All hail ceramic bearings When having balls of steel isn't enough

@ashwinmohan4503

5 жыл бұрын

haha good one buddy!

@ashwinmohan4503

5 жыл бұрын

Joe, what you are saying is your balls are steel and impotent. Im sure thats not true, but just couldnt resist making a joke. No hard feelings brother.

@matchesburn

5 жыл бұрын

Ceramic bearings would probably have fewer problems because of the surfaces. Would probably handle heating/cooling cycles better than steel and electrical discharge. But, then again, if the grease/lubricant being used is causing undue friction for some reason you'd still have failures.

@ashwinmohan4503

5 жыл бұрын

Joe I really didnt mean it as anything but a cheap joke, but thank you for taking it sportively.

@kaosinc

5 жыл бұрын

matchesburn Use no lube then!

Ah yes electric arc across a bearing is why you have to be careful to not ground across a bearing when welding.

@scottmanley

5 жыл бұрын

Yep, what amazes me is that because of the tiny gaps involved in the bearings even a few volts can create arcs with enough energy to melt steel.

@gordonlawrence4749

5 жыл бұрын

I dunno grounding across bearings can be hilarious when a trainee does it. Flames (from the lubricant), a "bearing" that is now rock solid, and mickey taking material for the next month at least.

@tempname8263

5 жыл бұрын

Well, there are no complete solids at atomic level anyway. Some particles sometimes get out of their places in grid. It's just a matter of amount.

@wb6anp

5 жыл бұрын

Not so funny for the welder that does it across multiple bearings in a turbine engine, We had one the was welding an exhaust nozzle crack, but grounded to the front fan assembly on the engine, welded every bearing in the engine.

@migkillerphantom

5 жыл бұрын

James Collier it's a wheel that you spin to spin your spacecraft the opposite way (hence reaction) without wasting propellant. Used to orient and stabilize. Every action has a equal and opposite reaction. In order to spin up something in space you need something else gaining the same angular momentum in the opposite direction

So I will begin with "I am not a rocket scientist" however as an industrial HVAC and commercial equipment service technician I replace bearings all the time and as a matter of fact I am currently covered in grease from a 15 hp electric motor that blew a rear bearing and cost my customer over $2000 to fix. There is this extreamly common thing that happens to electric motors that are being driven off what we call a VFD (variable frequency drive) it allows us to control the speed of a motor but because of how a vfd works and converts the voltage it creates voltage spikes in the rotor that hava no where to go but through the bearings and into the housing, this pits the balls, races and destroys the bearing over just a few months. The thing to keep in mind is that there is a very small amount of contact area from the ball to the race so it doesn't take much to destroy the bearing in a very short period of time. Something as simple as a rotor grounding shaft would have eliminated the bearing failure.

@Druicidal

5 жыл бұрын

Conductive lubricants will also eliminate these failures, Polyrex EM or Retinax EPX/M aerospace.

@WilliamDye-willdye

5 жыл бұрын

Thanks for taking the time to post a valuable comment. Respect to HVAC!

@mrinalthakur3459

5 жыл бұрын

Voltage spikes are easily suppressed just use a snubber a RCD snubber will do But what do I know , just a amateur hobbyist speaking

@CKOD

5 жыл бұрын

This is exactly what my mind went to when Scott mentioned solar flares. Searching for "bearing common mode current" provides lots of relevant results for anyone else looking for more info on the VFD/earthly sort of failures.

@darkwinter6028

5 жыл бұрын

wheelitzr2 - ok, next time I’m gonna use a VFD, I’m definitely going to ground the rotor! 🤔

Finally, the aerospace industry is catching up to fidget spinner technology.

@Rhynri

4 жыл бұрын

I mean hell, my MS explorer trackball has had ceramic bearings in it for years since the metal ones wore flat forever ago. You’d think they’d want ceramic just for lifespan if that holds true for this application.

@Mgl1206

3 жыл бұрын

@@gags730 haha so funny.... not

@Mgl1206

3 жыл бұрын

@@gags730 I’m sorry but I hate cranberry juice now some apple punch? That’s my jam. Also no fidget spinners sadly I broke them all by using them too much. And instead of a glowing one I did have one that flew so there’s that 😉.

@Mgl1206

3 жыл бұрын

@@gags730 too bad 😂 lemonade ain’t half bad either

@wolfboyft

2 жыл бұрын

Made me lol

Missed opportunity: "Bearings fail when the friction on them become unbearable."

@sundhaug92

5 жыл бұрын

Are you saying he should just roll with it?

@VulpeculaJoy

5 жыл бұрын

Rofl

@nuru666

5 жыл бұрын

Genius comment and replies.

@darioinfini

5 жыл бұрын

Rolling on the Races Laughing - RORL

@derain95

5 жыл бұрын

You three will make great dads if you aren't already.

"the pressure of the sun's light" now that's some awesome physics

@michaela.660

4 жыл бұрын

Now, if we could just figure out a massive photon gatherer and grab enough photon mass equal just 1/10 th the mass of what is being driven. Wow, ranks right up there with the wormhole thing.

@blackseac

3 жыл бұрын

Michael A. yes it’s called solar sail and the japanese has tested some in space already

@oleksiyalkhazov9201

3 жыл бұрын

Damn spoilers

@LVBRIP

3 жыл бұрын

Airbus have been using solar sailing to stabilise communication satellites since the 1980s. Old technology.

@dustinswatsons9150

3 жыл бұрын

I still don't understand why he said reaction control propellant.. when clearly their motorized wheels actually I don't know what kind of thing is propelling the wheels

I worked on commercial space communication satellites, and my dad worked on Hubble Space Telescope. Reaction wheels were always acting up. On Hubble some of the reaction wheels have been replaced on servicing missions, the only spacecraft (other than the ISS) that such replacement in orbit is possible. On our commercial satellites, there were usually more than 4 wheels, so there was some redundancy. I always wondered why such a (seemingly) simple device was so troublesome. Your video provides some interesting insight into this issue.

@kurtilein3

5 жыл бұрын

An easy fix, if someone would have guessed the issue, would be to add some radioactive material near the bearings, because ionizing radiation dissipates away static electrical charge as it accumulates. Or make the lubricant electrically conductive. Or, as they did by accident, switch to ceramic bearings.

@mememaster147

5 жыл бұрын

I was surprised that they were using BBs and not magnetic bearings. It's possible for metals to cold weld together in a vacuum if they've lost enough of their oxide layer so that could be happening if the lubrication film breaks down enough to allow bare metal to contact in the bearing.

@kurtilein3

5 жыл бұрын

Meme Master Lubricants that work long-term in a vacuum are used. Everything was and is lubricated very well and coated in a lubricant layer in any of these mechanical bearings out in space.

@TheToric

5 жыл бұрын

ed p anything using bearings will always fail at some point, and something spinning incredibly fast (some at the limit of their tensile strength) will fail more quickly.

@Duncan_Idaho_Potato

5 жыл бұрын

"...the only spacecraft (other than the ISS) that such replacement in orbit is possible." WAS possible. Since the retirement of the space shuttle fleet, there is no spacecraft currently able to rendezvous with Hubble and secure it sufficiently to perform any sort of maintenance on it. Its days are now numbered. HST might well last well into the 2020s. Even if the JWST is completely successful, HST is capable of "seeing" in wavelengths that JWST cannot. A 6th servicing mission may well be approved some day, using a spacecraft yet to be deployed, in order to save one of the most beloved spacecraft ever launched into orbit.... at least, for a time.

I remember when Bill gave that presentation to all of us former Ithaco Space Systems employees on the fifth anniversary of it's closing. He set up a projector in his barn and after our barn party reunion we all listened very intently. I saw the picture of a CME on the screen, looked back at Jeff Golden, then to Eric Stromswold, and my jaw dropped as they let me know that they agreed. The ball bearing is basically the gateway for static potential to discharge from a relatively massive rotor (hidden under a relatively thin cover) to a massive dish. Yes, of course it would be subject to ionic buildup, regardless of any Faraday cage of the rotor cover. Remember, the outer bearing cover is attached to the outside of the main cover housing. Essentially, it's all right there waiting to pick up these ionic discharges. I so miss working at Ithaco. Everyone there worked so hard at making those things work right... Laurie spent so many hours in the inner cleanroom taking so many measurements fir Bill and Eric WHILE ALSO building so many other RWAs. I stick to Torqrods so I didn't know much but I just remember how heartroken we we're when we lost the Iridium contract because of the failures. That was the death of a great company.

@amphibiousone7972

5 жыл бұрын

That's a cool personal story.

@xXUnoriginalNameXx33Meygaera

5 жыл бұрын

@therealnightwriter Are you a bot?

@SpenserRoger

5 жыл бұрын

Wow, any more stories? Such a small world. I was at that barn party too. I was the small, meek fellow in the back corner, nervously chewing on sunflower seeds expecting someone to step on me at any moment.

@MattThompsonOnGoogle

5 жыл бұрын

@@SpenserRoger You worked there, or family? I was only st Ithaco for the short remainder of its existence as a UTAS company, October 2011-March 2013. I built a prototype motor driver card for GOES-R and a lot of test cables. Also wound one SMAP Torqrod

@SpenserRoger

5 жыл бұрын

lol sorry I was just pretending to be a mouse in a corner. I did want to hear any other stories though. Thanks.

you know its also possible they realized this about 10 years ago said "yikes!" and quietly switched to ceramics

@3gunslingers

5 жыл бұрын

While this is absolutely possible, I rather think they switched because of weight saving.

@mytube001

5 жыл бұрын

Or durability. Ceramic bearings should wear a lot slower.

@mining1574

5 жыл бұрын

that is exactly what i though, also, if theses reaction wheels are "high quality" how bad is the competion????

@jfan4reva

5 жыл бұрын

Probably the same quality, just more expensive.

@Candesce

5 жыл бұрын

I work for a large organisation and look at equipment used at our facilities. One of our hardware vendors insisted that nothing was wrong after i directly showed them what i believed was a problem. They later admitted the issue but by that time they'd rolled out a new model, and guess what? The new model had exactly addressed the issue i pointed out, meaning that at least someone in their organisation knew about it for a long time. Corporations can be as dishonest with each other as they want if they feel they can get away with it. I wouldn't be shocked if it's true that they moved to ceramics here because they secretly knew about the defect.

You can get same failure mechanism with cheap frequency convert drives on electric motor bearings. The ceramic bearing is good but expensive fix the other solution is install grounding carbon brush but that's needs probably some maintenance over long periods of time so using just ceramic bearings on stuff like that is probably good idea, especially when they are already stupidly expensive :D

@youkofoxy

5 жыл бұрын

I see you are still doing research in to rocket science. how is going you rocket program?

@Seve82

5 жыл бұрын

His wünderwaffe rockets are nearly ready to be deployed for the next step in the secret world domination plan.

@HydraulicPressChannel

5 жыл бұрын

I have my big rocket with 1000 N of thurst still under work :D I have been to busy but I think I should get back to it

@CGoody564

5 жыл бұрын

@@HydraulicPressChannel = Elon Musk's alter ego confirmed 0.o

@thundercactus

5 жыл бұрын

ceramic bearings aren't even that much more expensive when you consider the cost of the spacecraft

Fascinating! Space is such an extreme environment and there's still so much we don't know yet.

A good experiment for the X-37A would be to put some reaction wheels in it and run them in space for a year or two then bring them back and take a look at them.

I absolutely love it that you insist on using the satellite girl figurine every time you talk about the Hayabusa. Maybe next time show a picture of the motorcycle :^)

@Sssaaatttuuurrrnnn

5 жыл бұрын

Which other times has he done that? I wanna see now.

@mik13ST

5 жыл бұрын

... or a picture of the Nakajima Ki-43 Hayabusa (WW2 fighter)

@muchozolf

5 жыл бұрын

kzread.info/dash/bejne/gque2MmYXZqnqdo.html

@muchozolf

5 жыл бұрын

It's right to the end of the video.

@xXUnoriginalNameXx33Meygaera

5 жыл бұрын

moe makes the world go round.

A friend who is building large CNC machines said it is a huge problem to ground these machines properly because ESD (when machining some matertials) and the currents of the motors are causing these problems with the bearings

@kurtilein3

5 жыл бұрын

Add some ambient ionizing radiation, this will dissipate electrostatic buildup, and it will give you cancer, but for grounding moving parts across an air-gap, it really works, by knocking electrons out of surfaces.

@bioriderfc

5 жыл бұрын

Balanced Ion showers are the only way to work on instrument grade CCDs.

@taraswertelecki3786

4 жыл бұрын

@@kurtilein3 An alpha emitting radioisotope would accomplish this.

@SparkyMcBiff

3 жыл бұрын

@@taraswertelecki3786 Actually it is Beta radiation that is composed of electrons. (Alpha is essentially a Helium nucleus).

I put ceramic bearings on my fidget spinner and it changed my life.

"I'm Scott Manley, fly ceramic!"

Damn Scott.. you always pick the most interesting things to talk about.. Plus you put them to us in a way that this 66 year old fart can actually understand.. or maybe it is just because of my Scottish heritage (Lamont clan) helps me to understand... Well done brother.. carry on...

@calanon534

5 жыл бұрын

And he seems to provide further, conclusive evidence that Scots will be the first Space Superpower. Because everyone else's stuff will be breaking down all the time.

@tinkmarshino

3 жыл бұрын

@Cosmo Genesis Sheesh... Now there's a thought for ya... Woof!

And here I thought it was Sun Rust caused by damp and salty photons. Boy, do I feel silly now.

5 жыл бұрын

Could be stowaway tin worms.

@patrickradcliffe3837

5 жыл бұрын

fogllama you are so weevil sir.

@dimitar4y

5 жыл бұрын

Special humor. I love it.

@Trident_Euclid

5 жыл бұрын

OMG 😂

@nunyabusiness3786

5 жыл бұрын

what?

Great food for thought, I've actually been wondering about this! Thanks Scott!!

New mod for KSP : Carbon ceramic reaction wheels

@soljafon

3 жыл бұрын

New mod for KSP: failing reaction wheels

People often fail to realize that there is no such thing as a perfect Faraday cage. You can't just wrap something in micron thick foil and expect infinite attenuation. Seems to me like you'd need something more than just a standard metal enclosure to keep voltages across the bearings below 6V during a decent size solar flare.

@3gunslingers

5 жыл бұрын

Good point.

@aleksandersuur9475

5 жыл бұрын

It's not the thickness, it's how good the connection is along all the joints. You use things like this: www.tech-etch.com/shield/images-shield/assortment-of-emi-shielding-products.jpg But ionizing radiation can also cause a voltage spike and flares give off some quite energetic particles. If that's the culprit, good luck shielding from that.

@AlexanderGoncharenko

5 жыл бұрын

So, the grounding is to blame, as usual

@mining1574

5 жыл бұрын

lets attach a long wire from the satellite to the ground, that should fix the problem.

@nelumbonucifera7537

5 жыл бұрын

Mining - you're confusing grounding with earthing. Neither have anything to do with effectiveness of a Faraday shield. That's determined by the conductivity/admittance of the cage.

I love videos like this, answering questions I never even knew I wanted the answer to.

- 🥺 Bombarded with audio all day I like to read the closed captions you provide in your always very informative video presentations. I really apreciate your thoughtful consideration. Keep up the good work. 👍

They should make a craft full of reaction wheels, send it to orbit, Wait for like 50% to fail, then have it rendevous with the ISS for inspection and analysis.

@jamestheotherone742

5 жыл бұрын

It would need to get out past the Van Allen belts to really soak up the rads. Might as well put it inside a heatshield, send it on a hyperbolic orbit out to L2 and then let it reenter.

@thePronto

5 жыл бұрын

Would only cost a couple hundred million dollars. Or, they could keep doing what they are doing: using ceramic bearings.

@Hamachingo

5 жыл бұрын

Meh, a cube sat, stiffed with fairings on different axis, all spinning and sensors or maybe a mechanism to open and photograph the bearings.

@damstachizz

5 жыл бұрын

Unless ceramic bearings aren't the only needed fix, it could be something like the lubricant not having the same conductivity across it leading to the exact same problems, where parts of the fluid will conduct the electricity and cause micro pits while others won't. What if the pits aren't the problem, but the sudden heat produced is burning off the lubricant on that spot and over time it just burns away enough to cause high friction/wear?

@jamestheotherone742

5 жыл бұрын

Have funding will travel...

@Scott Manley - Thank you for helping to reveal how and why these mysterious space borne failures took out many of my favorite missions. Not surprised and it makes very good sense. Appreciate the effort. Astrophysics and astronomy are my first loves... I too went into tech.. as a hardware engineer in multimedia telecom and network products. Retired now.. JK in Berkeley

I just love the picture you choose to represent Hayabusa.

This has to be one of my favourite videos on this channel yet. A nice inside on the engineering problems involved in rockets and space probes but easy enough to be understood by laymans.

Most fascinating. I work for a major satellite fleet operator. We've been seeing this exact type of wheel failure in some ~15 year-old spacecraft which were expected to last even longer. I'm going to go back and check the data for correlations. Glad that there seems to be a fix in the newer wheels, even if accidental. Thanks for this one, Scott!!

This is so awesome. In one video I learned that satellites use reaction wheels, that they malfunction, why they probably malfunctioned and how it likely has been solved.

I think things like this is why we should try to plan for a potential recovery of some probes. I'm no rocket scientist or astrophysicist, but surely it would be worth the extra trouble to actually get a good ol' fashioned 'MK-01 Eyeball' looking at things, right?

@logicalfundy

5 жыл бұрын

Maybe if some of them are in low Earth orbit, we can take a look. Otherwise, it's simply not practical. Spacecraft are only given enough fuel for their mission, and not enough fuel to return to Earth.

@brianorca

5 жыл бұрын

I think most of these craft are in solar orbits, or very high Earth orbit, so we don't yet have anything capable of reaching them and returning to Earth. They are also mostly outside of Earth's magnetosphere, and thus more exposed to solar radiation, which contributed to the problem.

@G5rry

5 жыл бұрын

Play some KSP and try to recover a probe you deployed into interplanetary space and I think you'll answer your own question.

@damstachizz

5 жыл бұрын

Pfft, you're clearly not thinking the real kerbal way. Just build another Saturn V and send up a little robot arm + capsule to grab and return one of these probes.

@firespawn01

5 жыл бұрын

Oh that's what I do. I just....misinterpret the numbers on occasion (read: all the bloody time), resulting in recovery vessels needing recovery vessels....Which need recovering in true Kerbal fashion.

Thanks, Scott. This deep-dive into an obscure facet of deep space exploration is why I keep tuning in.

This video is the kind of high quality content that makes me watch your channel. Great stuff Scott!

A Faraday cage will not help prevent differential charging due to high energy charged particles passing right through the housing. This is very compelling actually. And Scott, please keep up the good work!

Somebody once told me, the Sun is gonna roll me, and even r-wheels would fail.

@TomBaldwin2483

5 жыл бұрын

Electrostatic shocks, caused our ball bearings to block and left the Rocket Engineers looking pale

@raintrain9921

5 жыл бұрын

It was looking kinda bleak, till one paper found a cheet with the shape of the so-lar pan-els

@tempname8263

5 жыл бұрын

She was looking kind of smart with her paper and her chart in the top shared news on Nature

@tempname8263

5 жыл бұрын

(Ah, damn, I'm late)

@raintrain9921

5 жыл бұрын

Temp Name I had the same realization with an on's post, I liked yours before you removed it though ^^

Great content again: extremely educative material, brought with a flair of enthousiasm that makes it easy to pick up. Thanks for making these videos Scott!

Wow! That was absolutely fascinating information. So glad you could share.

I'm sure we'll see a conductive lubricant on the bearings in the future or more ceramic bearings. I'm really surprised ceramics were not used in the first place. With a much lower mass, smoother operation and longer life they seem like the go to choice. I'm sure there was more to it though. Great video!

Solar Freakin' Welding!

Good information as usual. Thanks for your work..

Interesting topic, thanks for covering it for us Scott!

Is the Parker Solar Probe using the new or old wheels?

Enjoying the new Transbay Terminal Park? It's nice up there

@timothyconover9805

5 жыл бұрын

I was wondering "where is this place!"

Fascinating as always Scott, thanks :)

Absolutely love your channel. Thank you for the work you put in your channel.

Not sure about the ceramic balls solution. Static charges can build up on the rotor before jumping out within a dramatically thousand volts spark. Saw this failure on high perfomance machine-tool spindles.

@prdoyle

5 жыл бұрын

I thought they would go in the direction of conductive lubricants.

@kurtilein3

5 жыл бұрын

What exactly would be the problem if the sparks go around the bearings instead of damaging them? Also, Einstein got his Nobel Prize not for relativity, but for the photoelectric effect. Add a bit of radioactive material, exposing the whole thing to some low level of ionizing radiation, electrons will get knocked out of surfaces and will travel to reduce any electrostatic charge. At high levels, this is poison to any electrical devices, this is why all robots fail inside the fukushima nuclear ruins. At low levels, this is poison only to any electrostatic buildup of charge. This works in air or in a vacuum. No further design considerations as long as you have conducting surfaces seperated by nothing other than air or vacuum, add some ambient radiation to drop voltages and electrostatic charges across the system.

@ergohack

5 жыл бұрын

@ Conductive lubricants tend to have higher viscosities and particulate content. Perfectly fine for an industrial motor, but completely unsuitable for high speed high precision applications like a reaction wheel.

@ergohack

5 жыл бұрын

Very interesting failure mode. Easy enough to remedy using a simple spark gap though. A few closely gapped sharp points in the right locations should allow any discharge to occur at non-critical areas of the spindle assembly. Or, as kurtilein3 suggested, use radioactive material to effectively decrease the work function, the results would be similar.

It could also be polymerization in the lubricant- secondary radiation can turn lube into glue pretty easily.

@kurtilein3

5 жыл бұрын

This idea is old enough that lubricants for use in space are tested for this in nuclear research facilities. You can just go and buy high-performance lubricants that are rated to withstand both a vacuum and intense levels of radiation. It is too obvious.

Great video. Keep educating the public!!

Thank you for putting the link to the paper in the description

try welding on an engine lathe see how well it works after. I learned this in high school.

Sounds like a solid theory. Nothing worse than a good theory that can’t be tested.

Fascinating! Thanks again for the great content.

My first thought to solve the problem was to use heat resistant ceramics to replace bearings; you can do a home experiment with anyone who has had an electric train set, to demonstrate what static discharge event being discussed looks like in real life: All you need is an outlet adapter for a race track or a train set. The racetrack or train set adapter will usually come with lead wires that travel to the racetrack or track connections. This is the wire I used as a child to conduct this experiment. With the adapter charged to any degree above zero, you will see a blue spark as the wire contacts the quarter and grounds out the current through the quarter in a short circuit. This would be the same effect as having the charge jump from one bearing to the next, as another aspect, the bearings themselves may have different charges from each other during a CME (Coronal Mass Ejection). Remember, these Coronal Mass Ejections were recorded to make sparks on telegraph wires within our own atmosphere during the 1800's when electricity was not as wide-spread and in use as a part of major industry as it is now. That is surely enough to make the same kind of spot scarring you see on the surface of the quarter you've been creating sparks on. You can feel the part of the metal where parts of the wire got fused to the quarter during the exchange of electrons, also used as a practical application in welding, called arc welding. These small imperfections would be catastrophic to bearings needing any degree of precision in a very highly machined quality product of microscopically precise application. Good article!

"Oh come on guys! It's so simple, maybe you need a refresher course. It's all ball bearings now days."

@jimt828

3 жыл бұрын

Fletch!

The more we study the more we find out.. human knowledge is increasing rapidly.

@MiniGui98

5 жыл бұрын

The more you learn, the more you realize you still have discovered nothing, and that you are nothing in the grand scheme of things. That is frightening and fascinating at the same time.

@DavidOfWhitehills

5 жыл бұрын

Theres a small pebble of attractive conglomerates in my batroom as an ornament. The story it could tell is millions of years old. It was as it is millions of years before our ancestors descended from the trees. I take a bath, many baths as I grow ancient, soon to die, but this pebble will remain as it is for millions of years to come.

@chris-hayes

5 жыл бұрын

And then a flat Earther appears

@maximo1590

5 жыл бұрын

@@chris-hayes Well, of course, stupidity is increasing as well. Don't worry, stupidity is deadly, but that's why it will die off soon.

@wheresmycar9559

5 жыл бұрын

OP and his edgewad suck buddies think they're deep because.... the universe.

Oh snap! I work in one of the buildings linked with Salesforce park and walk around it all the time. Crazy to see you standing there! Love your channel.

I had noticed this and had a strong curiosity as to why the reliability had seemingly not improved over quite a span of years. Thank you for speaking about this potential failure mode as it is both interesting and satisfying explanation.

Does this mean there could be a higher risk of failure for the Parker Solar Probe?

@prestoshelf4088

5 жыл бұрын

doubt is uses reaction wheels prone to failure. thats if it does use reaction wheels

Would it be feasible to create a zero-contact reaction wheel with magnetic rails like a maglev train? Even though there's no contact, angular momentum would still be transferred by pushing off the magnetic fields. As an added bonus, the system's magnetic field may offer some protection against solar winds if it's strong enough.

@radiationpony8449

4 жыл бұрын

Assuming you use superconductors then sure but spacecraft already have issues radiating heat

@stargazer7644

3 жыл бұрын

Conventional bearings are zero contact - they ride on a film of oil. Sparks jump the gap. Sparks can still jump the gap in your magnetic bearing..

@deanrensberger631

2 жыл бұрын

@@stargazer7644 except that oil can conduct electricity, whereas the vacuum of tinyfoxtoms mag bearing couldnt

@stargazer7644

2 жыл бұрын

@@deanrensberger631 Oil is a dielectric. It doesn't conduct electricity. In fact, all those large power transformers you see on poles and on the ground are filled with oil.

@deanrensberger631

2 жыл бұрын

@@stargazer7644 you dont understand what we're talking about. Oil isnt a perfect insulator like the vacuum. Its conductivity is what allowed these mcgs to fail.

This was an incredibly interesting video! I was honestly captivated

Great video buddy as always Scott. I'm a mechanical engineer , and it makes alot if sense. There 's a mechanica proces called "electric sprak erosion" , that is done in an oil bath . The work piece is connected to the + pole and a graphite electrode - When currency is switches on , the elektrode cavitates a hole in the workpiece. From the moment you mentioned static charge , i already knew what the study would say 😉😁... Grtz huge fan johny geerts

I was just about to suggest ceramics and... I'm some ten years late. XD

That’s an interesting problem, funny how some things we regard as non-significant can actually be in some ways!

Thank you for podcastposting this one Scott, I have indeed wondered. In a ball bearing there's very little surface on the top of the ball, so yes comparably little amps is needed to weld it in place or leave a residue as shown on your video. Ceramics seem to be the way to go, or at least in some part of the ball bearing to stop it from being conductive, especially on spacecraft that use Ion engines - or any space application that use the kilopower units.

That is fascinating, who knew we couldn't use the same materials on spacecraft because space is so harsh! Amazing video Scott!

Does this mean that the Parker Solar Probe is pretty f****ed or has that got the ceramic bearings in it?

@kahlzun

5 жыл бұрын

He said the last 10 years, so Parker is pretty likely using the new stuff.

It’s called bearing fluting, a ceramic coated outer race is the cure.

Great video Scott. Fascinating subject.

This makes perfect sense to me. I remember reading a story many years ago about how an electric motor bearing was found to be failing due to a short between the rotor winding and the rotor itself. The small electric current through the bearing caused increased bearing wear, and eventually, early bearing failure.

Didn't we return reaction wheels from Hubble? I assume they were able to measure the changes in material properties.

@scottmanley

5 жыл бұрын

The Hubble reaction wheels weren't built by Ithaco, so they weren't involved.

@EricAnthony1738

5 жыл бұрын

I was aware they were built by a different source but as long as they used metal parts similar to Ithaco instead of the newer ceramic they would still be able to use it to isolate the variable of who made it to narrow it down to possible common design flaws.

@steve_case

5 жыл бұрын

Deric Anthony Didn't Hubble servicing mission 3B bring back the gyros and the reaction wheel? I think the gyros and reaction wheels were designed in the early 80's. Someone should find out and correlate to any solar events.

@ergohack

5 жыл бұрын

@@scottmanley Even if these were made by Ithaco, they still shouldn't be susceptible to this particular failure mode since Hubble is within the Earth's magnetosphere.

@EricAnthony1738

5 жыл бұрын

Not sure this is true. While they are shielded partially there are solar flares that do damage to electronics on earth so I think it is safe to say Hubble is still able to be damaged by solar flares.

Fascinating! However, why aren't they using magnetic bearings? Without gravity, surely they would be a perfect solution, or are the reaction forces too great to maintain containment?

@CyrilLapinte

5 жыл бұрын

As far as I know, cost is one of the trade off. They're using them since over 20 years on some Earth observation satellites.

@bman12three43

5 жыл бұрын

I mean yeah the reason that so many satellites were using these reaction wheels is because they were cheap, if they didn't care about price they probably would have stepped it up a little bit. I am not sure of how much power magnetic bearings use though, for spacecraft going very far away from earth their power budget can be a lot smaller.

@ahaveland

5 жыл бұрын

Thanks for the replies... Obviously, if a billion dollar spacecraft fails because of cheap reaction wheels when magnetic ones would do, then they are very expensive reaction wheels! Magnetic bearings should in theory last indefinitely. If craft were capable of being refueled cheaply for desaturation, then they should also be able to last indefinitely.

@jamesharmer9293

5 жыл бұрын

That's the question that I'm thinking about. It seems obvious that magnetic bearings would last much longer and that steel ball bearings would wear out relatively quickly. Call me cynical if you want, but I suspect bribery.

@kurtilein3

5 жыл бұрын

Andy Lee Robinson Once you know the issue, solutions are cheap and easy. The same old reaction wheels would work just fine if you add some small radiation sources, like the americium used in smoke detectors. The ionizing radiation knocks electrons out of any conducting surfaces, these will travel through the air or through a vacuum, being attracted to any buildup of positive charge. Just pick the correct energy level and dose of radiation, so that electronics are not affected, but it is toxic enough against any static charge buildup. Magnetic bearings, unless superconducting magnets which require advanced cryogenics are used, constantly consume energy. In any case, the electronics required to actively control them in real-time also add a point of failure, cost, and energy consumption.

Metallic vs Ceramic bearings in those harsh conditions... that is such a no-brainer. Thank you Scott, we enjoy your amazing videos alot.

Awesome! Good explanatory pictures!

Great explanation. And I thought it was just more "space cooties" bogging up the works.

Here's a question: Is the manufacturer at fault? Assuming the best intentions, they did their best to make sure it worked. It took many people years of studying the data to figure out a possible explanation, not to mention a crtain one. On the other hand, it hardly seems like an unknown phenomenon. The manfacturer also seems to be the one that made it cheapest so maybe one with more money invested in each, would have been more resistant. If you look at the end result only, you might find that you would have been better off buying twice as expensive units from someone else even if all the available data said that these were just as good, but those maybe did not end up failing.

@3gunslingers

5 жыл бұрын

It's just the manufacturers fault if someone figured out the problem beforehand. But the reason for those failures was only discovered after many years. Also those spacecraft ALL functioned well beyond their intended lifetime.

@0xEmmy

5 жыл бұрын

Any other manufacturer that used metallic bearings would have had the same problem. This isn't an Ithaco problem, it's a we-don't-understand-spaceflight problem. And I'm surprised NASA didn't attempt a scientific analysis of this earlier. Reaction wheels failing in space but not on Earth is exactly the type of thing a space agency should be trying to solve.

@nazamroth8427

5 жыл бұрын

If only *someone* gave them funding...

@DSYomre

5 жыл бұрын

If it is designed to all of NASA's requested specifications, that is all they need to fulfill

@ripbanditgames

5 жыл бұрын

No, it's a design flaw that only could've been seen coming with either a multi-year test in space or them getting lucky and getting a solar flare very soon after launching said test. With NASA's current budget it's a bit hard to justify the cost of testing things like this sadly.

Great post Scott, thanks!

I love these vlogs with space anecdotes. :)

There's a lot of unanswered questions regarding this. I'm guessing that these bearings are in a sealed unit? Has anyone checked to make sure that whatever lubrication is being used will actually work long term exposed to vacuum? Has anyone tested to make sure some kind of vacuum welding isn't taking place? Generally the most inane things are studied when it comes to aerospace engineering, so I would be surprised if there wasn't a lot of documentation on it... But the problem is how much LONG TERM study is being done? What happens when this lubricant/grease is subjected to vast temperature changes (because going from being in the sun's light to behind a planet tends to cause a drastic heating/cooling phase) cycles? That's prime territory for metal fatigue from constant and continuous thermal expansion and cooling. What happens if something causes this grease/lubricant to dry up or harden? It might take months to do it. And, of course, you can run into issues with non-insulated metal and high voltage - we have have issues with melting, spontaneous welds and electrical discharge damage here on earth with some things (although admittedly probably not much in the way of ball bearings).

@0xEmmy

5 жыл бұрын

This is why so many people want these spacecraft recovered - so we can crack them open and see exactly what happened.

@nicksauer6749

5 жыл бұрын

Is it possible to create a conducting grease to dissipate the charge? Perhaps with graphite?

@zrobotics

5 жыл бұрын

It takes very little current to ruin a ball bearing, and this has been a known problem for a very long time. There's even a special term for this damage in electric motors: en.wikipedia.org/wiki/Shaft_voltage Bearing companies themselves have studied this to death: www.waukbearing.com/en/technical-resources/bearing-damage-index/bearing-damage:-electrical-pitting/ This is something any experienced mechanic or welder is aware of, I have seen multiple failed bearings from poor grounds.

@Mernom

5 жыл бұрын

Well, the obvious suspects are the most likely ones to have been adressed.

@mytech6779

5 жыл бұрын

Which makes you wonder if they ever consulted a bearing manufacturer(that would immediately point out shaft voltage) or if the design was fully home brew.

first thought was to 'go ceramic'. but then if the lubricant is conductive, a coated ceramic bearing will still arc.

@kurtilein3

5 жыл бұрын

The problem with the metal bearings is that the lubricant is a very good insulator, otherwise there would not be a problem, a conductive lubricant would be an elegant solution for metal bearings. Arcs are not an issue if they do not damage any surface needed for the bearing rolling smoothly. The trouble is only that the arcs hit precisely the contact points where the balls touch the tracks they are rolling in. For this problem, solutions are numerous and trivial once the problem is known.

EXCELLENT !!!!!!!!!!!!!!!! This video shows so wonderfully the degree to which no matter how much effort and intelligence you put into a design, you simply don't know what you don't know!!! But we do learn!

I wish you had reaction wheels to steady your camera!..ugh great channel and thank you for your efforts and sharing!

Why couldn't we test this theory on the ground? Surely we could simulate a sufficiently large enough plasma discharge...

@ergohack

5 жыл бұрын

John Drachenberg It's easy enough to test that electrical discharge will damage the bearings. Testing to see if solar flares will cause sufficient voltage across the bearing is a different story.

@gordonlawrence4749

5 жыл бұрын

It's not just that it's the type of radiation - protons and muons for starters as well as everything from about microwaves through to gamma. Even though the sun is 93 million miles away the amount of crud and energy that hits us per square meter has to be seen to be believed. 1kw/m2 is just the optical light. The amount of power the sun kicks out is mind boggling and it's not a big star.

@jukahri

5 жыл бұрын

We can and they did. The issue is figuring out whether that is actually what caused the reaction wheels in space to fail.

@RAFMnBgaming

5 жыл бұрын

That sounds like exactly the kind of thing we don't want to build on earth. Therefore I'm all for it.

@gordonlawrence4749

5 жыл бұрын

Jukelo we can replicate the type but nothing close to the intensity experienced after a CME.

"Hwy do Reaction hweels fhail?" ~Scott Manley.

Very interesting. Thank you!

I spent an extra 20 minutes on the toilet pondering this, Scott. I'm fascinated and completely evacuated as a result.

Scott Manley why not use ceramic balls and bearings? It would seem like a simple fix, can you tell us why they dont go with advanced ceramics and rather stick to SS or titanium? I mean there has to be some reason why they stick to metallic bearings. Ceramics in ball bearings is not a new tech at all, we have had it for quite some time now. Ceramics would overcome this problem and would last much much longer right? Especially Zirconium carbide based materials. Waiting to see a new video on this!! Thanks and fly safe!

@klobiforpresident2254

5 жыл бұрын

Did you see the end of the video?

@gavinoaw

5 жыл бұрын

He says in the end that Ithaco DID switch to ceramic bearings. I've seen a lot of comments suggesting ceramic bearings, did all of you guys comment before finishing the video?

@ashwinmohan4503

5 жыл бұрын

Ok Ok guys, Im sorry I jumped the gun on this one. Smarter people figured this one out! Klobi and gavinoaw thank you guys for correcting me and making sure I see till the end of videos. My bad, and ofcourse these space nerds figured it out before me, what was I thinking, duh!

@muninrob

5 жыл бұрын

You still came to the "right answer" even if you weren't the 1st. Remember, the early-bird gets the worm but it's the *second* mouse that gets the cheese.

@ashwinmohan4503

5 жыл бұрын

Thanks Robert, To be honest, Im feeling pretty foolish and embarassed that I didnt watch till the end. Live and learn right?

You get what you pay for, even in rocket science.

Cheers dude, I would never have looked for such news myself, brilliant.

I'm starting to like this channel more and more. Interesting stuff

One of the sad consequences of not having some replacement program for the former US Shuttle program is that we can't retrieve a sat to do a post mortem on it. I remember so many missions where the shuttle crew was just replacing parts on the Hubble.

@SocksWithSandals

5 жыл бұрын

The Kepler spacecraft is as far away as the Sun. Humans can only reach low Earth orbit.

Nasa. Scientists and engineers. "The reaction wheels have failed but its ok, we can use solar wind pressure to maintain one of the flight axis". KZreadrs. "Stop lying about space. Its just a projection on the inverted bowl above this flat earth"

I subscribed I really like the way you cover stuff.after several video's I had to sub.

I love your videos. Can you talk about gyroscopes in space?

Look into this video's link. Do you see that "PEMHU" part? Yes? It looks like "РЕМНИ", which roughly translates from screaming russian as "BELTS" Is this video trying to communicate with us? Does it want to suggest us using belts as bearings? Or is it telling us to brace for an impact? Creepy...~

@absalomdraconis

5 жыл бұрын

Subliminal advertising from a clothing manufacturer.

In before the electric universe nutjobs

@aPOTg

5 жыл бұрын

ive never pay any attention to electric universe, but just keep in mind. 2000 years ago they would have said "in before the round earth nutjobs"

@Trident_Euclid

5 жыл бұрын

@@aPOTg They believed the earth was a sphere even way back then.

@RedLeader327

5 жыл бұрын

Wat

@NikovK

5 жыл бұрын

Yep. Greek guy figured it out looking at shadows in wells.

@xx_redwood_xx9737

Жыл бұрын

@@NikovK And an Egyptian guy figured it out looking at an obelisk sinking below the horizon.

I'm starting to enjoy your channel. Thank You!

Awwwwsome info! Thanks Scott. I'm down here in South Texas.

Great information Scott. Ceramics have improved to the point that the new bearings should solve the problem.

Really nice video! Quick question: where do you find those papers you mentioned? I would like to read it too, but its always hard to come across them. :)

I have seen this exact problem in a welding fixture that was mounted on bearings. It worked great for months but eventually the bearings would be so damaged from arcing that they had to be replaced. This just became regular maintenance but that is a little tougher to replace in a spacecraft.

Thanks for that. It has relevance to less critical things down here too. Not the solar flare part but the spark erosion mechanism through the lubricant aspect.