[HN Gopher] NASA engineers make progress toward understanding Vo...
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NASA engineers make progress toward understanding Voyager 1 issue
Author : LinuxBender
Score : 234 points
Date : 2024-03-14 15:02 UTC (7 hours ago)
(HTM) web link (www.theregister.com)
(TXT) w3m dump (www.theregister.com)
| smackeyacky wrote:
| I don't want to personify it but it's like a last plea from space
| asking for help billions of kilometres from home. I hope the nasa
| engineers can either patch it up or quietly put it to sleep.
| Vecr wrote:
| There's no suffering issue, there's zero point in turning it
| off. The only thing you'd do is re-allocate DSN resources at
| some point if someone else really needs them.
| sph wrote:
| Is Voyager 1 in hibernation mode because the RTG is not producing
| as much power, or is it because most components have failed, but
| could in theory still be powered on? I do not know how long an
| RTG lasts for.
| tokai wrote:
| From wikipedia: "generate approximately 157 Watts of electrical
| power initially - halving every 87.7 years"
|
| It should still have power.
|
| https://en.wikipedia.org/wiki/MHW-RTG
| anotherhue wrote:
| The thermo couples also degrade so halve the power again.
| Biggest issue is keeping the fuel warm so the antenna can
| stay aligned.
|
| https://www.itsquieterfilm.com/
| nullhole wrote:
| Called a "poke" by the team, the command is meant to gently
| prompt the FDS to try different sequences in its software package
| in case the issue could be resolved by going around a corrupted
| section.
|
| The apparent foresight of the original programmers is impressive
| though maybe not too surprising given the conditions they
| expected.
|
| I'd be curious to know if anyone has any book recommendations on
| software design for space missions; I suspect there would be some
| lessons in there around testing and reliability that could inform
| more day-to-day stuff.
| isolli wrote:
| I can't recommend a book, but I watched this video a while ago,
| and I found it riveting: "Light Years Ahead | The 1969 Apollo
| Guidance Computer" [0]
|
| > Robert Wills introduces the amazing hardware and software
| that made up the Apollo Guidance Computer, walks you through
| the landing procedure step-by-step, and talks about the
| pioneering design principles that were used to make the landing
| software robust against any failure.
|
| [0] https://www.youtube.com/watch?v=B1J2RMorJXM
| araker wrote:
| Thanks for sharing, this is a great talk.
| isolli wrote:
| I also read this a while ago [1]:
|
| "The Voyager's computer system was very impressive as well.
| Knowing the craft would be on its own much of the time, with
| the lag between command and response from Earth growing longer
| the farther the craft went into space, engineers developed a
| self-repairing computer system. The computer has multiple
| modules that compare the data they receive and the output
| instructions they decide on. If one module differs from the
| others, it's assumed to be faulty and is eliminated from the
| system, replaced by one of the backup modules. It was tested
| shortly after launch, when a delay in boom deployment was
| misread as a malfunction. The problem was corrected
| successfully."
|
| [1] https://science.howstuffworks.com/voyager.htm
| anonymous_user9 wrote:
| Software isn't the sole focus, but you may enjoy "Computers in
| Spaceflight: The NASA Experience", a 406-page history of
| manned, unmanned, and ground computers from the beginning
| through the shuttle era.
| https://ntrs.nasa.gov/citations/19880069935
| CamperBob2 wrote:
| It's not specifically a text on software design, but _Sunburst
| and Luminary_ by Don Eyles is an enjoyable read (
| https://www.amazon.com/Sunburst-Luminary-Apollo-Don-Eyles/dp...
| ). He manages to capture the Apollo-era zeitgeist in more ways
| than one. Not just another tale from the trenches.
| maicro wrote:
| Also not a book, but I read this article a couple years ago and
| it's stuck in the back of my mind since:
|
| https://www.fastcompany.com/28121/they-write-right-stuff
| chasd00 wrote:
| > gently prompt the FDS
|
| do you suppose their system prompt ensures it responds more
| favorably to gentle commands? ;)
| KineticLensman wrote:
| Sunburst and Luminary by Don Eyles, one of the AGC coders, is
| an outstanding read. Specific to AGC but indicates some of the
| challenges
| piokoch wrote:
| Voyager 1/2 is a pick of human achievements in XX century. A
| piece of hardware run by the computer having a power that today
| car keys have is flying for over 40 years in the space, outside
| Solar system, delivering priceless information.
|
| People do not realize how amazing engineering it must be.
|
| One can watch https://en.wikipedia.org/wiki/The_Farthest to
| appreciate fully what all those great man did and are still
| doing.
| anotherhue wrote:
| There's a second film that's a little more recent, was on Prime
| video last I looked.
|
| https://www.itsquieterfilm.com/
| nickburns wrote:
| https://en.wikipedia.org/wiki/Women_in_NASA
| detourdog wrote:
| The inverse is also true. This demonstrates how underwhelming
| current engineering is.
| queuebert wrote:
| Or maybe hardware overkill. I have a soft spot for small,
| dedicated computers like the Apollo Guidance Computer that
| have physical buttons and simple functionality. The DDIs on
| jet fighters are another example.
| detourdog wrote:
| From my perspective microprocessor grew up around the
| general purpose computing model. Now the microprocessor
| power has far outpaced the the actual human needs the focus
| on general purpose is inefficient.
|
| I see efficiencies to be gained in the overall integration
| of very task specific computers in common network.
| malfist wrote:
| Is it? Key fobs probably cost dollars to manufacture. Voyager
| cost $865 million....in 1977.
|
| Maybe my key fob uses compute power wastefully. But I'd
| rather it cost a few dollars than everything that needs that
| amount of processing power costing hundreds of millions of
| dollars.
| detourdog wrote:
| I don't think a key fob is a good example. I think if you
| look at what goes into word processing for the average
| office or almost any other office task would be my example.
|
| My point is that early on general purpose computing was
| needed to drive the cost of computing down. I think we are
| past that stage and it is now time to look at making
| everything as simple and efficient as possible.
| class3shock wrote:
| I think most engineers from back then would be astounded with
| the engineering of today, not underwhelmed.
| detourdog wrote:
| I could see them being impressed with the human
| achievements. I have doubts if they would be impressed by
| the engineering. Everything I see looks more like the
| results of human hours spent.
|
| Consider giving those old timers the same problem with
| todays resources and I think we would get great results.
| magicalhippo wrote:
| Tried checking out how they make the processors you're using
| to read this site on?
|
| https://www.youtube.com/watch?v=rdlZ8KYVtPU
|
| https://www.youtube.com/watch?v=1fOA85xtYxs
| itsthecourier wrote:
| box office: $6,900
|
| Human race advances in leaps by a super small group of
| dedicated people, we are all indebted to
| ndiddy wrote:
| > But an engineer with the agency's Deep Space Network, which
| operates the radio antennas that communicate with both Voyagers
| and other spacecraft traveling to the Moon and beyond, was able
| to decode the new signal and found that it contains a readout of
| the entire FDS memory. The FDS memory includes its code, or
| instructions for what to do, as well as variables, or values used
| in the code that can change based on commands or the spacecraft's
| status. It also contains science or engineering data for
| downlink.
|
| Does this mean that someone could set up an antenna and get a
| copy of the Voyager software? Might be cool to see.
| sidewndr46 wrote:
| Yes. It would also need to be enormous and use the same type of
| supercooled receiver.
| CamperBob2 wrote:
| It's possible to receive signals from some spacecraft with
| reasonable amateur-level antennas, but not this one, sadly.
| You'd be lucky to get a photon every day or two.
| colechristensen wrote:
| You would need a dish measured in tens of meters across. When
| you were done you'd have a decent radio telescope.
| malfist wrote:
| Technically yes. But currently you need a 70 meter (230 foot)
| dish to hear/talk to it.
|
| To talk back to voyager, DSS43 uses 75kw to transmit, so you
| might have to have a commercial account with your local power
| company.
| subract wrote:
| For those interested in learning more about the challenges in
| keeping the probes alive, the 2022 documentary It's Quieter in
| the Twilight follows the small, incredibly dedicated team working
| the project. Free to stream on Prime.
|
| The simple fact that many of the original engineers are no longer
| alive presents significant challenges in and of itself.
| ojosilva wrote:
| I came to say the same, and post this link to the trailer:
|
| https://www.youtube.com/watch?v=8vJT8AW0wYw
| noelwelsh wrote:
| Those ancient Sun machines take me back a bit!
| Solvency wrote:
| I fundamentally don't understand why this project is seemingly
| so poorly documented? I've read articles describing the current
| teams having to still reverse engineer things by scrutinizing
| random documents and sketches as if it's still this very
| unknown system.
| nonethewiser wrote:
| I imagine its a problem of distance, feedback, and lack of
| any analogous test environment.
| xenadu02 wrote:
| The project was not really designed to reach interstellar
| space originally. It was a somewhat rushed program to take
| advantage of the "Grand Tour" where the gas giants would all
| be aligned enough that a gravity-assist orbit could allow a
| spacecraft to fly by each of them. The alignment in question
| only happens every 175 years.
|
| The interstellar portion was an add-on after the success of
| the original mission. The spacecraft were still operating so
| why not just keep operating them?
|
| No one designing or building the probes imagined they'd still
| be operating 50+ years later. Even if they did space programs
| are constantly under threat from budget cuts so you can't
| exactly waste money on what-ifs for the future: you must
| focus on making the official mission succeed.
|
| Also remember that the "desktop PC" was not yet a thing when
| this was designed. Engineers were drawing everything on
| paper. Storage space was extremely expensive in any case.
|
| A modern program would (and most do!) put various versions of
| drawings in a version control system. Source would use an SCM
| so code history would be available. Even things like meeting
| notes would be available and searchable digitally.
| 0cf8612b2e1e wrote:
| Shouldn't this software archeology have been done decades
| ago?
| RajT88 wrote:
| I have found that even the group I'm in being
| documentation-heavy, it's hard to read through everything
| and build the same context that another engineer has all
| stuffed into their head.
|
| As you mention:
|
| > available and searchable digitally.
|
| Even with 100% everything written down, it takes a while to
| build up that context, and even carefully written
| documentation can have subtleties which send a consumer the
| wrong way.
|
| Things are a lot easier than they used to be, but still not
| easy-easy.
| renhanxue wrote:
| >The project was not really designed to reach interstellar
| space originally.
|
| Not only that, Voyager 2's flyby of Uranus and Neptune in
| the late 1980's was originally not intended either. As an
| aside, to this day Voyager 2 remains the only spacecraft to
| ever have visited either planet, and there are no firm
| plans for a followup, just some loose ideas about maybe
| launching something in the mid 2030's. Anyway, doing the
| Uranus/Neptune part of the mission required extensive
| software upgrades, which introduced Reed-Solomon error
| correction and image compression capabilities, among other
| things - the software as launched would not have been
| capable of a meaningful mission to Uranus and Neptune.
|
| These days the Voyager program is lauded as an astonishing
| feat of engineering and one of the most inspiring science
| and engineering achievements of all time, but in the early
| 1970's the entire idea was NASA's red-headed stepchild and
| ended up cut down to a bare minimum. The Grand Tour mission
| concept (the opportunity to take advantage of the extremely
| rare opportunity to visit Jupiter, Saturn, Uranus and
| Neptune in a single mission) was pitched as early as 1965,
| and by the early 1970's there were plans for launching four
| spacecraft, two bound for Jupiter-Saturn-Pluto and two
| bound for Jupiter-Uranus-Neptune. These were referred to as
| TOPS, Thermoelectric Outer Planets Spacecraft. But then
| people started complaining that it might cost a billion
| dollars (Apollo had cost $25 billion) and the whole thing
| became intensely political. Quoting from Voyager: The Grand
| Tour of Big Science
| (https://www.nasa.gov/history/SP-4219/Chapter11.html) by
| Andrew J. Butrica:
|
| > Further complicating matters was Senator Clinton P.
| Anderson (D-NM), champion of the Los Alamos nuclear weapons
| laboratories and an enthusiast, until his retirement in
| 1973, of the development of a nuclear rocket engine called
| NERVA. As chair of both the Senate Aeronautical and Space
| Sciences Committee and the joint Atomic Energy Committee,
| Anderson provided NASA and the Atomic Energy Commission
| over $1.4 billion, about $500 million of which was spent in
| Los Alamos, for the development of the NERVA engine, which,
| Anderson held, was ideally suited for exploration of the
| outer planets, as well as for more advanced missions.
| Anderson worried that NASA and the OMB were shifting money
| from NERVA to fund Grand Tour. When the NASA budget came
| before Anderson's Aeronautical and Space Sciences Committee
| on May 12, 1971, his committee voted five to two to reduce
| Grand Tour's budget, while an amendment to increase NERVA
| funding passed. Werner von Braun worried that ardent
| congressional interest in NERVA would force a loss of Grand
| Tour in favor of a NERVA that had "no place to go."
|
| > Meanwhile, NASA was trying to include Grand Tour as a new
| start in its 1972 fiscal budget. The Friedman report moved
| the Office of Management and Budget (OMB), in March 1971,
| to ask NASA to study simpler, less costly spacecraft
| alternatives to TOPS. The OMB also attempted to delay the
| Grand Tour start-up to fiscal 1973.
|
| > (...)
|
| > As NASA prepared its fiscal 1973 budget, rumors spread
| that the "budget pinch" was going to affect planetary
| programs deeply and that the reduction of the Grand Tour
| payload from 205 to 130 pounds was "a likely fact of life."
| Furthermore, Grand Tour now began to compete for funding
| with the latest NASA human program: the Space Shuttle. The
| fiscal 1973 budget request NASA submitted to the OMB on
| September 30, 1971 included both Grand Tour and the Space
| Shuttle. Throughout the autumn of 1971, several press
| reports presciently reported Grand Tour's vulnerability to
| a possible elimination or reduction. On December 11, 1971,
| James Fletcher, NASA administrator since April 27, 1971,
| learned from White House officials that Nixon was prepared
| to approve the shuttle program and that Nixon would not let
| NASA simultaneously fund the shuttle and the full TOPS
| Grand Tour in the 1973 budget or in subsequent fiscal
| years. Fletcher had to decide which was more important:
| Grand Tour or human flight.
|
| Fletcher chose the shuttle, and what could be squeezed into
| the budget was an extension of the Mariner program to visit
| Jupiter and Saturn only. For budget reasons the spacecraft
| development was kept in-house at JPL rather than contracted
| out, and at JPL the dream of the full Grand Tour was still
| alive:
|
| > Despite the limited aim of the Mariner Jupiter-Saturn,
| the mission had the Grand Tour launch window, that rare
| planetary alignment, and the engineers at JPL still had
| every intention of building a spacecraft that would last
| long enough to visit Uranus and Neptune. This intention was
| not emphasized; however, it was stated that a Mariner
| Jupiter-Saturn spacecraft might continue to Uranus if its
| mission at Saturn proved successful. The scientists working
| on the project knew that Mariner Jupiter-Saturn was going
| to go to Uranus and Neptune, too. As Bradford Smith, Leader
| of the Imaging Team, explained: "We understood at the time
| the enormous potential of this mission, that it could very
| well be one of the truly outstanding if not the most
| outstanding mission in the whole planetary exploration
| program."
|
| Also for budget reasons, the spacecraft were limited to
| mostly reusing existing technology. Getting reprogrammable
| computers (without which they could never have been kept
| alive in the way they have) required a separate budget
| grant from Congress:
|
| > Despite the reliance on extant technology, some money was
| set aside to develop new technology. Congress and the OMB
| approved an additional $7 million to the Mariner Jupiter-
| Saturn appropriation for scientific and technological
| enhancements. Part of that appropriation went to develop a
| reprogrammable onboard computer, which proved vital to
| maintaining Voyager 2 as a functioning observatory in
| space. Without properly functioning hardware, no science
| could be conducted.
|
| In the end only Voyager 2 was launched on the full Grand
| Tour trajectory that would allow visiting all of Jupiter,
| Saturn, Uranus and Neptune; Voyager 1 was launched on an
| easier and much faster trajectory that would take it only
| to Jupiter and Saturn. Even then, the official decision to
| extend the Voyager 2 mission to Uranus was only approved in
| 1980.
|
| Human spaceflight and its enormous appetite for money has
| always been a huge threat to actually exploring the solar
| system beyond Earth orbit, and we should be very glad we
| got even the very diminished Voyager program that exists
| today.
| toast0 wrote:
| If they have random documents to scrutinize, doesn't that
| mean that it's documented?
|
| When I work on undocumented systems, it's because someone
| wrote code with no design docs, no (retained) notes, no
| requirements, no specs, and it's been determined that it
| doesn't work right. All I have is the code, and current
| observations.
| liquidpele wrote:
| Haha look at this guy, thinking you can trust the docs. ;)
| KineticLensman wrote:
| I remember reading about the inquiry into the UK RAF Nimrod
| aircraft that came down in Afghanistan in 2006 killing its
| crew of 14 [0]. A significant finding was that recovering the
| design history and maintenance records involved trawling a
| massive number of filing cabinets / cardboard boxes scattered
| in sites across the UK, and was a significant cause of the
| missed opportunities to uncover the design flaws and near
| misses that preceded the crash. (long story short: internal
| fuel leak near a very hot exhaust pipe)
|
| [0] https://en.wikipedia.org/wiki/2006_Royal_Air_Force_Nimrod
| _cr...
| mardifoufs wrote:
| I think it's because it was more of an awesome moonshot
| project that didn't really fit into NASA's shifting goals at
| the time and with the shuttle overshadowing everything else
| that happened then. No one was really expecting this much
| from the probes
| anigbrowl wrote:
| At the time engineers imagined it having a relatively short
| operating life, and (imho) also thought we would be putting
| out a lot more probes. During the Cold War space exploration
| provided both prestige and a technological proving ground.
| After the USSR fell, a lot of Congressional enthusiasm for
| space projects diminished and management became increasingly
| risk-averse because budgets were much tighter.
| TheCondor wrote:
| When was the first source code control system released? SCCS
| was like 1973 and the Voyager code was probably pretty much
| buttoned by then; with whatever practices that they thought
| was stable state of the art practices at the time. I imaging
| that this was a collection of "golden tapes" or something.
| Now the concept of revision control seems pretty self
| validating but you're talking about undergoing a culture
| change on your software team, pretty close to launch.
|
| Then the voyager hardware was bespoke.
|
| We just live in a different world now, they didn't _know_ how
| to do software engineering like we do. They were just
| figuring it out. I really don 't know the history of it but
| Voyager systems may have been produced on punchcard. Like the
| original source code might be physical for parts of the
| system.
| andyjohnson0 wrote:
| Looks fascinating, but the only place I can find to watch it
| here in the uk is Prime Video. Does anyone know of legal
| options for those who don't want to give Amazon their money -
| still less sign up for a Prime subscription?
| greazy wrote:
| Try one of the options listed here
|
| https://www.itsquieterfilm.com/where-to-watch
|
| Most of the options don't offer the movie in my region :(
| mintycrisp wrote:
| Here is the official list of options to see if any
| alternatives work for your location ->
| https://itsquieterfilm.com/where-to-watch
| dylan604 wrote:
| Thanks for the reco. I would have never found this browsing
| Prime hidden in all of their FreeVee push.
| jgalt212 wrote:
| hopefully not a Killer Poke
|
| https://en.wikipedia.org/wiki/Killer_poke
| NoMoreNicksLeft wrote:
| Wow. Some good news for once. Hope it's something they can
| repair/mitigate.
| tapoxi wrote:
| Is the Voyager's software or data stream documented anywhere? I'm
| a little disappointed by the high level descriptions we get back.
| I'd love to know what its actually sending.
| crispyambulance wrote:
| NASA does have a data portal (https://data.nasa.gov/). There's
| datasets relating to voyager, but just checking right now, I
| get '403 errors on those.
| tivert wrote:
| > Is the Voyager's software or data stream documented anywhere?
| I'm a little disappointed by the high level descriptions we get
| back. I'd love to know what its actually sending.
|
| This has a chapter on the Voyager computer system, it's a lot
| more technical than typical, but I don't think it gets to the
| detail of the literal programs or data stream:
|
| https://web.archive.org/web/20190714113800/https://history.n...
|
| I don't know why NASA took down this nice HTML version. The
| live link now just redirects to a scanned PDF.
|
| I read NASA has a lot less documentation about Voyager than
| you'd think, and apparently they don't have a ground-based
| simulator or anything like that (which they have for later
| probes).
| ChrisArchitect wrote:
| [dupe]
|
| Some more discussion on the official post:
| https://news.ycombinator.com/item?id=39701473
| dang wrote:
| Comments moved thither. Thanks!
|
| Edit: so many of those comments have to deal with the contents
| of this particular article (which does add more background) so
| I think we need to move them back. Let's keep the less baity
| title from the other post, though.
| vlovich123 wrote:
| > The availability of skills is also an issue. Many of the
| engineers who worked on the project - Voyager 1 launched in 1977
| - are no longer around, and the team that remains is faced with
| trawling through reams of decades-old documents to deal with
| unanticipated issues arising today
|
| At least part of the problem is that we don't regularly send long
| distance probes. Of course, even with that maintaining a relevant
| skill set to maintain a 50+ year old technology from over 100 AU
| seems difficult. I think having it be a single team's life's work
| is probably our limit to keeping it alive. Our next best window
| for sending out another group of probes is 2152 and hopefully
| it'll become cheap enough to send out a bunch of them with even
| higher resolution imagery & maybe actually hit all the planets
| this time. Unfortunately, it's likely no one reading this will be
| alive to see that happen.
| jamiek88 wrote:
| Likely? I'd say certain!
|
| If not then some wonderful healthcare breakthroughs will have
| happened and wouldn't that be great?
|
| I'd love to see us image exoplanets for example.
|
| I've often thought about a 'relativistic chamber'.
|
| Some device that is in space looping at an appreciable fraction
| of light speed.
|
| Enter the box.
|
| Exit a year later and it's 200 years passed down on earth. Have
| a mosey around, back in the box!
|
| Have a mooch, back in the box!
|
| And so on.
| TremendousJudge wrote:
| https://xkcd.com/989/
| ribosometronome wrote:
| It's a shame we probably live too early for cryogenic
| freezing to work, either.
| brabel wrote:
| In reality, they would wake up to find themselves in a
| landfill as everyone just forgot what those funny boxes
| were for and got rid of them.
| aembleton wrote:
| As predicted by Idiocracy
| Vecr wrote:
| Similar to the XKCD, Gwern says no:
| https://gwern.net/hyperbolic-time-chamber
| LeifCarrotson wrote:
| The HTC is the opposite of the cryogenic freezer or
| relativistic chamber - it accelerates time for people
| inside it, allowing you to meet external deadlines while
| the world passes by slowly outside. A cryo freezer or
| relativistic spaceship decelerates time for people inside,
| allowing external activities to be accomplished while you
| don't age.
| Vecr wrote:
| You are right, I'm wrong. I thought he had something in
| there for that anyway, but apparently not. Still, you're
| just on the other side of the Amdahl's law problems, so
| you better hope no one is depending on _you_.
| ghodith wrote:
| This is about a time chamber that works in the opposite
| direction.
| shagie wrote:
| The Worthing Saga by Orson Scott Card (
| https://en.wikipedia.org/wiki/The_Worthing_Saga
| https://www.goodreads.com/book/show/40304.The_Worthing_Saga )
|
| > It was a miracle of science that permitted human beings to
| live, if not forever, then for a long, long time. Some
| people, anyway. The rich, the powerful--they lived their
| lives at the rate of one year every ten. Some created two
| societies: that of people who lived out their normal span and
| died, and those who slept away the decades, skipping over the
| intervening years and events. It allowed great plans to be
| put in motion. It allowed interstellar Empires to be built.
|
| > It came near to destroying humanity.
|
| > After a long, long time of decadence and stagnation, a few
| seed ships were sent out to save our species. They carried
| human embryos and supplies, and teaching robots, and one man.
| The Worthing Saga is the story of one of these men, Jason
| Worthing, and the world he found for the seed he carried.
|
| ---
|
| Freeze Frame Revolution (
| https://www.goodreads.com/en/book/show/36510759 )
|
| > How do you stage a mutiny when you're only awake one day in
| a million? How do you conspire when your tiny handful of
| potential allies changes with each job shift? How do you
| engage an enemy that never sleeps, that sees through your
| eyes and hears through your ears, and relentlessly, honestly,
| only wants what's best for you? Trapped aboard the starship
| Eriophora, Sunday Ahzmundin is about to discover the
| components of any successful revolution: conspiracy, code--
| and unavoidable casualties.
|
| ---
|
| Also going to recommend the various Vernor Vinge books:
| The Peace War Marooned in Realtime A Deepness
| in the Sky
|
| and the short story "The Peddler's Apprentice" ( https://en.w
| ikipedia.org/wiki/The_Collected_Stories_of_Verno... )
| meragrin_ wrote:
| > Our next best window for sending out another group of probes
| is 2152
|
| Planet alignment?
| legobmw99 wrote:
| Yes, https://en.m.wikipedia.org/wiki/Grand_Tour_program
| dmead wrote:
| It'll be a good year for planetary astronomy anyhow.
| ck2 wrote:
| My favorite thought about the Voyager (and Pioneer) probes is
| that someday, thousands of years from now, humans will launch a
| ship or drone that will past by it in only a few days (if we last
| that long, odds are way down).
|
| Another far more hilarious thought is I am glad they chose the
| Voyager probe for the first Star Trek movie and not Pioneer
| (hint: the letters dropped in the "mystery name")
| ruune wrote:
| That's an incredibly interesting thing in my opinion. Even if
| we send colony ships now, the odds of them arriving to a planet
| thousands years later that is already inhabited by humans or
| human descendents because our technology evolved over that time
| it non zero. Combined with relative time it gets even more
| weirder, because an almost-lightspeed ship we'd send could be
| surpassed by something much more advanced in a matter of days
| (spaceship time). So when do we send ships? I think there's a
| Kurzgesagt video about this somewhere
| Vecr wrote:
| As soon as possible, because you don't know you'll last that
| long. You do need to use resources wisely though.
| ck2 wrote:
| That concept for tic-tac sized probes reaching 10% of the
| speed of light via laser power transfer seems remotely
| plausible in a few hundreds years but personally I don't
| think humans are making it off this planet. We are running
| out of runway with overpopulation, overheating,
| overpollution, toxic everything and cutthroat politics will
| only allow space investment for weapons when there's no money
| for food and health.
|
| Even if there was a near-future miracle invention for cheap
| plentiful power, it would be turned into a weapon of war far
| before space use. Beyond the power requirement, accelerating
| mass near the speed of light is beyond our comprehension, we
| can't even deal with radiation in space forget hitting dust
| that fast.
| krallja wrote:
| The mystery name for Pioneer could be "one" or "Pion" or
| "neer".
| DarmokJalad1701 wrote:
| I remember listening to a podcast where someone mentioned that
| there was a VM that they used for testing the flight software for
| Voyager -- possibly open source. Unfortunately, I do not remember
| what podcast it was.
| tetris11 wrote:
| Here's a nice CPUshack link detailing the CPUs that we have in
| space:
|
| https://www.cpushack.com/space-craft-cpu.html
| tetris11 wrote:
| > The availability of skills is also an issue. Many of the
| engineers who worked on the project - Voyager 1 launched in 1977
| - are no longer around,
|
| Can you just imagine that? You wrote software in your 30s, and
| then 50 years later your grandchildren have to come visit you in
| the old folks home to ask you:
|
| "Grandad, why did you write this goto statement at line 1892? Our
| AI think it might have to do with avoiding a hardware issue?"
|
| to which you then reply, "my dear, even if you asked me one year
| after I wrote it, I would not be able to tell you."
| zoeysmithe wrote:
| My understanding is that its very well documented, but the
| funding isn't there to do much with it. I mean most of the team
| behind things like the Atari computers, Acorn, Commodore, early
| Apples, etc are retired but we can emulate them and understand
| these things on a very technical level. I know this isn't a
| great analogy, but ultimately age of the project or the age of
| the original team members isn't the bottleneck.
|
| I sometimes see retro projects on hack-a-day done by people who
| could be the grandchildren of the original designers of those
| vintage chips and OS's. They probably know more about that chip
| or OS than the original people do just due to them being out of
| the game for so long. The same way people regularly lose to
| fifth graders in tests because they dont recall 5th grade
| science and civics. If anything your scenario might be the
| opposite! Grandpa might be asking his granddaughter how those
| registers worked or how to emulate his OS from 1982.
|
| I remember reading about the team that maintains the Voyagers.
| Its a skeleton crew using legacy equipment to keep the
| communication going with the assumption the next decade, or
| even earlier, is going to be it.
|
| NASA has the same problem the private sector has. Capitalism
| rewards things that will generate profit/prestige, not legacy
| cost centers, and NASA is not immune from that dynamic as NASA
| employees and managers want to maximize their income and
| prestige too. So the people maintaining or bug fixing old
| products are often lowest on the prestige, pay, recruiting, and
| profit spectrum than those chasing new things. They get the
| skeleton crew funding and can't do novel things, even if
| technically possible because of lack of staff and buy-in.
|
| Passion projects make for feel-good documentaries like 'It's
| Quieter in the Twilight' but ultimately if society isn't vested
| in these teams, their hands will always be tied.
| ngcc_hk wrote:
| I hate people just random throw in capitalism. Is the
| communism better in maintaining old code ... do they even
| exist. Not to mention please we are here not for the money as
| most does not, just awe of what can be done for a computer
| job which love to do and have such legacy.
|
| Capitalism does not really exist. It is money, incentives,
| job, human ... or love to hack.
| quickslowdown wrote:
| I'm going to just outright dismiss this comment the way
| you're dismissing people talking about capitalism, a very
| real economic system we're all living under, since it's
| ridiculous on its face.
| jcadam wrote:
| A young engineer must know that getting stuck on a legacy
| project is a career-limiting move. Happened to me when I got
| stuck on a old Ada codebase for a legacy aerospace system
| (unemployed in 2008, you take whatever job you can get), and
| it took years, and a good chunk of my spare time doing
| projects/studying, to find a company willing to give me a
| chance working on something modern again.
|
| Now, someday when I'm in my 60s/70s, and you have some legacy
| system written in some defunct language nobody under the age
| of 50 has any experience with, sure, I'll do it. But it'll
| cost you.
| trealira wrote:
| Why do companies do that? Shouldn't it be enough that you
| have experience contributing to a large project long-term
| and you can program decently? Is it that modern programming
| just requires different/additional programming skills
| compared to most old codebases, like writing asynchronous
| code?
| robocat wrote:
| I don't hire, but that story would make me want to hire
| you. It takes certain skills and pig-headedness to
| successfully work on old software!
|
| I once asked a company to rehire me saying that I only
| wanted to do software maintenance work (I wanted low
| stress). I am good at it, and it's hard to find people that
| want to do that work. They didn't rehire because although
| the manager really wanted me back, his idiot boss had taken
| it personally when I had quit. Idiot boss later got ousted
| to their dismay: I shouldn't enjoy that but I did!
| justin66 wrote:
| The thing Voyager has going for it is, it's a small team. JPL
| is laying people off all over the place lately.
|
| I'm not sure if it's really "society" that is responsible for
| these funding difficulties, it's the politicians. If you ask
| a random member of the public how much of the federal budget
| is allocated to NASA, they'll generally give you a percentage
| that's wildly higher than the actual figure.
| jacobriis wrote:
| _Can you just imagine that?_
|
| No this is not a plausible scenario.
| Vecr wrote:
| Because you never write gotos? Many embedded and kernel
| programmers still do. I think it makes sense in general.
| williamcotton wrote:
| It is known as error handling. Some languages renamed the
| practice to try/catch. Others added a Result type.
| trealira wrote:
| Likely you know this, and you're just being funny, but
| the try/catch statement is more like setjmp/longjmp in C.
| The Result type in Rust is syntactic sugar for integer
| return codes, returning early on errors, and tagged union
| structures. And where C programmers use goto statements,
| C++ programmers use destructors, and Rust programmers use
| the Drop trait. Walter Bright also says that nested
| procedures in D eliminate most use cases of goto for him.
|
| You can also _always_ avoid goto, in C, but usually,
| either it has excessive if-statement nesting, it uses
| boolean flag variables in loop conditions, or it uses
| structures to create state machines, but these are
| usually just uglier and more error-prone than the
| equivalent version using goto. The same applies to
| avoiding break, continue, and early returns.
| dotps1 wrote:
| I mean, this stuff does happen.
|
| There is an old electric station near me that is used for
| various things sometimes. Some band was in there shooting a
| music video and bumped something and somehow the whole area
| started filling with water. Nobody could stop it.
|
| The government, the water company, everyone was struggling to
| figure out what to do, and they decided to call the old guy
| that used to work there. He was in his 90s but he told them
| how to fix everything.
| flagged24 wrote:
| I would love to read the full story on this.
| thebruce87m wrote:
| > plausible scenario
|
| I'm not sure what you are calibrating against but I feel like
| the last 20 odd years are full absolute batshit crazy stuff
| that doesn't make sense and this seems rather tame.
| hathawsh wrote:
| I wouldn't dismiss that scenario. It seems plausible that the
| documentation is so extensive that it takes time and effort
| to answer some questions. It might be easier to just ask the
| authors, if they're still around.
| xcv123 wrote:
| > No this is not a plausible scenario.
|
| COBOL exists. Billions of lines of COBOL still in production
| today. The scenario is already happening now.
| jdminhbg wrote:
| > Can you just imagine that? You wrote software in your 30s,
| and then 50 years later your grandchildren have to come visit
| you in the old folks home to ask you...
|
| Yes, I have nightmares like this all the time.
| LeifCarrotson wrote:
| If only it was merely nightmares and not my day job.
| ceautery wrote:
| I never thought of this before now, but tech from 1977 might
| not even be using ASCII.
| kayodelycaon wrote:
| Great question! Voyager 1 does appear to be using ASCII. :D
|
| https://destevez.net/2021/09/decoding-voyager-1/
| cadr wrote:
| No, but I did find myself in the mid 90s as an intern trying to
| figure out code from the early 80s. It was really tricky code
| to get ECG processing working on some very small memory
| footprint or something. The name of the woman that wrote it was
| at the top of the file, and I looked her up in the HP company
| directory and she still worked there. As a hail-mary, I emailed
| her and asked a question about it. And she immediately got back
| to me with the answer. So, there are some engineers out there
| that _do_ remember this sort of thing.
| HeyLaughingBoy wrote:
| LOL. I remember being asked to consult for my last employer
| on a problem they had while attempting to port some software
| that I had written almost 20 years earlier. It's amazing the
| random details that you remember when your memory is jogged.
| selimnairb wrote:
| I would use my old person privilege to berate you for using
| "AI" to "understand" the code rather than getting your soft
| hands dirty.
| linsomniac wrote:
| I'm kind of surprised, what with all the retro computing
| emulation software and skills I see getting posted here, that
| we don't have a Voyager emulator scene and a group of people
| standing by to run scenarios and propose fixes.
| hathawsh wrote:
| That would be very interesting. Someone please tell me such a
| community exists somewhere.
| tetris11 wrote:
| DarmokJalad1701 below mentions about hearing a podcast where
| new engineers did work on VMs
| ngcc_hk wrote:
| Any details? We have people work on a dead moon
| lander...why not a live v1/2. If sadly one is dead, the
| other still has some life left ?
| bilegeek wrote:
| Not that I'm skillful enough to make an emulator, but I've
| tried years ago to find technical documents on the Honeywell
| HDC-402 used in Voyager and Viking (it's also apparently not
| related to the DDP-516 or 316 AFAIK.) There's SOME
| information[1], but not enough to make an emulator from what
| I've found.
|
| Aside from the lack of schematics or listings, there was the
| problem of the assembler being incomplete!
|
| "One problem Lander software developers had was that no
| adequate assembler was ever written for the computer, perhaps
| because of the changing nature of the instruction set.(110)
| Patches had to be hand-coded in octal, with many jumps to
| unused memory space because of the lack of an assembler with
| relocatable addressing." p.174 on Viking, which used the same
| computer
|
| [1]https://ntrs.nasa.gov/api/citations/19880069935/downloads/
| 19... (page 174 onwards)
| makomk wrote:
| As far as I can tell the HDC-402 wasn't even the Viking
| computer that got reused on Voyager anyway - it was
| something NASA developed in-house from the orbiter side of
| the Viking mission and that presumably has even less
| documentation available.
| bilegeek wrote:
| You're confusing the 24-bit HDC-402 on the lander with
| the custom 18-bit computer on the orbiter (p.164), which
| had it's origins in the sequencer for the Mariner
| missions (p.152-154).
|
| Though given the apparent level of NASA involvement in
| the 402's design, and the lack of evidence I can find for
| use outside of NASA, it might as well be called custom.
| supportengineer wrote:
| I know a developer in his 70's who maintains code he wrote in
| his 20's
| taylorfinley wrote:
| I would love to hear more about this if you can share any
| details
| bloomingeek wrote:
| Going out on a limb here, wouldn't code written that long ago
| be almost impossible to hack with modern tools? (not to
| mention still using the old hardware.)
| wredue wrote:
| I'm not sure why that would be the case. If anything, I'd
| expect earlier code to be easier to hack.
| HeyLaughingBoy wrote:
| One of the Best Practices for maintaining software that you
| expect to support for decades involves archiving the
| development tools used.
|
| Of course, finding a platform to run it on could be a
| problem. Also, the License Server that so many proprietary
| tools need before they'll run.
| myself248 wrote:
| I remember hearing about some hardware made for the
| government (military?) where the development tools ran on
| some 1970s minicomputer that had long since ceased to
| function, but it was no problem because in the 80s they
| wrote an emulator that ran on 68k, specifically an Amiga
| since that's what someone had sitting around the lab at
| the time. Then in the 2000's they realized the supply of
| Amiga parts wouldn't last forever so they bundled the
| whole thing up to run in an Amiga emulator that ran on
| whatever version of Windows was current at the time. Then
| 16-bit Windows ceased to be a thing, so....
| supportengineer wrote:
| This is pretty close
| pkaye wrote:
| There is a nice documentary about what remains of the Voyager
| project team. The video is not free however.
|
| https://www.itsquieterfilm.com/
| sho_hn wrote:
| I watched that a couple of months ago and loved it. It does a
| lot to humanize that team, I've been thinking of them during
| the recent news cycle.
| wredue wrote:
| It's funny which code I remember and which code I don't.
|
| There's code I wrote 10 years ago at work that I still remember
| and can point out exactly where everything is. Then there's
| code I wrote last week that is completely gone.
| kstrauser wrote:
| See also: engineers of the B-52 bomber. It first flew 71 years
| ago and is expected to have another 30 years left.
| KineticLensman wrote:
| There is at least one family that has three generations of
| B52 pilot (grandfather, father, son) [0]. Imagine being a
| coder who maintained code written by your grandfather and
| father...
|
| [0] https://www.minot.af.mil/News/Article-
| Display/Article/264580...
| kstrauser wrote:
| Well, my grandpa didn't know jack about computers, so I
| very well could have maintained code he's written based on
| the disquality of stuff I've had to work on in the past.
|
| But yeah. In "A Fire Upon the Deep", Vinge talked about
| archaeological programmers. There's no doubt in my mind
| we'll reach that point. "Tell me again why time_t is only
| 64 bits?" "Pull up a chair while I dig out the LKML
| archive. You know, this was originally stored in electric
| fields, if you can believe it!"
| acheron wrote:
| Fire up the subspace ansible and create a holodeck room
| for us to talk about it. You can't name the holodeck
| program "CON", "LPT1", "PRN", or "AUX", though, because
| those are MS-DOS device names. (
| https://news.ycombinator.com/item?id=37076523 )
| myself248 wrote:
| To this day, I use
|
| COPY CON FILENAME.TXT
|
| to make a quick-n-dirty note of something without leaving
| the terminal.
| kstrauser wrote:
| I use `cat > foo.txt` all the time for the same reason.
| bee_rider wrote:
| I bet they've replaced most of the computers by now, though.
| kstrauser wrote:
| Probably, but why's that spar here? Why did they route that
| wire around the screw, and why doesn't the 1960s bomb sight
| work right if the wire's only twisted 3 times instead of 4?
| jamesy0ung wrote:
| Bomb sights aren't used anymore. The weapons used by the
| B-52 are all gps guided and the computer on board simply
| gives a timer for the pilot to press the pickle button.
| The weapon then self guides to the target.
| kstrauser wrote:
| That sounds believable, but I bet they still have lots of
| surprisingly old equipment that works too well to bother
| replacing.
| HeyLaughingBoy wrote:
| I'm going to be a humorless pedant and reply by saying that
| with the level of forward and backward traceability required of
| aerospace software, it's unlikely that such a level of
| misunderstanding could occur. But maybe DO-178 wasn't a thing
| back then.
|
| That's just from what I've heard, though. I do medical devices.
| I'm told that my aerospace counterparts have it even tougher
| than we do.
| sho_hn wrote:
| > I do medical devices.
|
| Therac-25 happened in 1982 and changed that industry (and
| safety engineering in general) quite a bit, no?
| HeyLaughingBoy wrote:
| Yes, but I don't get your point.
| malfist wrote:
| Voyager launched in 1977, well before the therac-25
| HeyLaughingBoy wrote:
| OK. And?
| aardvark179 wrote:
| I have definitely had to do archeology on 20+ year old code,
| including disassembly to work out actual production code was
| when it clearly wasn't the version we had source for, and
| that's now 30+ year old code which I expect will still be in
| productions at least a decade from now.
|
| Equally I've seen COBOL compiled to new platforms because it
| has outlived all the systems it ran on.
|
| I'm pretty sure there must be areas of Java, or C++'s standard
| libraries that haven't changed for a very long time, and will
| continue to be used for decades.
|
| The thing is, it's often easier to just figure out the code, or
| rebuild the whole underlying platform, than to track down the
| original author and hope it wasn't a Friday afternoon commit.
| wolverine876 wrote:
| > A command from Earth takes 22.5 hours to reach the probe
|
| Voyager 1 is closing in on being the first human-made object to
| travel 1 light day.
|
| V1 has traveled ~22.5 light hours in ~46.5 years [0], and
| assuming that average rate of 2.07 years/light hour [1] it will
| reach 1 light day in around 3.1 years. Does anyone know its
| potential to have sufficent power to measuring anything and
| transmit at that point?
|
| [0] https://voyager.jpl.nasa.gov/mission/status/
|
| [1] Notes on Voyager's average rate:
|
| Remember that V1 did not travel in a straight line or at a
| constant rate from Earth through its planetary explorations, so
| the average rate now is probably higher than that simple
| calculation.
|
| Also, if we are looking at distance and speed relative to Earth,
| and Earth's orbit around the Sun would cause some variation
| throughout the year. Could Earth's relative orbital positions at
| V1's launch decades ago and when V1 approaches 1 light day in
| three years significantly affect V1's distance from Earth?
| Earth's orbital diameter is roughly 300 million km; V1 travels at
| ~61,000 km/hr relative to the Sun [0], so the worst case would
| add ~4,900 hours or ~205 days. (Those are some quick calculations
| and I have to run to a meeting, so I hope there are no glaring
| errors!)
|
| Also, I assume the Sun's movement relative to Voyager 1 has been
| constant since its launch.
| rebolek wrote:
| calling Voyagers V1 and V2 seems little bit strange...
| strangattractor wrote:
| President Biden recently announced that software should be using
| memory safe languages. The command sent to Voyager - poke - is a
| command to directly set a memory location with a value - totally
| not memory safe:)
| ciunix wrote:
| I hope the communication will be established again and correctly
| with the farest device made by mankind. Voyager is giving us a
| lot of important information about what we have in the near
| around.
| tcgv wrote:
| > The time lag is a problem. A command from Earth takes 22.5
| hours to reach the probe, and the same period is needed again for
| a response. This means a 45-hour wait to see what a given command
| might have done.
|
| Astonishing!
| IAmGraydon wrote:
| I can hardly imagine how frustrating that scenario would be.
| Think about how rapidly you hack away at the terminal, and
| imagine that every time you hit "enter", it takes 45 hours to
| find out if it worked. You would only be able to issue 194
| commands in an entire year.
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