International Space Station damaged by small meteor

Everything is fine for the astronauts over there, but a tiny meteor or space crap hit one of seven panes in the orbiting outpost's European-built Cupola, damaging the outer layer.

A protective shutter was quickly closed over the damaged window, which has four layers of glass, made from fused silica and borosilicate glass...

Everyone knows what a pain it is when you get a chip on your car's windshield from a bit of flying grit. But on Earth it is usually fairly easy to call someone in to repair it.

NASA are currently evaluating a similar spot of damage to one of the viewing windows on the International Space Station to see if that needs to be replaced.

The chip that left a visible scar on the outer pane was caused by a tiny meteoroid or scrap of space debris travelling many times faster than a bullet. It hit one of seven panes in the orbiting outpost's European-built Cupola - the space equivalent to a conservatory.

This particular impact is not thought to put the six astronauts on board in any danger. But it is a reminder that space is a dangerous place.

"If a similar-sized piece of debris had hit an astronaut on a spacewalk, the consequences may have been fatal." said Dr Lucy Rogers, space debris expert.

Source: SEN

reply to post by elevenaugust


Makes me wonder how they found out about it? Did they see it, hear it pick it up on a radar if possible? If this is a common problem are there sound detectors and sirens to alert those on board to prepare for an emergency?

No big deal. It is fireball season ya know.

reply to post by Numbers33four


Except that it wasn't a fireball...

I should know this, but I don't... Do they normally fly with the shutters open on the windows at all times? If so, maybe it would be a better idea to close them except when someone is using the cupola? One of those questions I have to ask next time I run into an astronaut.

reply to post by ngchunter


Good question!

Mr Oberg may be the man to ask...

I do know that usually they have at least a little bit of warning when an object might pass by too closely and they all gather together in the Soyuz capsule in case they have to make a quick exit.

Another question:

If they ever need to replace a window in the cupola, how exactly do they do it? I'm not saying this event will necessarily prompt a window replacement, but I still wonder. I don't think the closed shutters themselves act to keep the module pressurized.

I admit I haven't tried looking up the answer yet, but I would be interested to find out. I'm sure there is some contingency plan for cupola window replacement.



EDIT/UPDATE:

I think I have the answer to my own question. As I assumed, there is a contingency plan for replacing a cupola window if that ever becomes necessary. It should be noted that this meteor impact does not necessarily mean the window needs to be replaced.

I found an article online that answered my question:

In the event of the damage being more serious, on-orbit replacement of an entire window is a design feature. Such a replacement would require an EVA to fit an external pressure cover to allow for the changeout, with a pressure cover requiring a flight up to the ISS.

Source

reply to post by Soylent Green Is People


I would think that at worst, they would be able to depressurize the cupola, with it sealed off, and change it, then repressurize. But since they're so much smarter than I am, I'm sure they have a procedure drawn up for this. I can't imagine they would have put it in orbit without thinking something like this would eventually happen.

Originally posted by Zaphod58
reply to post by Soylent Green Is People

 

I would think that at worst, they would be able to depressurize the cupola, with it sealed off, and change it, then repressurize. But since they're so much smarter than I am, I'm sure they have a procedure drawn up for this. I can't imagine they would have put it in orbit without thinking something like this would eventually happen.

Thanks. I was actually editing and updating my post with the answer while you were posting.
See my post above for a short description of the procedure.

From the sound of it (considering they would need to fit it with a separate pressure cover), the closed shutters cannot serve to keep the module pressurized by themselves.

I wonder why they can't replace the window from inside the depressurized (and sealed-off) module while wearing a space suit, so as not to require the extra exterior pressure cover? Maybe the inside of the module is too small to allow enough freedom of movement required to replace a window while wearing the EVA suit.

Auto zone sells windshield crack repair kits.

I wonder if they deliver???

Originally posted by Soylent Green Is People

I wonder why they can't replace the window from inside the depressurized (and sealed-off) module while wearing a space suit, so as not to require the extra exterior pressure cover? Maybe the inside of the module is too small to allow enough freedom of movement required to replace a window while wearing the EVA suit.

The cupola is small enough that you can't really fit even an unsuited person entirely inside it if it were closed off:



The replacement procedure involves doing a spacewalk, where a pressure cover is attached to the outside of the window. The window would then be removed from inside the station and replaced. Another spacewalk would be conducted to remove the pressure cover from the exterior of the window.

reply to post by nataylor

Thanks. That's what I suspected was the reason for not depressurizing the module and doing it from the inside while wearing spacesuits (or at least one of the reasons). I assume that the temporary exterior pressure cover that would be installed via a spacewalk would allow the crew to replace a window from the inside, while in a shirt-sleeve environment -- or am I missing something else here?

Again, I realize that this current window damage is not necessarily prompting a window replacement, but I was just curious how they would do it if the need ever did arise.

reply to post by Soylent Green Is People

Yup, the window would be replaced from inside the station by unsuited crew.

It's unlikely this recent damage would prompt a whole window replacement. The windows are made up 4 layers. On the inside is a "scratch" pane that helps prevent any damage to the pressure panes. Then there are two pressure panes, meaning either one could fail and the other would act as a backup. And on the outside is a debris pane, which absorbs small impacts and protects the pressure panes. This recent damage is only on the debris pane. Flight rules call for a whole window replacement only if one of the pressure panes is compromised. In the case of the debris pane, it can actually be replaced by itself from outside with a spacewalk, with no need to remove and replace the rest of the window. I don't know criteria for replacement of the debris pane, but I doubt this minor damage would warrant it.

reply to post by nataylor


That's actually pretty smart engineering -- i.e., making the outermost pane separate from the parts that are necessary for pressurization. It's obvious once I think of it, but it's also good to know someone was smart enough to think of that.