10 ms·
Cable lacing on the Curiosity rover
- ktizo 14y agoI love the fact that there are people, who when faced with photographs sent from a robot on mars, will crop out all the bits of image with mars in them, so they can get a better look at the knots used to tie all the cables down. They must have absolutely immaculate sock drawers.
- dfc 14y agoOr they just really like knots. Why do you think that an interest in knots means that someone is going to be OCD about everything else in their life? Different people like different things. Just because they geek out on something different from what you geek out on does not make them abnormal.
- ktizo 14y agoI was being nice. I genuinely do love them for this and I found it really interesting. I am also allowed to find it funny though. And I am sorry for stereotyping an entire group so lazily. I am sure that many of them actually have really messy sock drawers, if only in the hope of waking up to a really interesting variety of knot.
- marshray 14y agoIt may be that their socks are all a mess, but I bet their shoes are laced perfectly.
- JonnieCache 14y agoIf you like this, then Ian's Shoelace Site will bring tears of joy to your eyes. http://www.fieggen.com/shoelace/ http://www.fieggen.com/shoelace/ I think it is perhaps the single greatest website on the entire internet.
- arkhaix 14y agoTonight I learned that I've been tying my shoelaces the wrong way (granny knot) for as long as I can remember. Thank you, JonnieCache.
- aidos 14y agoI've been using the Ian knot for years, it's absolutely brilliant. http://www.fieggen.com/shoelace/ianknot http://www.fieggen.com/shoelace/ianknot
- henrikschroder 14y agoJoin the club, I was 31 when I finally learned how to tie my shoes properly. So much for doing as my mother taught me...
- fusiongyro 14y agoI've been using Ian's secure shoelace knot for about two years now, it's really fantastic. http://www.fieggen.com/shoelace/secureknot.htm http://www.fieggen.com/shoelace/secureknot.htm
- zerostar07 14y agoCan't blame them. So far it's just rocks.
- VLM 14y agoIts hacker news, not daytime television. We don't have to pretend to be boring middle of the road when talking to each other. What I find fascinating about this story is I've seen much larger and much more elaborate cable lacing jobs that look just as good at telco central offices and data centers, but its always very vague about what exact part of my NDA or employment agreement I'd be violating by posting (or taking, or distributing) pictures. These mars pictures, cropped, may be the only chance for a civilian non-employee to ever legally see professionally done cable lacing, weird but true. There's a zillion other places to see the surface of mars, but only a few to see cable lacing. Its interesting that in advertising pictures they always use superglue to make the cables look "PHB-good". So you can't see cable lacing in ads, which is too bad. Done correctly, cable lacing is, literally, an art form. One guy I worked with "knitted" geometric patterns as he spaced the lacing in various locations and used different colors. Also I saw at least one large example of AT+T being "dot matrixed" into a large bundle of cables by careful spacing of lacing. Artistic cable lacing is kind of an "apprentice" masterpiece situation, you learn lacing well enough to do art, then you show it to other techs (and your boss) to prove you're not an apprentice anymore, then, sadly, for most techs, no more lacing art work. Oh well.
- mlni 14y agoWell, there's always http://www.reddit.com/r/cableporn http://www.reddit.com/r/cableporn
- jedc 14y agoWhoa! I literally had no idea there were sub-reddits so, um, specific.
- tripzilch 14y agoThere's way more than you can imagine (or at least, that I can). Another interesting point is that in general, the more specific the sub-reddit, the less it is infected with the type of "reddit culture" that gets so much bad rep here on HN (although occasionally it always gets some, cause Reddit has a shared culture--I personally don't mind, really).
- quux 14y agoI zoomed in on the cable lacing, and my sock drawer is a disaster.
- ktizo 14y agoI found it fascinating, and I have a randomly sorted bag of nearly identical black socks at the moment as I find it easier than bothering with the whole draw and sorting thing.
- flatline3 14y agoYour backhanded compliment is a bit disturbing for being the top comment. I've largely dismissed the complaints about the HN community becoming more negative, largely thinking that mature realism was being mistaken for unwarranted negativity. However, this comment, along with the negative comments about the uptime of Tindie's blog (http://news.ycombinator.com/item?id=4472348 http://news.ycombinator.com/item?id=4472348), has me thinking that these complaints of undue negativity are justified. I find the attention to detail involved in selecting knots to be a tremendously interesting aspect of sending a physical vehicle to mars, and I find it to be a testament to human specialization and intelligence that there's a whole community of knot experts that can provide so much insight into the knot choices. Implying some sort of OCD around sock drawers seems incredibly rude, and counter-productive to building or maintaining a culture of technical excellence.
- libria 14y agoI've read and reread ktizo and I'm not seeing the negativity. He drew a correlation based on their attention to detail and if mistaken should be about as insulting as mathematical error. Perhaps there's a cross-cultural interpretation associated with sock drawers that I'm missing. Granted there has been negativity on HN lately, but are we not manufacturing drama here? //edit: I read it that he's impressed with their focus and passion, which sounds more like a compliment.
- ktizo 14y agoPerhaps there's a cross-cultural interpretation associated with sock drawers that I'm missing I do hope so. As then there is a chance that we might find out what it is and then everything might just make sense. Otherwise I'm just going to paraphrase Keynes and assume that internets can remain irrational a lot longer than I can stay sober.
- flatline3 14y ago"I love that ..." is the rhetorical equivalent of "Don't take this the wrong way, but ..." There's a pretty clear implication that it's silly to "crop out" pictures of mars, focus on knots, and the kind of people that would do that would be OCD in their maintenance of sock drawers. It's a silly, vaguely cutting generalization. Observe the top reply, which takes a defensive stance: http://news.ycombinator.com/item?id=4474178 http://news.ycombinator.com/item?id=4474178
- kabdib 14y agoI love reading about flight hardware. I have a bookshelf full of this stuff. Mars itself is neat. But they haven't done much exploration with this rover yet, and so: Knots is what we got. :-)
- kghose 14y agoTwo words: zip tie.
- sosuke 14y agoPerhaps zip ties can't withstand the changes in pressures or heat. Expansion, contraction, and all that mess. I'm simply arm chair guessing here.
- skorgu 14y agoThe link itself addresses this: Overtightening of cable management bindings can cause conductor breakage, insulation damage, excessive chafing, and deformations between the conductive, dielectric, and shield parts of a cable, and no doubt a host of other issues. It is one of the classic problems with ratcheting plastic cable ties (i.e. "zipties") that they only have quantized adjustment steps and cannot be easily loosened. While zipties with a metal tooth insert do allow for smoother tightening, the possibility of this tiny metal part coming loose near electronics generally excludes their use. That zipties cannot easily be loosened or adjusted during tightening makes them more prone to being left in an overtightened state. Difficulty of adjustment might also be considered a possible strike against using the Constrictor Knot (and similar knots) for this application.
- kghose 14y agoI'm not convinced by this explanation. A skilled person will do fine with a zip tie. Knots once tied should not be easy to untie in such applications - you don't want possibility of failure. An over tightened zip tie can be quickly cut away. The thing that seems reasonable to me is lacing works for thin cabling, but if you have a fat bundle of cables (say 5mm or more in diameter) I can't really see a big problem for zip ties.
- jahg 14y agoLacing is lighter, and mass matters.
- deleted 14y ago
- antsam 14y agoAn entire forum about knot tying?! Sign me up!
- svdad 14y agoThis is awesome. I'm going to lace all my cables now. In these kinds of applications, what do they use to attach the cables to something? It looks like on the rover they have special tie points built onto the rover surface -- is that what is done in other applications too?
- stewartbutler 14y agoEither they are laced parallel to a support strut, which can be thought of as a very hard wire, or lashed down to some support point. You can also see this in large data centers. http://www.reddit.com/r/cableporn http://www.reddit.com/r/cableporn
- eckyptang 14y agoGreat link. There goes my afternoon :-) The first item is amazing as well (ST-124-M3 inertial platform i.e. Gimbal unit for Saturn V) About: http://en.wikipedia.org/wiki/ST-124-M3_inertial_platform http://en.wikipedia.org/wiki/ST-124-M3_inertial_platform Pron: https://upload.wikimedia.org/wikipedia/commons/4/44/ST-124_uncovered_%28IMGP3445%29.JPG https://upload.wikimedia.org/wikipedia/commons/4/44/ST-124_u... This sort of engineering is as much art as engineering and I truly respect the people who designed and built it.
- johnchristopher 14y agoWhy are the cables exposed ? Wouldn't it better to fix them inside the rover and only have the relevant ends pop out when there is a need to connect to a device located on the outside of the shell in order to reduce interferences and external damages ?
- natep 14y agoMy guess is that they have cables on the outside _and_ inside, and putting yet another cover over the outside cables would mean more mass. As-is, they only have to worry about wind and sand, so extra metal shielding is probably not necessary.
- marshray 14y agoIf an advanced alien species someday finds this rover on Mars (or probably any other space probe launched by NASA) and examines it, what will this method of knotting tell them about the state of human mathematics? For example, is it possible that there exists another, more optimal, type of knot that we should have chosen had only our knot theory had been more advanced?
- ars 14y agoI doubt it. See: http://en.wikipedia.org/wiki/Trefoil_knot http://en.wikipedia.org/wiki/Trefoil_knot
- nicklaforge 14y ago"Knot theory" always concerns strings that are joined at either end to form a closed circuit. Regardless, I don't think abstract mathematics does much for you when the problem is so simple and 'practical'.
- deleted 14y ago[deleted]
- ivix 14y agoDoes anyone know why so much cabling on Curiosity is on top of the vehicle, exposed to the elements? Surely it would be safer to contain those cables in the body? It would just take a rock to fall on the rover from a cliffside or similar to damage those cables.
- papercrane 14y agoJust a guess, but maybe its to make diagnostics easier. If something is wrong they can image the cables and look for breaks.
- noonespecial 14y agoFor just a moment, I found myself worried about how they would hold up when it rained...
- startupfounder 14y agoWouldn't that be a nice problem to have. The only way to fix it would be to send some humans to the rover for a repair job...
- Retric 14y agoThere is not much in the way of 'elements' on Mars. If you look closely the cables are encased in something, but static electricity and dust storms are the largest problems and fairly easy to deal with.
- eckyptang 14y agoJust had to post this photo which I found after looking around as it's related: http://upload.wikimedia.org/wikipedia/commons/4/46/System_Test_of_the_Saturn_V_Instrument_Unit_%286861934%29.jpg http://upload.wikimedia.org/wikipedia/commons/4/46/System_Te... Saturn V instrument unit. Awesome piece of engineering.
- snowwrestler 14y agoCool picture. It looks to me like most of those long-running cable bundles are secured with black plastic zip ties--ironic given the text of the article.
- towndrunk 14y agoIf anyone is interested in more of these standard practices in regards to aircraft construction the following book details the proper methods that should be used. http://www.amazon.com/Standard-Aircraft-Handbook-Mechanics-Technicians/dp/0071348360/ref=sr_1_2?ie=UTF8&qid=1346765869&sr=8-2&keywords=aircraft+standard+practices http://www.amazon.com/Standard-Aircraft-Handbook-Mechanics-T...
- delinquentme 14y agoCan I get an explanation as to how the OP is making the claim that these are IN FACT these kind of knots? I mean I cannot see how this image is of sufficient resolution to support this.