[HN Gopher] NASA reconnected with Voyager 1 after a brief pause
___________________________________________________________________
NASA reconnected with Voyager 1 after a brief pause
Author : Stratoscope
Score : 192 points
Date : 2024-10-30 06:48 UTC (16 hours ago)
(HTM) web link (scitechdaily.com)
(TXT) w3m dump (scitechdaily.com)
| Stratoscope wrote:
| So you're troubleshooting a 47 year old spacecraft that is 15
| billion miles away.
|
| The round trip time is 45 hours.
|
| That is some kind of latency!
| tanelpoder wrote:
| And "packet" loss!
| tomkarho wrote:
| Maybe Elon Musk could launch a couple of his Starlink
| satellites into deep space and reduce that latency.
|
| That or apply xkcd #303: https://xkcd.com/303.
| Stratoscope wrote:
| A cool idea. But will the additional hops reduce latency or
| increase it?
| KK7NIL wrote:
| It depends on whether they're running at a lower data rate
| due to the low signal power (which leads to low SNR,
| reducing channel capacity) or if it's just the speed of
| light delay.
|
| In the former case, a relay could help quite significantly.
|
| In the latter case, it would just add even more delay.
| akira2501 wrote:
| You can alter throughput. You cannot alter delay. You
| also can only really broadcast at high power from one
| side.
|
| Deep space RTT is unavoidable.
| snovv_crash wrote:
| Throughput impacts delay when you send non-zero packet
| sizes.
| akira2501 wrote:
| There isn't enough throughput to achieve a negative delay
| which offsets the actual flight of light time to reach
| the object. The ratio of throughput delay to actual light
| delay is so infinitesimal it might as well be zero.
| conradfr wrote:
| Space lasers?
|
| https://www.jpl.nasa.gov/news/nasas-deep-space-optical-
| comm-...
| me_me_me wrote:
| how would that even work? On the whole spectrum. From the
| starlink satellite receiving signal to it being remotely
| justified in economical terms.
| cwillu wrote:
| The round trip time is due to the speed of light, no amount
| of money and hardware thrown at the problem, on earth or in
| space, will improve that.
| dahousecat wrote:
| Maybe with enough money put into research into quantum
| entanglement, it might one day yield faster than light
| communication.
| thrance wrote:
| Elon Musk can improve the speed of light?
| tirant wrote:
| You can increase throughput by adding repeaters around the
| solar system, but latency has a hard limit due to the speed
| of light.
|
| Also throughput could be increased by changing or updating
| the modulation and coding schemes. AFAIK Pioneer and Voyger
| probes were still using PSK and FSK.
| leeoniya wrote:
| i wonder if the commands include some kind of conditions in
| them, so you could account for various things at once without a
| 90h round trip
| toomuchtodo wrote:
| https://voyager.gsfc.nasa.gov/Library/DeepCommo_Chapter3--
| 14... (start at pdf page 35) might have context [1].
|
| [1] Sourced via
| https://voyager.gsfc.nasa.gov/Library/VOY_library.html
| thunderbong wrote:
| > Voyagers 1 and 2 have been flying for more than 47 years and
| are the only two spacecraft to operate in interstellar space.
| labster wrote:
| Finally, a "breaks one's silence" headline that's not a celebrity
| posting something on social media.
| forinti wrote:
| You could say that Voyager is a celebrity. It even does cameos
| on sci-fi movies from time to time.
| whamlastxmas wrote:
| But I really need to know who Brad Pitt is endorsing before I
| head into the voting booth
| wiz21c wrote:
| FTA: "Voyagers 1 and 2 have been flying for more than 47
| years..."
|
| That should be written on a poster that is put on each desk of
| each employee of each car/washing machine/fridge/television
| manufacturer.
| akira2501 wrote:
| It only really needs to be on the upper managements desk:
|
| "The $3.57 you save on capacitors per unit will cost you $50 in
| lost good will."
|
| On the other hand there is a balance between longevity through
| simplified maintenance and replacing aged appliances with newer
| and significantly more efficient models.
| sandworm101 wrote:
| And being $3.57 more expensive than the other guy will deny
| you 90% of sales on amazon or any other online marketplace.
| asah wrote:
| Sadly, there's has no system for long term reviews. In my
| dreams, Amazon/etc would engage customers about their
| durable products and ask how often you still use the
| product and it/when you're thinking of replacing it...
|
| Given the economics, I wonder if best buy could pay
| customers $10 for a survey of their old products, knowing
| that it'll inspire upgrades etc.
| me_me_me wrote:
| i lost my faith in amazon. its all alibaba rebrands and
| mass fake reviews, plus amazon pushing their own chepo
| brand into every search.
|
| its shocking how amazon went from 'me getting a package
| every week' to 'i go there only if i have too'
| nucleardog wrote:
| Amazon is now, largely, just Aliexpress with faster
| shipping and easier returns (and higher prices).
|
| Even in areas where they have brand name products, it's
| often impossible to surface them through their search.
| (I've, many times, failed to find something there and
| then went and searched Google/etc and the top result has
| been... an Amazon link to exactly what I'm looking for.)
| And if you purchase through Amazon, there's no reason to
| believe it's not gray market or something else where you
| may end up having issues with support/warranty if you
| ever need.
|
| And combined with the inventory commingling, even if you
| find brand name products there you can't be sure you'll
| actually receive it and not a knock-off. So it really
| only makes sense to order things that are already the
| cheap/knock-off quality anyway.
|
| So... yeah, there was a nice period of time there where
| Amazon was just "shopping made more convenient". These
| days it's "Aliexpress made more convenient". Unless I'm
| setting out to buy cheaply made Chinese imports with no
| warranty, I'm not even go to start looking on Amazon.
| There's little reason to.
| lancesells wrote:
| That's Anti-Amazon behavior. Whatever is going on with
| their Alibaba-like store is not about finding good
| products.
| SoftTalker wrote:
| I would not spend 10 seconds of my time writing a product
| review or answering a survey like that. If Amazon is
| interested in selling good products they can hire product
| testers who will do teardowns, destructive testing, and
| running them through a 5-year simulated use durability
| test.
| themaninthedark wrote:
| Do you pay for Consumer Reports?
| kristopolous wrote:
| They have the data to infer reliability rates based on
| things like returns, time to purchase similar item,
| frequency of repeat purchase, etc.
|
| Over the volume of say Amazon, The noisiness of varied
| intent will normalize itself out across a sector.
|
| They could surface this as a reliability metric on some
| kind of relative scale.
|
| They could...
| ffsm8 wrote:
| Alternative phrasing: "the $3.57 you save (per unit) today
| will give you a $100.000 end of year bonus, but cost the
| company millions in future lost sales"
|
| Guess what theyre gonna do?
| andsoitis wrote:
| > but cost the company millions in future lost sales
|
| Isn't the company going to make _more_ sales in the future
| (and hence more profit)? And isn't replacing stuff with new
| versions going to lead to improvements in people's lives
| through more efficient, quieter, and more effective
| technology?
| pilchard123 wrote:
| Sure, but if the exec in question has moved on to another
| company by then, what do they care?
| godshatter wrote:
| It's been my experience that newer technology, though
| being more efficient, etc, breaks much faster than the
| old powerhouse tech from the 50's, 60's, and the 70's. I
| don't see my 1950's-something oven dying anytime soon. It
| will outlive me if I don't replace it for that one shiny
| new feature I convince myself I just have to have, or
| because it doesn't match my curtains.
|
| So, yes, replacing stuff with new versions will bring
| more and more sales as opposed to building something that
| will last. Hence "planned obsolescence" and the war on
| making things repairable that we've seen lately. Great
| for business, bad for the customer.
| Sanzig wrote:
| To be fair, it's a bit more subtle than that. There's a
| level of survivor bias involved - all the unreliable
| appliances from the 50s-70s have long since been hauled
| off to scrap metal recycling, so what's left are the
| long-lived ones.
|
| Modern electronics certainly _can_ be made with much
| higher reliability than their mid-century ancestors, but
| the driving factor that prevents this is aggressive cost
| cutting that happily shaves pennies off COGS to shift the
| statistical distribution to the left. Unless consumers
| are willing to pay more for long-lived devices, this is
| doomed to continue.
| philistine wrote:
| This. Survivorship bias is somehow not allowed to exist
| when talking about old appliances.
|
| Yet people understand it with cars. Maybe because it's
| moving?
| wongarsu wrote:
| > Isn't the company going to make more sales in the
| future
|
| Only if you don't overdo it. When your products break too
| quickly many customers will stay one-time customers and
| switch to products from the competition. There's also the
| reputation damage to consider.
|
| And of course it works best if you have a fairly high
| market share. If you have a low market share most
| products on the market are from your competitors, so you
| can you are better off boosting your reputation with
| longer-lasting products (compared to other products at
| the same price point).
|
| Come to think of it, the "break it faster to sell more"
| strategy works mostly in monopolies, duopolies or with
| market collusion (like the Phoebus cartel that lowered
| the lifespan of light bulbs)
| tirant wrote:
| Or in other words, the $3.57 in savings will allow the
| product to compete in a lower price segment and increase
| sales significantly.
|
| It is the behavior of the buyers that drives costs down.
| People are extremely cost sensitive in the mid to low
| segments, shifting their purchase decisions from one
| product to another just because of less than $1 price
| difference. Some companies cannot survive at all without
| saving those $3.57.
| soulofmischief wrote:
| Buyers do not exist in a vacuum, and consumer behavior is
| commonly manufactured. Consumer behavior has never been a
| substantial justification for optimizing for wasteful and
| environmentally business practices in pursuit of
| quarterly growth.
| llimos wrote:
| > Buyers do not exist in a vacuum
|
| Unlike Voyagers 1 and 2
| aeyes wrote:
| > replacing aged appliances with newer and significantly more
| efficient models
|
| Are we still expecting to make significant efficiency
| improvements for appliances in the next 30 years? Will it be
| enough to justify the production of a new appliance?
|
| Legal warranty for appliances like washers, dryers,
| refrigerators among others should probably be raised to at
| least 5 years.
| vel0city wrote:
| The thing that gets me about modern warranties on
| appliances is how weasely they'll market their warranties.
| I've got GE clothes washer and dryer proudly proclaiming
| their 10 year warranty. It's a 10 year warranty on the
| motor and the drum (IIRC). _Not_ on the motor inverter
| unit, which had a one-year warranty. Guess which part is
| likely to fail? Guess what that GE service tech is going to
| recommend you do after he prices out several hundred
| dollars of parts he thinks he might need because he 's too
| lazy to actually diagnose the issue?
|
| An LG dishwasher with a similar 10 year warranty on the
| pumps and what not in the dishwasher. Awesome, great. The
| display panel has failing LEDs. Is that under that
| warranty? Nope. Who cares about the pump not technically
| failing if one can't know what mode the dishwasher is in?
|
| If they're going to stick a sticker on the face advertising
| their warranty on an appliance it should cover the whole
| appliance. Not just a small handful of parts that should
| practically never fail under regular use while all the
| surrounding stuff has a nearly useless warranty.
|
| I'm so salty about warranties and support these days I
| usually try and do every possible thing I can do to fix the
| problem myself before obviously voiding a warranty before I
| ever bother calling their support. So worthless most of the
| time.
| aaron_m04 wrote:
| Not to mention binding arbitration with opt-out that is a
| pain in the ass. I had to go through this for an LG
| washer recently.
| VoodooJuJu wrote:
| >if you cut corners, you may be rich, but then I'll think
| you're a bad boy!
|
| Uh oh, a moral judgement from a peasant? Say it aint so.
| Anything but that. I'm literally shaking right now.
|
| Anyway, here are some actual incentives:
|
| - If you do some shady corner-cutting, you'll be legally
| compelled to trade in your Bugatti and drive a used Kia the
| rest of your life
|
| - If this chemical causes bodily harm to me, we shall inflict
| bodily harm on thee
|
| - A portion of the profits will be placed in a trust and will
| be passed down to your children, if and only if your product
| lasts long enough to be passed down to our children
|
| - If you (banker) lose our money, you will lose your head
| saturn8601 wrote:
| These rules discourage new businesses from starting and you
| end up in a situation like France where their largest
| company is some fashion company formed eons ago (probably
| before all the regulations).
| mmooss wrote:
| France is an extremely wealthy country with possibly the
| best quality of life in the world - many would say better
| than in the English-speaking countries home to most of
| HN.
| askvictor wrote:
| On the other hand, it's environment isn't particularly hostile
| (no moisture, dust, vibration, though it gets more radiation
| than on Earth), and I think it doesn't have much in the way of
| moving parts (?)
| passwordoops wrote:
| Space is pretty hostile:
|
| https://theconversation.com/explainer-how-hostile-is-
| space-2...
| daedrdev wrote:
| If I recall its gets more hostile after leaving the
| heliopsphere
| jampekka wrote:
| > That should be written on a poster that is put on each desk
| of each employee of each car/washing machine/fridge/television
| manufacturer.
|
| And consumer. Very few people would use 50 year old devices
| even if they were/are perfectly functional.
| dano wrote:
| My sunbeam automatic toaster is working just fine thank you
| very much. :-)
| pilchard123 wrote:
| Alec? Is that you?
| ajdude wrote:
| I found one in a thrift store and I was so excited until I
| realized that they wanted $150 for it... even local thrift
| stores know what they have now
| HKH2 wrote:
| Plenty of people buy secondhand equipment. Manufacturers want
| to stop that; spare parts are hard to get or needlessly
| expensive, and manuals are woefully incomplete or
| nonexistent.
| Arnt wrote:
| I've contracted for someone whose customers thought so. (My
| job involved making stuff work with without an important
| part from a defunct vendor.)
|
| Their costs really did increase all the time. Not
| needlessly, despite what some people thought: their cost
| per spare part really did grow quite a lot, as the number
| needed per year decreased and the fixed overhead slowly
| increased.
| The-Old-Hacker wrote:
| Speaking as a writer, I would use an IBM Model M keyboard in
| a heartbeat. Made in 1985, so 40 years old.
| yial wrote:
| I have a few of those, I love them. They just work
| perfectly.
| pif wrote:
| Nice idea, if you want to go out of business!
|
| People don't buy quality: people buy cheap!
| Szpadel wrote:
| and that's why iPhones never catched up
| AxelLuktarGott wrote:
| Ironic that iPhones are both expensive _and_ come with
| planned obsolescence
| nephy wrote:
| Dog no they don't lol. My family has been in both
| ecosystems over the years and by far the iPhones outlast
| the Android phones they buy both in quality and in
| updates.
| sangnoir wrote:
| Counterpoint: one can only unlock the bootloader on
| Android phones and extend the device life for much longer
| than intended or supported by the OEM.
| kelnos wrote:
| Both what you are saying and what the GP is saying can be
| true at the same time.
| 05 wrote:
| Some products do better as Veblen goods than others. You
| can't show off your dishwasher as easily as your new
| Ferrari or iPhone :)
| ajdude wrote:
| About a decade ago I bought a USB fan to plug into my
| computer at work. It has been turned on and running for
| almost 10 years straight. I thought to myself "I should
| actually leave a good Amazon review for this fan, it's held
| up to the test of time for little consumer electronics like
| this."
|
| I went to look up my purchase but not only is that listing
| gone, the brand no longer exists.
| kulahan wrote:
| Exactly. You want a W/D combo that'll last forever? No
| gimmicks? No nonsense? Get a speed queen. Ugly as hell, basic
| as hell, and built like a brick shithouse and made right here
| in the good ol' US of A.
|
| Problem is... they're expensive. Real pricey. This kinda
| industrial-tier consumer stuff does exist, but very few
| people bother buying it.
| bigstrat2003 wrote:
| Thanks for the recommendation - I had never heard of them,
| but I'll definitely give them a look whenever my current
| appliances die.
| tatersolid wrote:
| Speed Queens were exclusively installed each of the
| dozens of coin-operated laundromats I've visited in my
| life. This is because a machine awaiting repairs doesn't
| make the owner a penny.
|
| As always, ask or imitate an expert _with aligned
| incentives_. A seasoned local auto shop owner guided me
| towards Acura after two of my fancy German cars needed
| multiple expensive repairs. He doesn't service Honda
| group vehicles, but drives an Acura himself and I
| couldn't be happier after listening to his advice.
| tweetle_beetle wrote:
| Conversely, the system which has been described as the longest
| running computer system after Voyager is the UK's Police
| National Computer - turning 50 and still in use today. Most UK
| citizens will be on it in some way, shape or form.
|
| Keeping it alive is a remarkable feat, but costing taxpayers
| eye watering sums of money, due to the ever increasing shortage
| of skills, while a modern cloud alternative is developed. Be
| careful what you wish for.
|
| https://en.wikipedia.org/wiki/Police_National_Computer
| blensor wrote:
| Voyager is something that I keep thinking every time I see
| people talking about what great things musk/spacex are doing
| with their fail often/fail fast approach.
|
| I do get the value of iterating quickly towards a solution but
| that does not invalidate the conservative engineering approach
| other people have to take to build something much more
| stable/reliable where they have to be very cautious and can't
| just break things until you have a solution.
| jballer wrote:
| They're optimizing for different priorities. Obviously you
| need to be conservative when launches cost so much you can
| only afford ~one shot.
| glzone1 wrote:
| Voyagers were built by JPL and not contracted out so align to
| a degree with the spacex model. In part this was because
| budget got cut badly.
|
| "In order to reduce costs and overheads, NASA decided to
| leave design and construction of the Mariner Jupiter-Saturn
| spacecraft to JPL, rather than to Boeing, General Electric,
| Hughes, Martin Marietta, and North American Rockwell, all of
| which had some level of preparation for a Grand Tour
| proposal. The largest aerospace firms lobbied NASA
| Headquarters and Congress for the contracts. In order for
| expensive projects to pass congressional scrutiny as part of
| the NASA budget, they often had to include an intention to
| contract out much of the work" voyager - Andrew J. Butrica
|
| I think they also did build a test spacecraft ?
|
| Anyways the approach (smaller focused team) contrasts with
| the big SLS type projects that are contracted out for
| political reasons.
| ck2 wrote:
| I have a Sharp carousel microwave oven that is 40 years old and
| works fine.
|
| The "secret" solution is it was one of the last years made in
| Japan, not China.
|
| I just move it from apartment to apartment over the years while
| everything else breaks.
| raxxorraxor wrote:
| To be fair, space is quite the decent preservation chamber.
| Night_Thastus wrote:
| I know people get frustrated with broken appliances and
| electronics, but I feel like once you look at the forces
| involved it seems fairly obvious that it'll happen:
|
| * Environmental regulations require additional or more
| complicated systems - which adds points of failure (IE:
| Variable-speed motor controllers, Exhaust Gas Recycling, etc).
| They also require other changes - like using lightweight
| plastics where metals would have been used previously. Plastic
| fan blades crack, metal ones don't.
|
| * Consumers, on the whole, only care about price and features.
| Those are tangible. Some people care about things like
| maintainability and longevity - but they make up a tiny,
| _insignificant_ fraction of consumers. Thus, companies optimize
| for price - even if it comes at the cost of longevity. Any
| company that _doesn 't_ quickly loses market share to global
| competition from dozens of others that are more than willing to
| make that sacrifice and offer a better deal.
|
| Those two factors explain everything about why modern
| appliances fail the way they do.
| themaninthedark wrote:
| The engineers know this.
|
| Now, how do you get the people buying these things to buy the
| better engineered one when the one sitting right next to it is
| $200 cheaper?
| apnew wrote:
| There should be a list of manufacturers who build durable
| consumer electronics.
| Aachen wrote:
| > [The S-band] uses a different frequency than the X-band
| transmitters signal is significantly fainter. The flight team was
| not certain the S-band could be detected at Earth due to the
| spacecraft's distance, but [it turned out to work]
|
| This is the most fascinating part to me. Isn't it well-
| established how sensitive a signal we can hear? Did they
| implement something like a new signal analysis method that
| enabled it?
|
| And it says this wasn't used or even tried since the 80s anymore,
| I guess it grew too faint. Looking up the frequencies, X is 8-12
| GHz and S is 2-4. Doesn't that mean X gets more data across at
| the same redundancy level? Why have this slower transmitter at
| all for only the first years, power conservation despite the
| fresh RTG?
| drmpeg wrote:
| > Did they implement something like a new signal analysis
| method that enabled it?
|
| They arrayed three antennas together.
|
| > Doesn't that mean X gets more data across at the same
| redundancy level?
|
| There's nothing special about the frequency itself. The
| advantage for X-band is that the antennas at both ends have
| more gain. 12 dB for the spacecraft and 11 dB for the ground
| station for a total of 23 dB.
| Keysh wrote:
| > They arrayed three antennas together.
|
| No, they didn't. The three antennas are in California, Spain,
| an Australia; they can't all point at the same point in the
| sky at once, and even if two could do so, they're not
| designed to work as an interferometric array.
| drmpeg wrote:
| There's more than one antenna at each site.
|
| https://x.com/CanberraDSN/status/1851446497453494663
|
| https://x.com/vlex26/status/1849618522823065655
| Keysh wrote:
| Ah, OK, thanks for the link.
| shagie wrote:
| https://eyes.nasa.gov/apps/dsn-now/dsn.html for the "what
| is it looking at right now"
|
| If you catch a site commutating with Voyager you will
| sometimes see it using two dishes... though most often it's
| just the one big one at the site. When they do, its not
| getting signal on two, but having one of the track the
| carrier wave (I think).
|
| https://www.cdscc.nasa.gov/Pages/antennas.html
|
| ... and to "even if two could do so, they're not designed
| to work as an interferometric array." They can.
|
| > The DSN anticipates and responds to user needs. The DSN
| maintains and upgrades its facilities to accommodate all of
| its users. This includes not only the implementation of
| enhancements to improve the scientific return from current
| experiments and observations, but also long-range research
| and development to meet the needs of future scientific
| endeavours.
|
| > Interferometry
|
| > The accurate measurement of radio source positions;
| includes astrometry, very long baseline interferometry,
| connected element interferometry, interferometry arrays and
| orbiting interferometry. Measurement of station locations
| and Earth orientation for studies of the Earth.
|
| > Very Long Baseline Interferometry
|
| > The purpose of the Very Long Baseline Interferometry
| (VLBI) System is to provide the means of directly measuring
| plane-of-the-sky angular positions of radio sources
| (natural or spacecraft), DSN station locations,
| interstation time and frequency offsets, and Earth
| orientation parameters.
| jgrahamc wrote:
| _Did they implement something like a new signal analysis method
| that enabled it?_
|
| Well, we do keep building bigger and bigger antennas and
| antenna arrays. So while Voyager can't change, we do. And we
| can build more and more sensitive (i.e. noise rejecting)
| equipment.
|
| _X is 8-12 GHz and S is 2-4_
|
| I don't know much about the Voyager design but the beam width
| is related to the frequency and so the S-band transmitter will
| have a larger beam width and thus can point less accurately
| that the X-band when trying to talk to Earth. Conversely,
| X-band is higher frequency than S-band and it's likely they
| would be able to use more bandwidth. So, interesting trade
| offs.
| prettyStandard wrote:
| I'm wondering also. Based on the wording here. I suspect we
| have more and better telescopes than we did when it launched.
|
| > The flight team was not certain the S-band could be detected
| at Earth due to the spacecraft's distance, but engineers with
| the Deep Space Network were able to find it.
| Aachen wrote:
| Certainly, but then isn't it expected now with the new
| antennas? They installed some upgrade but don't know to what
| sensitivity it goes? Surely they do so the article must be
| handwavy about it if I'm understanding things correctly
|
| Someone else commented about a wider spread in this other
| band, though. Perhaps the operators were not sure what that
| does for adsorptions and reflections by intervening dust or
| so?
| quotemstr wrote:
| Haven't you ever written code that you thought should work,
| but didn't due to a reason you couldn't foresee? I don't
| think the uncertainty here comes from question marks in the
| link budget equations but from the possibility of
| unforeseen problems making detection not work when it
| should.
| andrewstuart wrote:
| It's beyond my average brain how it's possible at all for a
| machine that far away to get data to us.
| 0x1ceb00da wrote:
| Can't wait for them to open source the code once it finally dies.
| Right now they probably can't do that because of security
| concerns.
| andyjohnson0 wrote:
| > security concerns
|
| Does anyone know whether the Voyagers even do any command
| authentication?
|
| Probably doesn't matter now as only the dsn has the ability to
| talk to them, and that happens comparatively rarely.
| mrsilencedogood wrote:
| Even if you magically had your own DSN, would anyone but NASA
| even know exactly where they are with enough precision to
| communicate with them? In a way, that's now your layer 1
| authentication key. The coordinates of where to "point" your
| DSN.
| 0x1ceb00da wrote:
| I don't think they are the kind of people that will take
| unnecessary risks.
| evoke4908 wrote:
| I'd be _very_ surprised if its exact position in the sky is
| not public information.
|
| Even if not, it should be fairly straightforward to compute
| its position from the initial flightplan. Once it escaped
| Jupiter its trajectory is just a straight line.
| wongarsu wrote:
| I was about to say that Voyager likely also suffers from
| the Pioneer anomaly, which is suspected to be caused by
| the RTG's thermal radiation pushing the craft off course
| [1]. But according to wikipedia we can't really tell
| because the effect of the maneuvering thrusters that keep
| Voyager aligned is much bigger than the Pioneer anomaly
| (Voyager 1 has fuel until about 2040).
|
| 1: https://en.wikipedia.org/wiki/Pioneer_anomaly
| evoke4908 wrote:
| Given how simple the computer is, I very much doubt it. If
| anything, it might have a very simple xor encryption or just
| a passphrase. If anyone were sufficently motivated, it
| _probably_ would be trivial to snoop on the DSN transmissions
| and crack any authentication. I 'm sure it'd be susceptible
| to a simple replay attack at any rate
|
| The problem is simply that you need a huge transmitter with
| (AIUI) some special and unique modulation hardware. Also
| there's nothing to be gained from interfering with the
| Voyagers. Really the only practical thing you could do is
| shut them down a couple of years before they die anyway.
| There's just no point.
| Ductapemaster wrote:
| Check out this talk:
| https://www.youtube.com/watch?v=dF_9YcehCZo
|
| The source code isn't hiding in a repo somewhere for security
| reasons -- it's spread around on various pieces of paper and
| computers over the last 50 years. There isn't a single source
| of truth. Adds a whole other level of wizardry to keeping the
| thing running.
| 0cf8612b2e1e wrote:
| Like, maybe that was originally true, but they have had
| decades. Numerous times contact has been lost, hardware
| failed, key people died, etc.
|
| How has nobody at the top ordered a digitization and
| consolidation of all known code and supporting documentation
| during that time frame.
| kulahan wrote:
| It costs money that would better be sent towards other
| projects, and NASA needs to be as careful as possible with
| spending their very limited budget.
|
| Having a ton of people run around the office for a couple
| months to collate a bunch of documents so you can better
| pass info on to a new generation of workers when the
| satellite might not even be _usable_ anymore isn 't very
| efficient. Might as well just pay an extra 50% or whatever
| to the 5 dudes who know what's going on until the thing is
| inop. Even if it died _today_ , the mission still would've
| been a massive success.
| HenryBemis wrote:
| (thinking aloud/voice in my head) If 'those things' are recharged
| by sunlight, I wonder how will they get the energy to continue
| transmitting (assuming they have whatever source AND solar panels
| - for when the fuel runs out and they can't catch any sunlight?)
|
| my dialogue with ChatGPT: Voyager 1 and Voyager 2
| are powered by \*Radioisotope Thermoelectric Generators (RTGs)\*.
| These RTGs use the natural decay of \*plutonium-238\* to generate
| heat, which is then converted into electricity using
| thermoelectric materials. Here's how the process
| works: 1. \*Radioactive Decay\*: Plutonium-238, a
| radioactive isotope, decays over time, releasing a consistent
| amount of heat. 2. \*Thermoelectric Conversion\*:
| Thermocouples in the RTGs convert this heat directly into
| electricity. 3. \*Power Supply\*: This generated
| electricity powers the instruments, computers, and communication
| systems on each spacecraft. Each year, the power
| output of the RTGs decreases slightly as the plutonium decays, so
| the Voyager missions have had to shut down non-essential systems
| over time to conserve power. Despite this, both Voyager 1 and
| Voyager 2 have enough energy to continue transmitting until at
| least the late 2020s, when their power levels will likely drop
| below the minimum required for communication.
| maples37 wrote:
| That's the problem, they won't have enough energy to transmit
| anymore.
|
| The Voyager probes are powered entirely from their RTGs, they
| have no solar panels nor batteries[1]. So if the power output
| from the RTGs drops below the level needed to power the
| transmitter, Voyager can't talk to us anymore. There's no
| batteries that can be recharged and no solar panels it ever
| drew power from.
|
| The exciting part from this discovery is the potential to keep
| talking to Voyager longer than we thought. If the S-band
| transmitter uses less power and we're still able to detect that
| signal, we may be able to communicate with the probes with
| lower RTG outputs than we initially thought. Though at that
| point, if the radio is the only thing still running and there's
| no instruments operating, the usefulness is probably pretty low
| at that point.
|
| [1] https://en.wikipedia.org/wiki/Voyager_1#Power,
| https://en.wikipedia.org/wiki/Voyager_2#Power
| whamlastxmas wrote:
| I wonder how long we could make an RTG last today
| 93po wrote:
| wiki has the answer, ballpark is around twice as long, and
| they're using this new design for an upcoming probe
| Sanzig wrote:
| Fundamentally there isn't any change in the underlying
| physics. You're limited by the half life of the isotope, so
| you either choose a longer-lived isotope (which actually
| may be even harder post Cold War as much of the ideal
| isotopes were byproducts of nuclear weapons manufacturing)
| or launch a bigger RTG than you need so you have enough
| power later on in the mission.
| daedrdev wrote:
| I think the more interesting thing is its suddenly become
| so much cheaper to put things in orbit, we could simply put
| a larger satellite with a larger nuclear battery out there.
| Nginx487 wrote:
| On such a distance solar panels won't make any difference.
| Sun looks like just a very bright star from that far.
| jeffrallen wrote:
| Wow: Triggering the protection system a second time turned off
| the regular radio:
|
| "While the S-band uses less power, Voyager 1 had not used it to
| communicate with Earth since 1981. It uses a different frequency
| than the X-band transmitters signal is significantly fainter. The
| flight team was not certain the S-band could be detected at Earth
| due to the spacecraft's distance, but engineers with the Deep
| Space Network were able to find it."
|
| Heros, both those who made the S-band radio and those who managed
| to retrieve the signal.
| standardUser wrote:
| Hey smart people, if we were to launch a similar probe today
| using the most advanced technology available, how long would it
| take a probe to reach the same distance as Voyager 1?
| jlawson wrote:
| Really depends how much money you want to spend and if you're
| willing to wait a bit longer for Starship orbital refueling to
| be tested.
|
| We could build a more or less arbitrarily large rocket in orbit
| by adding more and more fuel. More fuel means more delta-V
| means the probe is faster.
| AStonesThrow wrote:
| "Launch today" is a very undesirable constraint for this
| goal. All of the probes that have escaped made extensive use
| of gravitational slingshot effects, which are only available
| during favorable launch windows.
|
| https://en.wikipedia.org/wiki/List_of_artificial_objects_lea.
| ..
|
| Long story short: they plan these out for decades at a time,
| and take your best shot when the planets align, literally.
| ceejayoz wrote:
| We needed the slingshotting because until recently on-orbit
| construction was mostly a pipe-dream.
|
| If you can build larger ships in orbit, relatively cheaply,
| you can go a lot more direct, a lot faster.
| datameta wrote:
| Even on-orbit refueling is a huge boon for orbital assist
| flexibility.
| wafflemaker wrote:
| It's ineffective, you need more stages.
|
| Tsiolkovsky's equation shows how much dV you get with a given
| wet : dry (empty) mass of a rocket stage. Very quickly it's
| becoming very inefficient.
|
| Unless you are talking about some untested rocket that dumps
| empty fuel tanks in pairs. (Like in the dV book by Daniel
| Suarez).
| divbzero wrote:
| The Voyager probes enjoyed gravity assists from all of the
| outer planets [1] which won't align again until the middle of
| the next century [2].
|
| [1]: https://space.stackexchange.com/a/3522
|
| [2]: https://space.stackexchange.com/a/5076
| standardUser wrote:
| But...
|
| "The beauty of the gravity assist is that you use the gravity
| field of a large body to change course. A common
| misconception is that the gravity assist increases speed, but
| it actually leaves speed unchanged. It's more accurate to say
| that the gravity assist changes direction, since velocity is
| both a magnitude (speed) AND a direction."
| LeifCarrotson wrote:
| That's only thinking about it from the perspective of the
| planet. Relative to the planet, the magnitude of the
| incoming velocity vector is equal to the magnitude of the
| outgoing velocity vector. But in the reference frame of the
| sun, the planet loses an infinitesimal bit of momentum, and
| the spacecraft gains that momentum.
|
| And that's assuming you don't do an extra burn at
| periapsis, which is far more efficient at changing speed
| than doing the burn in interplanetary space.
| AnotherGoodName wrote:
| There's an upvoted sub comment to that which has a good
| correction. That statement as a whole is just not true and
| a meaningless statement. When you pass an orbiting body you
| will take some of that body's orbital momentum and add that
| to your current momentum. There's really no semantic
| argument in my mind that could justify the above statement.
| You change direction because you have more in total.
| There's no bending of the direction here, just addition of
| new vectors but that's exactly how all acceleration works
| anyway so it's a bit meaningless to make that statement and
| I'm really not sure what they are trying to get at. Maybe
| from the pov of the orbiting body there's no change but
| that's not the thing anyone cares about when doing a flyby.
| vikingerik wrote:
| The lineup barely matters for gravity assist. Jupiter is the
| vast majority of the total you can get. Saturn has 30% of the
| mass and 2/3 the orbital velocity, so adding Saturn gets you
| only 20% more above using Jupiter alone (and the Voyagers
| didn't really try), and the ice giants are smaller and slower
| yet.
|
| We could easily overtake Voyager via only Jupiter if we
| wanted to (and New Horizons eventually will), and Jupiter-to-
| any-target launch windows come at least every 12 years.
| Denvercoder9 wrote:
| New Horizons was launched in 2006, and it will reach the same
| distance from the Sun as Voyager 1 is _currently_ in about 32
| years.
| farrelle25 wrote:
| There's a good documentary about the quirky team of NASA
| engineers that keep in contact with the Voyager probes...
|
| It's slightly melancholic, the engineers are aging, the mission's
| heyday is long past... but there's something gripping about it...
|
| "It's Quieter in the Twilight" (2022)
|
| https://www.imdb.com/title/tt17658964/
| mmooss wrote:
| The mission's heyday is right now! They are in interstellar
| space!
|
| We can and have send other probes to the planets.
| dazhbog wrote:
| Started watching after your comment.. Fantastic documentary!
| And its great to see some shots of the screens they use to
| manage the probes and stuff. And yes, some ninjas cutting
| onions..
| Ancalagon wrote:
| favorited this post just to be able to come back to this
| comment and watch the documentary. Thanks!
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