The Hubble Space Telescopes Main Camera is Down

[James Kerman]

Quote

Hubble in Safe Mode as Gyro Issues are Diagnosed

NASA is working to resume science operations of the Hubble Space Telescope after the spacecraft entered safe mode on Friday, October 5, shortly after 6:00 p.m. EDT. Hubble’s instruments still are fully operational and are expected to produce excellent science for years to come.

Hubble entered safe mode after one of the three gyroscopes (gyros) actively being used to point and steady the telescope failed. Safe mode puts the telescope into a stable configuration until ground control can correct the issue and return the mission to normal operation.

https://www.nasa.gov/feature/goddard/2018/hubble-in-safe-mode-as-gyro-issues-are-diagnosed

[Spaceception]

Yeah Watching this right now

 

[satnet]

The gyros were replaced in Service Mission 3A (1999) and again in Service Mission 4 (2009), so it is maintaining its 9-10 year period between gyro failures. Three of the 6 gyros installed in the last service mission were of a newer design that was meant to be more resilient. The older ones used a pressurized oxygen to deliver the suspension fluid which corroded the wires, but the newer ones were constructed with nitrogen and were expected to be more resilient. Two of these new gyros are still up and running. The one they are trying to activate is the third one of this new design, but it does not seem to be operating correctly. Hopefully they can get it back up and running, it would be a shame to lose functionality, especially with JWST still on the ground.

[Kerbart]

What's the advantage of using oxygen as a pressurization agent? To the layman (me) it's seems as intuitive as using gasoline in a fire extinguisher. And yet there must have been a reason to use oxygen over nitrogen at first before they learnt it corroded (who knew?) the wires.

[satnet]

1 hour ago, Kerbart said:

What's the advantage of using oxygen as a pressurization agent? To the layman (me) it's seems as intuitive as using gasoline in a fire extinguisher. And yet there must have been a reason to use oxygen over nitrogen at first before they learnt it corroded (who knew?) the wires.

Your guess is as good as mine. The sources I found actually said oxygen pressurized air, so I don't think it was pure oxygen, though it sounds like a higher than normal concentration of oxygen. It struck me as both counter intuitive and interesting, but I don't know exactly why.

https://www.spacetelescope.org/about/general/gyroscopes/

[Scotius]

Maybe because oxygen was cheaper than helium?

[magnemoe]

2 hours ago, Scotius said:

Maybe because oxygen was cheaper than helium?

Launch cost would be so expensive the few kg of gas would not be an budget post. I guess it was pressurized air rather than pure oxygen. Still nitrogen is used so many places its pretty standard for an fire safe air replacement for everything from tires to pipelines. If you have an natural gas or similar pipe its standard to flush it with nitrogen then you empty for gas. 
 

[YNM]

9 hours ago, Kerbart said:

What's the advantage of using oxygen as a pressurization agent? 

High-pressure normal air composition is enough to make it act as if it's pure oxygen.

 

I hope they get to solve the problem quickly. Or just put JWST up (though then you can't service that one at all !)

Edited October 9, 2018 by YNM

[DAL59]

Why can't they just send up a Dragon and fix it?  Even without crew rating, they could send up robonaut.  

[mikegarrison]

14 hours ago, magnemoe said:

Still nitrogen is used so many places its pretty standard for an fire safe air replacement for everything from tires to pipelines. If you have an natural gas or similar pipe its standard to flush it with nitrogen then you empty for gas. 
 

Now. Not in the early 80s.

[Superfluous J]

19 minutes ago, mikegarrison said:

Now. Not in the early 80s.

It wasn't the 1880s. And Nitrogen isn't some crazy exotic element or anything.

[Ultimate Steve]

6 hours ago, DAL59 said:

Why can't they just send up a Dragon and fix it?  Even without crew rating, they could send up robonaut.  

Neither Dragon nor Dragon 2 is equipped for EVA, and Robonaut is currently undergoing repairs, and to my understanding it is not as suited for repair work as a human is.

In fact, I don't think any currently operating or near future spacecraft is EVA-rated, although with most of those you could just depressurize the whole thing, so I guess you could do it with a Dragon...

...Actually, you could stick Robonaut in the trunk. That could actually work, providing Robonaut can be equipped to work with tools, and can be equipped to attach himself to the Hubble, this could work.

Someone tweet this to Elon!

[mikegarrison]

1 hour ago, 5thHorseman said:

It wasn't the 1880s. And Nitrogen isn't some crazy exotic element or anything.

Were you around in the 1980s? I was. Nobody was using nitrogen in their tires, airplanes were not using to inert fuel tanks, etc. I'm sure they could have done it, but nobody did.

[Kerbart]

But Helium was already used as a pressurizer/purge gas. And the, ehm, oxidative qualities of oxygen have been known since the 18^th century.

By the way, everyone was using nitrogen in their tires. Usually at 80% partial pressure though.

[Superfluous J]

56 minutes ago, mikegarrison said:

Were you around in the 1980s? I was. Nobody was using nitrogen in their tires, airplanes were not using to inert fuel tanks, etc. I'm sure they could have done it, but nobody did.

I was as well. I had a wart on my hand and it was removed with liquid nitrogen that was stored in a very cold pressurized tank. If they could do that with it for such a menial purpose I suspect NASA could put some on a satellite.

NASA did a lot of things that random people didn't do. I don't recall everyday businesses driving cars on the Moon, either.

I'm sure there was a reason, but "we couldn't figure out how to pressurize nitrogen" is not it.

[mikegarrison]

54 minutes ago, 5thHorseman said:

I was as well. I had a wart on my hand and it was removed with liquid nitrogen that was stored in a very cold pressurized tank. If they could do that with it for such a menial purpose I suspect NASA could put some on a satellite.

NASA did a lot of things that random people didn't do. I don't recall everyday businesses driving cars on the Moon, either.

I'm sure there was a reason, but "we couldn't figure out how to pressurize nitrogen" is not it.

Look, just go back and read the quote again, OK? It wasn't about whether there was any nitrogen back then. It was about whether nitrogen was commonly used "for everything from tires to pipelines". Which it wasn't.

I also don't know why they would have used compressed air rather than an inert gas, but it's quite possible that nobody really thought about it all that much until it turned out to be a problem.

[ZooNamedGames]

2 hours ago, Ultimate Steve said:

Neither Dragon nor Dragon 2 is equipped for EVA, and Robonaut is currently undergoing repairs, and to my understanding it is not as suited for repair work as a human is.

In fact, I don't think any currently operating or near future spacecraft is EVA-rated, although with most of those you could just depressurize the whole thing, so I guess you could do it with a Dragon...

...Actually, you could stick Robonaut in the trunk. That could actually work, providing Robonaut can be equipped to work with tools, and can be equipped to attach himself to the Hubble, this could work.

Someone tweet this to Elon!

My idea was to launch two missions; the first would carry all the hardware and tools to repair HST (unmanned), then launch a second mission with CST-100/Dragon V2/Orion (which is the only one to fly to space to this point mind you). From there, the crew would EVA (even if it just meant opening the hatch and getting out) and doing the work.

Though Hubble's issue is bad news, it appears it can still operate, albeit at reduced effectiveness. So we could wait a few years to see these new crew vehicles tested and proven capable of handling crew.

In my mind, I would use a F9 for the cargo mission, and Orion for the crew, as Orion is intended to go to the moon, and this could act as a stepping stone for Orion. Orion being launched (again) on the Delta IV Heavy. Last I heard, Orion and it's SM was ready, just waiting for SLS which is always being pushed back. According to NASA's Performance Chart, The Delta IV Heavy would barely not be able to lift Orion and it's SM. So I would launch them seperately and attach them together in orbit and then let it fly to Hubble with it's crew and rendezvous with HST where it would be greeted by the cargo vehicle already waiting for the crew. 

So 3 launches. Still not terrible.

[Canopus]

@ZooNamedGamesyou can‘t just mate Orion and its service module in orbit though. 

Orion is the only upcoming Spacecraft that allows for EVA though. You could probably launch it with its Tanks slightly drained, Apollo style. Biggest problem is that the DeltaIV isn‘t manrated so this mission is impossible from the start.

The only way i could see Hubble being serviced in a long time is roboticaly and the easiest way would be to build a service module that duplicates stuff like gyroscopes and reaction control wheels and just attaches to the outside.

[magnemoe]

8 hours ago, 5thHorseman said:

It wasn't the 1880s. And Nitrogen isn't some crazy exotic element or anything.

This, used nitrogen made at university for cooling an vacuum chamber back in the 80s. You could just go an pick up bottles with it. 
Same with the use for flushing pipes. 

1 hour ago, Canopus said:

@ZooNamedGamesyou can‘t just mate Orion and its service module in orbit though. 

Orion is the only upcoming Spacecraft that allows for EVA though. You could probably launch it with its Tanks slightly drained, Apollo style. Biggest problem is that the DeltaIV isn‘t manrated so this mission is impossible from the start.

The only way i could see Hubble being serviced in a long time is roboticaly and the easiest way would be to build a service module that duplicates stuff like gyroscopes and reaction control wheels and just attaches to the outside.

As it has an docking hard point this should probably work. Main problem would be accuracy as the docked module would not be entire rigid at least if it also handled the reaction wheels. 
 

[wumpus]

4 hours ago, magnemoe said:

This, used nitrogen made at university for cooling an vacuum chamber back in the 80s. You could just go an pick up bottles with it. 
Same with the use for flushing pipes. 

As it has an docking hard point this should probably work. Main problem would be accuracy as the docked module would not be entire rigid at least if it also handled the reaction wheels. 
 

I've heard that liquid nitrogen "costs as much as milk", although I don't really know where to pick of a liter of the stuff.  There's a reason people got excited about superconductors that worked above 80K (for some reason I have 40K as the boiling point of Nitrogen in my head, but wiki says 80K).

[DerekL1963]

4 hours ago, wumpus said:

I've heard that liquid nitrogen "costs as much as milk", although I don't really know where to pick of a liter of the stuff. 

Most any serious welding supply place will have it.  There's two in my small town waaay out on the outer edge of the outer commuter belt...  and a truckload in the Big City itself.  Plus both liquid gas suppliers have production plants in the Big City.

[magnemoe]

18 minutes ago, DerekL1963 said:

Most any serious welding supply place will have it.  There's two in my small town waaay out on the outer edge of the outer commuter belt...  and a truckload in the Big City itself.  Plus both liquid gas suppliers have production plants in the Big City.

Yes, the milk cost might be if you buy small scale, cheaper if you use bulk of it. 

DId an 3d work for an maintenance manual of the flare tower setup for an oil platform. As flaring gas is non standard and only used if you can not deliver gas, either of pipeline or more common platform problems or you get an serious spike in gas production the flare system works a lot like an drain system. Pipes is filled with nitrogen who is produced on site. This is also used to flush pipes and equipment so you don't have methane pockets mixed with air places you want to weld
In short don't mix natural gas and air, mix it with nitrogen if you can not keep it pure. 

Coolest part was that they light the flare tower with an rocket fired from an revolver style magazine up an pipe and to the flare tower there it got stuck and worked as an pyrotechnic device to light the gas until burned out. 
Maintenance was reloading the revolver and emptying the bucket at the top of the tower  

[Mitchz95]

17 hours ago, Ultimate Steve said:

In fact, I don't think any currently operating or near future spacecraft is EVA-rated

I would hope BFR is capable of doing EVAs! With 100+ people on board, you can't exactly decompress the whole ship to do repairs.

[Ultimate Steve]

2 minutes ago, Mitchz95 said:

I would hope BFR is capable of doing EVAs! With 100+ people on board, you can't exactly decompress the whole ship to do repairs.

As enthusiastic and optimistic as I am about BFR, it is not set in stone and if it is near-future, it's late near future. Once it is flying, NASA will have to be onboard, which will take at least a few more months, probably more, and after they realize the mission is possible they would have to make the new gyros and plan another repair mission starting from that point most likely, given they way they operate. By that time Hubble may very well be dead.

Cargo Dragon, however, is a demonstrated vehicle that is currently flying. If they could get a robonaut derivative working with the required precision then I think NASA would want to give this a shot.

[DerekL1963]

2 hours ago, Mitchz95 said:

I would hope BFR is capable of doing EVAs!

It's not sufficient just to do EVAs.  You also have to grapple and hold Hubble adjacent to the spacecraft.  You also have to be able to transfer and store tools and parts, etc...  It's a not trivial thing.