SpaceX Is Insane! Starship Flight 4 Campaign Continues! Mechazilla Catch Problems!
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- čas přidán 2. 05. 2024
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Why did SpaceX ditch the legs? The advantages of catching Starship!
Ship 30 rolls out for a static fire! Booster 13 undergoes cryo testing! Can SpaceX hit 144 launches in 2024? And Rocket Factory Augsburg is getting close to launching RFA One!
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Editing: John Young, Alex Potvin, Stefanie Schlang
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What do you think? Are the Chopstick vibrations a serious concern? Let me know your opinion in the comments!
the attempt will not succeed. The arm need to be in the shape of the booster round shape.
Too much publicity/product/self publicity placement, I am getting tired of it and I have been watching since years (feedback comment)
If the hold downs change was just geometric, I would assume you would check only one....
they make it entirely non-viable, which puts them in good company with the rest of the misguided program
i find it hilarious that you are speaking about this actually working when the last booster came in backwards and on fire they are so far from reliably catching a moving object without 1 out of 2 hitting the tower its untrue
“One ping only” The hunt for Red October… awesome movie
In 1990 I was stationed on the submarine tender USS Orion AS-18 in La Maddalena, Sardinia. One night after The Hunt for Red October had premiered, the crew was watching the movie aboard ship and to top it off one of the submarines we were servicing just happened to be the USS Dallas. Talk about great timing.
@@user-ed7ve1tw6y that is awesome!
So damn true =)
@@user-ed7ve1tw6y Damn, this is something to keep as a memory =)
I'm impressed that you know about PID controllers. but the chop stick controller needs something a bit more sophisticated. (PID is just a quick COTS solution for simple feedback systems, e.g. some sort of fluid level control in an industrial process)
The chop sticks need to control position, velocity, and acceleration with accuracy. So they need at least a Type 3 controller. That means at least three integrators in series. But the hydraulic cylinder is an integrator (it's length is proportional to the accumulation of fluid inside it) so they only need two integrators implemented in hardware or software.
Important note: The ringing we saw when they moved the arm quickly and stopped abruptly was probably INTENTIONAL. They could be trying to verity their model of the arm's transfer function. In other words, they are probably checking it's vibrational modes.
You make it sound so simple, just 1,2,3 and all done.
@@Mentaculus42 PID is 123 !
@@marinmitu995
Maybe so, but what sx needs to deal with the control issues of the chopsticks is more complicated. But sx does have some competent control systems engineers but it is unlikely that they can band-aid a solution onto the existing chopsticks to get the desired results.
Nah, if you wanted to do it properly you would be adding in force feedback and other sensors, particularly one for detecting the catch and adding the manually calculated mass of the rocket. You could bake all this into a series of integrators (you would need MANY to account for the many oscillation modes and corrections) but you might as well just run a proper sensor-driven simulation since that is just generally easier these days and is way more flexible. I'd be surprised if they are not doing that.
On the whole I think that arm catch method is very silly though. It's perfectly doable but it requires a totally unnecessary amount of precision and opens up many failure paths (that they don't seem to be good at predicting). Arms should just be there for stabilisation and rely on a pad for vertical force. I do at least like the ability to move downward to compensate for some landing speed error, but that can be done far better with a moving pad since it just needs a huge vertical actuator that could be easily built to handle any crash that crew could survive (drop from 20m or such). All separate from the launch pad of course, even if it's just on the other side of the tower.
@@samheasmanwhite
That sounds interesting, someone who is thinking about it from a systems perspective. Maybe sx can borrow some tesla people that are working on FSD (F..l Self Driving) and that humanoid robot and graft that technology into a giant catcher for the rockets landings.
It seems that sx is extremely motivated to capture from the top to keep the rocket in tension to avoid buckling. Probably one of the reasons to not first start with a rocket that is both slender and mega big before working the “kinks” out of your recovery system. Definitely requires too much precision in too little time with too many failure paths while it is burning remaining fuel too fast with too little fuel margin all while trying to index & 3D position the huge rocket vs the oscillating chopsticks. Not sure that silly quite covers it considering that it all has to work flawlessly 100% of the time or things too bad to contemplate will happen to your stage zero. This should be entertaining to watch.
I think the booster should do a hop to practice the catch, if it works great, lot's of data and they can repeat the maneuver to build confidence ahead of the real return to launchpad catch. If it goes wrong then at least there isn't a whole lot of additional velocity coming down on the launchpad and maybe they can crash somewhere designated. Either way I think a hop would be a good move.
Instead of a landing tower, why not have a landing pit?
It's a big cylindrical hole in the ground that's a little deeper than the height of the booster. The diameter can be wide enough so that there is a large target for the booster, which would reduce the likelihood of missing. The booster is caught by a circular aperture door at the top of the pit that closes in toward the center catching the booster as in descends. The door can be designed so that the central catching aperture can be offset to the side a bit depending on where the booster enters as the booster would not always be perfectly centered. In other words there would be built in adaptability.
If the engines fail when landing, the booster explodes underground, minimizing damage to any surrounding infrastructure above ground. Even better, you can have an emergency carbon dioxide release system in the pit to smother the engines and prevent or greatly limit combustion thus reducing the explosive power of a hard landing. This system can activate once it's known that the landing engine isn't working as it should.
It's also even possible to design some sort of cushioning system at the base of the pit to soften a hard landing - maybe with water or some kind of net or something.
Digging a deep hole in wet sand is harder than building a tower. It can and has been done for subways etc, but it takes forever.
@@phik It might be harder, but it would probably be better in the long run.
No, it makes it unnecessarily complex. You would need to deal with the engine exhausts. Thus needing to calculate how big you would need to dig offshoot tunnels for that, and how to build them for them not to disintegrate after a few uses. And you still need to maintain them. Much more costly over time. Especially considering that not every landing might be perfect causing damage to any of the tunnels or the pit.
@@phik Consult The Boring Company for information.
I think a circular tower with a camera shutter type catching mechanism (or multiple ones) would be easier to construct than a vertical pit. If the mechanism could be perfected, the launch pad could be fully integrated too.
Tower 2 has short arms ?well it's kind of obvious it's going to be called T-Rex. I'm calling it- catchZilla and T-Rex
I was thinking alligator arms, but I like T-Rex.
T-Rex? Yes!!!!
Rexzilla?
With raptor engines
The arm shaking was most definitely part of the test and measurement process, to see what vibration mode and its amplitude would be.
Those white square patches on the chopsticks, "could" be preliminary placement of a set of Load cell sensors on the chopstick arms. For measurements of forces during the catch or even during the stacking. You would like those forces nicely distributed and within the design limits.
The vibrations look to me (I could be very wrong) like a classic robot arm control problem. The arm is sent to the intended position but overshoots and has to come back, but overshoots.... What you want the arm to do is smoothly approach the intended position and come to a stop at that position without overshooting. A similar problem occurs when a tank is traveling over uneven terrain and has to keep its main gun accurately aimed at a target. The solution is fairly well known and involves using laplace equation or even a simplification thereof to apply the correct 'smoothing' of the robot arm. In short it looks like a software problem to me rather than a mechanical one, and so should be relatively simples to fix.
Thinking about it, the vibrations look exactley like what I would expect from a system under development. You need the frequency of the oscillation in order to cancel it out efficiently. Get it wrong in the other 'direction' and the arm will never quite reach the intended position.
You forgot to mention the SR75 launch in Australia that took place early this morning. Of course, that launch was hardly covered, and it seemed very low profile, but it is still a rocket going to space
The counter movement would turn the wiggle into a wobble (because the actuators are at the hinge point but the mass is further out). Probably still too much motion for the precision maneuver of a catch.
I am so excited for IFT-4!!!! I feel it coming around the corner as everything is almost ready for it!!!
I would like to see them fast track the fabrication of the second launch tower so it is capable of catching the booster on the launch after this one.
Mitigates risk of damage to their launch infrastructure.
They don't need launch capability from that tower right now so the initial fabrication could be simplified and streamlined.
When booster catches on the second tower work they could move the booster catch to the main tower and starship catches to the second tower.
Keep the higher risk operations further from the launch infrastructure.
Everything at Spacex is fast tracked
FYI, The crane is called Marvin because Elon loves the science fiction novel 'The Hitchhikers Guide to the Galaxy', and the dull robot is called Marvin.
The shorter arms means less mass so the arms can respond more quickly. The whole system has some springiness. But the unsprung mass is an unavoidable mass that will contribute to stresses on impact. Since the mass has to move on impact the lower the mass the lower the stresses on impact. Also the lower the delta-V the lower the stresses. Matching the speed of the arm with what it is catching reduces the delta-V which reduces stress. With all the testing SpaceX does I'm surprised they haven't unit tested this. Like, have a booster take off for about a few meters off the arms and catching it.
Yeah, vibration in such heavy and large arms will be important to catch the heavy load.
Only nowadays, we are able to potentially cancel such things out at this scale.
Amazing! 😎
The whole thing is insane, it is like trying to catch a flying California Redwood tree right out of thin air
Talk about risk someone is gonna go up in a Boeing starliner lol.
Long as they don't do any whistleblowing before they'll probably be alright.
If NASA says it's ready for crew, it's ready for crew.
They have done multiple uncrewed tests, simulations and hardware upgrades to eliminate as much risk as possible, and now (after almost a decade of additional work) they are finally ready for a crewed flight test with minimal risk.
2 of them actually. What goes up...
@@plainText384
DEI decision.
@@plainText384 all of this might be totally cool and it might be totally fine. I love space and would love more then anything to go to space. But no way in hell would I get on that thing.
Yes, the T-Rex move was iconic, but the headphone bopping was hysterical.
2:56 where i worked, we call this « transient response management » (but my translation might be not perfect, cause I'm just a French guy ^^).
i think using the gridfins is still a better idea than those little pins, even if they can't hold it at half of their length, they should be able to manage at a quarter, and if they do have a suboptimal catch, they can quickly put it on the ground instead of having no grip, causing it to swing. i'm sure they've done the math, just makes me uneasy seeing the pins so small
The problem with the gridfins is having all the force on the motors would completely wreck them.
Those pins, they can make them bigger if they need to. Gridfins, would not be able to survive one landing.
The ‘you will probably be forgotten’ for booster 1060 got me. 😂
I have had to deal with issues that require input shaping in oil pumps. It can be a giant pain in the a**. Very small things like oil temp can change viscosity of the oil and hence the feed back pressures. In turn this can change your resonance causing either an over correction or under correction. So they need would need some way to adjust that in real time.
You guys are a total class act. Your #1 of 2 sources of information about space that I trust.
Kudos, Kaplak to RFA!!!!
YOU GO BOI'S AND GIRLS!!!!
Another idea is that instead of chopsticks the tower simply has a landing pad on the chopstick arms. The pad starts at a near matching speed of the booster, lowering downwards at an increasingly resistant speed, an opposing force until the booster has slowed down and is on the ground. The resistance controlled by AI. A pad with clamps?
Consider catching a modified Falcon 9 booster that is built out to the specs of a regular booster to see the coordination of the catch and the tower.
One might use one of the older boosters launched to 10,000 feet and then landed in the tower. That would prove the catch and the older booster if lost would not be as big a loss.
Thank you for answering the "Landing tower" question
A question for those who know more about SpaceX launches than me:
In the future when Starship launches become more and more routine, will they always have to conduct spin prime tests and static fires before every launch? Or will Raptor and Starship be able to get to a point it’s so reliable those tests aren’t needed?
No one can answer that. Raptor was designed and is being developed to be as reliable or more than commercial jet engines, and according to a majority of experts inside and outside Spacex theoretically there is nothing preventing that.
Probably ‘yes’, it’s sensible to always have those tests before launch on Earth.
Especially this early into the program.
PID has been a viable option for large hydraulic systems fro a long time. I used them with ships autopilot and fin stabilizers for years. Fin stabilizers are large, like sterships fins. Accelerometers come into plat as well. This is a solvable problem.
Thank you for covering the upcoming launch by RFA
@4:54 The problem with this _counter-movement strategy_ is that while this might be fine for the _chopsticks_ at the top, it will accentuate the motion around the engine nozzles, which will swing wildly by up to a meter.
At that point, I'd worry about the _chopsticks_ ability to hold onto the booster. (It _might, maybe_ work properly for the *StarShip...* )
This is pre-catch to allow the catch. Post-catch, a similar routine should be engaged to dampen the combined arm/vessel system.
Excellent visual on the PID 👏
Landing on legs exposes the aft of the vehicle to reflected thrust, creating pressure waves and vibrations that travel through the the entire structure, so the added mass is much more than just the legs, themselves. Catching it in mid-air, well above the ground massively reduces the mass requirements (sorry, I had to). The ship needs legs for the reasons noted, and generally has to have a robust structure to carry and deploy cargo, so the additional mass to handle landing stress is minimal or zero. The booster doesn't need that, so it's a great place to save some mass (and catching it from near the top also means that the structure is in tension rather than compression during the landing, potentially reducing the mass requirements further).
I like pid tuning. I use it on my drone.
Felix, with regard to the Shaking of the arms, it could be a few other things. First, any looseness in the mechanical system would have to be corrected. This could be a pin fit that is too loose, or something along those lines. Second, Making sure all the air is out of the hydraulic system is critical. Any air in the system would be like bouncing a ball on concrete, which is what you see when the arm stops. Third, a validation there is not an issue with the servo valve. Fourth, a slightly feathered ramp to stop can help, kind of like when you let off the brake when stopping your car so it doesn't jerk to a stop. This will certainly be solved, much larger equipment than this is regularly moved in industry without the shaking, it will just take some work and tuning. Shorter arms won't necessarily help if the problem is one of the issues I mentioned above.
Great Episode! Thank You Felix and WAI Team.
Thank you so much for the help, Owe!!! :)
PID controllers are 1950s technology that were originally implemented using analog instrumentation. Given the relatively slow speed of the chopstick arms, more sophisticated digital algorithms such as model predictive control could be used. This would get them up to 1980s technology.
I am an will always be for a separate catch location that is not very far away and designed to quickly catch and place booster onto spmt to either go right to launch tower or back to mega bay if needed. this would allow faster turn around overall because does not require tower to be busy and can be prepping for next launch. also if catch system in m=semi mobile it is replaceable if failure with no risk to launch tower. the catcher would essentially be 2 spmt with uprights built in to straddle and catch booster and or starship. then having multiple give ability for multiple booster and starship landings quickly with redundancy build in. if destroyed just remove wreckage and bring in spare one. no risk to tower or permanent hardware.
Thank you for a very honest evaluation
Like the landing legs of the Falcon 9, a pair of deployable short arms attached to the hard point and the stabilization booster`s point may be works to avoid the closest approximation and the roll orientation needed. If these are damaged they can be replaced beetwen flights
I would suggest a design similar to a gyroscopic boat damper to stabilize the arms
Excellent info, video, graphics, editing, as usual! WAI delivers a top-notch production. And special thanks Felix for that unexpected 'short arm' visual demonstration....literal LOL 🤣
@whataboutit. Are you able to give any information on commercial launches in Australia?
Seems to me that catch towers
and launch towers should be separate.
Propellant tank issues
Motorcycles use dampers, ie. shocks or McPherson struts. Instant reaction and adjustable
Yeah you’re exactly right smoothing out the acceleration/deceleration curve should solve excessive oscillation. It seems to start because of its immediate stop at its end of travel which then reverberates around the structure
The sound wave canceling method is what is used in our quite helicopters.
Maybe they are tuning PID with Ziegler-Nichols method. So they induce the oscillation to calculate proper initial PID components 🤔
With proper control system design the movement can be very precise. Wish this tech was applied to cranes and other machinery.
Appreciate the concept all I can imagine is fumble sticks we all fall down. Too many variables one fail is reducing the economy of catch and reshoot to a net negative.
Definitely should have or should build a "catch only" tower, using the launch towers as backup. The risk of destroying the launch complex is very high. It will always be needed; the risk never goes away. No chance it will ever be obsolete.
Now it makes sense to make an catch tower you upgrade to an second launch one.
I am wondering if a couple steel cables in parallel would be strong enough but still provide a way to disperse the energy of the starship on landing. I don't know, I was just considering a second possibility for catching starship if the chopsticks don't work out.
Thanks!
Space X could fit some stabilizing gyros of suitable sizes upscaling of the type used in small boats to control any shaking.
A new Mechazilla with shorter arms will be more analogous of a T Rex at any rate.
It needs giant googly eyes. 😉
@@getinthespace7715 That would be hilarious 😂
@@Dinfes, Do you think if I took a trip to Texas, fabricated some 20 ft diameter googly eyes and dropped them off at starbase they would understand the assignment and weld them to the top of the tower. 😆 👀
I hope Elon sees this, I think it’s a great idea 🙌😂!
@@getinthespace7715 Make it where the rotating eyes are counterweights that dampen vibrations for the win.
Not having landing legs saves weight and catching the booster at its top means it will not be subject to being blown over by wind gusts like it might if standing on legs. The booster will be like an empty soda can in the wind after landing with little fuel on board.
Then dont fly when strong Winds occur...Problem solved. One failed Catch attemt and starbase is history. And so will the FAA Approval be. it will set SpaceX back Years.
You are forgetting the weight of engines located far away from catching arms. The arms should be flexible to dampen swinging of the booster.
Just enough fuel to blow up the entire area. Don't you remember those failed Starship landings? The fuel tanks were almost empty but still blew the area sky high.
Not having landing legs also means that a lot of complicated processes all have to function with great precision with zero margin of error and catastrophic consequences for failure. It's a bad trade off to save weight.
3:30 its like a giant tuning fork! You ring one and the other vibrates. They should make one longer than the other and the vibration should go away.
Love your educational and fun videos even though I barely understand much of this. Thanks!
DUDE... You started to talk about PID tuning... and I was thinking, OK, 3D printing next? THEN Input Shaping! You have my attention
PID tuning!
Now that is a skill I can appreciate!
"One ping only" .. I cracked up!
The best solution I think, would be to fit an electromechanical dampner - it’s clear that the chopsticks have a natural resonant frequency of about 2 Hz.
A driven mass corrector on the end of the arm could help to cancel that out.
But that’s just one of several different solutions. The control method is particularly interesting.
The hydraulic cylinders moving the arms are likely controlled by VFD or variable frequency drives. A bit of fine tuning to the drive itself will get rid of any pesky un wanted movement
Maybe one tower is for launch and the other for catching hence the arm length difference
Chopstick wobble may require a bit more D to reduce the overshoot. Have to be careful with adding Derivative as you still want to hit your mark.
The mechanical answer for the wobble would be the most Ideal. Some kind of shock absorber or spring system to provide tension or dampening will eliminate the wobble completely.
Ahhh were talking about control systems today.
Great job Felix! So nice to have you back! You Rock!
The argument against the landing gears being the need of a special landing zone, needing a crane, transport etc.. sounds a bit weak...
They could have the landing pad right next to the "Catch Tower". Simply picks it up, afterwards, and place it on the landing pad.
If they are aiming to have enough precision to catch the rocket mid-air, they should be able to precisely land on a small landing zone next to the tower.
The belly flop alone was already weird to see.. No idea how that would feel like, as an astronaut coming back to earth, not to mention anything inside the ship. Although I don't know what they are planning for those types of mission. Perhaps "habitable" Starships are not designed to come back to earth (not talking about moon/mars missions)
I understand the issue with weight, although the rocket will be a lot lighter during landing, compared to the launch which wouldn't need the legs since it would be mounted to the launch pad.
But other than that... I honestly don't see why... But I'm no engineer. I'm just a enthusiast enjoying watching the whole progress.
Catch (via chopsticks) is likely wrong in the long run... Catch at the base is likely correct... with chopsticks to stabilize for environment/wind.
2.58 Better a LQR control law
Linear quadratic Regulator.
The valve actuators on mechazilla were originally digital, either opening or closing with no speed control. They will need analog actuators, which allow speed control. There is no PID in a digital actuator.
You can do ‘time integration’.
@@peterclarke3020 You can't do anything with digital actuators other than open or close them at a fixed rate of speed. Though you can use snubbers to make the speed change at different phases of stroke. There are many ways to skin this cat.
An easy fix for the arm occilation is to use torsion bars to keep it always under tension. Like a vehicle suspension in some ways, don't let it be able to move freely.
The engines wouldn't survive firing so close to the ground even if the mass of legs weren't too much. You'd need like 20 meter tall legs to avoid shockwave damage.
Where do you get that 20 meter number? The booster will be nearly empty and without a starship or payload on top. A few lighted engines with low throttle would probably be sufficient. Besides if 1 or 2 engines would get damaged they could be replaced at a fraction of the cost of the whole booster.
I’m so excited for ITF-4 and really hope SpaceX succeeds in catching the booster!
Nice, 420k subs guys! Smoke to your success!
Ich denke das SpaceX denkt ist es besser wenn der alte Tower kaputt geht als der neue. (Belastungstest) Der neue Tower kann dann noch wieder verbessert werden.
Love the arms through the sleeves, a real LOL!
Shorter arms doesn’t necessarily mean faster, smaller radius of rotation requires greater actuation input to achieve the same relative speed. I think this may be done more so to reduce the cantilever weight when lifting. They maybe are seeing a bit of yielding to the current arm design.
didn´t know that im a space x crane xD nice video felix enjoy it every time! keep this great work ^^
ZV AL GORE RYTHM? Big glaring mistake in on-screen captioning
PID is very powerful to dampen movement
as far as the records for launches, this is a lot like the record for recovery - they aren't even trying for that record, the record is incidental, not the goal. it's a demand for those launches.
@Felix, the best part was when you acted with the Ty-Rex arms! LOL, loved it. It is a good skill to bring informative news while showing your playful side!
I was glad I was not drinking my coffee when that unexpected visual occurred....literally laughed out loud!
1. There is a second tower, in Florida. Land it there.
2. Most actuators come with built in dampeners for end of stroke in both directions, but they all have to be adjusted after the 1st time they are used. They come factory set, usually fully open causing the visible bounce at the end. Who ever installed them should have tweeked them down a bit more.
I think SpaceX should test with a scaled down version of the booster
what about reaction control wheels? large ones with the appropriate weight to control unwanted oscillations
I think that those new white pads on the Mechazilla arms are strain gauges not conduit mounts. This would provide valuable feedback to engineers about how much strain the arms are under when the booster lands in IFT5, and possibly data to feed in realtime to the catch algorithm when moving the arms.
Pretty cool episode !
You do not need active control to stop the chopsticks wobbling - it sounds way too complicated, especially as the software would need to be tuned for different scenarios. A better solution would be a hydraulic damper - a cylinder filled with oil and a piston with a hole, like a shock absorber on a car. The drag force is proportional to velocity or the square of the velocity (depending if the reynolds number of the flow is laminar or turbulent.) If this slows movement too much, a bypass valve can be opened to increase the size of the leakage path. Closing the leakage path completely would make the chopstick immovable.
THANK YOU!! for the update on the Falcon 9 launches. I was JUST going to request that. A deeper dive into the pictures of the production facilities would be cool to see also. The future of STAR LINK is going to be more unbelievable then one can imagine. It is what will pay for the Mars missions.
similar to the problem of catching a moving cargo container to its waiting truck, up 60ft - across 50 feet - down 70 to within 1ft then jiggle, fighting the mass and rotation and pendulum forces to nail it every time, no input shaping works as the mass variable isnt fixed. no pid will be accurate as wind forces vary. years of container juggling has proven only one computer architecture has the right learning model to be 'on the money'...
They should have kept one of the offshore riggs to test booster retrieval. I'm just saying 🤷. Regards
A single shock absorber on a large semicircular cam at the proximal end of the chopsticks solves the vibration problem.
Very interesting to compare the diversity in the Starbase control rooms with the lack of diversity in the German one.
Pid and input shaping will not be applicable to hydraulics due to fluid dynamics, and delayed outputs.
Pertinent question! When they go to Mars they will have to land on legs. That's why they should test this technique now, which has much less risk. They could try to land in a landscape similar to Mars.
It would be the ship landing on Mars or the moon not the booster. They have already proved they can land a ship on legs.
@@RoadkillbunnyUK Also martian gravity is only about 1/3 that of Earth
Completely different set of parameters from lower air resistance on reentry, lower gravity at landing zone, and probably higher initial velocity from orbital insertion. All of which create different requirements for landing on Mars, the moon, and earth. Landing on earth is much harder.
Baby steps man…the priority currently is the prove they can catch the booster. The rest will follow
You have that backwards, it's the riskiest parts that need to be tested first
They should try extending the arms through the backside of the tower and adding dampers to them or weights that can move to counteract the vibration even further...
OR... Arms that rotate into position, while closing making it so they don't have to move quite as far and implement the damping systems still. Just throwing ideas at the wall.
The whole concept of the catch is a serious concern. Spend your bonus t/w ratio with R3 on landing legs.
They need to fill the arms with dehydrated sand to help dampen vibrations like roller coasters do. Cheap effective but maybe heavy… maybe they can reuse the per light from the cryro tanks in place of sand…? Idk just ideas