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Abandoned in space in 1967, a US satellite has started transmitting again
- samuell 10y ago> "This proves electronics built around 50 years ago, 12 years before Voyager 1, and far before microprocessors and integrated circuits are still capable of working in the hostile environs of space." I think in some aspect, it might be even more so (robust), than today's technology: Simpler, more to-the-point technology, leading to greater robustness. I think today's tech and IT industry has something to learn there, and I'm really happy about the "back to basics" trend in IT, going back to compiled, to-the-point languages like Go, closer-to-the hardware cloud systems etc.
- oxide 10y agoI wonder what kind of lifespan they were expecting out of this thing back when it was launched. I'd think you'd want a decent return in terms of longevity, considering the size and (I would assume) weight of it. I'd bet modern satellites are much more disposable by comparison.
- lexicality 10y agoI very much doubt anyone would consider something that costs hundreds of millions of dollars to build and fire into space "disposable". It's not like you can buy a new one for cheaper 5 years later.
- dogma1138 10y agoThey are considered disposable because the operating costs usually outpace their value once obsolescence sets in. Which is why many satellites are resold on secondary markets after their primary mission timeframe has passed.
- hollander 10y agoHow about Rosetta?
- gambiting 10y agoWell, you sort of can. The majority of cost is R&D, once that's done and you have a template for a satellite, you can definitely build more of them cheaper than the first one.
- deleted 10y ago[deleted]
- anexprogrammer 10y agoNo they wouldn't launch a spy satellite disposable camera that took one roll of film and was then useless after the film was jetisoned. https://en.wikipedia.org/wiki/Corona_%28satellite%29 https://en.wikipedia.org/wiki/Corona_%28satellite%29
- InclinedPlane 10y agoThe reverse is the case. Longevity of satellites had increased over time. This is due to a variety of reasons ranging from materials and design improvements to more advanced electronics and superior stationkeeping thrusters as well as reduced reliance on consumable components. Early spy satellites, for example, relied on film that was returned to Earth, once the film ran out the satellite was useless. Other satellites simply became obsolete or lost attitude control and were no longer useful. Telstar had a service life of only about a year, the first half dozen TIROS weather satellites had lifetimes of about a year or less. Today satellites with similar missions are expected to last decades, which they often do.
- mikeash 10y agoAnother reason is that nobody is detonating nuclear bombs in space these days. A major cause of Telstar's short life was intense radiation from high-altitude nuclear tests. I'm not sure how long it would have lasted without that....
- InclinedPlane 10y agoHah, well, that only happened once. And even so the overall lifespan of satellites was not very long back then.
- mikeash 10y agoYeah, I definitely get the impression that Telstar might have lasted two years instead of one if not for the nuclear tests, but not decades.
- deleted 10y ago[deleted]
- sorokod 10y agoUm... isn't this indicator of further decay of the system? Like a cadaver that fills up with gas and starts emitting sounds.
- qbrass 10y agoImagine the cadaver was just some person who walked on a treadmill of a windmill when the wind wasn't blowing. The person died on the treadmill, and since this was out in the middle of nowhere, the whole scene was left untouched. The corpse gets wedged into the gearing and the machine stops until the body rots enough that what's left falls free and the gears start moving again when the wind blows.
- Someone 10y agoI think the main lesson would be that making your transistors and switching currents enormously large is good for longevity in space, but that's nothing new.
- samuell 10y agoWell, I was also thinking about (but didn't write) that most mission-critical systems aren't written in javascript :) ... but rather something "ancient" like ada or pascal.
- dom0 10y agoI kinda doubt that any satellite from this era ran a high level language.
- kuschku 10y agoWhy? The first high level languages were already existing in 1942, so it’s not that far fetched. EDIT: As I can’t answer to comments due to the retarded "you are submitting too fast" rule, here is a source: https://en.wikipedia.org/wiki/Plankalk%C3%BCl https://en.wikipedia.org/wiki/Plankalk%C3%BCl
- pjc50 10y ago.. on room-sized computers. VLSI hadn't been achieved yet, so Apollo flew with a suitcase-sized computer made from discrete gates and core memory programmed in assembler by Margaret Hamilton and others. https://github.com/chrislgarry/Apollo-11 https://github.com/chrislgarry/Apollo-11 I doubt the satellite bothered with a processor.
- Rooster61 10y agoNot trying to be pedantic or a dick, but you should refer to that language as assembly, not assembler. It is a non trivial difference as assembly refers to the language and assembler refers to the software written to parse assembly commands into machine code (binary strings defined in the given machine's instruction set that are meaningful to the processor). Otherwise it's similar to referring to the language C as Compiler, which is just silly :) http://stackoverflow.com/questions/1176138/assembly-vs-assembler http://stackoverflow.com/questions/1176138/assembly-vs-assem... Also, to your point, agreed. It took several years before we could actually fly high level, compiled languages in space, the first being HAL/S on the Shuttle (completed in 1975). https://www.cs.toronto.edu/XPL/hal.html https://www.cs.toronto.edu/XPL/hal.html Cheers
- kalleboo 10y agoUnlike this one that never worked properly, two other satellites launched in the same series, LES-8 and LES-9 are still functioning as designed. They were powered by RTGs (radioisotope thermoelectric generator) rather than batteries/solar though.
- pjc50 10y agoRecently I've been working my way through the PPrune megathread on Concorde: http://www.pprune.org/tech-log/423988-concorde-question-77.html http://www.pprune.org/tech-log/423988-concorde-question-77.h... , in which (somewhere) is a discussion of the control systems. Analog fly-by-wire! A complex set of "synchro" and "resolver" systems connected to op-amps, giving it autostabilisation and autothrottle all the way up to Mach 2. The pilots would just push the throttles full open on the runway and leave them there until it was time to come down.
- concerned_user 10y agoAFAIK Concode only uses ~80% thrust on takeoff due to vibrations engines create and risk of overheat. Also fuel gets pumped around to change CG, it is a fascinating piece of machinery.
- pjc50 10y agoIt's all in that thread :) The 80% limit was only on one engine, due to vortex issues. The others had to be at "100%" and full afterburner to get off the ground. The actual volume of fuel flow for a particular power level was also determined by an analogue computer measuring the inlet air temperature and pressure. http://www.pprune.org/tech-log/423988-concorde-question-4.html#post5887403 http://www.pprune.org/tech-log/423988-concorde-question-4.ht...
- anexprogrammer 10y agoRelevant distraction: Nice in cockpit vid of pre takeoff CG and fuel transfer checks, take off, and after checks. 10m. http://www.liveleak.com/view?i=16a_1231096566 http://www.liveleak.com/view?i=16a_1231096566 Low light takeoff, because pretty: https://www.youtube.com/watch?v=l7mt6AKKhq4 https://www.youtube.com/watch?v=l7mt6AKKhq4
- digler999 10y agoNSFW warning for the liveleak vid, if you're at work the site contains porn ads.
- friendzis 10y agoOne thing about tech in hostile environments is resilience to radiation, which is more or less proportional to number of electrons in junction. With smaller fabrication process we win lower energy consumption and much better integration, but at a cost of radiation resilience.
- vasaulys 10y agoThere's a certain level of intuition that one can grasp with hardware as opposed to software. I suspect this might contribute to most robustness in design.
- mc32 10y agoDidn't they used to build navigation systems using analog components so in the event of EMP your systems would have a chance of keeping on working?
- nowarninglabel 10y agoReminds me of: "It is then determined MPU is actually an old spy satellite disguised as a weather satellite, that was programmed to reactivate after a certain period of receiving no commands."
- fader 10y agoTo save others from having to Google this, it's a Cowboy Bebop reference: http://cowboybebop.wikia.com/wiki/Jamming_with_Edward http://cowboybebop.wikia.com/wiki/Jamming_with_Edward
- ttyl0125 10y agoThis situation sounds similar to what happened with AO-7: https://en.wikipedia.org/wiki/AMSAT-OSCAR_7 https://en.wikipedia.org/wiki/AMSAT-OSCAR_7 Satellite is launched, goes silent after a few years due to electrical problems. Decades later, the onboard batteries have deteriorated such that they're just a short (no storage capacity), and the satellite works intermittently when the solar panels are exposed to enough sunlight.
- madengr 10y agoActually an open circuit.
- rhaps0dy 10y agoNo, a short. Or closed circuit.
- klodolph 10y agoThe short in the battery was the original problem. The short eventually became open 21 years later, which made things work.
- LeifCarrotson 10y agoThe solar panel, battery, and load are all in parallel. Like this: https://www.circuitlab.com/editor/#?id=swpddv https://www.circuitlab.com/editor/#?id=swpddv There's probably some charge control electronics, but that's the gist of things. When the battery is discharged or shorted, the solar panel would need to raise the voltage to power the load. When the battery fails as an open circuit, the solar panel can power the load directly.
- userbinator 10y agoIn 2013 in North Cornwall, UK, an Amateur Radio Astronomer picked up a signal which he determined to be the LES1 that was built by MIT in 1965. The date in the URL and article says 2016 though, so I'm still not completely clarified on whether this is 3-year-old news or if the satellite is now transmitting again, again --- actually, looking at the name of the site... I'm leaning towards the former.
- grendelt 10y agoIt's 3 year old news rehashed in 2016 by this blog. Look up history of LES-1.
- rubyfan 10y agodaisy, daisy give me your answer do
- mgleason_3 10y agoDoesn't this remind anyone of "Star Trek IV: The Voyage Home"? ...Where an alien probe comes into earths orbit wreaking havoc to check on the whales and turns out to be an early satllite from earth... Man, I'm gettin' old.
- oldmanjay 10y agoYou're getting old enough to mix the plots of the 1st and 4th movies together. V'ger was the early earth satellite that the enterprise chased down. The probe seeking humpback whales was of alien origin. According to what I remember of the novelization, the aliens had visited earth before recorded history. I'm not happy I read the novelization of a Star Trek movie, but there we are.
- outworlder 10y agoV'ger stands for Voyager, with some letters faded-out. Thus, not an earth satellite... I guess we are all getting old here.
- Saturnaut 10y agoYou are mixing up two different Star Trek movies. The ship from 'The Voyage Home' wasn't a man made satellite, it was an alien "whale" ship. However in the first Star Trek movie, a massive ship threatens Earth but turns out to be Voyager 1 returning home.
- mgleason_3 10y agoDang, that right! Always thought those two were stangely similar...