Space Station Solar Equipment Showing Damage

bhmit1 writes "The latest space walk has turned up some bad news for the problematic solar panels: metal shavings. From the article: "The rotary joint, 10 feet in diameter, has experienced intermittent vibrations and power spikes for nearly two months. Space station managers were hoping a thermal cover or bolt might be hanging up the mechanism. That would have been relatively easy to fix, so they were disheartened when Daniel Tani radioed down that metal shavings were everywhere. 'It's quite clear that it's metal-to-metal grating or something, and it's widespread,' Tani said.""

Comments

Will a replacement fix it?

[_merlin]

I noted that they intend to fit a replacement joint, and are limiting the travel of the solar panel(s) in the mean time. My question is, do they know what the source of the problem actually is? Is it a manufacturing defect, damage or wear and tear in the currently fitted joint? If it is, replacing it is a reasonable solution. But if it isn't - i.e. if there's a design or operational problem - replacing it will just be a temporary band-aid, and the same thing will happen again sooner or later.

Re:Will a replacement fix it?

[Guysmiley777]

The problem is with the right side solar alpha rotary joint, what I infer from that is the joint on the left side panel joint is working fine. Which would seem to indicate a part failure rather than an engineering problem. But I'm sure nobody can say for sure until they get a look at the failed joint.

Re:Will a replacement fix it?

[mha]

It *is* the same, however you twist it. Of course you try a little harder when lifes are at stake. You also drive more carefully when the road seems dangerous or you are not wearing a seatbelt (on the average). Not sure what you're trying to say. When flying was discovered and aircrafts developed many died. When we went into space the human cost was low ONLY because of the enormous effort - very few people have been up there at all, and many, including those who went to the moon, were just lucky - there was no backup plan (or option) for them. Besides, unlike with those first aircraft we now get better at using computers to pilot those things.

And to your hardware/software comparison, you ARE aware who's piloting the shuttle during the most dangerous parts of a mission, right? Hint: it is not the pilot...

Re:Incredible Spending Sink

[elrous0]

ut we're figuring out how to live in space with this project

Wouldn't it be a lot cheaper just to ask the Russians?

Re:Incredible Spending Sink

[mha]

Even if we just assume they know so much more (which certainly used to be true in the past when they basically had the monopoly on staying up there long-term), the answer is: depends.

Globally, for the world as a whole, sure. Locally: no. If you never do it yourself but always ask the others they will get better and better, and you'll depend on them more and more. That's specialization all right, and according to economic theory that's a good thing. You just have to make sure you have something of equal or greater value to trade with... because if you don't, and I'd say in the foreseeable future there won't be many things more high tech (and therefore potentially valuable) than space-faring knowhow, you are screwed. Unless you believe that human nature is going to change completely.

One hell of a gear box

[BadHaggis]

The SARJ, 10.5 ft in diameter and 40 inches long, will maintain the solar arrays in an optimal orientation to the sun while the entire space station orbits the Earth once every 90 minutes. Drive motors in the SARJ will move the arrays through 360 degrees of motion at four degrees per minute. The joints must rotate the arrays smoothly without imparting vibrations to the laboratories and habitation modules on the station that would impact microgravity-processing activities. At the same time, 60 kW of power at 160 volts and multiple data channels are carried across each joint by copper "roll rings" contained within. From: Google Cached Lockeed Martin Article on the Panels.

The joints in question are huge and as this article points out any vibrations back into the ISS could cause problems with other equipment or experiments. Additionally power is transferred back to the ISS through copper rings in the unit itself. Any metal which provides a better circuit path than the copper would cause the power spikes.

Opening this thing up would be something like trying to rebuild an Automatic Transmission, then add the complexity of doing this in micro-gravity. It would probably be easier for NASA to send up a complete replacement instead of trying clean out all of the metal shavings and replace the parts that are damaged.

Re:One hell of a gear box

[mikelieman]

Isn't this, then, *exactly* the time to learn how to do this stuff on-site? No-one said that learning was ever "easy".

Re:Towing in space

[twostar]

over-engineering doesn't mean tight tolerances or precision parts. It means you just spent 3/4 of your budget to go from 95% accuracy to 96% when you only needed 95%.

Actually, we did

[WindBourne]

They supplied part of the computer system and the O2 Generator.

In addition, they have never done anything near this big. As it is, the ISS is already double the mass of MIR, and it will go up by 50%. In addition, it is about 50% more living volume than mir and will still double over the next 2 years. This is WELL beyond what russia has done. This is all an new learning experience for the world. Fortunately, this experience will enable us to go to the moon and mars a lot cheaper and faster.

Heck, look at China. Their space program is now outspending yearly what Apollo did at its' height. And with that, they launch a fraction of the flights that did and currently do. That is because they are busy trying to acquire the same technology (generally buying it from Russia or simply stealing it from NASA and RSA).