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Voyager 2’s Discoveries from Interstellar Space
- ChuckNorris89 7y agoI'm amazed and still can't get my head around how today we can receive images and valuable data from a device which is currently lightdays away from us and was built with 60's technology & know-how and is operating well beyond it's expected lifetime. I raise my glass to the engineers who worked on this. Makes my daily programming tasks feel stupid in comparison. Edit: corrected, thanks for the numbers
- classified 7y agoYes, the notion of engineers knowing what they are doing and actually creating a reliable system seems to be largely alien to the HN crowd.
- Ancalagon 7y agoJust FYI nothing man made is even close to light years away from the Earth. EDIT: I don't understand the downvotes. Isn't this just fact? EDIT 2: I see the OP changed his original comment, so I can understand the confusion. Thanks all :)
- bobdole99 7y agovoyager 1 which is currently the farthest man made object from earth is approx 147 AU away, where as 1 light year is equiv to 63241.1 AU... so it has a little ways to go still :)
- jniedrauer 7y agoOur radio broadcasts are.
- Ancalagon 7y agoOk, nothing man-made of the spacecraft type...
- klyrs 7y ago> EDIT: I don't understand the downvotes. Isn't this just fact? Nobody's questioning that fact (barring well-deserved pedantry about radio signals), but GP's claim was light days so the downvotes are probably about the nonsequitur.
- RosanaAnaDana 7y agoDo radio signals count as man-made?
- mwcremer 7y agoFYI Voyager 1 is about 20 light hours away.
- tjoff 7y agoVoyager 1 is about 0,0023409 lightyears away from earth (voyager 2 is a bit closer than that). https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/
- Diederich 7y agoVoyager 1, the most distant probe, is about 0.002 light years away from the earth.
- petschge 7y agoVoyager 1 is 0.00234 light years from Earth, Voyager 2 is 0.00194 ly. Or in more useful units: 20.5 and 17 light hours. Also we do not receive images any more (the cameras were made for planetary encounters and have been turned off long ago). But yes, getting data (at 160 bits per second) from man made objects that are the better part of a light day away is impressive. Even more so because they have been working for 42 years now, 30 years past the initial planetary mission.
- wyldfire 7y agoAre they powered via PV? IIRC one of them (satellite/probes) had some nuclear fuel.
- FredFS456 7y agoThey're powered by Radioisotope Thermoelectric Generators. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
- Ductapemaster 7y agoBoth Voyager 1 and 2 use RTG's (Radioisotope Thermoelectric Generators)[1] for power. Every year the RTG puts out less and less power, so instruments are gradually powered down to preserve the functionality of the critical ones for as long as possible. According to JPL[2] at least one scientific instrument will continue functioning until about 2025, and the crafts will remain in range of the Deep Space Network until 2036. [1] https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge... [2] https://voyager.jpl.nasa.gov/frequently-asked-questions/ https://voyager.jpl.nasa.gov/frequently-asked-questions/
- outworlder 7y agoThe interesting thing is that they have plenty of fuel still, but the parts are degrading.
- 7y ago
- cryptozeus 7y agoAnyone has any details of how its implemented ? Arch diagram of some sort ?
- mopsi 7y ago"Uptime 15,364 days - The Computers of Voyager" is a pretty good introduction. https://www.youtube.com/watch?v=H62hZJVqs2o https://www.youtube.com/watch?v=H62hZJVqs2o
- mlthoughts2018 7y agoYeah but did they use Agile methods and have good team velocity as they burned down the backlog? If not, how can we really be sure the project was a success?
- mrbonner 7y agoI like your comment but it got down voted into oblivion probably because you forgot the /s tag. Some folks are serious here.
- saagarjha 7y agoHacker News isn't very accommodating of trite humor in my experience, so I doubt /s would have helped much here.
- kolinko 7y agoAgile shares a lot in common with practices mentioned in „Mythical man-month”, which in turn was based on the good practices from the Voyager era. Also, extreme programming was based in part on the TDD from Mercury program, iirc. Having said that - yes, cargo cult agile sucks, we all know that.
- mlthoughts2018 7y agoThe surgical team analogy at the core of TMMM is totally incongruent with agile principles. The book espouses a ton of anti-agile (small a) ideas.
- mixmastamyk 7y agoMaybe, I know he highly recommended iterative development in the silver bullet essay: http://eppsnet.com/2006/06/respect-the-classics-man-no-silver-bullet/ http://eppsnet.com/2006/06/respect-the-classics-man-no-silve...
- james_s_tayler 7y agoThey had escape velocity.
- dekhn 7y agoI know a person who worked on voyager. He is a very smart person who has contributed to a wide range of technologies over a long period of time. I have talked to him and the reality is that by the time that project was being done, the people who ran it had a lot of experience, and they applied the hell out of it to the project. I've spent a lot of time since then looking into how to build reliable systems that operate for decades and... there are no easy answers. You have to have an amazing amount of knowledge about the engineering context (what's it like to run a computer in space), the scientific mission (IE, given this payload mass, what instruments can we fit), judicious software engineering skills (just updating the firmware on a machine that's millions of miles away is a challenging problem, worse yet if updating the firmware bricks your control plane), project management skills (to ensure you make your launch date), and the dedication to keep things going long after most people got bored of them. After a long time playing with complicated systems I went back and played with 8-bit microcontrollers and they were actually really fun because it forces you to build systems that are reliable without a terminal and resource constrained (you'd have a hard time fitting a program as large as this comment into an arduino...)
- classified 7y ago> ...and the dedication to keep things going long after most people got bored of them. ... has become a virtual impossibility in the age of short-lived consumerism and fad-driven development.
- jacquesm 7y agoThe biggest factor working to their advantage was that the tech back then was much simpler and more robust. To get todays tech to work for a decade without interruption would be a very tall order. Layer upon layer of abstraction has made it impossible to know for sure that there are no edge cases that will only trigger once every 3 years or so.
- dekhn 7y agoI sort-of agree, although actually there is a lot of older stuff still made on fabs with huge (transistor) feature sizes and limited (software) feature sets that could be used to build extremely reliable long-term systems.
- russellbeattie 7y agoI used to have it in my head that the Voyager probes were about as powerful as an Apple II computer. But it's hard to make a direct comparison as the probes have three computers made of two processors each, running at 1/20th or 1/6th the speed of an Apple. So it's not a one-on-one comparison in any way, but for discussion purposes: An original Apple II used a MOS 6502 8-bit word CPU clocked at 1.023 MHz and typically had 4Kb to 48Kb of RAM. It ran about 500,000 instructions per second [1]. Computer Command System (CCS) - two 18-bit word interrupt-type processors with 4096 words each of plated wire memory. It ran about 25,000 instructions per second. [2] Flight Data System (FDS) - two 16-bit word machine with modular memories and 8198 words each of memory. It ran about 25,000 instructions per second. [2] Attitude and Articulation Control System (AACS) - two 18-bit word machines with 4096 words each of memory. The AACS ran about 80,000 instructions per second. [2] So maybe the total amount of computing power is equal? The total memory on a Voyager was about 32K [3], and since the word sizes were bigger, theoretically they could access larger chunks of memory in a single instruction? What's for sure is that a single CCS is at least an of magnitude less powerful than an Apple II. More info: 1) http://www.classiccmp.org/cini/pdf/Apple/Apple%20II%20Reference%20Manual%20-%20Woz.pdf http://www.classiccmp.org/cini/pdf/Apple/Apple%20II%20Refere... 2) http://www.cpushack.com/space-craft-cpu.html http://www.cpushack.com/space-craft-cpu.html 3) https://web.archive.org/web/20110721050617/http://voyager.jpl.nasa.gov/faq.html https://web.archive.org/web/20110721050617/http://voyager.jp...
- zaarn 7y ago>So maybe the total amount of computing power is equal? Probably not. Those 18bit words likely contain 2 bit parity to prevent space radiation from making this go bad. Plus, it's only one machine, not two, the two always run in parallel (for the CSS, the FDS only has one running at a time and AACS is turned off if not needed) and redundantly in case on fails, so in total you're running about 180'000 instructions per second, not 360'000. The memory totals 34 kilobytes (18bit words in two of the memories, 16 in the third), with a simple redundancy like the computer itself (ie, each computer has it's own memory). The CCS is also responsible for managing the memory of the other two systems (MEMLOAD), so their realistic instruction speed may be limited by slower memory access in memory heavy applications. Even all systems combined, I don't think the voyager is faster than an Apple II within an order of magnitude.
- Aperocky 7y agoImagine the systems that they worked with. In the 1970s, dealing with primitive electronic systems, often without screen and most definitely without a full OS. Goosebumps. To imagine that the tech phenomenon that we can only regard as recent (2000-) but there are people from as far as 30 years back before that, working on things that have lasting impact to us. I recently read bwk's Unix history and memoir, it's a great read, to see many of these pioneers being old and passed away is a great sadness.
- pvg 7y agoYou're making it sound like the Voyager software and hardware was developed by poking soft clay tablets with a pointy reed. The systems had OS's, screens were surely available, ICs and high-level languages were in use. The '[computer-ish] tech phenomenon' itself is a fair bit older - 'Silicon Valley' is named after literal, not figurative silicon-based electronic components.
- journalctl 7y agoMy favorite part is how everyone is jumping down your throat over a simple mistake in what was meant to be an expression of awe and admiration.
- wazoox 7y agoRelated, and relevant: https://en.wikipedia.org/wiki/Pale_Blue_Dot https://en.wikipedia.org/wiki/Pale_Blue_Dot Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there--on a mote of dust suspended in a sunbeam. The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known. — Carl Sagan
- cryptozeus 7y agoIts just simple is awe-inspiring
- daveslash 7y agoNot a comment of the article itself, but for anyone interested in both Voyagers, PBS recently did a great documentary called "The Farthest". I highly recommend it. http://www.pbs.org/the-farthest/home/ http://www.pbs.org/the-farthest/home/
- ngcc_hk 7y agoThanks but only for American
- daveslash 7y agoDo you mean that the website is not available outside of the U.S.? "The Farthest" is also on Netflix, but I don't know about non-US availability. It's also available for rent/purchase on Youtube. https://www.youtube.com/watch?v=Cu3kuUB1sOQ https://www.youtube.com/watch?v=Cu3kuUB1sOQ. If all else fails, it's available on DVD -- I bought two copies myself so I can loan it to friends without worrying about it being lost.
- Sendotsh 7y agoThe link just goes to a trailer for the movie which is available on DVD/iTunes/etc. You can see the same trailer on YouTube: https://www.youtube.com/watch?v=VwT3QgKORuQ https://www.youtube.com/watch?v=VwT3QgKORuQ
- stevenwoo 7y agoBBC made a series called The Planets (2019) that talks about almost all space probes from the last 30 years and the data retrieved so far, you might have access to that but not sure of your country.
- flurdy 7y agoI am always baffled by the conundrum of the futility of launching a spacecraft to go far away by our own ability to invent faster engines. Say it takes 300 years to get to Alpha Centauri. If you launch it you have 150 years to invent a spacecraft that goes twice the speed of the first one. Very likely. If you launch that one it will overtake the other one. Now you have 75 years to find an even faster engine. Launch it and you got 37 years. etc. Quite likely you can keep doing this until you can reach it in e.g. a year. So why not hold all launches until then.... Does this have a name? Or original source? Did I get this from Futurama?
- pm90 7y ago"Why should I buy a computer today, when a computer in 10 years can do a ton more for less money?"
- vardump 7y agoSay you built a computer in late 2009 with AMD Radeon HD 5870, Intel Core i7 975, Intel's X25-M SSD and 16 GB RAM. That computer would still feel pretty snappy today for desktop tasks, running dual 2560x1440 screens. Although new AAA games would probably have issues, either low frame rates or not running at all. Most indie games would work just fine. I think the change will be even less in next 10 years. 2019 hardware will perform just fine in 2029. Unless something dramatically different pops up, we're in the era of diminishing returns.
- stan_rogers 7y agoThat's more or less the result of having already waited. There was a time, not very long ago in the grand scheme of things, when the computer you wanted would cost $5000 and be essentially obsoleted by the $5000 computer coming in 60-90 days. (Perspective: PC review magazines of the day would usually include the time for a Gaussian blur on a 1MP image as a meaningful test.) When you were talking about cutting minutes off of a large spreadsheet recalc, the immediate gain from upgrading today had to be measured carefully against the even greater gains possible next quarter.
- 7y ago
- ngcc_hk 7y agohttps://www.space.com/22787-voyager-1-signal-interstellar-space-photo.html https://www.space.com/22787-voyager-1-signal-interstellar-sp... From her elder sister. Or “of”. It is just awesome.
- 2ion 7y agoFrom where no man will go.
- skvj 7y agoHere's a great illustration of Voyager 1 and Voyager 2 outside of the heliosphere: https://www.nasa.gov/press-release/nasa-s-voyager-2-probe-enters-interstellar-space https://www.nasa.gov/press-release/nasa-s-voyager-2-probe-en...
- SenHeng 7y agoIs there a reason why the left side of the heliosphere is so elongated? Is it simply because we haven't sent any probes there and so don't really know where it ends or is it really this oblong shaped?
- petschge 7y agoBecause the solar system is moving relative to the local interstellar medium. So effectively you get a "headwind".
- AcerbicZero 7y agoI'm disappointed that it even as it become very obvious we were going to continue gathering useful information from Voyager 1/2 and yet no follow on missions have been launched. I suppose the idea is that there is more to be gained via specialized missions inside the solar system, compared with new long running extreme range probes, but you would think there might be some value in starting to send a chain of probes out, so that communication can be maintained even further.
- toyg 7y agoThe cynic in me thinks that there is little marketing value in throwing probes into the void, whereas landing and taking pictures of “the new frontier” can be sold to the (taxpaying) public more easily.
- CDSlice 7y agoThe problem is we can't launch another Voyager mission. The Voyagers took advantage of the planets being aligned in just the right way to allow them slingshot through the outer solar system. This won't happen again for another 100 years or so. Now we could design probes that are just for going into interstellar space but it would be a hard sell when you are competing against missions like sending a drone to Titan. Even the New Horizons mission to Pluto barely made it through NASA's project selection process and IMO expanding our knowledge of Pluto is more valuable (and sellable to the public) than a mission to literally nothing.
- adventured 7y agoNew Horizons can and may do exactly that. http://pluto.jhuapl.edu/Mission/2019-Onward.php http://pluto.jhuapl.edu/Mission/2019-Onward.php "Future New Horizons extended missions, if funded by NASA, could explore even farther out. The spacecraft is on an escape trajectory from the Sun, traveling about three astronomical units per year. Moreover, New Horizons and its payload sensors are healthy and operating perfectly. The spacecraft has enough power and fuel to operate into the mid-2030s or longer, perhaps enough to reach the boundary of interstellar space."
- RosanaAnaDana 7y ago
- neonate 7y agohttp://archive.is/eOtiZ http://archive.is/eOtiZ
- Razengan 7y agoI've always fantasized about drifting out there in person. Wouldn't a human operator in such spacecraft gather more data by being able to reorient instruments in realtime etc. and spotting minute phenomena that would otherwise be missed? If NASA or Elon Musk or anyone has considered such a mission but can't imagine asking for volunteers for it, let me know. I don't need a ride back.