rufey writes "This week there have been two pieces of bad news from the International Space Station. First was the discovery of metal shavings inside a problematic rotary joint used to keep one set of solar panels in the optimal position for power generation. At the close of a subsequent spacewalk, after it was relocated to its permanent location, the unfurling of the 4B solar panel resulted in it tearing in two places. A spacewalk is now planned for November 4th to attempt to fix the tear. The upcoming spacewalk is not without risks, including the remote possibility of electrocution since it is impossible to stop the solar panel from generating electricity during the repair attempt. NASA says the ripped wing needs to be fixed or the solar rotary joint problem solved before any more shuttles can fly to the space station and continue construction. With a hard deadline of 2010 for Shuttle retirement, NASA does not have much wiggle room in the schedule in order to finish ISS construction."
If there were an easy way to fix this, NASA would have figured it out. Don't forget, these fix rovers millions of miles away by changing computer code. I'm sure any suggestion here on/. has been thought of already.
It doesn't matter. My point is the NASA folks are pretty bright people who have the ability to fix their stuff. And it amazed me that they can fix their stuff from a distance by changing computer code - regardless of what project it was.
And I know there's going to be a ton of posts implying that the NASA folks should have thought of [insert idea here]. Of course they did.
And I know there's going to be a ton of posts implying that the NASA folks should have thought of [insert idea here]. Of course they did.
While I largely agree with all you've said here... Sometimes people just don't think of things, no matter how bright they are. Case in point: an actual phone call I received at 1:30 AM the other day -- "the dishwasher is stuck on and we can't figure out how to stop it". My response: um... just unplug it? "oh, heh, yeah, okay." This was from a grad student (physics) working for me part time. She's very bright and generally has practical skills too. Sometimes people just don't think of things.
Sure you can. I've known everyone from Joe Sixpack to Ivory-Tower Intellectuals and in-the-real-world problem solvers to make stunning displays of stupidity, such as not unplugging an appliance, or walking away from an ATM without the money, or simply forgetting to have breakfast AND lunch and suddenly feeling hungry at 3pm and not knowing why.
brightness is irrelevant to whether someone happens to have the right synapses fire in the right order to solve a particular problem. And that was my point. Just because someone is bright, doesn't mean they will automatically think of every solution to a particular problem. Intelligence is not a free pass to discovering stuff (though it helps a lot!).
In the case of this particular example, she had done several other things in an effort to solve the problem, any number of which were potentially viable solutio
One thing, is that someone coming from a computer or engineering background will hesitate to have "just unplug it" as a good suggestion, due to the possibility of interrupting the process causing a catastrophic failure.
I guess that's why we've never lost an astronaut, Oh wait. . .
NASA has made errors that have killed people by ignoring somebody who got it right. Of course, the original question about working while the station was on the dark side of the earth forgets the fact that the station rotates earth in less than an hour, and few spacewalks last fewer than 3 or 4 hours.
The panel cannot withstand the stress of rotation while the tear exists. The spacewalk will repair the panel to the point where it can be fully extended. Once fully extended, the tension on the panel helps it withstand the stresses of rotation.
The damage to the joint affects the opposite panel.
Why didn't they take up a big blue tarp, to cover the panel and shut it down? Better yet, why not take up a big space blanket, which would be lighter and provide better shade?
As for why they can't just wait for night, the period of the ISS orbit is about 93 minutes [wikipedia.org]. They'd have to work fast.
Because the tears in the panel happened while it was being re-deployed on this flight. When the shuttle launched, there was no tear to be repaired, hence no need to carry tarps, space blankets, duct tape, or anything else intended to repair a panel.
Apparently [heavens-above.com] due to the inclination of the orbit, only about a quarter of those 93 minutes is in the Earth's shadow. So, the bad news is that they get slightly less than 25 shock free minutes to fix the problem. The good news is they get 15 attempts per day.
Mod parent insightful, not funny, as it is valid question, and was indeed asked ("why not limit the the repair time to night passes") on yesteray's NASA's mission status briefing. The response was that sacrificing basicly spending half of the spacewalk to do nothing is not worth the added safety - note that the 'electrocution' mentioned is very extreme case, as the panels itselves are coated with insulation, the tools are insulated etc, but as they spend years in space and were damaged, there is concern tha
Why is 2010 such a "hard" deadline? Was it not created solely by politicians who wanted to divert resources to go to Mars? As such, can it not be moved just as easily as it was created? It is, after all, three years away. If we can't move deadlines that far out, isn't there a chance we're overplanning, and leaving ourselves completely vulnerable to unexpected circumstances, exactly like this solar panel issue?
Remember "Man on the Moon by the end of this decade?"
Nothing motivates like a deadline.
It may seem arbitrary, but NASA is doing lots of good, hard work on the ISS these days, and I think maybe that's because the pressure's on.
Why is 2010 such a "hard" deadline? Was it not created solely by politicians who wanted to divert resources to go to Mars?
No, it was created by the CAIB subsequent to the loss of Columbia.
As such, can it not be moved just as easily as it was created?
No, because the CAIB requires the vehicles be recertified to extend their lives beyond that date - a very expensive and difficult process.
That being said - another limit, currently, is contractural. NASA has only contracted for so many External Tanks, SRB refurbishments, etc... Unless Congress coughs up more money (and approves the delays in converting facilities to support Ares/Constellation - I.E. more money) it simply isn't going to happen.
It is, after all, three years away. If we can't move deadlines that far out, isn't there a chance we're overplanning, and leaving ourselves completely vulnerable to unexpected circumstances, exactly like this solar panel issue?
NASA routinely plans from 3-5 years out, to a decade or more. This is made necessary by the fact that planetary launch windows, if missed, may not recur for two years (Mars) or two _centuries_ (Pluto). Also, the hardware takes from months to years to assemble, on top of months to years of design and review effort. Training for a flight takes months. The Shuttle also has to be overhauled so often, a process taking months, so you have to plan ahead to make time available for that. Etc... Etc...
By definition, electrocution means death. It is one of those misused words of the English language.
What's a better word that leaves no ambiguity? Shock, needs to be specified and the wording will be awkward as it sounds odd to say he will be "electrically shocked," or could experience "electric shock." The etymology of the word from dictionary.com says is came from "electric" + "(exec)ution." It's clever, because it provided nearly an instantaneous and seamless integration into the English language since e
So, will he return to Earth as V'Ger? Or, will he come back as Nomad, seeking one Jackson Roykirk. In either case, he'll probably return to "eliminate carbon-based infestation"... Yikes... Is this a job for Shatner, or will he just holler "Khhhaaaaannn!"?
Good luck to them. I hope all goes well, the repair is made, and nobody gets hurt.
That bit about not being able to take it down for repair, well, that's going to make it into some future book on industrial design. Oh, and into future space stations. I hope.
That bit about not being able to take it down for repair, well, that's going to make it into some future book on industrial design.
Pray tell, short of covering the solar array from view of the sun, how do you stop solar cells from generating electricity? It is a passive electricity generating device, not an active one (like a fuel cell or a conventional gas-powered generator). As long as it has a sufficient view factor of a light source, it generates electricity.
including the remote possibility of electrocution since it is impossible to stop the solar panel from generating electricity during the repair attempt
Forgive my ignorance, but are they going to do this spacewalk repair bare-handed? Is there at least two exposeds part of a spacesuit that is conductive from the outside to the inside (you need two points to complete a circuit)? If there's something like aluminum ring seals at the wrists, have another crewmember double wrap them with duct tape or electrical tape before sending them outside.
How does electrocution come into play with this? Dielectric breakdown through the suit shouldn't be an issue as I seem to recall on a previous story that we're talking roughly 160VDC potential, nearly the same as US household wall socket voltages. Deadly? Yes. Arc through your spacesuit (twice)? Hardly.
Flight controllers have already warned Parazynski not to touch the electricity-generating solar cells that cover virtually the entire wing. If the metal of a tool he was holding melted, it could burn a hole into his glove.
But wouldn't result in a burn injury or the risk of death due to decompression and not electocution?
Maybe I'm being too pedantic on the definition of electrocution, which is death from electric shock, not death resulting from some failure caused by an electrical discharge.
Yes, that [slashdot.org] is a valid concern, but that is not from TFA [msn.com]. In fact, the only mention of electrocution comes directly from the slashdot editor's/submitter's summary:
including the remote possibility of electrocution since it is impossible to stop the solar panel from generating electricity during the repair attempt.
The above quote rather explicitly attributes the danger of electrocution from electricity being generated from the solar panel, not the discharge from static build up.
The short of it (no pun intended): Electrocution from the electrical current from the solar array? No. Electrocution due to a static discharge? Possibly yes, but it's not the
Simple solution: make sure his tether is non-conducting. Use one of those MMUs so the astronaut can be autonomous instead of on an umbilical. Or am I overlooking something?
If you read the article, in fact if you had merely completely read the summary, you would understand that solar panels can not be turned off. Even in the absence of direct sunlight (which only occurs for a maximum of 36 minutes each orbit) they will still develop some power due to reflected light. You would also have noted that electrocution is a "remote risk."
If the problem were anywhere downstream of the sequential shunt units, they could lockout/tagout (btw, there is no OSHA in space), but it's upstre
Impossible to stop the solar panel from generating (Score:5, Funny)
Re:Impossible to stop the solar panel from generat (Score:2)
Because.... (Score:3, Insightful)
If there were an easy way to fix this, NASA would have figured it out. Don't forget, these fix rovers millions of miles away by changing computer code. I'm sure any suggestion here on /. has been thought of already.
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Irrelevant to my point. (Score:3, Insightful)
And I know there's going to be a ton of posts implying that the NASA folks should have thought of [insert idea here]. Of course they did.
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And I know there's going to be a ton of posts implying that the NASA folks should have thought of [insert idea here]. Of course they did.
While I largely agree with all you've said here... Sometimes people just don't think of things, no matter how bright they are. Case in point: an actual phone call I received at 1:30 AM the other day -- "the dishwasher is stuck on and we can't figure out how to stop it". My response: um... just unplug it? "oh, heh, yeah, okay." This was from a grad student (physics) working for me part time. She's very bright and generally has practical skills too. Sometimes people just don't think of things.
Now, having sai
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No offense, but I don't think you can apply "very bright" to someone that didn't think of unplugging an electrical appliance on their own......
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Actually, I'm kinda hungry right now.
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And that was my point. Just because someone is bright, doesn't mean they will automatically think of every solution to a particular problem. Intelligence is not a free pass to discovering stuff (though it helps a lot!).
In the case of this particular example, she had done several other things in an effort to solve the problem, any number of which were potentially viable solutio
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NASA has made errors that have killed people by ignoring somebody who got it right. Of course, the original question about working while the station was on the dark side of the earth forgets the fact that the station rotates earth in less than an hour, and few spacewalks last fewer than 3 or 4 hours.
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The damage to the joint affects the opposite panel.
Blue tarp? (Score:2)
As for why they can't just wait for night, the period of the ISS orbit is about 93 minutes [wikipedia.org]. They'd have to work fast.
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Re:Blue tarp? (Score:4, Interesting)
In fact, I seriosly doubt that any non-magnetic glue will work well at that temp.
Parent
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Re:Impossible to stop the solar panel from generat (Score:2)
I mean, the Emperor from Star Wars should be able to blast cosmic rays at him and he should just shrug it off like morning dew.
Re:Impossible to stop the solar panel from generat (Score:4, Funny)
Parent
Re:Impossible to stop the solar panel from generat (Score:3, Insightful)
Re:Impossible to stop the solar panel from generat (Score:2)
Re:Impossible to stop the solar panel from generat (Score:3, Funny)
Silly, the astronauts would be asleep at night. :-P
Deadline (Score:5, Interesting)
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Because they missed 2001.
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Nothing motivates like a deadline. It may seem arbitrary, but NASA is doing lots of good, hard work on the ISS these days, and I think maybe that's because the pressure's on.
Re:Deadline (Score:5, Informative)
No, it was created by the CAIB subsequent to the loss of Columbia.
No, because the CAIB requires the vehicles be recertified to extend their lives beyond that date - a very expensive and difficult process.
That being said - another limit, currently, is contractural. NASA has only contracted for so many External Tanks, SRB refurbishments, etc... Unless Congress coughs up more money (and approves the delays in converting facilities to support Ares/Constellation - I.E. more money) it simply isn't going to happen.
NASA routinely plans from 3-5 years out, to a decade or more. This is made necessary by the fact that planetary launch windows, if missed, may not recur for two years (Mars) or two _centuries_ (Pluto). Also, the hardware takes from months to years to assemble, on top of months to years of design and review effort. Training for a flight takes months. The Shuttle also has to be overhauled so often, a process taking months, so you have to plan ahead to make time available for that. Etc... Etc...
Parent
Hope they brought the duct tape... (Score:5, Funny)
Away Team extra crewman (Score:5, Funny)
Of all the crewmembers aboard the ISS/Space Shuttle, Parazynski is the most experienced.
If NASA were going to kill off a character, they'd send out one of the junior redshirts to do the repair job.
- RG>
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By definition, electrocution means death. It is one of those misused words of the English language.
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Language isn't something you find in a book.
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What's a better word that leaves no ambiguity? Shock, needs to be specified and the wording will be awkward as it sounds odd to say he will be "electrically shocked," or could experience "electric shock." The etymology of the word from dictionary.com says is came from "electric" + "(exec)ution." It's clever, because it provided nearly an instantaneous and seamless integration into the English language since e
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D'oh! (Score:4, Insightful)
That bit about not being able to take it down for repair, well, that's going to make it into some future book on industrial design. Oh, and into future space stations. I hope.
Re:D'oh! (Score:5, Insightful)
Pray tell, short of covering the solar array from view of the sun, how do you stop solar cells from generating electricity? It is a passive electricity generating device, not an active one (like a fuel cell or a conventional gas-powered generator). As long as it has a sufficient view factor of a light source, it generates electricity.
Parent
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4B or not 4B (Score:2, Funny)
(An upgrade to Hamlet's rhetorical question)
We're gonna need a bigger roll of Cello Tape.
Electrocution? (Score:3, Interesting)
Forgive my ignorance, but are they going to do this spacewalk repair bare-handed? Is there at least two exposeds part of a spacesuit that is conductive from the outside to the inside (you need two points to complete a circuit)? If there's something like aluminum ring seals at the wrists, have another crewmember double wrap them with duct tape or electrical tape before sending them outside.
How does electrocution come into play with this? Dielectric breakdown through the suit shouldn't be an issue as I seem to recall on a previous story that we're talking roughly 160VDC potential, nearly the same as US household wall socket voltages. Deadly? Yes. Arc through your spacesuit (twice)? Hardly.
Re:Electrocution? (Score:4, Informative)
Parent
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But wouldn't result in a burn injury or the risk of death due to decompression and not electocution?
Maybe I'm being too pedantic on the definition of electrocution, which is death from electric shock, not death resulting from some failure caused by an electrical discharge.
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Blame the summary. (Score:2)
Yes, that [slashdot.org] is a valid concern, but that is not from TFA [msn.com]. In fact, the only mention of electrocution comes directly from the slashdot editor's/submitter's summary:
including the remote possibility of electrocution since it is impossible to stop the solar panel from generating electricity during the repair attempt.
The above quote rather explicitly attributes the danger of electrocution from electricity being generated from the solar panel, not the discharge from static build up.
The short of it (no pun intended): Electrocution from the electrical current from the solar array? No. Electrocution due to a static discharge? Possibly yes, but it's not the
Perpetual power generation you just can't turn off (Score:4, Funny)
Man, do we need one of these things on Earth, RIGHT NOW!
Electrocution? (Score:2)
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As long as he makes repairs with one hand ... (Score:2, Funny)
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If the problem were anywhere downstream of the sequential shunt units, they could lockout/tagout (btw, there is no OSHA in space), but it's upstre