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. 😃😃
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.
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.
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.
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.
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….
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…
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 😂
@@Fannystark007 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!
*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 TH-cam 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.
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.
@@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.
@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.
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... 😂
@@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.
We would need a really big spacecraft with a really big payload door, 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
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.
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.
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!"
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 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.
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.
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
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.
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.
@@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
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.
@@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.
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. ;-)
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.
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 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.
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.
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 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.
@@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?
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.
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.
@@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.
@@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
@@Edino_Chattino 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.
@@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!
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.
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 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.
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.
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.
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.
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
@@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.
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."
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?
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.
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.
Also worth pointing out that the original plan was to bring it home using the Shuttle, but that's not an option. They left a docking port so we could launch a future spacecraft to safely deorbit it, but that port only has the soft capture mechanism so isn't useful for servicing missions.
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.
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.
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. 🚀🏴☠️🎸
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.
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.
@@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.
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.
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.
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.
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.
@@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.
@@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.
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
We'd all love to see this happen, but the only thing capable of doing that is the Space Shuttle, and the surviving shuttles are already in museums themselves.
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
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
4:14 Can the telescope see any jitter of guide stars which would allow a computer to shift the image from one pixel to another? Is that like what is already done with fancy still and movie cameras?
I imagine exposure time makes this impractical. You're exposing something for potentially multiple seconds before you actually collect the individual pixel data on the sensor, so any jitter would be like motion blur or shaky camera during a long exposure. Everything needs to be very still to get a clean exposure.
@@Jaker788 if the exposure time is really short, and the data forwarded to quick storage where it could be retrieved and analyzed then you would have the best of two worlds. Snappy quick exposures and ability to get rid of jitter. Also resolution would increase as frames don't match and computers can "read between the lines" to find that pixel 3.25 is a little darker than 3, and also 3.5 is still darker but not as dark as 4.
@@greggweber9967 That doesn't work for interesting (dark) astronomical objects. You get slow (many minute long) exposures. I used to make autoguiders for research grade ground-based telescopes. We had to use bright guide stars (>M14) and move the tracker camera that was picking off the main mirror. Hubble has fixed star tracker cameras on the outside, and FGS (fine guidance sensors) that look at main mirror images that are autoguiders like I'm used to. The gyros were designed to be an intermediate source of precision between the star trackers and the FGS. Which is how come Hubble can run in single gyro mode at all. And yes you do get more resolution from centroiding the multipixed blobs of stars than pixel resolution. Science instruments are run very cold (Hubble is in space so that's 'just' a sunshade) [Webb has a massive sunshade and runs colder, because it's an infrared telescope, not surrounded by heat from earth.] Instruments accumulate charge from photons over very long periods. The low temperature reduces thermal noise. For practical reasons, for example; the Wide field camera takes exposures for about half an orbit. Any longer and apparently cosmic ray noise ruins the image. (Compton suppression was not practical when Hubble was launched, as it would have probably doubled the weight of the instrument.)
@@greggweber9967 Unfortunately, you can't just combine separate exposures to get combined brightness. There's no way around the need for long exposure to image faint objects
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.
Usually structural support, the indentations make the side stronger, probably for the initial launching. Putting the bends in there probably made that pitciular side be able to handle twice the amount of force without any extra meteral added to it. I'm sure the other side has it too.
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.
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.
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 ?
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.
@@GrunttamerTechnically yes, but I think the problem would be not having the hardware. NASA test every contingency in the neutral buoyancy pool. That included an accurate replica of the Hubble. IF they still have it then maybe it's feasible. Plus, not having the Shuttle would be a deal breaker as there is no other space flight system that is capable of supporting the mission.
@@crazybrit-nasafanThe only other option I can think of - assuming it can fit inside of a SpaceX Starship - is a robotic mission to capture and return it to earth for repairs. If it can't be repaired (I believe there is actually a second perfect primary mirror still in storage) and relaunched then it deserves a spot in the Smithsonian Air & Space museum.
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.
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?
11:40 "gyro can't sense the rotation orthogonal to its axis" shouldn't it be the other way round? gyros should be able to detect the angular velocity component that's perpenducular to their own axis of rotation. in other words, each gyro should be able to read 2 angular velocity components, not one.
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!
The fact we only got one Hubble while the various intelligence agencies have had dozens and dozens of Keyhole Satellites ought to infuriate any space nerds.
Why? The Keyholes are just as interesting from a tech perspective and apparently worked great. The only difference is they were photographing stuff that doesn't generally make such great desktop wallpaper. Any need with an appreciation for practicality would likely be far more excited about Keyhole.
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?
We need a telescoping version of the Canadian arm that can be fitted to the available or soon to be space vehicle That way we can do maintenance without contaminate Hubble
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?
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.
I wonder if an especially built cargo vehicle, such as Dragon, could be outfitted with gyros, and sent to connect with Hubble, and use it's gyros to control the telescope.
There was a plan to attach a module to the docking port that could do that. Nasa was studying a plan from Jared Isaacman to use dragon to go up there. Not sure what the status is on that but Scott did a video about that a while back.
@@samuraidriver4x4ultimately NASA decided that they don't want anyone near their precious telescope while it's still operational. They want to play it safe. Hopefully SpaceX will be capable of (and interested in) docking to it after it's not operational anymore...
*Summary* * *(**0:24**)* *The Problem:* Hubble is down to two working gyroscopes, one less than the minimum needed for optimal pointing. * *(**7:43**)* *Gyroscopes Explained:* These devices detect rotation rates with extreme precision, crucial for maintaining Hubble's steady gaze. They work by measuring the deflection of a spinning mass inside. * *(**9:01**)* *Why They Fail:* The main culprit is tiny wires called flex leads that wear out over time due to constant micro-movements. * *(**9:45**)* *Reduced Gyro Mode:* Engineers developed a new control algorithm allowing Hubble to operate with one gyro and other sensors. * *(**10:10**)* *How it Works:* * *(**10:22**)* *Coarse Pointing:* The sun sensor, magnetometer, and one gyro roughly orient the telescope. * *(**11:48**)* *Finer Pointing:* Fixed-head star trackers (three small telescopes) take over, using stars to refine the pointing. * *(**12:25**)* *Ultra-Precise Pointing:* Fine guidance sensors within the main telescope lock onto faint guide stars to achieve the final, ultra-precise aim. * *(**13:55**)* *The Downside:* Switching targets takes longer, reducing Hubble's observation time. Some fast-moving objects are no longer trackable. * *(**14:22**)* *The Future:* A servicing mission is unlikely. Hubble's lifetime is now limited by both gyro failure and its increasingly low orbit causing atmospheric drag. Q: why do they use mechanical gyros and not some fiber optic interferometer? A: Here's why Hubble likely stuck with mechanical gyros: * **Heritage and Reliability:* Mechanical gyros, while complex, have a long and well-understood track record in space. Hubble's design heavily relied on technology available in the 1970s and 80s when it was conceived. Back then, mechanical gyros were the gold standard for precision attitude control. * *Maturity of Technology:* While fiber optic gyros (FOGs) were being developed in the 80s, they weren't as mature or space-proven as their mechanical counterparts when Hubble was being built. Putting a new, untested technology on such a critical and expensive mission would have been a huge risk. * *Performance Requirements:* While FOGs offer advantages like longer lifespan and no moving parts, they might not have met Hubble's extreme precision demands at the time. Hubble needs to stay locked on target with incredible accuracy (milliarcseconds) for long durations, and early FOGs might not have been up to the task. * *Size and Weight Constraints:* Early FOGs were also larger and heavier than comparable mechanical gyros. Every gram and centimeter counts on a spacecraft, especially one designed for a shuttle launch like Hubble. www.quora.com/Why-didnt-NASA-use-ring-laser-gyroscopes-on-the-Hubble-Telescope-instead-of-mechanical-ones-that-break-over-time *However, times have changed:* * *FOGs in Modern Spacecraft:* Today, FOGs are common in spacecraft, especially those requiring high reliability and long lifespans. For example, the James Webb Space Telescope uses FOGs for its pointing system. * *Hubble's Legacy:* Hubble's reliance on mechanical gyros underscores the longevity of older technology in space. While those gyros had a finite lifespan, they've enabled decades of groundbreaking science. In summary, Hubble's use of mechanical gyros was likely a calculated decision based on the technology available at the time, its proven track record, and the specific performance demands of the mission. i used gemini 1.5 pro to summarize the transcript
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...
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.
Even if we never manage to get fusion figured out for power-generation, this thing will be one of the most amazing engineering achievements ever. 19000 RPM!
It's not that wild, many cars have turbochargers these days and the turbine spins near 30k rpm when you floor the accelerator, and small electric brushless motors can easily pass that. The reliability at that RPM is something special though!
If they had asked one of the NASA astronauts who previously repaired Hubble to join the mission it might have gotten support. Thruster contamination is still a legitimate concern though.
@@jull1234 If Hubble loses control of its orientation, it would be difficult. Ideally SpaceX could build a custom Starship outfitted with a Canada arm to grapple it. Realistically, I think they will just let it reenter and hope it doesn't hit anyone.
@8:47 You think they'd be using an optical sensor. I'm old enough to remember trackballs on computer mice which weren't very good. Optical mice came along, and then the blue light ones. My joystick has hall effect sensors, no sticking there either.
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?
Wow, this really drives home just how OLD Hubble really is. As far as I know, nobody still manufactures or flies rotating mass gyros. Today they're usually based on ring lasers or vibrating hemispherical resonators. And star trackers these days have much larger fields of view, about 30 degrees half angle instead of the 8 degrees Hubble has. That's important because the tracker can see enough stars to determine its orientation in a few seconds, so called "lost in space" capability. If Hubble were built today, it would probably use a Northrup Grumman Scalable Space Inertial Reference Unit for gyros and one of the many star trackers on the market. And it might well be able to slew with no gyro at all.
Amatuer astrophotographers now use guide telescopes along side the imaging scope to finely control the pointing accuraccy of the telescope mount (e.g. gear imperfections, polar misalignment etc) as well as plate solving against a star catalog to determine where to point, all with open source software.
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. 😃😃
It's like a 300D Benz
Loving the fact that your comment stopped at "we all get stiff..." Yes I'm a child. 🤷
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.
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.
Try Voyager I and II. 46 years and counting.
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.
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.
Thanks!
Quality post thank you.
Thanks for the info and additional reading!
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….
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…
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 😂
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!
You can't overestimate love and its effects on humans. You can't explain it to young people, too.
@@Fannystark007 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!
Your 5-year-old self was not wrong about Worf.
*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 TH-cam 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.
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.
@@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.
@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.
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... 😂
@@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.
Hubble needs to be boosted to a higher parking orbit and stored until we can retrieve it safely. That telescope belongs in a museum.
We would need a really big spacecraft with a really big payload door, 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
Space X is looking at doing that.
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.
@@briansantana3157 I think there are other solutions to boost an object. Space X and NASA have explored the concept.
@@robertsonsid is there no plan to essentially do a service mission on Hubble? is it not worth trying to extend the lifespan?
"Look, kids! W...We're entering the Science Floor!" Miss Frizzle's voice breaks, her eyes glued to the external hull temperature readouts...
I didn't know I needed this.
Genre: Tragedy tab on the Magic School Bus fanfic archive.
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.
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!"
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.
It would be better to include your credentials at the top, I dont undersrand ehat you mean by we.
@@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.
I have a suspicion that you are one of those rare few who can't wait for Monday morning 😁
@@635574 - "I dont understand what you mean by we."
NASA, JPL, Ball Aerospace (now BAE Space Systems)
To paraphrase something said to military personnel in appreciation for their efforts:
*_Thank you for your science._*
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.
That is sick!
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
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.
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.
@@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
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.
@@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.
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. ;-)
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.
What motivated the choice to use beryllium oxide ceramic components?
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.
spinning gyros were obsolete tech by the early 70s...
@@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.
@@AKAtheA obsolete for us. good enough for lowtech terrorists.
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.
@@oldfrend a working ICBM is hardly low tech
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.
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
That's the same sort of thinking that got Skylab destroyed before Shuttle flew.
@@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.
@@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?
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.
@@darrinkinney2268Tumbling would present a challenge but I don't think it would necessarily be an insurmountable problem.
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.
Hubble's _Ultra Deep Field_ view will go down in history as one of the best, simplest, ideas that yielded *insane* results!
Hi Scott! We would love to see a video about the star trackers, how they actually work, and perhaps a history of them :)
I have always wondered how they are able to tell stars apart
@@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.
As a Star Trek fan, I want to know more about star tracking too :D
I want to know how they see stars in earths atmosphere in the day time like the ones on the sr71
+1
I hope the hubble goes as long as possible, maybe even one day they might be able to save it and bring it back!
if the starship is quick enough we might be able to bring it back with a cargo version of starship
If it can last a couple more years, we could even see it being brought back to Earth by a Starship!
@@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
@@Edino_Chattino 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.
@@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!
Favorite new concept, "the science floor"!!
We've hit the science floor, pack it up...
Has Hubble broken through the Glass Ceiling yet 😮
Sounds like something GLaDOS would ask you to step onto, before trying to crush you or something.
Super Video and explantions, as allways. Thank you Scott.
Thank you, Scott, for keeping track of the Hubble and its status. If only we could afford all the things that we would like.
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.
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.
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.
@@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.
No way to bring it back
@@womble321 ⭐🚢
that Smithsonian should be on the moon.
It's wild to see the names of co-workers come up in a Scott Manley video.
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!
🤘😫🤘
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.
As always Scott, thank you for your efforts to educate. love it.
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.
0:16 Perfect shot of the tyvek covers blowing off of the maneuvering thrusters on launch.
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.
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.
@@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.
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
@@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.
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."
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?
"Cause the end of the Hubble Mission faster than anticipated."
You mean the Hubble mission they thought would originally be over 19 years ago?
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.
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?
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.
And NASA wonders why they don't get tax money.
Cowards and idiots.
Also worth pointing out that the original plan was to bring it home using the Shuttle, but that's not an option. They left a docking port so we could launch a future spacecraft to safely deorbit it, but that port only has the soft capture mechanism so isn't useful for servicing missions.
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.
hubble is great. But we need a new optical range space telescope to replace it. It's long overdue.
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.
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.
🚀🏴☠️🎸
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.
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.
@@chrimonyHubble cost nearly 100 million dollar a year to operate
Scott, is there a reason ring laser gyros we’re not added on servicing missions? No moving parts is good!
A ring laser gyroscope is a sensor. The gyroscopes on Hubble are used to control its orientation.
@@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.
I think the ring gyros don’t have nowhere near the accuracy required for the Hubble
To think Hubble was over 20years old before it got into orbit, you've explained it well.
You mentioned a floor at which point Hubble will be unable to do science because of atmospheric turbalance. About what year will that be?
Depends on solar activity 🤷♂️.
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.
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.
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.
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.
@@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.
@@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.
@@44R0Ndin oh I see. Sorry! I've been 100% sure (until Scott mentioned exactly that) that those were the control moment gyros.
Thanks for all the info Scott!
Thanks for all you do Scott!
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
We'd all love to see this happen, but the only thing capable of doing that is the Space Shuttle, and the surviving shuttles are already in museums themselves.
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
One of your best! Thanks!
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
11:58 Believe this technique type is called Plate Solving for the curious
Sad to see tracking overscan in video footage taken at such a high level of professionalism.
That's a feature, not an error. Those lines are reserved for data that was used by the display monitors of the time.
I like the thought of the Hubble telescope changing it's orientation through it's orbit to literally SCOOP up light
4:14 Can the telescope see any jitter of guide stars which would allow a computer to shift the image from one pixel to another? Is that like what is already done with fancy still and movie cameras?
I imagine exposure time makes this impractical. You're exposing something for potentially multiple seconds before you actually collect the individual pixel data on the sensor, so any jitter would be like motion blur or shaky camera during a long exposure. Everything needs to be very still to get a clean exposure.
@@Jaker788 if the exposure time is really short, and the data forwarded to quick storage where it could be retrieved and analyzed then you would have the best of two worlds. Snappy quick exposures and ability to get rid of jitter. Also resolution would increase as frames don't match and computers can "read between the lines" to find that pixel 3.25 is a little darker than 3, and also 3.5 is still darker but not as dark as 4.
@@greggweber9967 That doesn't work for interesting (dark) astronomical objects. You get slow (many minute long) exposures. I used to make autoguiders for research grade ground-based telescopes. We had to use bright guide stars (>M14) and move the tracker camera that was picking off the main mirror. Hubble has fixed star tracker cameras on the outside, and FGS (fine guidance sensors) that look at main mirror images that are autoguiders like I'm used to. The gyros were designed to be an intermediate source of precision between the star trackers and the FGS. Which is how come Hubble can run in single gyro mode at all. And yes you do get more resolution from centroiding the multipixed blobs of stars than pixel resolution. Science instruments are run very cold (Hubble is in space so that's 'just' a sunshade) [Webb has a massive sunshade and runs colder, because it's an infrared telescope, not surrounded by heat from earth.] Instruments accumulate charge from photons over very long periods. The low temperature reduces thermal noise. For practical reasons, for example; the Wide field camera takes exposures for about half an orbit. Any longer and apparently cosmic ray noise ruins the image. (Compton suppression was not practical when Hubble was launched, as it would have probably doubled the weight of the instrument.)
@@greggweber9967 Unfortunately, you can't just combine separate exposures to get combined brightness. There's no way around the need for long exposure to image faint objects
Thanks for the information Scott, I can finally complete the ICBM I've been building in my garage.
Best use of "to be clear" I've ever heard 😂
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.
9:37 What is the purpose of that cross-indentation on the side-panel there?
Usually structural support, the indentations make the side stronger, probably for the initial launching. Putting the bends in there probably made that pitciular side be able to handle twice the amount of force without any extra meteral added to it. I'm sure the other side has it too.
Thirty four years is a long time for any satellite to remain functional.
It's the only one that has been thoroughly serviced in orbit. Without that it would have failed years ago.
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.
9:10 but you had a video about how it was basically static discharge caused by solar wind which destroyed the bearings in the gyros
That was different hardware.
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.
1:55 is it just me, or did anyone else think for a moment that you were looking at an image of a Star Wars star destroyer? 😅
Take a shot every time scott says Gyroscope
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 ?
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.
Are the gyros not replaceable on a spacewalk? Seems like a great mission to test spacex
The gyros are replaceable, this was done on Shuttle missions (STS109 iirc) but NASA hasn't got the hardware to accomplish that now as far as I know.
@@crazybrit-nasafan if we could do it in 2009 we can do it better now.
@@GrunttamerTechnically yes, but I think the problem would be not having the hardware. NASA test every contingency in the neutral buoyancy pool. That included an accurate replica of the Hubble. IF they still have it then maybe it's feasible.
Plus, not having the Shuttle would be a deal breaker as there is no other space flight system that is capable of supporting the mission.
@@crazybrit-nasafan that is so 60’s era. We have the specs, build some new units and test in production it’s 2024
@@crazybrit-nasafanThe only other option I can think of - assuming it can fit inside of a SpaceX Starship - is a robotic mission to capture and return it to earth for repairs. If it can't be repaired (I believe there is actually a second perfect primary mirror still in storage) and relaunched then it deserves a spot in the Smithsonian Air & Space museum.
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.
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?
11:40 "gyro can't sense the rotation orthogonal to its axis"
shouldn't it be the other way round? gyros should be able to detect the angular velocity component that's perpenducular to their own axis of rotation. in other words, each gyro should be able to read 2 angular velocity components, not one.
Really interesting. Just the ability to point the telescope is a feat in itself
5:20 Here I thought "The Science Floor" was just part of a museum
Scott Manley's Videos about Telescopes are the most awesome.
Mostly because his Pronunciation of "Mirror"! ;)
Me during the explanation of arc seconds:
‘Ah. Yes. Numbers.’ *nods sagaciously
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!
I look at those little wires and I keep wondering "there has to be a better more robust design".
Because you’re not thinking about how those wires act as springs and can affect the gyroscope’s measurements.
I read recently that the reason NASA declined the service offer was that they were afraid of mirror contamination by the rescue vehicle.
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.
The fact we only got one Hubble while the various intelligence agencies have had dozens and dozens of Keyhole Satellites ought to infuriate any space nerds.
Why? The Keyholes are just as interesting from a tech perspective and apparently worked great. The only difference is they were photographing stuff that doesn't generally make such great desktop wallpaper. Any need with an appreciation for practicality would likely be far more excited about Keyhole.
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?
Hope some day commercial mission will be allowed to go up there to fix it.
Great video. I'm curious why fiber-optic gyroscopes weren't used? My understanding is they have unparalleled accuracy and no moving parts. Thanks!
that „unparalleled” accuracy isn’t good enough for Hubble, it needs „astronomical” accuracy 😅
We need a telescoping version of the Canadian arm that can be fitted to the available or soon to be space vehicle
That way we can do maintenance without contaminate Hubble
Very informative segment, on a bit of an arcane topic like gyros.
Fascinating how many approaches to the required precision can be used to make an otherwise derelict craft do science.
It's interesting that ring laser gyros are essentially unregulated but quartz gyros can't be exported without a licence.
Scott in the house!! You da man!
Why would Greek sandwiches make the Hubble fail? I imagine they are still just as tasty in space even if there is only one of them.
Maybe the grease got into some if the electronics or plumbing
Why doesn't it use laser gyros? Were they not yet available at those times ?
I had to do a double take when I see the word Gyros, I was really confused for a second. 😂
I'm so hungry now
Hmmm, lecker!😋🥩
Just woke up, living mate bought some Gyros Pita for me. Checked TH-cam and was confused, too.
Spinning meat is a spinning mass. I also love Tzatziki.
Love dem kebabs.
They should of used Schawarma instead.
Tzatziki is important for lubrication, did they use a good recipe?
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?
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.
I wonder if an especially built cargo vehicle, such as Dragon, could be outfitted with gyros, and sent to connect with Hubble, and use it's gyros to control the telescope.
There was a plan to attach a module to the docking port that could do that.
Nasa was studying a plan from Jared Isaacman to use dragon to go up there.
Not sure what the status is on that but Scott did a video about that a while back.
@@samuraidriver4x4ultimately NASA decided that they don't want anyone near their precious telescope while it's still operational. They want to play it safe. Hopefully SpaceX will be capable of (and interested in) docking to it after it's not operational anymore...
*Summary*
* *(**0:24**)* *The Problem:* Hubble is down to two working gyroscopes, one less than the minimum needed for optimal pointing.
* *(**7:43**)* *Gyroscopes Explained:* These devices detect rotation rates with extreme precision, crucial for maintaining Hubble's steady gaze. They work by measuring the deflection of a spinning mass inside.
* *(**9:01**)* *Why They Fail:* The main culprit is tiny wires called flex leads that wear out over time due to constant micro-movements.
* *(**9:45**)* *Reduced Gyro Mode:* Engineers developed a new control algorithm allowing Hubble to operate with one gyro and other sensors.
* *(**10:10**)* *How it Works:*
* *(**10:22**)* *Coarse Pointing:* The sun sensor, magnetometer, and one gyro roughly orient the telescope.
* *(**11:48**)* *Finer Pointing:* Fixed-head star trackers (three small telescopes) take over, using stars to refine the pointing.
* *(**12:25**)* *Ultra-Precise Pointing:* Fine guidance sensors within the main telescope lock onto faint guide stars to achieve the final, ultra-precise aim.
* *(**13:55**)* *The Downside:* Switching targets takes longer, reducing Hubble's observation time. Some fast-moving objects are no longer trackable.
* *(**14:22**)* *The Future:* A servicing mission is unlikely. Hubble's lifetime is now limited by both gyro failure and its increasingly low orbit causing atmospheric drag.
Q: why do they use mechanical gyros and not some fiber optic interferometer?
A: Here's why Hubble likely stuck with mechanical gyros:
* **Heritage and Reliability:* Mechanical gyros, while complex, have a long and well-understood track record in space. Hubble's design heavily relied on technology available in the 1970s and 80s when it was conceived. Back then, mechanical gyros were the gold standard for precision attitude control.
* *Maturity of Technology:* While fiber optic gyros (FOGs) were being developed in the 80s, they weren't as mature or space-proven as their mechanical counterparts when Hubble was being built. Putting a new, untested technology on such a critical and expensive mission would have been a huge risk.
* *Performance Requirements:* While FOGs offer advantages like longer lifespan and no moving parts, they might not have met Hubble's extreme precision demands at the time. Hubble needs to stay locked on target with incredible accuracy (milliarcseconds) for long durations, and early FOGs might not have been up to the task.
* *Size and Weight Constraints:* Early FOGs were also larger and heavier than comparable mechanical gyros. Every gram and centimeter counts on a spacecraft, especially one designed for a shuttle launch like Hubble.
www.quora.com/Why-didnt-NASA-use-ring-laser-gyroscopes-on-the-Hubble-Telescope-instead-of-mechanical-ones-that-break-over-time
*However, times have changed:*
* *FOGs in Modern Spacecraft:* Today, FOGs are common in spacecraft, especially those requiring high reliability and long lifespans. For example, the James Webb Space Telescope uses FOGs for its pointing system.
* *Hubble's Legacy:* Hubble's reliance on mechanical gyros underscores the longevity of older technology in space. While those gyros had a finite lifespan, they've enabled decades of groundbreaking science.
In summary, Hubble's use of mechanical gyros was likely a calculated decision based on the technology available at the time, its proven track record, and the specific performance demands of the mission.
i used gemini 1.5 pro to summarize the transcript
Failed Gyros? That's what my local Middle Eastern fast food joint sells.
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...
How about we wait until Starship actually manages to get to orbit once before gushing about about what it can and can't do.
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.
Even if we never manage to get fusion figured out for power-generation, this thing will be one of the most amazing engineering achievements ever. 19000 RPM!
It's not that wild, many cars have turbochargers these days and the turbine spins near 30k rpm when you floor the accelerator, and small electric brushless motors can easily pass that.
The reliability at that RPM is something special though!
What do we think about the Polaris repair proposal?
If they had asked one of the NASA astronauts who previously repaired Hubble to join the mission it might have gotten support. Thruster contamination is still a legitimate concern though.
Would it be too late once it truly goes offline?
@@jull1234 If Hubble loses control of its orientation, it would be difficult. Ideally SpaceX could build a custom Starship outfitted with a Canada arm to grapple it. Realistically, I think they will just let it reenter and hope it doesn't hit anyone.
@8:47 You think they'd be using an optical sensor. I'm old enough to remember trackballs on computer mice which weren't very good. Optical mice came along, and then the blue light ones. My joystick has hall effect sensors, no sticking there either.
Thanks Scott!
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?
Wow, this really drives home just how OLD Hubble really is. As far as I know, nobody still manufactures or flies rotating mass gyros. Today they're usually based on ring lasers or vibrating hemispherical resonators. And star trackers these days have much larger fields of view, about 30 degrees half angle instead of the 8 degrees Hubble has. That's important because the tracker can see enough stars to determine its orientation in a few seconds, so called "lost in space" capability. If Hubble were built today, it would probably use a Northrup Grumman Scalable Space Inertial Reference Unit for gyros and one of the many star trackers on the market. And it might well be able to slew with no gyro at all.
Amatuer astrophotographers now use guide telescopes along side the imaging scope to finely control the pointing accuraccy of the telescope mount (e.g. gear imperfections, polar misalignment etc) as well as plate solving against a star catalog to determine where to point, all with open source software.