Hubble Telescope Goes into Safe Mode

AlphaAtlas

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After another gyroscope failure, the Hubble Space Telescope went into a "safe mode" this weekend. Only 2 of the Hubble's 6 onboard gyroscopes are working now, and it needs at least 3 to function properly. While operators on the ground saw this kind of failure coming and planned for it, the lost gyros will limit the Hubble's future capabilities. The Hubble's successor, the James Webb Space Telescope, isn't expected to launch until 2021 at the earliest.


On the question of switching to one gyro, she added: "The plan has always been to drop to 1-gyro mode when two remain. There isn't much difference between 2- and 1, and it buys lots of extra observing time. Which the Astro community wants desperately." Prof Nial Tanvir, from Leicester University, UK, told BBC News: "You can in principle, with relatively little impact, continue to observe with one gyro. It may place some limitations on which part of the sky you can look at at any one time, and take a little longer to move from one target to another." He explained: "In that sense, it's not a catastrophe. However, if it's indicating another component on the telescope has died now, it does lead you to believe that the clock is ticking away on the overall lifetime… it would be a very great shame."
 
She had a good run.

Time to send up a new one on a Falcon Heavy. James Webb will have a much larger aperture but [if it ever launches] it will be observing a different part of the spectrum.
 
Enough with the melodrama. Hubble has NOT failed and can still observe, even with less than 3 Gyroscopes.

Apparently they only need one Gyroscope to actually observe using Hubble. 3 is ideal, but there isn't much difference between using two and one, so once they are down to two they are going to shut one off as a spare. This might not be ideal but Hubble isn't going anywhere for a while.

Also, seems that there is some hope still of getting the "malfunctioning" gyroscope to work again, not the failed one, but the replacement one they tried to activate that didn't work at first. So there is still some hope of going back to using 3 again.
 
The project has already become extremely cost effective, AFAIK it has already massively exceeded its anticipated lifespan. Next ISS trip could potentially include repair of it.

I suspect it would be worth repairing instead of just scrapping. The most expensive part is already done, it's in orbit.

 
Why not send up a crew to replace the broken gyros?

The project has already become extremely cost effective, AFAIK it has already massively exceeded its anticipated lifespan. Next ISS trip could potentially include repair of it.

I suspect it would be worth repairing instead of just scrapping. The most expensive part is already done, it's in orbit.

No. It launched on a Shuttle. To repair it we had to send up additional Shuttle missions... repeating the most expensive and dangerous part over and over again.

The Shuttle repair missions were never cost effective. The idea made sense back in the early 80s when they expected to fly a Shuttle every two weeks. The Shuttle ended up costing 100x more than expected, took 6+ months minimum to prepare for flight, and weren't particularly safe to fly. It would have been cheaper to build a handful of Hubble-class telescopes and launch replacements on unmanned rockets as needed like the DoD does with their spy sats.

At the moment we have relatively cheap reusable launchers from SpaceX, it makes even more sense just to build and launch a new series of disposable scopes.

How do 4/6 gyros fail? I never thought gyros were the most unreliable parts

Depends on the kind of gyroscope. The gyros on Hubble have to be extremely precise and spin at nearly 20,000 RPM, they're not like the vibrating structure gyros you'd find in consumer electronics.
 
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How do 4/6 gyros fail? I never thought gyros were the most unreliable parts

From https://www.spacetelescope.org/about/general/gyroscopes/ :
"Each gyroscope contains a wheel spinning at 19,200 revolutions per minute inside a sealed cylinder. This cylinder is immersed in a thick, motor-oil-like fluid. Fine, hair-like wires, surrounded by this thick fluid, carry electricity to the motor. Oxygen-pressurized air, used to force the thick fluid into the float cavity that contains these wires, has corroded the wires and caused them to break. Pressurized nitrogen, used in the new gyroscopes, will eliminate the introduction of corrosive oxygen."

In 2009, there was a servicing mission where they replaced all the gyroscopes; they're installed in pairs, two pairs were new, and the last pair was a refurbished unit because of difficulties with installing the other new pair they brought. I didn't see any indication of which units failed to see (everybody wants to know if they should buy refurbished gyroscopes!)
 
From https://www.spacetelescope.org/about/general/gyroscopes/ :
"Each gyroscope contains a wheel spinning at 19,200 revolutions per minute inside a sealed cylinder. This cylinder is immersed in a thick, motor-oil-like fluid. Fine, hair-like wires, surrounded by this thick fluid, carry electricity to the motor. Oxygen-pressurized air, used to force the thick fluid into the float cavity that contains these wires, has corroded the wires and caused them to break. Pressurized nitrogen, used in the new gyroscopes, will eliminate the introduction of corrosive oxygen."

In 2009, there was a servicing mission where they replaced all the gyroscopes; they're installed in pairs, two pairs were new, and the last pair was a refurbished unit because of difficulties with installing the other new pair they brought. I didn't see any indication of which units failed to see (everybody wants to know if they should buy refurbished gyroscopes!)

so a major design flaw. I also dont know if they just simplified their response but its pretty easy to obtain nitrogen or pretty much any gass to solve this issue that seams like no one knew basic chemistry when making it. that or they designed with the estimated lifetime in mind and hand no intention of designing a part to exceed that.
 
so a major design flaw. I also dont know if they just simplified their response but its pretty easy to obtain nitrogen or pretty much any gass to solve this issue that seams like no one knew basic chemistry when making it. that or they designed with the estimated lifetime in mind and hand no intention of designing a part to exceed that.

The ones that were there were the "new" nitrogen ones.
Don't knock the design. Crazy-precise mechanical devices most certainly will fail at some time. Lasting for a decade in the most extreme environment of space is an achievement.
 
so a major design flaw. I also dont know if they just simplified their response but its pretty easy to obtain nitrogen or pretty much any gass to solve this issue that seams like no one knew basic chemistry when making it. that or they designed with the estimated lifetime in mind and hand no intention of designing a part to exceed that.

Hubble was launched in 1990, I fail to see how this is a major design flaw given that it has been in service for over 28 years with minimal servicing.
 
Hubble was launched in 1990, I fail to see how this is a major design flaw given that it has been in service for over 28 years with minimal servicing.

I mean are you shocked there would be someone on a forum that would know how to build spacecraft better than those who actually do it? Kerbal has trained a lot of people.

I wish anything I owned would last that long TBH.
 
The ones that were there were the "new" nitrogen ones.
Don't knock the design. Crazy-precise mechanical devices most certainly will fail at some time. Lasting for a decade in the most extreme environment of space is an achievement.

Hubble was launched in 1990, I fail to see how this is a major design flaw given that it has been in service for over 28 years with minimal servicing.

once again this is under the assumption that "Oxygen-pressurized air, used to force the thick fluid into the float cavity that contains these wires, has corroded the wires and caused them to break" is the actual reason it has failed. if that is the cae dont you think the people who designed it should have a pretty decent idea of how all the parts interact with themselves both chemically and physically. aditionally it was stated this problem was resolved by filing them with nitrogen instead. thats not exactly a major change and why that wasnt concidered in 1990 but is a valid solution now shows that it may have been a design flaw.

lets also not forget they had to make this thing a new lens because they badly messed up the first time they designed it (if I recall corectly the lens was ground exactly to the specifications that were provided but those specifications were incorrect)
 
I mean are you shocked there would be someone on a forum that would know how to build spacecraft better than those who actually do it? Kerbal has trained a lot of people.

I wish anything I owned would last that long TBH.

my car is almost going on 28 years with very little service and some parts that have never been touched ;)
 
zero g and solar radiation does some fucked up things to hardware considering it's been up there for 28 years under constant use it's not surprising they've failed.
Heh, I will agree with constant radiation being a problem to some hardware, but I have a hard time believing 0g reduces hardware reliability . Maybe you are thinking of humans? :p . Or are there specific difficulties with 0g I am not aware of?
 
Looks like they will have to get the space shuttle out of retirement and get the gyro's fixed !!
 
Heh, I will agree with constant radiation being a problem to some hardware, but I have a hard time believing 0g reduces hardware reliability . Maybe you are thinking of humans? :p . Or are there specific difficulties with 0g I am not aware of?
Temperature swings of 215 F.
Micro-meteor and debris impacts.
Ionizing radiation chewing up microchips.
Induced electrical currents causing micro-pitting in metal bearings.
Solvent outgassing changing material properties and redepositing chemicals in unexpected places.
 
Why not send up a crew to replace the broken gyros?

The US currently has Zero manned flight capability. Don't know if the Russian craft has enough lift and space to get a crew plus parts to Hubble's orbit. If the Webb scope schedule slips again(likely based on past performance), it might be worth exploring the possibility of a Dragon or Orion mission to refit Hubble again. As long as you don't have to bring it back, you don't really need a shuttle to fix it. IIRC, Columbia was the only shuttle that could fit Hubble and when she burned up, we lost any ability of a soft recovery of Hubble.
 
The US currently has Zero manned flight capability. Don't know if the Russian craft has enough lift and space to get a crew plus parts to Hubble's orbit. If the Webb scope schedule slips again(likely based on past performance), it might be worth exploring the possibility of a Dragon or Orion mission to refit Hubble again. As long as you don't have to bring it back, you don't really need a shuttle to fix it. IIRC, Columbia was the only shuttle that could fit Hubble and when she burned up, we lost any ability of a soft recovery of Hubble.

it doesn't, nor does it have the ability to capture the satellite to work on it, nothing currently does other than the ISS and there's no way i could see them ever trying to use the ISS for that. as long as it can continue to work with just 1 gyro being active they'll leave it that way.
 
it might be worth exploring the possibility of a Dragon or Orion mission to refit Hubble again.

Orion/Dragon don't have an integrated Canadarm or an airlock, so there's no way to capture the Hubble or perform the multiple EVA's necessary. I have to imagine that it would be cheaper just to launch a new telescope than to design a separate disposable auxiliary module and train a Dragon/Orion crew for servicing the Hubble again.

The DoD has/had more than 10 Hubble-class spy satellites. They gifted 2 of the spares to NASA a few years back. It's cheaper and safer just to launch new scopes.
 
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As part of the last shuttle Hubble mission a special docking adapter was added to allow a future unmanned mission to attach a pusher motor to aid in the deorbit if the current orbit decay was a hazard. Hubble was never intended to be safely returned to Earth and its orbit can't be changed to match the ISS orbit. Hubble's orbit was near the maximum a shuttle could launch and catch up to if they made it to the mission flights MECO with all systems running.
Where's Elon and his mad science to fix it when you need him.
 
once again this is under the assumption that "Oxygen-pressurized air, used to force the thick fluid into the float cavity that contains these wires, has corroded the wires and caused them to break" is the actual reason it has failed. if that is the cae dont you think the people who designed it should have a pretty decent idea of how all the parts interact with themselves both chemically and physically. aditionally it was stated this problem was resolved by filing them with nitrogen instead. thats not exactly a major change and why that wasnt concidered in 1990 but is a valid solution now shows that it may have been a design flaw.

lets also not forget they had to make this thing a new lens because they badly messed up the first time they designed it (if I recall corectly the lens was ground exactly to the specifications that were provided but those specifications were incorrect)

The mirror wasn't a design flaw it was an manufacturing and quality control error.

As a matter of fact Hubble was designed with periodic maintenance in mind. The fact that it has had less than 5 maintenance visits in 28 years is simply an incredible feat of engineering. Saying otherwise simply denigrates those who worked on it.

I am sure the engineer designed the part to the exact specifications NASA requested. They probably specified pressurized oxygen. I have no proof of that. But the repair mission specs say nothing of it being a mistake https://asd.gsfc.nasa.gov/archive/sm3a/overview.html. Hell it couldve been planned maintenance to replace those gyros. Someone with more time on their hands can go look up the original specs ;)
 
Temperature swings of 215 F.
Micro-meteor and debris impacts.
Ionizing radiation chewing up microchips.
Induced electrical currents causing micro-pitting in metal bearings.
Solvent outgassing changing material properties and redepositing chemicals in unexpected places.
Those are all difficult things to design around! But what do they have to do with 0g? :)
 
So are we shit out of luck with seeing incoming asteroids and comets then or what?
 
So are we shit out of luck with seeing incoming asteroids and comets then or what?

Not within its mission parameters. Hubble was primarily used for wide area shots of deep space objects (DSOs). Planets are much smaller in resolution on its cameras compared to a DSO. A DSO might take up 3,600 pixels where as Pluto might take...3.

I believe they shot some images of planets on special occasions but I dont think it was used for planets on a regular basis.
 
I found a small screen capture of what the main computer menu is currently displaying:
abortretryfail.jpg
 
so a major design flaw. I also dont know if they just simplified their response but its pretty easy to obtain nitrogen or pretty much any gass to solve this issue that seams like no one knew basic chemistry when making it. that or they designed with the estimated lifetime in mind and hand no intention of designing a part to exceed that.

ummm, you realize when it first launched, the whole thing was kinda junk. Had to fix it later.
 
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