for efficiency"
If they can perfect this landing system it will be an engineering triumph and a paradigm shift for the space industry. A true "game changer".
Falcon 9 has already changed the game :D
G'day,
Yeah, and if it arrives sideways accross the Fueltank Farm, and blows Bocca Chica off the map...; Elon will be tarred and feathered and run out of Town on the Rails of his fraudulent HyperLoop.
How reusable will it be, after the Choppy Stucks miss those TINY little load-beading Lugs, and tears the Grid Fins off...,?
How well will it work after Thwaites Glacier goes "Plop !" and raises Sea Level by 3 ft ?
Such is life,
Have a good one...
Stay safe.
;-p
Ciao !
It is mechanical suicide.
no, it won't.
The only reason SpaceX is doing that is because otherwise Starship's payload mass requirement would not be achieved (no engineer would suggest such high complexity that could possibly destroy the booster if the project's requirements were already being met).
Also, rocket structure is too damn fragil to fly again without a major maintenance and possible repairs, then the 24 turaround or even 3 flights a day with the same booster is just bulshit.
@@Chris.Davies yeah, and they said the electric light was impossible too, I'm sure. Ask Edison.
And, closer to home, how many said Tesla couldn't make a practical electric car with "laptop batteries"?
I was totally right back in August when you asked about how mechazilla would catch the booster and I said "Maybe something like vice plates that track along the arms and close in on the hooks?”
As for tiny movements to cushion the shock, this is F=ma deceleration basics. Tiny distances mean massive deceleration. A few centimeters of cushion might literally be millions of times less force.
There was a design someone posted a while back with four towers forming a square and steel wires strung between them that would contract and "lasso" the starship when it lands. This seemed much more practical than what they have chosen but it will still work I think.
Millions no, but hundreds yes. Sometimes even half the force is a big change between breaking and holding. 10cm of cushion means 20x less force than 0.5mm (just deflection of catch points), which for a booster is a LARGE reduction. Also, 10cm is on the small side, with such big arms, they could easily decelerate over 1 meter.
I can’t wait to see this happen. Either a spectacular catch, or spectacular explosion.. going to be worth every second.
im betting on it smashing into the tower and exploding destroying both the rocket and the tower in one glorious eruption of carnage.
@@jebes909090 don't forget the fuel plant right next to it holding multiple Starship fuel loads. It would be literally like setting off a small nuke.
Not if you live close by....
It's not much at all. Just a few centimeters in theory. That’s all that’s needed from 100 kilometers above the planet down to the resting position. If that last tiny bit is soft, it would work. Is that all it takes? What’s your thought?
Edit: 550kg is NOT the weight of a Falcon 9 booster, that was a typo. The correct number would be 22,200 kg dry mass.
They have already mastered the landing, this is more fine tuning.
It's hard to be precise without firm numbers, but the cable supporting the catch arms should stretch appreciably as it is loaded by the weight of Super Heavy. My back-of-the-envelope calculation is 1 meter, but that could 0.1m to 10m based on accurate assumptions for the cable diameter and stiffness. Regardless, it'll provide some cushioning to the landing.
i have no doubt that would be sufficient! then add in a little flex from arms and a lil from the winch cable ! my biggest worry would be a catastrophic engine failure !
I really like it when you respond to your own show. The TH-cam algorithm should give you extra credit. Cute way to introduce sneak in the request for click and subscribe. Well done. me likeeeeeeeeeeee You know I ♥ your show.
Here we go!
Yes it is go time
Please, soon
Can't wait to see that beast slowly hover when landing. I think we will be all so satisfied when we see it approach Mechzilla and have a buttery soft landing.
Superheavy can be even more accurate with its angle, since the landing burn uses 3 engines which enables controll of roll axis additionally to the gridfins
Wow, nice input. Haven't even thought about that yet!
Considering that SpaceX only accomplished getting 3 Raptors to finally work reliably ONCE to land the orbiter and how much the tightly packed plumbing of the 30 (or whatever it is now) Raptors at the base of the booster look like a cascading failure waiting to happen (N1), I hope they have great insurance on the incredibly expensive infrastructure at the launch site when they attempt to land (or even just launch) that booster. Yes, I know they plan to land (ditch) at sea at first.
@@Whataboutit Yeah dang this thing could really be airplane reliable can't it? I want to believe
What about the cold gas thrusters too?
Add to that the throttling capability of the raptor. This is very nice
This is going to be so wild to watch in action! 🔥🚀
Absolutely! It will be as exciting as the Apollo 11 take-off!
Catching the rocket from the top will prevent the skin from buckling, due to compression. These rockets rely on the propellants pressure to prevent them from collapsing easily. If it lands on it's feet the compression of the skin could cause it to buckle. If they catch it from the top, the skin is only in TENSION. Even if it is a rough catch, the skin will easily withstand the tension.
On launch it is going to have 7500+ tons of thrust and a 1200t+ second stage, not sure what max q load is but this already has to take high compressive loads. It will still be pressurised on return, presumably?
@@danm6189 I don't see why not, as long as there is propellant kept in the tanks.
Thanks for always breaking everything down for me Felix. I appreciate you alot
Really cool videos always! Check some of mine out, if you have an opportunity. I am an aspiring astronaut and am trying to share my journey with as large an audience as possible.
That was the smoothest call to subscribe I’ve ever seen
@16:08 I think there is a bit of a typo regarding the weight of a Falcon 9. 550kg is less than the weight of a very small car. If it were so a single Merlin running at minimum thrust would accelerate the rocket at about 100G. I believe it is actually about 25 tons. The figure of 550kg would sound about right if it were referring to the mass of a single Merlin engine rather than the entire Falcon 9 first stage.
He probably confused it with the weight of a fully loaded Falcon 9 Booster, which weighs around 550t.
Indeed, that was way too low, so I paused and googled: dry weight(mass) is 25,600 kg.
All of this is possible because each and every person that works at SpaceX are pioneers and visionaries with a singular goal in their mind. Anything is possible if we give constant collective effort. Respect to all of them who made this possible.
It's weird to me that most of the discussion re: landing legs seems to gloss over the fact that Starship will not have a landing system available on Mars. If it can't land on Mars, then the Starship project is Dead On Arrival™️. Starship will definitely need legs; there is no question.
For Moon and Mars, yes. The HLS Starship has legs and the ones for Mars will have them too.
Most likely a mars starship won't land on Earth. So the legs only need to support martian gravity and can be built much lighter. Similar to the lunar StarShip's legs (and that of the apollo landing) being rated for martian gravity only.
@@TomLeys good point! Even if it comes back to earth, it won’t need to use legs to land on earth.
There will be many Starship variants. Those going to other worlds will need the ability to land without ground infrastructure - but far more common will be those going to Earth orbit and back (tankers, satellite launchers, etc), and those will always be returning to a properly-equipped landing site.
Also, note that most of the discussion around landing legs so far is about SuperHeavy - not Starship.
currently, that's the case. legs or no legs. They have no way to lose enough speed after an interplanetary flight in an almost non-existing atmosphere.
and I find it cute that they wanna test it all here on Earth, after only an orbital flight. They can demonstrate that they can land here. IF they can.
spacex is pushing the boundaries so hard but so well in the last years
Very good episode, very well explained, amazing renderings. You're slowly becoming aware of how much Spacex is stirring up space travel if everything works out like this. They will literally be like they are from another planet for the competitors. The degree of reuse, of cost-efficiency, of frequency of starts, the mass that can be transported. It must be years before anyone can even come close.
Trailblazing and innovation are hard, but copying is easy. Many will simply copy what Musk/SpaceX have done, and govt space agencies will lead the way in doing that. Govts don't innovate as well as private companies do, but have the deep pockets to imitate or reverse-engineer a good idea, especially when it has strategic value.
@@manofsan i'd like to see them copy the crazy software
@manofson I beg to disagree that copying is easy.
SpaceX Falcon 9 has been launched over 100 times, yet the nearest would be "copy cat" Blue Origin is still stuck in suborbital fligts.
Make no mistake, it aint about money because Jef Bezos has loads of that(maybe more than some state actors imho).
The cutting edge technology and out of this world innovations at SpaceX, is the deal maker here.
@@odurthomasmande1723 - look at Chinese & Russian efforts, and you'll see that they're working on their own versions of Falcon9. They understand that such vehicles offer new strategic capabilities which are becoming important for the future. Satellites are very strategic - and nobody wants to be left behind.
Man all this stuff is so cool to me. I hope that one day we'll be exploring space traveling from planet to planet.
I come for the news but I stay for the out-takes
😄👍
Yea I made a German Chocolate cake I am going to put some icing on and eat it. yum Felix got his game on. Can't wait for what is coming up or going up as the case may be. Fire this puppy up please and thank you. Cake in the green room.
Nothing leaves this captured operation
This was a really great episode. The landing trick is perhaps the most innovative part Starship.
that would be the bellyflop landing manovre I think, no? maybe the most innovative part of the booster alone
_EXCELLENT EPISODE. BRAVO._ 🥰
Thanks Felix! I wasn’t sure that you were going to explain the difference between the suicide burn and how starship and superheavy will be able to hover. It’s really a tremendous difference that a lot of people don’t get. Thanks!
i don't know if it was even supposed to be funny but somehow you really got me with that "5 mississippi's of hover" lol
I can't wait to witness this truly landmark achievement in technology as I am very sure that Space X will make it happen! Witnessing the amazing achievement of landing Falcon 9 boosters was something I jumped and cheered and brought my excitement back to space exploration!
❤️
Wow. The more you show the more I want to know, being the nerd I am this feeds my hunger for knowledge in Space X and I appreciate your channel while I work in the hospital.
When the question "why risk it?" Came up, I said out loud "because he can!!" And I keep thinking that fact is a large portion of his motivation in anything he does
Failure is the best way to learn...
Probably said by a spectator at Kittyhawk about Orville Wright! LOL.
A small correction for people wondering. In the SpaceX's simulation, the horizontal plane is the YZ plane. X-axis goes upwards through the booster. You can confirm by looking at the plots, where acceleration in the X-axis is proportional to the engines thrust and acceleration in Y and Z axes is negligible. You can also see green and blue lines coming from the booster in the horizontal plane perpendicular to each other. There is no red line as it is probably hidden in the booster model.
Really appreciate the thorough breakdown of elons video and the comparison to the current falcon 9! You rock!
Really cool videos always! Check some of mine out, if you have an opportunity. I am an aspiring astronaut and am trying to share my journey with as large an audience as possible.
6:10 Oh god the sound this metal on metal sliding would make makes me wince
we need more lubricant !!! :P
I’m certain they will eventually succeed, however, I don’t believe for a moment they’ll be able to rapidly refuel and relaunch the same booster and same starship immediately upon return and successful tower-catch or acquisition.
Both rockets will need to cool down to ambient temperatures prior to refueling, and the main booster (BN#) will need to be fully refueled to maintain structural integrity prior to yet another starship again being stacked on top of it (it would collapse otherwise).
If they go with a triple set of main boosters (BN#) and triple starships (i.e. two or three separate launch towers/pads) then rotate each launch within a few minutes or hours of each other, it’s far more likely to succeed. Otherwise, it’s not going to happen.
In the end, I believe this is exactly what they’ll do, or possibly launch both tankers first, leave them in orbit for the refueling event, then launch the lunar starship last, then bring the empty tankers home, and finally, send the newly and fully refueled lunar version of starship off to its intended landing destination (Shackleton Crater?). This could work.
Super Heavy will need to be pressurized, but refueling isn't necessary to re-stack the Starship. This has already been done.
In my opinion, the turn around time will certainly be shortened with time and confidence in the process and reliability of the systems. Getting it down to under 24 hours will be an amazing achievement, but it should be possible to reduce it from there.
I agree with you about additional launch towers being needed. I seem to remember another tower planned at Boca Chica and of course there are the repurposed oil drilling platforms.
It is a very exciting time for Space Enthusiasts! I love watching the progress and out-of-the-box thinking Space X is willing to try. It wasn't that long ago that we were rooting for Space X to successfully land the first Falcon 9 booster (and then on a drone ship at sea). That crazy idea has become routine.
Really professional program. Your rock
Even if the launch cadence would be just one launch each third day, this would be staggeringly fast. Three launches per day just boggles the mind.
There will never be 3 launches of Starship in one day.
NEVER!
Lol calm down, let them try it first before you say that. Many things that were once thought impossible are part of the daily life now
@@Chris.Davies lol i hear you saying this like an evil genius :)
Vid published one hour ago. And 268 comments ...!
SpaceX fans can never have enough of SpaceX. 😊
It's an active community! Love it! I've been reading and talking since release again! Fantastic people! Thank you!
Thanks for the uptade, appreciated !
I wonder how it is possible to catch a landing starship without damaging the heat shield with the arms ? Is there a way to catch it without touching the heat shield, or does SpaceX aims to make the tiles strong enough to survive that?
the tiles are quite fragile, most definitely no support of the starship by the tiles.
Most likely pegs just like the SHB.
I don’t think they are ditching the legs for starship, it needs them to land on the moon and on mars
@@bkreativepainting7461 the first starships to land on other planets will have legs. Until they build these towers there. The starships intended to land on Mechazilla towers will not have legs.
As I was watching the catching/repositioning animations, the Thunderbirds theme music popped into my head. Now it's stuck there🥳
Another superb presentation Felix and team. You consistently push our understanding forward. Wow. Now... a reflection on why SpaceX is so public about what they are doing. I suspect it is a combination of factors; some obvious, some less so.
1) They need massive enthusiasm for what they are doing because they are a disruptive company that threatens the rest of the industry with irrelevance if it doesn't step up to the plate
2) Since Musk's goal is to make the species multiplanetary AND he feels that there may only be a finite and shortish period to do so, he actually would want the rest of the industry to learn from what SpaceX is doing
3) The quality of your presentation today is an example of how being open about what they are doing in fact creates a huge basin of intelligent minds thinking about what they are doing and potentially pushing forward ideas that might be useful to SpaceX. Recall for instance how a comment by Everyday Astronaut in his interview with Musk caused the latter to stop, ponder, and integrate a change in how Starship is engineered.
4) So publicly being the coolest space company around will generate a constant stream of smart new hires who want to be part of what's happening.
5) SpaceX is so far ahead of all their competition that even if they "disclose" the new stuff they are trying to pull off, their competition can't really get more than the most general level understanding of what SpaceX is doing. As you pointed out "a hundred times more data is being collected and processed behind the scenes.
All in all a net win for SpaceX with little downside that I can see.
Yes, it's a brilliant ploy!
It’s been comparatively quiet with space x. But I foresee a resurgence of activity! Great video….again
Great video as always keep up the great work !!!
Ditto
Space X has done all right so far, no point to question anything else
"If it works, that's the reason for taking the risk." A quote worth of Yogi Berra.
Nice info. I would have love you had covered landing accuracy of the rocket which is the most vital part of the equation IMO. SpaceX seems highly confident they can achieve it. Interesting because we did not see that accuracy in any of the previous test flights.
Perhaps this talks more to the difference between ship and booster - so far we've seen low accuracy after ship flip to vertical, the presumption here is that the booster landing will be closer to a falcon 9 because of its almost identical approach. Share your interest around the ship though, perhaps need a lot more flip manoeuvre testing.
But dozens of successful F9 landings...
Very informative. Thank You
Falcon launches most often require a drone ship to recover the booster as the trajectory required for orbit takes the booster too far away from the launch pad for recovery there. With Starship, this will require return to launch pad for each launch. How will SpaceX accommodate this? The re-entry burn will require a huge amount of extra fuel (and weight) to return to the pad. This goes against their apparent goal of reducing weight and increasing mass to orbit efficiency. Would love to hear your thoughts and analysis on this in a future video.
This would hurt their range, but I'm pretty sure they plan on alleviating/solving that problem with two strategies. 1: Launch and Land in the ocean, which they are already working on (with the oil rigs they purchased). 2: Orbital Refueling and rapid launch cadence to do so.
@@Thorhian Neither of those scenarios are "return to original launch site" scenarios. The boosters don't reach orbit and thus can't refill in orbit to be able to "burn" back to the original launch site.
Now, I'm no expert, but SpaceX engineers and literal ROCKET SCIENTISTS are. I imagine they've either figured out a special point in flight which stage 1 boost back would be early enough to bring it back at a moderately low fuel cost or they simply won't use it for orbital missions. (Remember they also would like to use StarShip for inter-continental travel eventually but it isn't priority... so I'm left to assume the former.)
@@vpmcgeath Agreed... except it's not the cost which is the issue, it's the weight in fuel. Seems to me this will limit the potential range of trajectories, orbital options, and many other variables... Also, watching many of Elon's interviews and how he stresses simplicity, the best part is no part, etc etc. All which sounds wonderful. But the complexity, cost and sheer size of the infrastructure they are building... all to eliminate the weight of landing legs... seems illogical. The extra weight in Fuel to return the booster back to the pad, would likely be as much if not more than the landing legs... I know... they'll get it figured out... just seems to this mechazilla system doesn't fit into the "the best part is no part" philosophy...
Sure, they have already modelled the achievable payload, fuel, launch site and landing site configurations. They are working out the mechanical and construction details now, not wondering if boost back and return to base consumption will surprise them.
I was mesmerized throughout this video.
Great explanations and great graphics.
Thanks for sharing!
I wonder how much crosswind they will be able to handle on landing. I'm sure they can cancel it out with TVC, but not while also keeping the rocket perfectly vertical as shown here.
Yeah, weather will be a challenge. The booster has a large surface area for the wind to act on.
You're right. "Even this simulation gets my heart rate up". Great video. Thank you.
Felix, what about the blast from the landing rocket engine? As it would have to be close enough to the tower to be moved onto the booster would it not damage the booster or the tower it's self or the pad?
That's an excellent question I've been trying to answer a few times now. Musk has said that it might have been a mistake to not have a flame diverter.
The OLM and its surroundings are designed to bear the brunt of 29 Raptors (33 next!). There will be a water deluge system too. Landing with 2 or 3 and 10-20m higher in the air will pale in comparison. The main difference will be to the top of the chopsticks which is why they will probably get metal shielding.
@@Whataboutit hmm, yes, this could be a fly in the ointment.
That final burn might just toast Mechazilla.
@Felix Have you/anyone seen anything current regarding the Crew Access ARM ? I'm curious on how it would be intergrated into the OLT and where, considering how the Catch Arms travel the towers structure (three sides are non usable, only leaving the rear of the structure for additional mounting.) At some point people will need to board Starship, and or load cargo, etc... This seems to be something not totaly clear right now, and the existing elevator doesn't seem capable of moving cargo, so it seems like that might be upgraded at some point, as it still looks like a construction grade elevator right now. Will there be other cranes or structures constructed alongside the towers ?? Likely the Crew Access arm will either attach on the rear of the tower and swing completely around, or possilby extend out of the back of the tower, and then move foreward through the center of the tower to make contact with Starship and or the cargo bay.. These are necessary items not officialy addressed yet. If they are going to go into regular launches later this year (or even intrernal SpaceX payload testing .) We should be seeing these topics addressed relatively soon, as that is more construction, and Elon doesnt like to waste time when he's ready to go.
I dont think theyll ever launch Crew from the current tower design but I think the crew arm could extend through the front side of the tower like these extendable laser swords do?
Probably very similar to the Quick Disconnect arm, just higher up on the tower
I'd think SpaceX will launch crewed Starships from the Cape, not Texas. The OLT there might be designed for that purpose.
I would say the starship would be loaded inside one of the high bays and rolled to the site before being stacked. I doubt they will launch people from this site.
We must remember that the Boca Chica site is a DEVELOPMENT site... once you try to launch people, you've moved away from dev....
Felix, you and the WAI Crew outdid yourselves. Explaining the tradeoff for launching without legs covered a big question. It also shows SpaceX is thinking steps ahead, as we hoped. Great depth of story we can't get anywhere else. You guys Rock.
Im early, Excited for March
You forgot about the rocket equation. Not having legs, saves weight. This weight saves 10x the weight of fuel. This weight reduction saves fuel, and that weight saving adds more payload capacity to orbit.
Space travel and returning to Earth is in it's infancy . This would have been a cool addition to a Sci Fi movie 20 years ago . SpaceX will get this working
You missed the main reason why catching the booster mid-air is necessary: an empty booster doesn't have the internal pressure needed to provide structural rigidity. An empty booster has barely enough rigidity to stand upright, which is not enough to handle the impact of a landing without crumpling catastrophically. Hanging the booster from the top puts much less stress on the empty rocket body, same reason why Rocket Labs will be hanging their Neutron payloads from the top of the fairing. Making a rocket that's able to land on legs when empty would have required heavy reinforcement of the body, which would have added a lot of weight, much more than that of the legs themselves. The idea of the chopsticks most likely didn't come as an answer to the question "how can we save the weight of the legs" but to "how can we prevent the booster from crumpling from the forces of landing on is bottom".
about the precision in rotating the Super Heavy: yes, it has the same grid fins as the Falcon 9 (albeit much larger) but to my knowledge they are fixed
They rotate, just don't fold
This video has something. I call it wisdom.
You rock, Sir.
I love waking up in the morning and find out that there's a new episode of WAI
Watching this video makes me realize that SpaceX probably doesn't care too much about reducing the dry mass of their booster anymore. At a certain point, the raptors would need to throttle deeper to reduce mass unless SpaceX wants to start doing suicide burns into the tower.
I wonder if they keep enough weight on there for a set of landing legs.... big waste of time
10:19 I think that Falcon9 booster weights "a bit more" than 550 kg, even if empty 😉
Super heavy being able to hover and position itself gently is actually a major advantage over Falcon, which is forced to a suicide burn by too much thrust.
Those are not the main reasons for not wanting to use legs.
The rocket equation shows that to carry essentially deaf weight to space and back would severely limit your payload to LEO. Remember legs capable of supporting superheavy would weigh tonnes, carrying that to space and back would decrease the payload capability by many times that weight.
SpaceX is about the best thing going on in these crazy, troubled times.
Thanks Felix!
Arthur C Clarke would have been astonished by this technology.
But Robert A. Heinlein wouldn't be.
Another highly technical explanation brought clearly and concisely. very appreciated especially with a lack of real-world landings to display at the moment. Thanks!
Thank you so much, El! It was a joy to produce this one.
o
Thank you Felix, this appraisal and explanation of the catch operation /system was one of your finest works.
Much appreciated,
Thank you from Sydney/ Australia.
10:18 The dry mass of a Falcon 9 booster is 25,6t not 550kg please correct this or pin one of the various comments on this. It is hard enought to grasp the size of these things.
Don't check El's profile pic xD
My theory is that the chopsticks will be elevated to MEET not to ARREST the fall at the very end.
I.e, those bars primary task isn't as cusions (because lets face it, metal to metal does not cusion), but they act as potentometer, an actuator if you will, that gives feedback to the drawworks system. This way they can have instantaneous speed match sent to the drawworks, matching the analogue input of the "pedal bar" being pressed down by the booster as they connect.
The booster will aim to keep itself hovering as best it can (if this means its slightly moving up or slightly moving down) does not matter IF the chopsticks are hoisting to meet them, rather than having the booster slam down into it.
The thing you are talking about Felix, with the drawworks and load, you have to remember this is a 12 fall traveling block which means that the fast line tension at the drawwork is (under dynamic conditions) 32t if the block weight and hook load is 300t total.
No problem making these type of movements with such a load, there's 6k hp that is PLENTY. I could do a drill line calculation if I wasn't on my phone :) ...but I'm quite sure it's plenty.
I think this makes most sense to me, control system wise. We typically do operations on these oilrigs where we just incrementally nudge the drillstring up and down jsut by a few cm, so if you have the drill string/chopstick moving upwards, the inertia is already overcome and all you have to do is time it perfectly as you mate with the booster.
You heard it here first folks ;)
Great feedback! Thank you! ❤️
Whew, impressive wealth of knowledge in a single video.
So basically SpaceX is trying to capture a massive rocket reentering from space with chopsticks while i still struggle with Sushi?
SpaceX's survival hinges on superheavy actually working. Starship is the dream, Booster is the reality. Go booster 7!
Clear, ready, and go!
This channel should have at least a few million subscribers! Great vids and info! Thnx Felix
Moving the whole assembly down as the booster arrives doesn't provide any damping, it just changes the delta-v required by changing the target speed. That's not to say they won't do it - but the reason why is different. They'll also need to provide damping separately.
edit: The arms can move to provide damping - i mean the arms moving down before contact "to make it softer" doesn't provide damping. Cluches on draw works etc can help provide this though.
When SpaceX first announced that they will land the booster on legs in one piece, People did questioned the same " Why so?", "Why so much risk?", " It's not gonna work!"
Youve really stepped up your game lately Felix!
Had some difficult times in my life at the end of 2021. Personal things I don't want to talk about. That's over now and rule number 1 is back. Try to improve on each episode! 😄
It really shows (content was really great then as well but recently its mind-blowing) happy to hear it is over. This is important work; if this project really takes of and takes us interplanetary this will be one of the best documentations how it happened.
If/when starship boosters start flying three times a day, I'll have so many people to go back to with an "I told you so"! I can't wait lol
You can notice in the simulation, the booster hover right above the chopsticks, to softly touch down on them. The chopsticks wont be moving down with the booster, to be a sort of suspension, it'll stay in place. This likely is to save it from unnecessary wear and tear
That simulation isn't from SpaceX so we don't know what is really going to happen.
Well put together video
There is another advantage of this approach. The booster can be lighter. You have no legs to carry and the material is subjected to tensile stress.
Excelente información, felicitaciones, mi saludo desde URUGUAY.
Very great short on how the chopsticks catch the fatty! It's going to be one of the biggest pillars of space exploration, ( if achieved??
Never stop making these videos. They make it easier for people getting into space exploration), easier to understand. I'm working on the first three of mine. Whish I had your help.
Keep on keep'in on! ☘
Exceptional presentation - very well done !!
Seems on par with landing a booster on a bobbing floating platform out on the waves.