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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.""
Towing in space has been done before. Grumman sent North American Rockwell an invoice for towing their crippled spacecraft home. The rate per mile seems pretty reasonable too.
All joking aside, this is going to be a bear to fix. The best scenario would be that the drive gear was munching an insulation blanket. The debris would be friendly to space suits, and should only be labor intensive to clean out. If the gears are grinding on each other, the debris will be sharp and hard. That would be "bad" and I'd expect NASA to seriously consider returning the entire assembly to earth for repair. Expensive, but much less likely to kill someone.
I'm of the opinion that the drive system on this beast is probably over-engineered. It should resemble a Ford F-150 differential - loose tolerances, and designed to run for many millions of rotations without much maintenance. There's absolutely no need for the solar array to have precision pointing capability. I really do hope that the problem isn't due to over-engineering, but I wouldn't place a bet.
So how would you propose these things are done? I mean, things that no one's ever done before, and which you can't really simulate?
An anecdote from my days of working for a huge German company (240000 employees) at Oracle (first job after university): I was part of the 32-64bit porting team. The question came up, are customers going to need additional or larger hard drives for the 64bit version of Oracle?
The answer from the Germans: Well, you've got the source code. Examine all structures in the code that end up on disk and count the bytes. (we know how many Bytes an "int" takes up on 32 vs. 64bit, etc.)
The answer from the Americans: Well, you've got the source code there. Just compile it and see what happens!
You know, while the German approach (I *am* German) sounds a lot more "scientific" and exact I would say the American way was not just better, but the only one that actually WORKS outside a simulated computer environment with a limited number of known-in-advance factors.
So again, how would YOU go about discovering the unknown? *I* would do just what NASA does, and what humans have done for millenia: Try, fail and try again, never approaching any ideal solution but something that works for now, until the next unforeseen thing happens.
Of course, in the western world everything that even LOOKS like risk has to be eliminated: from hot coffee to horses with tourists on them going any faster than a slow walk (I'll NEVER go on any tourist expedition on a horse in the US again, in Germany my friends who've never been on a horse before were forced to "survive" gallop several times in a 2 hour tour - and did so with relative ease).