How Failed Gyros Are Making Hubble's Life Harder

After decades of operation on orbit, the Hubble Space Telescope is now missing critical hardware which was required in its original design. Three Gyroscopes are supposed to be needed, so the telescope launched with 6, but they keep failing and now there are only two.
However, engineers have come up with new control algorithms to allow operation with fewer gyroscopes, and this is what I want to explain.
NASA's explanation of the process
science.nasa.gov/mission/hubb...
The scientific paper on these new control laws:
HUBBLE SPACE TELESCOPE REDUCED-GYRO CONTROL LAW
DESIGN, IMPLEMENTATION, AND ON-ORBIT PERFORMANCE
ntrs.nasa.gov/api/citations/2...
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[@nealwright5630]

The fact Hubble is still operational after 34 years is simply amazing. It has more than doubled its expected lifespan. I'm almost 60 and I'm having some equilibrium problems myself. We all get stiff joints and such when we get old. 😃😃

[@zaffo757]

It's like a 300D Benz

[@Alex.The.Lionnnnn]

Loving the fact that your comment stopped at "we all get stiff..." Yes I'm a child. 🤷

[@ehsnils]

It had a rough start but it was fixed, and it has produced an incredible amount and quality of pictures that we can be amazed by as well as it really has made a huge leap in science. The day we lose it then it's a day for mourning the loss of a very important landmark tool.

[@XanthinZarda]

Can't have said it better myself. Of course, a lot of orbital objects are still there. I'd love for someone to scoop up the original Telestar 1, if it's up there.

[@advorak8529]

Try Voyager I and II. 46 years and counting.

[@georgehill8285]

Recently I found a letter that 5 year old me wrote to my grandma, saying “they launched the big telescope.” It was kinda neat to see my grandma kept my letters, even though she wasn’t interested in space. Also, 2/3rds of the letter was me explaining why Worf is the best Klingon, and how grandma should watch Star Trek. Again, it’s nice she kept that…

[@volvo09]

Haha, yeah my mom has some of my kids stuff in a box! I was obsessed with goldfish, cats, and later RC cars, i'd put them in as many writings as i could 😂

[@Alex.The.Lionnnnn]

Of course she kept them! She doesn't give a fuck about Hubble, but her little boy is her world! LMAO Warf is pretty good. Darmok and Jalad at Tanagra!

[@tilmerkan3882]

You can't overestimate love and its effects on humans. You can't explain it to young people, too.

[@Alex.The.Lionnnnn]

@@tilmerkan3882 Don't underestimate young people. I taught primary school for a lot of years and the youngens are good people. I just realised you meant that you can't teach wisdom, and holy shit would the world be better off if we could!

[@TheTiffanyAching]

Your 5-year-old self was not wrong about Worf.

[@Valkyrie9000]

"Look, kids! W...We're entering the Science Floor!" Miss Frizzle's voice breaks, her eyes glued to the external hull temperature readouts...

[@thorodinson3597]

I didn't know I needed this.

[@xitheris1758]

Genre: Tragedy tab on the Magic School Bus fanfic archive.

[@cadekachelmeier7251]

Miss Frizzle would never be frazzled by that. She's put the kids in WAY more grave danger than orbital re-entry. Arnold takes his helmet off on Pluto in the first episode.

[@ianglenn2821]

Ms Frizzle looks away from the re-entry heating alarms, and with a faint smile, flips a panel open, revealing a big red button labeled "singularity". She whispers to herself, "we're about to get messy, and make some mistakes." With her hand on the button, she looks over her shoulder, gazing at each empty seat, one last time. She knows what she has to do. As she presses the button and the tidal forces rip the bus apart, she manages to shout her last words, which echo into the unforgiving atmosphere: "SEATBELTS, EVERYONE!"

[@Muonium1]

8:30 it should be noted that the precise reason the wires are failing is because the engineers chose to make them out of silver to get the maximum electrical conductivity possible for such thin wires, but the damping fluid mentioned (a kind of oil) had dissolved oxygen in it, this corroded the reactive silver and the wires snapped over time. The new gyros installed on the servicing missions had nitrogen sparged and pressurized damping fluid instead, and use copper coated silver wires. This extended the lifetime of the lead wires dramatically, and pushed the gyro lifetimes out to 3X their original values. One lived an amazing 142,000 hours. In modern spacecraft of course, there are no electromechanical gyros, resonating structure gyros are used instead and have effectively infinite lifetimes with minuscule power consumption. See the video "The Future Is Simple" by Joe Belcovson for a rudimentary explanation of how they work.

[@Twinsungamer]

Thanks for the explanation and source ! I was wondering why they sue such complex apparatus and why there aren't present in modern telescopes like JWST.

[@volvo09]

Thanks!

[@metatechnologist]

Quality post thank you.

[@ErulianADRaghath]

Thanks for the info and additional reading!

[@marksinclair701]

Neat explanation and video, thanks. Any idea what they use in NRO surveillance satellites? Presumably they don’t use electromechanical gyros, or we’d have a solution….

[@lerkzor]

Hubble needs to be boosted to a higher parking orbit and stored until we can retrieve it safely. That telescope belongs in a museum.

[@briansantana3157]

We would need a really big spacecraft with a really big payload food, and a giant robotic arm. Basically only the space shuttle would be able to do it :/ I wish we could have it in a museum one day that would be amazing

[@robertsonsid]

Space X is looking at doing that.

[@RozyShaman]

With what budget? NASA is constantly being underfunded that you’re basically asking them give up budget for the Roman Space Telescope or the Mars sample recovery mission, which are already barely scrapping by, for a vanity project. Unfortunately, we just have to let Hubble go.

[@robertsonsid]

@@briansantana3157 I think there are other solutions to boost an object. Space X and NASA have explored the concept.

[@Nate7.75]

@@robertsonsid is there no plan to essentially do a service mission on Hubble? is it not worth trying to extend the lifespan?

[@stuartgray5877]

During the Mission of the Deep Impact flyby spacecraft towards the encounter with Tempel-1, we had one entry into safe mode due to what was believed to be a "Inertial Reference Unit marked failed". This was because the spacecraft was SO STABLE for hours that the system THOUGHT the gyro had failed because the rates were not changing by even one data number. The numbers seemed "Stuck". They were not, the Spacecraft had just obtained such a stable attitude during cruise that the fault protection said "thats TOO good". The ADCS Engineers at JPL literally said "We have not seen such a stably pointing spacecraft since Hubble". We also did the fine guidance sensors in the Kepler Space Telescope and used the reaction wheels to point. I could explain how I helped accidentally wear the reaction wheels on Kepler before launch, and how Kepler helped solve the years-old mystery of why these reaction wheels were failing in space. I am helping plan the integration of the NEO-S Observatory for NASA next.

[@635574]

It would be better to include your credentials at the top, I dont undersrand ehat you mean by we.

[@stuartgray5877]

@@635574 I am an Integration and Test Engineer that builds spacecraft for BAE Space Systems (recently Ball Aerospace). Ball fixed the Hubble, built most of JWST, all of Kepler and IXPE and we are building the Roman space telescope from a spare Hubble structure.

[@dougerrohmer]

I have a suspicion that you are one of those rare few who can't wait for Monday morning 😁

[@stuartgray5877]

@@635574 - "I dont understand what you mean by we." NASA, JPL, Ball Aerospace (now BAE Space Systems)

[@bobblum5973]

To paraphrase something said to military personnel in appreciation for their efforts: *_Thank you for your science._*

[@tonywilson4713]

*AEROSPACE ENGINEER HERE:* I am going to try and explain how this gyroscopic control sounds straight forward but its anything but straight forward. The math involved is actually the hardest math there is in all of engineering. Sorry for the length of the explanation, but there is an interesting story at the end I promise. FYI - I love Scotts channel its fantastic. The only thing I don't like is he's flying and I'm not at the moment. In my final year when we had to do 2 high level aerospace options and a few chose to do *Spacecraft Dynamics* which we foolishly thought would "be cool" because it sounded cool (sort of). For those unfamiliar most universities have a ranking system for classes at my college (U. of Illinois) everything was a 100, 200, 300 or 400 level class. Most undergraduate classes are 100 & 200 level while 300 & 400 are for postgraduates. However most degrees required 2 x 300 level classes. In engineering (as far as I remember) every 300 level class had a 400 level equivalent. The difference was the 400 level required a term paper that had to be presented like it would be for a conference. So when you do an engineering 300 level class you do it with the 400 level students but they have to do their term paper and present it to the class *(see below).* The 2 most common classes my senior class did 2 were Finite Element Analysis and Orbital Mechanics. FEA because its reasonably straight forward and is used across many engineering fields and OM because that's what both NASA and the satellite industry want. Spacecraft Dynamics is an alternative to Orbital Mechanics and the difference is like the difference between a pilot and a navigator on an airplane. A navigator works out the path you will fly while the pilot flies it. Orbital Mechanics is analogous to navigation while Spacecraft dynamics is analogous to piloting. Within 2 weeks of starting that class EVERY undergraduate tried to get out of it once we realised how hard the math was. Orbital Mechanics is generally regarded as one of the most math intensive classes any engineer can take because its done on spherical coordinate systems and nothing travels in a straight line. Spacecraft Dynamics is another level up on that because not only does it require solving simultaneous non-linear differential equations but doing it with coordinate transformations as well. The Basics To most human beings we see the world in Up-Down-Left-Right-Forward-Back. We call that a cartesian coordinate system. Think of a normal X-Y graph and then look up "smith chart" in KZbin search. In space everything is in spherical coordinates. Further every major body (like the Sun and the planets) there's its own spherical coordinate system and those systems are moving at different speeds and different orbits. That's what makes orbital mechanics the headache that it is. There's no nice simply x-y-z its all r, θ, φ. Navigating from just the earth to the Moon one you have to translated from the Earths (r, θ, φ) to the Moons (r, θ, φ) but if you want to go to Mars you have to go from the Earth (r, θ, φ) to the Mars (r, θ, φ) while dealing with the Suns (r, θ, φ). Yeah its coordinate systems within coordinate systems. The problem with flying a spacecraft. Why Spacecraft Dynamics gets so hard is because you have the spacecraft's own coordinate system which is in cartesian coordinates because that makes it possible to write the basic math out in the first place *BUT THEN* you have to translate that system into the orbital reference frame that the spacecraft is flying in and that system is a spherical coordinate system. Because the equations for gyroscopes are differential equations you start with a set of 3 dimensional simultaneous non-linear differential equations that you then have to translate into another coordinate system as well as solve it. And why is that needed - because things like Hubble have to fly in a spherical coordinate system while orientating in a cartesian system. Gyroscopes are great because they don't need fuel but there's a things called precession. Go look at Wikipedia for the page title Gyroscope. Down the right hand side there's 2 labelled pictures and 2 animations. Look at the 2nd animation where they show the effect of twisting a gyro about an input axis. This is the problem you can't just turn a gyro and expect an opposite rotation because precession causes a twist in the other axis. That's the effect of precession. This gets even more complex as you move from singular to multi-axis gyroscope systems because as you twist one gyro it causes the other gyro or gyros to also twist and then you get a compound precession and that math gets so horrible it still haunts me 37 years later. *I said at the start I'd give you a good story.* I did that class in 1987 during the height of Ronald Reagans Star Wars program and most (if not all) the post graduates were sponsored by DARPA and working on Star Wars stuff. I remember the term papers 2 of them presented. One was on the dynamics of rail guns but that's for another day. *The other guy was doing high accuracy pointing of space based laser platforms.* He was quite possibly the smartest human I have ever met in terms of applied math to an engineering problem. He could not only solve the basic math but link it to tracking other objects on other orbits as well as ballistic trajectories but what really made his work exceptional was the anti-shake system he developed. Oh Yeah and he put this into software and could make it work in 2 dimensions. It was an amazing achievement but it then needed to be done in 3 dimensions. The real problem with a space based laser platform is the platform wobbling or vibrating when it pans. There's nothing odd about that as every thing wobbles or vibrates when it pans. Things like robotic arms and satellite dishes all wobble when they pan. The difference is when they are attached to a large object like a planet or is in an fluid like air or water that gets damped out. In space however there's nothing but the structure of the spacecraft itself to dampen vibrations out. One way to deal with that is just pan slowly which is fine for telescopes like Hubble or a probe out at Saturn or Pluto but for a laser cannon you want to zap missiles NO, it has to pan fast, stop without any additional motions and shoot. So even if you could solve what's arguably one of the hardest math problems ever conceived there's still the basic mechanics of a space based laser. If you just want to hit something on the ground from space we know the basics of how fast the gun will be travelling (28,000kmh) and what the range is (240km), but what does that mean. Here's how to think of the problem. Imagine a target 2.4km away that you have to shoot. Sounds straight forward until you check the list of longest sniper shots on Wikipedia and find only 6 times in recorded history has anyone successfully shot past 2,400m and hit the target and they were snipers in a stationary position. So just hitting something that far away is hard. Now imagine being in a Ferrari ripping along at almost 280kmh and trying to make the same shot out the window. Now multiply each of those numbers by 100 and that's the basic problem of shooting a stationary object from Low Earth Orbit. which is 28,000kmh at a range of 240km. Now take the target put it on a rocket and fire it into the sky where its going Mach 10 (or more) and its maybe 10x further away at about 2,400km and that's the basic problem of shooting an ICBM from space. Once we realised what the basic task actually entailed we knew that part of Reagan's Star Wars could NOT work. There were other methods in the Star Wars program like the ground based interceptors that we know have. However 37 years ago we knew that shooting ICBMS with a space based laser was not practical. Even 37 years later with all the advances in computers its still NOT practical because the mechanics are still the same problem and you still have to solve the math problems before you even try and make it work. And those math problems are a nightmare because its a gyro problem.

[@StevePemberton2]

Great explanation and stories! And at 1,500 words it disproves my theory that the YT algorithm now automatically deletes posts more than a few hundred words long because you rarely see long posts anymore. By the way the upcoming Polaris Dawn mission will be testing laser communications between satellites and they will be having to deal with the same issues that you talked about regarding wobble.

[@tonywilson4713]

@@StevePemberton2 Everything shakes, its just that in most cases there's a way to dampen it or its naturally dampened or it simply doesn't matter, but if your trying to hit a target it does.

[@Retired-Don]

@stevepemberton2 just a note 😃starlink satellites already do laser communications with other starlink satellites (a total of 42 petabytes per day of data is moving between starlink satellites) @tonywilson4713 that was a great comment. Definitely worth the read. Scott Manley videos are already interesting and well done And then the comments section just adds so much high quality related info.

[@BlueSpruce2]

Surely they have thought of other ways of pointing a laser from a space based platform without requiring panning or slewing of the entire spacecraft bus. I will only say I actually lost the ability to do arithmetic in my head after taking differential equations but could, back then, solve second order non-linear diff eqs... 😂

[@BlueSpruce2]

​@@Retired-DonI'm sure the math is still difficult but with the right algorithms and computing power available today vs. the 80's it's much more manageable. The laser comms between Starlink sats probably doesn't require the same focus and precision required to knock out an ICBM in boost or coast phase.

[@StevePemberton2]

3:03 _“They had another Space Shuttle orbiter stack all integrated and ready to launch"_ just to elaborate a little more it was Shuttle Endeavour and it was actually already sitting out on pad 39B when Atlantis launched from pad 39A. I got to watch the launch from the NASA causeway and it was a rare sight to see two Shuttles on the launchpad at the same time. And somewhat sobering since we knew what Endeavor was there for.

[@realzachfluke1]

That is sick!

[@slinkerdeer]

Did learning how accurate the pointing ability of Hubble is blow anyone elses mind? This telescope continues to impress. I sincerely hope it is recovered and preserved for historical value when it's career finally comes to an end

[@ceejay0137]

If NASA refuse to allow another servicing mission Hubble's orbit will decay. Eventually a Starship will go up and retrieve it, and it can spend the rest of its life in the Smithsonian Museum, along with other landmark aviation and space hardware.

[@dianapennepacker6854]

Yeah, but at the same time I understand NASA. Their funding is limiting. If it means save Hubble versus something better I can't understand them letting it decay. Remember to vote! Make your voices heard.

[@GlutenEruption]

@@ceejay0137 it's not that they're refusing, it's mainly that there isn't currently a man rated system that has the required capabilities or certification to carry out a servicing mission, and since congress told NASA they were going to put people back on the moon in 6 years while refusing every budget funding request every time they're told how much they need to actually do it, NASA doesn't have a ton of extra funds to spend on that kind of project at the moment. Luckily SpaceX has been independently working on a plan to use a F9 and Dragon to do a simple service and reboost mission but who knows. Fingers crossed

[@stargazer7644]

My telescope can point with a repeatable precision of 7 arc seconds. I was blown away by that. There is no way to recover the Hubble. The Space Shuttle was the only craft that could do that.

[@cyphi474]

@@ceejay0137 Starship isnt designed to deliver heavy payloads to the earth, but vice versa. It would be hard and dangerous even for Shuttle. Only way to preserve Hubble, when time come, is to push it to high orbit and hope someone in future build spaceship that can.

[@antonzanki8398]

It’s always fascinating when even you run into Nat’l security walls on spacetech. “Exactly the same as what’s used to guide ballistic missiles to target” isn’t something you see everyday.

[@AKAtheA]

spinning gyros were obsolete tech by the early 70s...

[@05Matz]

@@AKAtheA Unfortunately, anything that was considered 'high tech' during the Cold War is still stupidly restricted. I can't even get some commodity chips used in smartphone/etc. parts MADE IN CHINA delivered here in Canada by any American-affiliated hobby electronics company without signing some thing swearing fealty to the free market and promising I will protect them from Cubans with my life. It's sickening. the USA just keeps those policies around because they feel they can suppress technological development around the world (or at least slow the spread of manufacturing) to prop up established American companies, even though they rarely manufacture much of anything any more.

[@oldfrend]

@@AKAtheA obsolete for us. good enough for lowtech terrorists.

[@NatesRandomVideo]

Ever think about how they knew how to point Hubble so accurately while not ruining the sensors and which direction the first satellites that did that pointed? Heh.

[@AKAtheA]

@@oldfrend a working ICBM is hardly low tech

[@patchvonbraun]

A friend of mine (now retired) worked for CSA. He spent a goodly fraction of the last few years of his career testing the FGS systems for JWST.

[@HylanderSB]

It's wild to see the names of co-workers come up in a Scott Manley video.

[@DUKE_of_RAMBLE]

I find it more wild that people working in the space and science industries, actually watch Scott's videos! I think it's absolutely awesome! 🤘😫🤘

[@rj66600]

I love the Web images. But Hubble was a game changer and altered humanity’s perception of the universe. It will always have a special place in my heart.

[@DUKE_of_RAMBLE]

Hubble's _Ultra Deep Field_ view will go down in history as one of the best, simplest, ideas that yielded *insane* results!

[@henningerhenningstone691]

For anyone interested in dates: NASA says that Hubble is expected to remain operational until until the late 2020s, and its current orbit keeps it aloft for around a decade from now

[@saundby]

That's the same sort of thinking that got Skylab destroyed before Shuttle flew.

[@FrankyPi]

@@saundby Except Skylab was in a lower orbit and produced more drag. Hubble will reenter no earlier than mid to late 2030s, they include the solar cycles and modern estimates are more accurate.

[@cherriberri8373]

​@@saundby not only did FrankyPi say what i was already about to but also, do you seriously think modeling and safety culture is at all the same now as it was back then?

[@darrinkinney2268]

It might stay in orbit for awhile, however, it will start tumbling. Its the tumbling that will prevent any future service missions or even the concept we can save it. The window to get in there apparently closes in 2027. after that, its just a rock till it burns up (2037). Its going to be a fascinating story as I think nasa is going to pivot its mission to save hubble.

[@StevePemberton2]

​@@darrinkinney2268Tumbling would present a challenge but I don't think it would necessarily be an insurmountable problem.

[@Sonnell]

Hi Scott! We would love to see a video about the star trackers, how they actually work, and perhaps a history of them :)

[@chandlerlund5712]

I have always wondered how they are able to tell stars apart

[@Pharisaeus]

@@chandlerlund5712 They don't, not individually. What you do is take pairs or triplets of stars and construct lines / triangles. The idea is that those triangles will not "repeat" - any 3 stars you pick will result in slightly different triangle! So you make some triangles in the field of view of startracker and then compare those triangles with tabular reference and look for identical triangle. Once you find one, you immediately know where you are looking and how you are rotated.

[@unematrix]

As a Star Trek fan, I want to know more about star tracking too :D

[@Xsiondu]

I want to know how they see stars in earths atmosphere in the day time like the ones on the sr71

[@crcpeart]

+1

[@FazeFalcon]

I kllike the idea I've heaard (including from you, I believe) to retire the telescope and bring it up to a virtually permanent parking orbit for historical preservation.

[@user-dq5xx9hi4q]

The Hubble sat in clean room storage for years when I was in my 20s and then launched not long after I turned 30. Today I am 64 and half-way to 65, so not surprise it's feeling it's age as I do. ;-)

[@jedidiahhenry6020]

Favorite new concept, "the science floor"!!

[@volvo09]

We've hit the science floor, pack it up...

[@BrassLock]

Has Hubble broken through the Glass Ceiling yet 😮

[@kjgoebel7098]

Sounds like something GLaDOS would ask you to step onto, before trying to crush you or something.

[@jeromeprater183]

These gyroscopes are based on the MIT/Charles Stark Draper designed 2.5 inch diameter fluid floated Inertial Rate Integrating (25 IRIG). This technology goes back to the 1950's, when MIT constructed highly accurate gyros for various ballistic missiles such as Mace, Thor and Titan II. Similar technology was incorporated in the first two generations of (Polaris and Poseidon) submarine launched ballistic missiles (SLBM). The primary Apollo LM and CM inertial guidance systems used a variant of the Polaris and Titan II 25 IRIG. It incorporated a 24,000 RPM spinning rotor within a sealed in a beryllium housing and floated in a high density Chlorofluorocarbon fluid. The Poseidon missile version was upgraded to a highly stable beryllium oxide ceramic float structure and a gas spin rotor bearings (as opposed to earlier ball bearing versions). The biggest changes to the HST version of this Bendix (later L3) manufactured 25 IRIG gyroscope was to modify it to be directly body mounting onto the spacecraft structure as opposed to decoupling with a separate gimbal structure and reducing the rotor RPM to around 19,000. A permanent magnet pulse rebalance torque motor was needed to keep the float assembly within a few Arc-seconds of rotational alignment. There are no actual mechanical springs used as a restraint. The structural stability of the gyro rotor bearing assembly was usually held to within the Angstrom range.

[@Muonium1]

What motivated the choice to use beryllium oxide ceramic components?

[@davidbeck9066]

0:16 Perfect shot of the tyvek covers blowing off of the maneuvering thrusters on launch.

[@shanemeyer9224]

I hope the hubble goes as long as possible, maybe even one day they might be able to save it and bring it back!

[@SimonBauer7]

if the starship is quick enough we might be able to bring it back with a cargo version of starship

[@NotAnAlchemist_Ed]

If it can last a couple more years, we could even see it being brought back to Earth by a Starship!

[@robertstuckey6407]

​@@SimonBauer7the extra weight of hubble would make re-entry more hazardous and landing more difficult. Unless starship can use all of its propellant to lower its initial orbit enough and land using parachutes its a far way off

[@volvo09]

​@@NotAnAlchemist_Ed I really wish they tried to land this starship! it seemed to me like it would have made it (no idea on accuracy though, but it was a soft touchdown)... I'd love to see how much burnt up to see how close they are to a functional spacecraft that can be outfit with a cargo hold.

[@shanemeyer9224]

@@SimonBauer7 Absolutely, if they can get it ready before the gyro completely stops, I worry if it gets to the point the last gyro is out we wont be able to grab it as it will likely begin to tumble, but fingers crossed!

[@user-li7ec3fg6h]

Super Video and explantions, as allways. Thank you Scott.

[@brunonikodemski2420]

We developed the HRG (hemispheric resonating gyro) and it is indeed used on later missions, and many satellites. The HRG also a peculiar drift-mode problem, in that the fused quartz used for the resonator does have residual ions in it which drift ionically and thermodynamically through the quartz. This causes and unknown long-term directional drift. However, for short term pointing the HRG still works great. Some of this drift can be minimized by using an AC forcing system, which randomizes the drift in all of the axes. The Safran company now has the development rights to this technology, and is using it for commercial INS systems. The HRG is limited now by its own electronics lifetimes, and although the gyro can withstand solar and cosmic radiation, the electronics have a much lower limit. There is no need anymore to have the old style PIGA accelerometers or gyros, with any kind of fluids or moveable parts. Arachic now.

[@bksnider157]

As always Scott, thank you for your efforts to educate. love it.

[@TheChoyamoya]

Thanks for all the info Scott!

[@Mtlmshr]

Thanks for all you do Scott!

[@RadioactiveLobster]

"Cause the end of the Hubble Mission faster than anticipated." You mean the Hubble mission they thought would originally be over 19 years ago?

[@frankgulla2335]

Thank you, Scott, for keeping track of the Hubble and its status. If only we could afford all the things that we would like.

[@canuckcorsa]

One of your best! Thanks!

[@douro20]

The superconducting spherical gyros on the Gravity Probe B satellite were probably the most precise gyroscopes ever produced. I believe the Wikipedia article on the phenomenon known as "London moment" gives the best description on how these gyros worked.

[@linyenchin6773]

Beautiful explanation 🙌 ...baring my bias against misused suffix...

[@guyh3403]

Thank you for these insights.

[@michaeldunne338]

Very informative segment, on a bit of an arcane topic like gyros.

[@artysanmobile]

Thanks so much for the detail of your report. You answered a lot of questions I’ve had about the telescope’s aiming method. It will be a sad day when this fantastic machine fully fails.

[@douginorlando6260]

Scott … you did another video explaining how static change building up inside the spacecraft caused failures due to static discharge. Does that play a role shorting through these fine wires causing them to burn open?

[@AdrianFreakout]

All I can think about reading this title is a Greek restaurant chef looking at burned gyros that were cooked too long. I want to believe that mental image was intended :D

Great insights on this fantastic piece of hardware built at a time when computers were still big and much less powerful than today. Thanks a lot for the interesting video as always.

[@stevet100399]

The DF-224 stands for "Damn Fast"-224 and it was... at least in the 70's. The original deployment code (written in assembler) had a 40 Hz loop for reading gyros and the fine guidance sensors and 10 Hz and 1 Hz loops for other parts of the control law. The Lockheed folks did a fine job of developing and testing the spacecraft.

[@brettwoodard167]

Thanks Scott!

[@friedrichanton4280]

Scott Manley's Videos about Telescopes are the most awesome. Mostly because his Pronunciation of "Mirror"! ;)

[@rallymax2]

Scott, I'm always staggered by the amount of research you do for your videos all whilst having a full time day job and family. On behalf of your followers, 1.69Million thank you's.

[@stefanschneider3681]

I do a little astrophotography. It's very easy to orient my camera with the 50mm lense on my star tracker. Depending on what I point at it's already a little trickier when I switch to the telephoto lens of 300mm. But when I go crazy and put my little 6'' telescope that equals about a 2000mm lens on my little star tracker I sometimes really struggle to find my target because the field of view gets so tiny. Imagine Hubble with its incredible size and magnification! And doing this in space, at full speed and all these factors you mentioned! Some pretty clever thinking behind all this I guess ... thx for another great video with some stunning footage as a background, well done 👍!

[@patricks_music]

Take a shot every time scott says Gyroscope

[@Muonium1]

It will be a shameful travesty if this machine doesn't end up in the Smithsonian, and instead at the bottom of the Pacific. It has become the single most important, productive, and revolutionary telescope in the history of astronomy with the possible exception of Galileo's first and Hubble's 100 inch Hooker.

[@olasek7972]

Talk to Musk, no one else would have a suitable rocket. But I would rather put the monies that it would cost towards the next telescope.

[@volvo09]

​@@olasek7972 and even then nothing is close to being ready to take cargo onboard. The space shuttle was it's only hope until that hopefully changes some day.

[@womble321]

No way to bring it back

[@Muonium1]

@@womble321 ⭐🚢

[@Relkond]

that Smithsonian should be on the moon.

[@NotMyActualName_]

hubble is great. But we need a new optical range space telescope to replace it. It's long overdue.

[@volvo09]

Modern tech could do a lot. It's amazing that it's still holding on, from the days when a 486 processor (my favorite processor by the way) was a huge upgrade for it. Materials and science has improved vastly since it's creation.

[@MichaelWinter-ss6lx]

Absolutely. Somehow though, its a really stupid time to start that. Spend a few $millions for pre-studies and buy the first parts. Oh, Starship works. No need for an Origami Telescope! And before even the actual assembly starts, the whole thing is obsolete. 🚀🏴‍☠️🎸

[@javaman4584]

The Roman telescope due to be launched in 2026 has the same size mirror and the same optical range as Hubble but with a wider field. When/If Starship becomes a viable vehicle it might be possible to launch an 8 meter version of Hubble, but unfortunately it seems to require 20 years to design and build these things.

[@chrimony]

I don't know why people are in such a hurry to retire a working telescope. It costs billions and billions, and years and years, to get a new space telescope launched. They should nurse the Hubble along for a long as is feasible.

[@meikhochakre3309]

​@@chrimonyHubble cost nearly 100 million dollar a year to operate

[@davidmcsween]

Best use of "to be clear" I've ever heard 😂

[@JamieSwitzer]

I had to do a double take when I see the word Gyros, I was really confused for a second. 😂

[@michaelcorcoran8768]

I'm so hungry now

[@benjaminhanke79]

Hmmm, lecker!😋🥩

[@stoerenungeheuer543]

Just woke up, living mate bought some Gyros Pita for me. Checked KZbin and was confused, too.

[@jull1234]

Spinning meat is a spinning mass. I also love Tzatziki.

[@Codysdab]

Love dem kebabs.

[@Kioley123]

Hello Scott Manley, I would like to tell you that the manual you recommended several years ago "the kerbal player's guide" actually got me my first girlfriend when I was in a space summer camp back in 2018, she was into nerds and I was the only person on the bus reading, so she decided to sit next to me and we hit it off from there. Thanks.

[@davidjernigan8161]

Thirty four years is a long time for any satellite to remain functional.

[@ceejay0137]

It's the only one that has been thoroughly serviced in orbit. Without that it would have failed years ago.

[@ShieldAre]

I don't know if Scott talked about it earlier, but NASA's logic is basically that it still works at the moment, and letting someone meddle with it might break it, so they don't want anyone touching it. But if it breaks to the point where it is no longer useful, I think NASA wouldn't mind a mission to try to service it, provided the price of doing so was low enough.

[@jtjames79]

And NASA wonders why they don't get tax money. Cowards and idiots.

[@Dak3]

11:58 Believe this technique type is called Plate Solving for the curious

[@albr4]

Thanks for the information Scott, I can finally complete the ICBM I've been building in my garage.

[@seanlavoie2]

Interesting analysis. Nice video 🙂 How many people think Scott looks like the guitar adverts on KZbin recently?

[@General12th]

Hi Scott! Fly safe!

[@fateunleashed9680]

Just so we the public are clear to those who control what goes on with Hubble... you must bring back Hubble for it to sit in a museum. That's not optional, either you do what's right by humanity, or you admit that you're okay with committing a crime against humanity. As Scott said it's easy to park it in orbit so we can bring it back later if needed there's many options. If we go through such lengths to keep the Mona Lisa in good condition, then saving THE most important modern scientific tool shouldn't be a large request. I feel the same with the ISS, but at least the ISS is so massive it's harder to justify taking it apart to return each piece with multiple trips.

[@jj4791]

No. That is dumb. We are going to be traveling into space periodically in 50 years. Like, space tourism. And what are we going to go visit?

[@TimothyLipinski]

Great Video ! The Boeing Starliner has extra fuel to raise the orbit of the ISS or the Hubble Space Telescope (HST) ! The SpaceX Cargo Starship after transporting contracted Cargo to the low inclination LEO CSS can then pick up the HST for return to the KSC ! Also the Blue Origin Blue Moon HLS with a Crew Module for a four person Crew, a LIDS docking port to mate with the HST, an Air Lock/Dust Lock (per Mike Griffin-NASA Management), a Canadian Arm (tested and used on the ISS) and a 6.1 km/sec delta-V ! The HLS/LEV/LLV with a 6.1 km/sec delta-V can do Round Trips from the LEO CSS to the HST or GEO ! Also one way missions to the LS South Pole Lunar Outpost/Base (Clementine Base) can also be done to bring down cost in Cis-Lunar Space ! The Tech developed to return to the moon to stay, can take US and the world to Mars and beyond ! tjl P.S. Going from the Mars surface to a low Mars orbit can be done with a 5 km/sec delta-V and using an Aero braking shield can go from a Mars orbit to the Mars surface with 1.0 km/sec delta-V...

[@stargazer7644]

How about we wait until Starship actually manages to get to orbit once before gushing about about what it can and can't do.

[@bj_]

I like the thought of the Hubble telescope changing it's orientation through it's orbit to literally SCOOP up light

[@jasonmethot9573]

Scott in the house!! You da man!

[@44R0Ndin]

Sure would be nice to have the Hubble get upgraded with Ring Laser Gyros instead of these ones. No moving parts to break! Not so sure about the precision, maybe you could do a video on the pros and cons of various inertial navigation sensors (in broad terms only of course). Of course, it just popped into my head that maybe RLG's would have a lower on-orbit lifespan anyways, because of the radiation environment degrading the laser diode and optical sensors. On the other hand, RLG's are much lighter than conventional gyros, so maybe the mass savings from switching to an RLG could be diverted into encasing the RLG's in a radiation vault the same overall dimensions as the existing gyros.

[@MarcoTedaldi]

RLGs are to detect rotation. The Gyros Scott is talking about are used to control the attitude of the spacecraft. Same principle but opposite function.

[@SaberTail]

There's a Quora post by HST engineer Keith Chamberlin that says that RLGs were considered, but NASA was against changing anything unless absolutely necessary.

[@44R0Ndin]

@@MarcoTedaldi nope, the gyros that are failing are not control moment gyros or reaction wheels, they're rate gyros, which tell Hubble how fast it's turning in all 3 axes (if there are enough of them working at the same time that is). That's why I suggested RLG's, the function is indeed identical. Scott did briefly go over the different systems used to CAUSE Hubble to point at something of interest, but the video is about sensors that tell Hubble how fast it is turning.

[@44R0Ndin]

@@SaberTail Given that the failure mode was "the wires keep getting corroded until they break", and that they failed once again in the same way despite the changes in the advanced gyros which replaced the original ones, I'd say that a change was indeed warranted. If nothing else, they could have replaced the wires with a flexible printed circuit board trace such as used to connect the arm carrying the heads of a magnetic hard drive to the main circuit board, even back in 2009 that technology was highly suitable for such since it's rated for millions of cycles of motion (if that respects the minimum bending radius specs), and since the metal that carries the current is surrounded on all sides by polymer, the issue becomes fluid compatibility with the polymer rather than fluid corroding the current carrying conductor, which to my mind seems like an easier problem to solve conclusively.

[@MarcoTedaldi]

@@44R0Ndin oh I see. Sorry! I've been 100% sure (until Scott mentioned exactly that) that those were the control moment gyros.

[@kennethng8346]

You mentioned a floor at which point Hubble will be unable to do science because of atmospheric turbalance. About what year will that be?

[@loonatic90]

Depends on solar activity 🤷‍♂️.

[@owengrossman1414]

I worked on a satellite alignment system that used a combination of inertial sensors and star trackers. The inertial sensors were only used as the star trackers were passing through the direction of the sun.

[@Allan_aka_RocKITEman]

Great video, Scott...👍

[@MoritzvonSchweinitz]

I think Star trackers are very underappreciated tech. They've been used for so long in planes and satelites and always do the dirty work. But how do they work exactly? Especially the ones from before computer vision days?

[@oeq57]

Loads of great discussion here on mechanical gyros. I think you would all find ring laser gyros interesting. They work using a ring laser cavity with a laser beam going around in both directions. There is an output where the beams are interfered to produce a rotation rate signal. The interference arises because as you rotate the path for a beam going in one direction is shortened and the other is lengthened. Pretty cool. They are not fool proof and they have limitations at certain frequencies that causes lock in. Would be a cool idea for a video?

[@KyleDB150]

5:20 Here I thought "The Science Floor" was just part of a museum

[@jacara1981]

There are several companies that could possibly get to it to service it and let it run another 20 years. Or if needed move it into a higher parking orbit for future recovery. Letting Hubble burn up would be a massive lost to history and our species.

[@burningchrome70]

I think a giant SpaceX sticker across the side of Hubble would not be too much to pay for another 20 years of amazing science.

[@RCAvhstape]

@@burningchrome70 You put the sticker on a transparency across the mouth of the telescope so that the SpaceX watermark shows up in every image lol.

[@cherriberri8373]

Maaaybe, but there isn't a point while it's still working. Anything could end up breaking it, from moving it to attempting to service it. Once it breaks, there's a chance NASA does something about it, but I personally think they will let this one burn up too

[@RCAvhstape]

@@cherriberri8373 If you are going to dock with or grapple with it, you need to do it before it loses attitude control completely. Once it starts tumbling there may be no safe way to physically contact it.

[@aritakalo8011]

At some point it is just cheaper and more effective to build and send replacement. Stuff like "we can just make the base mirror, the main chassis, the main spacecraft buss so much better". At some point making space telescope of Theseus is not worth it anymore. At the cost of complex servicing mission working around the limitations of the old architecture one might get way better new space telescope. Telescopes on Earth usually stay in service even century, but that is due to low operating cost and simple maintenance and upgrades. Plus typically what happens is they ladder down. From main research instrument to second line supporting telescope doing more minor projects not on the cutting edge. Then from research instrument to training instrument (new researchers need something to with mess about with and make mistakes of taking useless pictures until they learn how to do it properly without disrupting actual service telescopes) and possibly experimental ones (telescope you can dismantle for months at a time to mess about and implement a new experimental instrumentation potentially needing major modifications to the actual telescope) just so new concepts can be tested atleast on something. Since before anyone lets one put a new instrument on more in demand telescope, one has to prove the instrument works, doesn't damage telescope, is otherwise sound. Then they let one come to bolt it to say a second line telescope and then maybe one of the big tubes decided on project to have a larger improved version of that instrument to be built for the big light bucket. Final realm is giving it to amateur and hobby use and stuff like public out reach viewing telescope. Space has none of the latter lower tiers. Given spaces inherent cost, space telescope is/has to be always tier one telescope. (unless it's one of the micro cubesat jobbies, but those are always inherently short lived due to orbital parameters) It's costs are always so high even second line won't probably justify it. Thus one has to ask "this telescope can't function anymore to tier one research standards without massive costs. Also there would be upgrades we would like to update it to the bleeding edge again. We can't afford two space tubes. So it is time to ask, will we just shut the old one down and send in a brand new replacement. Where we know each component is new down to the frame rails."

[@Astlaus]

This part about the HST pointing needing to compensate for sideways motion... that's new to me.

[@TomHill-xh7ec]

I worked on a mission with FHSTs. The maintenance on them is pretty intense. We had to load new star catalogs every four days because that was all the on-board memory could hold. This spacecraft was non-agile as well (it only pointed at/near Earth). I bet they have to load new catalogs for any slewing done by Hubble.

[@ianborthwick2092]

I feel like it’s deserved retirement and should be brought home safely, this telescope is probably the most famous and should be kept in a museum for all to appreciate

[@entropyachieved750]

Really interesting. Just the ability to point the telescope is a feat in itself

[@Space30MINUTES]

Listening to Scott talk about Space Shuttle Discovery and the STS 31 mission, I thought about the hero in a superhero movie on a mission to save the world. Hubble is a 'space hero' who has devoted 34 years to astronomy research!

[@rabidmonkey32]

Fascinating how many approaches to the required precision can be used to make an otherwise derelict craft do science.

[@TarisRedwing]

I hope they are able to save the Hubble one day when it needs to be parked but I am also glad we now have the Webb space telescope.

[@joyl7842]

Sad to see tracking overscan in video footage taken at such a high level of professionalism.

[@blshouse]

That's a feature, not an error. Those lines are reserved for data that was used by the display monitors of the time.

[@danielburges8176]

Fascinating - the fact that a 35 year old piece of technology is still working in orbit doing science just blows my mind! As a follow-up, any news on what's going on out at the Lagrange Points with the James Webb telescope? It's not been in the news - is it all working correctly and doing good science?

[@chrisglen-smith7662]

Wow, amazing it has to compensate for its latteral motion relative to the light it is collecting. That has never occurred to me. Shows just how fast LEO velocity is.

[@Arturo4586]

Complement: Occasionally the Actuation, the gyroscopic momentum wheels are confused with the sensors. The Hubble space telescope has 4 momentum wheels, three, along the vehicle axes and the fourth along a cube diagonally. So redundancy was there. How do I know? I was at LMSC working on the magnetic desaturation system, before it needed glasses to correct the correctly ground mirror. The team that did the correction installation included Claude Nicollier

[@danieldmg]

Hope some day commercial mission will be allowed to go up there to fix it.

[@Cannabian]

They should of used Schawarma instead.

[@Necro3Monk]

Tzatziki is important for lubrication, did they use a good recipe?

[@ruspj]

curious - can reaction wheels double as less accurate reaction wheels and vice versa while that is not designed for but surely gyros need spinning back up occasionally and reaction wheels have sensors

[@joakimlindblom8256]

Thanks for a great review of Hubble's guidance and pointing systems! The systems are significantly more complex but also more robust and redundant than I had previously realized 🙂

[@demacherius1]

I would love a episode about the magnetometers. They sound interresting. Pusching against the earth's magnetic field ?

[@n1vg]

If you haven't done so already, it might be nice to have a little explainer about how "gyro" can mean an angular rate gyro or a control moment gyro and what they do.

[@TiagoTiagoT]

Once they reach zero-gyros, could they use just astrometry and other sensors, and then gyro-stabilize using reaction wheels and the other official attitude control mechanisms, and with more extreme deterioration, use some of the moving parts as solar-sails and/or plain passive thermal thruster (heat it and ensure asymmetric exposure to space and let the radiative heat thrust), leaving the very center of the instrument pointing at the object while it spins, and do some deconvolution if needed to the circular motion blur around the center, or perhaps apply some sort of shutter mechanism to keep the exposure only for a fraction of the rotation to make it easier to de-smear things by having starting and ending points to the smears ?

[@ryanstout22]

Great video. I'm curious why fiber-optic gyroscopes weren't used? My understanding is they have unparalleled accuracy and no moving parts. Thanks!

[@olasek7972]

that „unparalleled” accuracy isn’t good enough for Hubble, it needs „astronomical” accuracy 😅

[@benjaminsmith3625]

It'd be interesting to hear about how 1970s star trackers work. I can see how you can do it today with a mobile phone camera or a raspberry pi, but in the 70s? For example, is there a limit of how many stars can be in the field of view when it's working at 10 Hz?

[@ILikeDoritos456]

I talked to a Greek guy about Greek food one time. Inevitably the topic of Gryos came up. When i used Scott's pronunciation of Gyro, he said you mean "Yerros" (with a tongue roll)? And I'm like, yeah those.

[@adrianf.5847]

As far as I understand it, the rotation of the Hubble telescope that has to be counter-acted is caused by the inverse square law, meaning there is a non-constant force gradient.

[@bonose12]

Scott, is there a reason ring laser gyros we’re not added on servicing missions? No moving parts is good!

[@tyttuut]

A ring laser gyroscope is a sensor. The gyroscopes on Hubble are used to control its orientation.

[@Termini_Man]

@@tyttuut The gyroscopes are sensors to detect rotation by detecting pressure caused by the spinning masses axis of rotation changing. They do not play a role in the actuation of Hubble, that is handled by reaction wheels and magnetorquers that prevent the reaction wheels from becoming saturated.

[@olasek7972]

I think the ring gyros don’t have nowhere near the accuracy required for the Hubble

[@DanielSolis]

Science Floor is my favorite band

[@aizquier]

Hey Scott, how feasible do you think is to make a robotic service mission just to install an ensemble of new 'external' gyros attached to the telescope?

[@kevinavillain4616]

Please let's preserve Hubbell and keep passing it down even all the way to high school.

[@piggyinthemiddle]

Hey Scott! What's with the phrase ON- ORBIT? is it just language drift or does it mean something different to IN orbit? Thx.

[@mikenicholas7132]

Off on a tangent...Curious, had a thought ..if coming back from the moon is too hard on tiles could a rendezvous with an ion drive sun/battery powered intercept/docking tug step be added to slow it down to low orbit velocity. Where is Kerbal when I need it.🤔

[@Nathan-vt1jz]

We really need to move Hubble to a parking orbit until we can bring it down to put in a museum. More than anything else Hubble deserves that honor (we should put the ISS in a parking orbit as well, but that’s a bigger task.) I’d donate to a mission to bring Hubble back to earth intact. Perhaps it could be combined with a Starship propellant transfer mission?

[@mytube001]

I would love for them to build 2-3 new ones. They don't have to take decades to build, if you decide to go with older, proven designs. Better is often the enemy of good enough. The fact that this old piece is still in very high demand, and still getting great data, is proof enough that you can get by with something similar.

[@estraume]

I know that they have mounted an adaptor to easily connect future spacecraft to the end of Hubble, but is that connection stable enough to attach a spacecraft with gyros to control orientation?

[@stefanklass6763]

Could a Mission Extension Vehicle be used? Dock a spacecraft to it that can take over attitude control completely if necessary.

[@muriwatch]

Why doesn't it use laser gyros? Were they not yet available at those times ?

[@RwingDsquad]

I just realized Hubble was launched on my 3rd birthday!