[HN Gopher] Voyager 1 is about to reach one light-day from earth
       ___________________________________________________________________
        
       Voyager 1 is about to reach one light-day from earth
        
       Author : ashishgupta2209
       Score  : 685 points
       Date   : 2025-11-26 14:02 UTC (8 hours ago)
        
 (HTM) web link (scienceclock.com)
 (TXT) w3m dump (scienceclock.com)
        
       | jmclnx wrote:
       | Kind of a dup, but the article linked here is different
       | 
       | https://news.ycombinator.com/item?id=46046260
        
       | homarp wrote:
       | also discussed at https://news.ycombinator.com/item?id=45908483
        
       | NooneAtAll3 wrote:
       | november 202 _6_
        
       | jesprenj wrote:
       | > Error establishing a database connection
        
         | kondro wrote:
         | You might need to increase your connection timeout to at least
         | 172800 seconds.
        
         | rconti wrote:
         | Cannot send email to recipients more than 1 light-day away
        
       | uyzstvqs wrote:
       | Site is down? Archive: https://archive.is/55yNp
       | 
       | Headline is also misleading. It will do so in November 2026,
       | about a year from now.
        
         | croisillon wrote:
         | well, that's only about 30 light-minutes left
        
         | firefax wrote:
         | >Site is down?
         | 
         | They got Slashdotted ;-)
         | 
         | https://en.wikipedia.org/wiki/Slashdot_effect
        
       | TechRemarker wrote:
       | No, not "About to". It's this time "next year".
        
         | troupo wrote:
         | > No, not "About to". It's this time "next year".
         | 
         | 48 years in space and a light-day from Earth? I think it
         | qualifies for "about to" :)
         | 
         | (At this point 1 year is ~2% of total time in space)
        
           | chrisweekly wrote:
           | sure - but this time next year is obv more relevant
        
             | knorker wrote:
             | Christmas also starts earlier every year.
             | 
             | I guess ScienceClock wanted a "first!".
        
         | mlmonkey wrote:
         | I've been reading such posts for years. Every few months,
         | "Voyager 1 is the most distant man-made object ever!" or
         | "Voyager 1 about to leave the Solar System!"
         | 
         | Well duh!
        
       | tonyhart7 wrote:
       | cant wait when Voyager 6 reach earth
        
         | nntwozz wrote:
         | V'ger, was looking for a Star Trek reference and HN delivered.
        
           | SAI_Peregrinus wrote:
           | V'ger raises the question of how Starfleet missed it for so
           | long, given how slow the Voyager probes were and how near-
           | future the Star Trek timeline is.
        
       | chistev wrote:
       | Wrote about the Voyager probes two days ago in my blog - The two
       | Voyager spacecraft are the greatest love letters humanity has
       | ever sent into the void.
       | 
       | Voyager 2 actually launched first, on August 20, 1977, followed
       | by Voyager 1 on September 5, 1977. Because Voyager 1 was on a
       | faster, shorter trajectory (it used a rare alignment to slingshot
       | past both Jupiter and Saturn quicker), it overtook its twin and
       | became the farther, faster probe. As of 2025, Voyager 1 is the
       | most distant human-made object ever, more than 24 billion
       | kilometers away, still whispering data home at 160 bits per
       | second.
        
         | Sharlin wrote:
         | Voyager 2 was the real beneficiary of the rare outer planet
         | alignment, as it went on the famous Grand Tour, visiting all
         | four of the giants. It did gravity assists at Jupiter, Saturn,
         | _and_ Uranus. [1] shows the rough velocity of V2 over time.
         | 
         | Voyager 1 was directed to perform a flyby of Titan, at the cost
         | of being thrown out of the ecliptic and being unable to visit
         | the ice giants like its sister. But this was deemed acceptable
         | due to Titan's high science value.
         | 
         | [1]
         | https://commons.wikimedia.org/wiki/File:Voyager_2_-_velocity...
        
           | creata wrote:
           | To save someone two seconds of searching,
           | 
           | NASA animation of Voyager 2's trajectory (time in the bottom-
           | left corner): https://youtu.be/l8TA7BU2Bvo
        
             | snowwrestler wrote:
             | This is great. I did not realize Voyager 2 also left the
             | ecliptic at the end of its tour.
        
               | vikingerik wrote:
               | That happened because Voyager 2 went over Neptune's north
               | pole rather than an equatorial trajectory. Both to get a
               | look at a giant planet's polar regions, and because that
               | would get it closest to the moon Triton. So Voyager 2's
               | trajectory got bent southward out of the ecliptic plane
               | as a result of that.
               | 
               | While I'm here: why didn't Voyager 2 continue to
               | slingshot to Pluto? The answer is that its trajectory
               | would have had to bend by about 90deg at Neptune, which
               | would have required an apex closer to Neptune's center of
               | mass than the planet's own radius - it would have crashed
               | into the planet instead.
        
           | namirez wrote:
           | There isn't much value in gravity assists from Uranus or
           | Neptune since they move much more slowly than Jupiter and
           | Saturn.
        
         | detectivestory wrote:
         | And that love letter came with a very nice mixtape.
         | https://en.wikipedia.org/wiki/Voyager_Golden_Record
        
           | chistev wrote:
           | Yea, I mentioned that too.
        
         | chistev wrote:
         | Extended piece from my blog.
         | 
         | The two Voyager spacecraft are the greatest love letters
         | humanity has ever sent into the void.
         | 
         | Voyager 2 actually launched first, on August 20, 1977, followed
         | by Voyager 1 on September 5, 1977. Because Voyager 1 was on a
         | faster, shorter trajectory (it used a rare alignment to
         | slingshot past both Jupiter and Saturn quicker), it overtook
         | its twin and became the farther, faster probe. As of 2025,
         | Voyager 1 is the most distant human-made object ever, more than
         | 24 billion kilometers away, still whispering data home at 160
         | bits per second.
         | 
         | Each spacecraft carries an identical 12-inch gold-plated copper
         | phonograph record.
         | 
         | The contents:
         | 
         | - Greetings in 55 human languages.
         | 
         | - A message from UN Secretary-General at the time and one from
         | U.S. President Jimmy Carter.
         | 
         | - 115 analog images encoded in the record's grooves: how to
         | build the stylus and play the record, the solar system's
         | location using 14 pulsars as galactic GPS, diagrams of human
         | DNA, photos of a supermarket, a sunset, a fetus, people eating,
         | licking ice cream, and dancing
         | 
         | The record is encased in an aluminum jacket with instructions
         | etched on the cover: a map of the pulsars, the hydrogen atom
         | diagram so aliens can decode the time units, and a tiny sample
         | of uranium-238 so they can carbon-date how old the record is
         | when they find it.
         | 
         | Sagan wanted the record to be a message in a bottle for a
         | billion years. The spacecraft themselves are expected to
         | outlive Earth. In a billion years, when the Sun swells into a
         | red giant and maybe swallows Earth, the Voyagers will still be
         | cruising the Milky Way, silent gold disks carrying blind, naked
         | humans waving hello to a universe that may never wave back.
         | 
         | And it was Sagan who, in 1989, when Voyager 1 was already
         | beyond Neptune and its cameras were scheduled to be turned off
         | forever to save power, begged NASA for one last maneuver. On
         | Valentine's Day 1990, the spacecraft turned around, took 60
         | final images, and captured Earth as a single pale blue pixel
         | floating in a scattered beam of sunlight -- the photograph that
         | gives the book its name and its soul.
         | 
         | It was the photograph that inspired this famous quote -
         | 
         | "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 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. 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.
         | 
         | 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. "
         | 
         | That picture almost didn't happen. NASA said it was pointless,
         | the cameras were old, the images would be useless. Sagan argued
         | it would be the first time any human ever saw our world from
         | outside the solar system. He won. The cameras were powered up
         | one last time, the portrait was taken, and then they were shut
         | down forever.
        
           | shagie wrote:
           | That legacy of the Pale Blue Dot has been something that has
           | been repeated to remind us again. I personally like the
           | Cassini one - https://science.nasa.gov/science-
           | research/earth-science/23ju...
           | 
           | There's also the MESSENGER family portrait
           | https://science.nasa.gov/resource/a-solar-system-family-
           | port...
        
       | Mistletoe wrote:
       | When I read stats like this I realize how stuck in this solar
       | system we are. I wonder if billionaires would care for the planet
       | more if they knew that Earth is honestly just it for humans, for
       | maybe forever.
        
         | im_down_w_otp wrote:
         | Nah, the whole second-Earth, terraforming nonsense is pure
         | rationalization for whatever they want to do. If they weren't
         | using that as a post hoc justification, they'd just land on
         | something else.
        
         | lm28469 wrote:
         | It gets even better when you think about all the damage we've
         | done in ~200 years of industrial revolution.
         | 
         | We can't keep our perfect home in working order after so little
         | time but they believe we'll transform dead rocks with no
         | atmospheres in paradise...
        
           | mr_toad wrote:
           | I'm not aware of any organisation or individual that has
           | actual plans (backed with actual investment) for terraforming
           | anything. This is a straw man argument.
        
             | lm28469 wrote:
             | Dork in chief always delivers: https://en.wikipedia.org/wik
             | i/SpaceX_Mars_colonization_progr...
             | 
             | > "We bring you Mars", a rendering of a terraformed Mars at
             | SpaceX Headquarters
        
         | astroflection wrote:
         | Carl Sagan's reflection on the Pale Blue Dot(
         | https://en.wikipedia.org/wiki/Pale_Blue_Dot ) image seem
         | relevant:
         | 
         | "From this distant vantage point, the Earth might not seem of
         | any particular interest. But for us, it's different. Consider
         | again 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. "
        
         | optimalsolver wrote:
         | They're not going to be alive in 100 years (barring AGI
         | intervention), so why would they care?
        
           | thmsths wrote:
           | This. It's not a spatial problem, it's a temporal one. They
           | are somewhat aware there will be nowhere to run to (I say
           | somewhat because they still spend millions in luxury
           | bunkers), they are just betting that it won't get really bad
           | during their lifetime, maybe their kids lifetime for the more
           | empathetic ones.
        
         | 1970-01-01 wrote:
         | Nuclear propulsion is the answer to this problem, but we're too
         | busy with internal affairs to get around to trying it.
         | 
         | https://en.wikipedia.org/wiki/Project_Longshot
        
         | foxglacier wrote:
         | You people should stop demonizing billionaires. You're the ones
         | burning the fossil fuels, not them. If their wealth way
         | distributed among more people then those people would spend it
         | damaging the environment which is what people generally do with
         | their money anyway.
        
           | throw9174 wrote:
           | Doesn't this kind of argument prove too much?
           | 
           | Consider an alternate reality without food standards and
           | regulations. Things like the melamine incident are
           | commonplace and people regularly suffer due to contaminated
           | food. Someone argues "perhaps the corporations should stop
           | poisoning our food". Then someone else responds "Stop
           | demonizing the executives, their objective is to make a
           | profit, which they get from the consumers. The consumers are
           | the ones buying the contaminated food, the executives aren't.
           | If people don't want to get sick, they should exercise more
           | diligence."
           | 
           | It's easy to offload coordination problems on the people who
           | make imperfect decisions as a consequence, but saying "just
           | don't have coordination problems, then" is rarely useful if
           | one wants to mitigate those problems.
        
             | foxglacier wrote:
             | People don't want to buy poisonous food knowing it's
             | poison. They might take a gamble on if it the odds seem
             | good enough. (even in highly safety regulated western
             | countries, people sometimes die from contaminated food). In
             | contrast, people do want to burn petrol knowing that it
             | 100% will pollute the environment every single time they
             | drive their car. We do what benefits us personally despite
             | the cost to the environment. So it's our fault. It's hard
             | to correct your own faults while you're blaming somebody
             | else for them instead of accepting responsibility.
        
         | aylmao wrote:
         | The way I see it, it takes a very selfish person to be a
         | billionaire in the first place-- one that not only doesn't care
         | about people today, but also doesn't care about future
         | generations of humans, let alone other living beings.
         | 
         | Any billionaire pointing at space exploration as humanity's
         | salvation is, IMO, either really just craving the attention and
         | glory of conquest (much like Caesar, Napoleon, Alexander, etc)
         | or seeking the conditions of the age of exploration (XV to XIX
         | centuries), when companies were as powerful as governments and
         | expansionism was unfettered.
        
       | iberator wrote:
       | This is an absurdly simplified article :/ Wikipedia is way better
       | and more technical.
        
       | snowwrestler wrote:
       | At current pace, Voyager 1 will have taken 49 Earth years to
       | reach one light-day.
       | 
       | That means it will reach a light year in approximately the Earth
       | year 19,860.
        
       | acec wrote:
       | 50 years for 1 light day... so to arrive Alpha Centauri that is
       | 4.2 light years far away... 76549 years and 364 days :-)
        
         | pjerem wrote:
         | Less than that is you are constantly accelerating.
        
           | malfist wrote:
           | Longer than that if you are constantly decelerating.
        
             | SAI_Peregrinus wrote:
             | And exactly that if you're talking about Voyager 1, which
             | is on a ballistic trajectory.
        
           | jandrese wrote:
           | If you can figure out a way to apply thrust that doesn't
           | require you to lug mass with you and throw it out the back of
           | your spacecraft you will open up the stars to exploration. If
           | not the rocket equation will wreck your plans every time.
        
             | deadbabe wrote:
             | Why?
             | 
             | 75k years in geological timescales is nothing.
             | 
             | If there are creatures who could live longer than that,
             | perhaps by hibernating or just having really long
             | lifetimes, space exploration is feasible with slow craft.
        
               | jandrese wrote:
               | 75k years of reliable operation for complex machines
               | operating in a hostile environment is a different story.
               | This includes organic life. You can't just bottle
               | everything up and wake up thousands of years in the
               | future, you will be under constant bombardment by high
               | energy particles, micrometeorites, and the relentless
               | cold vacuum of space with no access to new raw material
               | or energy for almost the entire trip.
               | 
               | If you can make that kind of trip the question becomes
               | why bother? You could have used the same technology
               | (actually a much easier version of the tech since you
               | will have access to external resources and don't need to
               | attach enormous engines to get it moving and then
               | stopping at the destination) to use the almost unlimited
               | space in your home solar system instead.
               | 
               | Unless your sun is literally about to explode it is hard
               | to make the argument for the incredibly difficult and
               | long journey to a neighboring solar system.
        
         | lysace wrote:
         | I believe there's a semi-common sci-fi construct to send probes
         | containing human brain dumps running on silicon to these far
         | away star systems. Just hit pause until a week before arrival
         | :).
        
         | shagie wrote:
         | One of the neat things that I've stumbled across is
         | https://thinkzone.wlonk.com/SS/SolarSystemModel.php
         | 
         | Make the model scale to be 10000000 (10 million). The sun is a
         | chunky 139 meters in diameter. Earth is 15 km (9 miles) away.
         | Pluto is 587 km (365 miles) away. The speed of light is 107 kph
         | (67 mph).
         | 
         | Alpha Centauri is 4.1 million km (2.5 million miles) away...
         | that is 10 times the earth moon distance.
         | 
         | Another comparison... Voyager 1 is moving at 30 light minutes
         | per year. (Andromeda galaxy is approaching the Milky Way at 3.2
         | light hours per year)
        
         | thangalin wrote:
         | At Voyager 1's velocity, it would take ~456 million years to
         | reach the heart of the Milky Way (Sagittarius A*), some ~26,000
         | light-years away. That's roughly the same amount of time that
         | has passed since the Ordovician-Silurian extinction, when
         | volcanic eruptions released enough carbon dioxide to heat up
         | the planet and deoxygenate the oceans, resulting in the
         | asphyxiation of aquatic species (about 85% of all life was
         | snuffed out). The oceans remained deoxygenated for more than
         | three million years.
        
       | dtgriscom wrote:
       | "Space is big. Really big. You just won't believe how vastly,
       | hugely, mind-bogglingly big it is. I mean you may think it's a
       | long way down the road to the chemist, but that's just peanuts to
       | space."
        
         | vee-kay wrote:
         | This old video is a beautiful and astounding demonstration of
         | just how vastly, hugely, mind-bogglingly big the Universe is,
         | and where in all this endless space our dear favourite little
         | Pale Blue Dot (Earth) resides:
         | 
         | https://m.youtube.com/watch?v=X-3Oq_82XNA
         | 
         | We all Earthlings are extremely lucky to be alive and thriving
         | (or trying to) in such a beautiful bountiful rarest-of-rare
         | ecosystem that somehow survived and thrived despite all the
         | vagaries and vastness of spacetime.
        
           | chistev wrote:
           | WHAT!
           | 
           | I've read a ton about immense distances and time, but still
           | get wowed when I read analogies or see visualizations like
           | this.
           | 
           | Crazy stuff, man.
        
           | dtgriscom wrote:
           | The classic, from 1977:
           | https://www.youtube.com/watch?v=0fKBhvDjuy0
        
             | vee-kay wrote:
             | Awesome, thanks. I think the video I had linked was
             | Google's tribute to this Power Of Ten video that you have
             | linked, a classic video that demonstrates the scale of the
             | Universe from the micro to the macro perspectives in a
             | scaling increase by a factor of ten for each scene.
             | 
             | Another relevant video (thanks to user christev for sharing
             | the link): A Brief History of Geologic Time:
             | https://youtu.be/rWp5ZpJAIAE
             | 
             | Absolutely humbling to realise how infinitesimally small
             | and irrelevant our existence is, in the grand scheme of
             | theme. Nature and science are amazing.
        
       | glenstein wrote:
       | Not that we would literally do this with Voyager, but it makes me
       | wonder at the potential utility of a string of probes, one sent
       | every couple of [insert correct time interval, decades,
       | centuries?], to effectively create a communication relay
       | stretching out into deep space somewhere.
       | 
       | My understanding with the Voyagers 1 and 2 is (a) they will run
       | out of power before they would ever get far enough to benefit
       | from a relay and (b) they benefited from gravity slingshots due
       | to planetary alignments that happen only once every 175 years.
       | 
       | So building on the Voyager probes is a no-go. But probes sent
       | toward Alpha Centauri that relay signals? Toward the center of
       | the Milky Way? Toward Andromeda? Yes it would take time scales
       | far beyond human lifetimes to build out anything useful, and even
       | at the "closest" scales it's a multi year round trip for
       | information but I think Voyager, among other things, was meant to
       | test our imaginations, our sense of possible and one thing they
       | seem to naturally imply is the possibility of long distance probe
       | relays.
       | 
       | Edit: As others rightly note, the probes would have to
       | communicate with lasers, not with the 1970s radio engineering
       | that powered Voyagers 1 and 2.
        
         | Aperocky wrote:
         | Not useful, because the signal are too weak to be picked up
         | probe to probe.
         | 
         | On earth, the tiny signal from Voyager at this distance is
         | picked up by dish the size of a football field; same with
         | sending of the signal.
        
           | nntwozz wrote:
           | What if the probes carry smaller probes left behind at
           | specific intervals that act as repeaters?
           | 
           | These baby probes could unfold a larger spiderweb antenna the
           | size of a tennis court.
        
             | jandrese wrote:
             | The problem is each relay needs its own power source so
             | it's not going to be as light and small as you would like.
             | Solar power doesn't work very well outside of the solar
             | system, or even really in the outer solar system.
             | 
             | On the plus side your big probe could push off of the small
             | probe to give itself a further boost, also necessary
             | because otherwise the small probes need thrusters to slow
             | themselves to a stop.
        
             | keepamovin wrote:
             | We need quantum entanglement based communication. Maybe
             | without full collapse, using weak measurements, like Alice
             | continuously broadcasts a "retrocausal carrier wave" by
             | sequencing planned future post-selection measurements on
             | her entangled qubits, which backward-propagates through
             | time-symmetric quantum evolution to create detectable
             | perturbations in the present states, biasing Bob's qubits
             | away from pure randomness to encode message patterns.
             | 
             | Both parties perform weak measurements on their qubits to
             | extract these subtle signals without collapsing the
             | entanglement, preserving high coherence across the stream.
             | A quantum Maxwell's demon (e.g. many experiments but can be
             | done: https://pubmed.ncbi.nlm.nih.gov/30185956/) then
             | adaptively selects the strongest perturbations from the
             | wave, filters out noise, and feeds them into error
             | correction to reliably decode and amplify the full message.
        
             | foxglacier wrote:
             | You can't leave anything behind. That would need to be
             | accelerated to 50,000 km/h or have even bigger rockets than
             | launched Voyager in the first place.
        
           | malfist wrote:
           | The dish isn't the size of a football field, it's a 70 meter
           | dish (football field is 110 meters), it can however, transmit
           | at 400 kilowatts of power
        
           | jcims wrote:
           | Laser communication could potentially address some of those
           | issues.
        
             | jandrese wrote:
             | Maybe, but if your probe is heading directly towards
             | another solar system then it will be backlit by its
             | destination.
        
               | glenstein wrote:
               | My understanding is that's a solved problem - NASA's Deep
               | Space Optical Communication has demonstrated laser
               | communication even with the sun in the background. Laser
               | wavelength and modulation are noticeably different than a
               | stars noise if you filter and just look for the
               | wavelength and modulation of the laser, which is notably
               | shorter and faster than most of the noise coming from the
               | star.
        
               | shagie wrote:
               | https://space.stackexchange.com/questions/33338/why-is-
               | the-o... is a neat question that addresses this issue.
               | 
               | And yes, the transmitters will need to be powerful enough
               | be a distinct signal over the background of the star that
               | is in the line of sight of the receiver / beyond the
               | transmitter.
        
           | BobbyTables2 wrote:
           | Football field might even be too small...
           | 
           | Wasn't Arecibo used for Voyager?
        
             | shagie wrote:
             | It might have from time to time... but it had limited
             | ability to track.
             | 
             | As I type this, DNS Now is _currently_ receiving data from
             | Voyager 1. https://eyes.nasa.gov/apps/dsn-now/dsn.html
             | 
             | https://imgur.com/a/kXbhRsj for a screen shot of the
             | relevant data.
             | 
             | The antenna data is
             | https://www.mdscc.nasa.gov/index.php/en/dss-63-2/
        
             | FireBeyond wrote:
             | No. Or not any more, DSS-43 at the Canberra Deep Dish
             | Communication Complex is the only antenna that can
             | communicate with the Voyagers.
        
           | pseudocomposer wrote:
           | This is a silly counterexample - why would we launch them
           | that far apart? It's a terrible idea for multiple reasons.
           | We'd want them close together, with some redundancy as well,
           | in case of failures.
           | 
           | What dish size would be required for a "cylindrical/tubular
           | mesh" of probes, say, 1AU apart (ie Earth-Sun distance)? I'm
           | pretty sure that would be manageable, but open to being
           | wrong. (For reference, Voyager 1 is 169AU from Earth, but I
           | have no idea how dish size vs. signal strength works:
           | https://science.nasa.gov/mission/voyager/where-are-
           | voyager-1...)
        
             | ianburrell wrote:
             | Light year is 63,241 AU. That means tens of thousands of
             | relays. It would super expensive and super unreliable. The
             | other problem is that achievable speeds are super slow,
             | Voyager is 25,000 years per light year which means that
             | would wait 100,000 years for relays to Alpha Centauri to be
             | possible.
             | 
             | Much easier just to send probe with large antenna or laser,
             | and make a large antenna at Earth.
        
           | rootnod3 wrote:
           | You could send a good amount of small probes and make them
           | become the big antenna dish basically. As long as you cover
           | the bases, you can have layers of "big antenna dishes" in
           | onion layers.
        
           | JumpCrisscross wrote:
           | > _the tiny signal from Voyager at this distance is picked up
           | by dish the size of a football field_
           | 
           | Lots of small fishes can resemble a large fish.
        
           | glenstein wrote:
           | Very true insofar as it's a description of Voyager
           | communications. Voyager was 1970s radio engineering. Radio
           | signals spread wide, so you need a big dish to catch it.
           | These days we are using lasers, and laser divergence is
           | several orders of magnitude smaller. And regardless of tech,
           | relay enforces a minimum distance for any signal to spread.
        
           | boznz wrote:
           | Unlike the other comments I actually agree, physics has not
           | changed since the 1970's, even the most focused laser and
           | detector would need to be positioned perfectly to where the
           | next probe would be, and with the nearest star 4 light years
           | away we would be talking a chain of dozens, any of which may
           | fail some way. The probes would also likely be small, cell-
           | phone sized, power restricted, and difficult to shield (you
           | couldn't just throw in the latest wiz-bang 2025 electronics
           | as it all has to be hardened to work multiple decades) Best
           | is a big, transmitter and good receiver one end.
        
         | Fokamul wrote:
         | Hmm, do you realize, that even if you have 1B probes
         | everywhere. You're still bound by speed of light communication
         | speed, right?
         | 
         | It's faster than probe speed in this age, yeah. But still not
         | enough, if we're talking distances to other specific planets,
         | stars, etc.
         | 
         | Two possible ways to solve this, humans will become immortal or
         | speed of light bypass method will be discovered.
        
           | serf wrote:
           | the post office has utility even if the messages have very
           | high latency.
           | 
           | also if this probe network reduces the transmission costs to
           | normal terrestrial levels (and not requiring , say, a 400kw
           | tx dish..) it could drastically increases the utility of the
           | link -- and all of this without discussing how much bandwidth
           | a link network across the stars might possess compared to our
           | current link to Voyager..
           | 
           | (this is all said with the presumption of a reason to have
           | such distance communications channels.. )
        
           | LargeWu wrote:
           | Seems like the problem OP is trying to solve for here is not
           | latency, it's signal power and redundancy.
        
             | glenstein wrote:
             | You're exactly right and thank you for carefully reading! I
             | very explicitly said that there was a multi year round trip
             | for information even in the best case (e.g. Alpha
             | Centauri), to get out ahead of the well-actually's.
             | 
             | As you noted, some of the gains could be signal power,
             | redundancy, the ability to maintain a quality signal over
             | arbitrary distance; but most importantly, seeing the
             | universe from the perspective of the lead probe in the
             | relay, some arbitrary distance away.
        
         | tpurves wrote:
         | What you are describing has been proposed before, for example
         | within context of projects like Breakthrough Starshot. In that
         | the case the idea is to launch thousands of probes, each
         | weighing only a few grams or less, and accelerating them to an
         | appreciable fraction of the speed of light using solar sails
         | and (powerful) earth-based lasers. The probes could reach alpha
         | centauri within 20-30 years. There seems to be some debate
         | though about whether cross-links between probes to enable
         | relaying signals is ever practical from a power and mass
         | perspective vs a single very large receiver on earth.
        
           | Tepix wrote:
           | Indeed. I think the main reason to send thousands of probes
           | is increasing the odds that they will survive the trip and
           | also be in the right position to gather usable data to
           | transmit back.
           | 
           | Also once you have created the infrastructure of hundreds or
           | thousands of very powerful lasers to accelerate the tiny
           | probes to incredibel speeds, sending many probes instead of a
           | few doesn't add much to the cost anyway.
        
           | dbacar wrote:
           | If I don't recall wrongly, Breakthrough Starshot was not a
           | means for commnunicaiton relay as he describes.
        
             | octaane wrote:
             | It wasn't intended for a communications relay, but it was
             | intended to have 2-way communication. I went down a rabbit
             | hole reading ArXiv papers about it. Despite their tiny
             | size, the probes could phone home with a smaller laser -
             | according to the papers I read, spinning the photons a
             | certain way would differentiate them from other photons,
             | and we apparently have the equipment to detect and pick up
             | those photons. The point of the communication would be for
             | them to send back data and close-up images of the Alpha C
             | system. Likewise, they could receive commands from earth by
             | having dozens of probes effectively act as an
             | interferometry array.
        
         | omoikane wrote:
         | I wonder if we can go the reverse direction, where instead of
         | launching more probes from Earth to serve as relays, the
         | spacecraft would launch physical media toward Earth packed with
         | whatever data it has collected. Given advancements in data
         | storage density, we could achieve higher bandwidth than what's
         | possible with radios.
         | 
         | The logistics would be difficult since it involves catch those
         | flying media, especially if the spacecraft were ejecting them
         | as a form of propulsion, they might not even be flying toward
         | Earth. I was just thinking how early spy satellites would drop
         | physical film, and maybe there are some old ideas like those
         | that are still worth trying today.
        
           | mcdonje wrote:
           | I think they're working on laser data transmission.
        
           | iainmerrick wrote:
           | The spacecraft is moving away from the sun at escape
           | velocity. How is it going to launch anything backwards and
           | have it make it all the way back to earth?
        
         | zamadatix wrote:
         | With current probes being so "slow" (peak speed of the Voyager
         | probes was on the order of 0.005% the speed of light) I wonder
         | if even doing 10 probes at once per decade gets you more data
         | back than working towards faster probe for less total time.
         | 
         | You could use this to create a relay in reverse order, but I
         | also wonder if having a 50-100 year old relay would be any
         | better than just using modern tech directly on the newest,
         | fastest probe and then moving on to the next when there are
         | enough improvements.
        
         | threethirtytwo wrote:
         | No one likes to think this but it's very possible voyager is
         | the farthest humanity will go. In fact realistically speaking
         | it is the far more likeliest possibility.
        
           | sph wrote:
           | Based on what? That we will never be able to make probes
           | travelling faster than ~17km/s (relative to the Sun) that
           | will eventually reach and overtake Voyager 1?
           | 
           | I certainly wouldn't bet against technological progress, and
           | I say that as a complete doomer.
        
             | gregable wrote:
             | Well voyager depended on a solar system alignment that only
             | happens every 175 years(?) so it'd be a while before we get
             | that same advantage again. The longer it takes the further
             | of a head start voyager gets?
        
               | phkahler wrote:
               | Starship could be refueled in orbit. That should then be
               | able to reach those kind of velocities with enough
               | capacity to even include a small 3rd stage inside with
               | the payload.
        
               | kentm wrote:
               | Yeah, Voyager 1 was launched on a Titan IIIE. I don't
               | really want to do the delta v calculations, but if we
               | look at mass to LEO as a rough proxy, Titan IIIE does
               | 15,400 kg and the Falcon Heavy does around 50,000 kg
               | (with re-use). New Glenn can apparently do 45,000 kg.
               | Doesn't take into account gravity assists, but 3x the
               | capacity before Falcon Superheavy or refueling gives us a
               | helluva lot of leeway.
               | 
               | Its not "interstellar speeds" but I'm pretty sure we
               | could get probes further out than Voyager 1 faster if we
               | put the money behind it.
        
               | Mogzol wrote:
               | The headstart doesn't really matter, anything faster than
               | Voyager will catch up eventually
        
               | shagie wrote:
               | Voyager 1 is traveling at 16.9 km/s.
               | 
               | New Horizons (which has the distinguishing feature of
               | being the fastest human-made object ever launched from
               | earth https://www.scientificamerican.com/blog/life-
               | unbounded/the-f... ) is traveling at 12.6 km/s.
               | 
               | The key part there is that it got multiple gravity
               | assists as part of the Grand Tour
               | https://en.wikipedia.org/wiki/Grand_Tour_program . You
               | can see the heliocentric velocity
               | https://space.stackexchange.com/questions/10346/why-did-
               | voya... https://www.americanscientist.org/article/the-
               | voyagers-odyss...
               | 
               | The conjunction for the Grand Tour is once every 175
               | years. While you _might_ be able to get a Jupiter and
               | Saturn assist sooner, it is something that would take the
               | right alignment _and_ a mission to study the outer
               | planets (rather than getting captured by Jupiter or
               | Saturn for study of those planets and their moons).
               | 
               | While I would love to see a FOCAL mission
               | https://en.wikipedia.org/wiki/FOCAL_(spacecraft) which
               | would have reason for such a path, I doubt any such
               | telescope would launched... this century.
        
               | swores wrote:
               | You've given numbers for how fast New Horizons launched,
               | and for how fast Voyager 1 got thanks to the
               | 1-in-175-years boost, but is there an easy way to
               | actually compare them?
               | 
               | IE either what speed Voyager 1 launched at excluding the
               | gravity assists, or what speed New Horizons would have
               | reached if it were launched 175 years after Voyager 1 (to
               | take advantage of the same gravity assists)?
        
               | shagie wrote:
               | Not easily. The tricky part is also in the relative
               | numbers. The Voyager 1 data (and New Horizons data now)
               | is in heliocentric velocity. The bit with NH being the
               | fastest was with _Earth_ centric velocity.
               | 
               | Another part in this is the "the probes are slowing down
               | over time" - and you can see that with the Voyager 1 data
               | that while the velocity after assist is higher than
               | before, its not a _line_ at slope 0 but rather a curve
               | that is slowly going down.
               | 
               | This is _further_ complicated because New Horizons had a
               | launch mass of 478 kg and voyager was a twice as massive
               | at 815 kg.
               | 
               | They also had different mission profiles (Could Voyager 2
               | taken a redirect from Neptune to Pluto? That trajectory
               | change would have required a perigee inside the radius of
               | Neptune...)
               | 
               | Voyager was done with a Titan III-Centaur rocket (that
               | had a misfire) https://en.wikipedia.org/wiki/Titan_IIIE
               | 
               | > Voyager 1's launch almost failed because Titan's second
               | stage shut down too early, leaving 1,200 pounds (540 kg)
               | of propellant unburned. To compensate, the Centaur's on-
               | board computers ordered a burn that was far longer than
               | planned. At cutoff, the Centaur was only 3.4 seconds from
               | propellant exhaustion. If the same failure had occurred
               | during Voyager 2's launch a few weeks earlier, the
               | Centaur would have run out of propellant before the probe
               | reached the correct trajectory. Jupiter was in a more
               | favorable position vis-a-vis Earth during the launch of
               | Voyager 1 than during the launch of Voyager 2.
               | 
               | Note also in there that a few weeks difference between
               | Voyager 1 and Voyager 2 had different delta V profiles
               | (which is why Voyager 1 is faster)
               | 
               | New Horizons was done with an Atlas
               | https://en.wikipedia.org/wiki/Atlas_V
               | 
               | ... and I don't have enough KSP background to do the
               | orbital mechanics for this.
        
               | aylmao wrote:
               | 175 years isn't a lot of time when we speak in humanity's
               | time scale. We've been around 200,000 - 300,000 years.
               | 
               | That alignment will happen many more times in the history
               | of humanity. That is to say, I don't know if a spacecraft
               | to overtake Voyager will be launched on the next
               | alignment or one 10,000 years from now, but it doesn't
               | seem unlikely to happen.
        
               | kmm wrote:
               | That alignment is only necessary to do the Grand Tour, to
               | visit all four outer planets in one mission. Voyager 1
               | actually didn't do the Grand Tour, it only visited
               | Jupiter and Saturn, you're thinking of Voyager 2. This
               | alignment is also not even necessary to attain the
               | highest speed, Voyager 1 is even faster than Voyager 2.
               | 
               | A flyby of both Jupiter and Saturn can be done every two
               | decades or so (the synodic period is 19.6 years)
               | 
               | https://en.wikipedia.org/wiki/Grand_Tour_program
        
           | jacobgkau wrote:
           | If I understand correctly, you're just basing that statement
           | on climate change or war destroying us before we can do any
           | better than Voyager, right? Because if we don't assume the
           | destruction of humanity or the complete removal of our
           | ability to make things leave Earth, then just based on
           | "finite past vs. infinite future," it seems incredibly
           | unlikely that we'd never be able to beat an extremely old
           | project operating far beyond its designed scope.
        
             | threethirtytwo wrote:
             | Many reasons why. The probability is based on many many
             | many factors. What you mentioned is just a fraction of the
             | factors.
             | 
             | If we do ever reach that distance again it will be even
             | less likely we do it for a third time.
        
               | jeremyjh wrote:
               | I'm pretty bearish on human interstellar travel or even
               | long-term settlement within our solar system but I
               | wouldn't be so pessimistic on unmanned probes. The
               | technical hurdles seem likely to be surmountable given
               | decades or centuries. Economic growth is likely to
               | continue so relative cost will continue to drop.
               | 
               | Absent a general decline in the capacity of our
               | civilization the main hurdle I see is that the cost is
               | paid by people who will not live to see the results of it
               | but I don't think that rules it out, I'd certainly
               | contribute to something like that.
               | 
               | What are some of the other factors you are thinking of?
        
           | roflmaostc wrote:
           | This is all based on the assumption that we are not able to
           | build spacecrafts with faster speeds.
           | 
           | There was simply no incentive to do so yet. But one day we
           | will build faster spacecrafts and then we are going to
           | overtake it quite quickly.
        
           | Sanzig wrote:
           | Provided we don't wipe ourselves out, there's no technical
           | reason why we _can 't_ go interstellar. It's just way harder
           | and more energy intensive than most people imagine, so I
           | doubt it's happening any time in the next few hundred years.
           | 
           | But we already understand the physics and feasibility of
           | "slow" (single-digit fractions of _c_ ) interstellar
           | propulsion systems. Nuclear pulse propulsion and fission
           | fragment rockets require no new physics or exotic engineering
           | leaps and could propel a probe to the stars, if one was so
           | inclined. Fusion rockets would do a bit better, although we'd
           | have to crack the fusion problem first. These sorts of things
           | are well out of today's technology, but it's not
           | unforeseeable in a few centuries. You could likewise imagine
           | a generation ship a few centuries after that powered by
           | similar technology.
           | 
           | The prerequisite for interstellar exploration is a
           | substantial exploitation of our solar system's resources:
           | terraform Mars, strip mine the asteroid belt, build giant
           | space habitats like O'Neill cylinders. But if we ever get to
           | that point - and I think it's reasonable to think we will,
           | given enough time - an interstellar mission becomes the
           | logical next step.
           | 
           | Will we ever get to the point where traveling between the
           | stars is commonplace? No, I doubt it. But we may get to the
           | point where once-in-a-century colonization missions are
           | possible, and if that starts, there's no limit to humanity
           | colonizing the Milky Way given a few million years.
        
             | bena wrote:
             | Yes, it's incredibly easy to do these things once you've
             | done all these other, incredibly difficult things first.
             | 
             | The furthest a human has been is 250k miles (far side of
             | the moon). The fastest a human has traveled is only 0.0037%
             | the speed of light.
             | 
             | The ISS is about 260 miles from the Earth. At that height,
             | the gravity is actually roughly the same as on the surface,
             | it's only because it is in constant freefall that you
             | experience weightlessness on it.
             | 
             | Mars is 140 million miles away. And not exactly hospitable.
             | 
             | I like how you treat "the fusion problem" with a throwaway,
             | "Yeah, we'd have to solve that" as if we just haven't
             | sufficiently applied ourselves yet.
             | 
             | All of those incredibly difficult things we have not even
             | begun to do _are_ the technical reasons we have not gone
             | interstellar and may be the reason we will never do so.
             | 
             | And _even_ if we solve the issue of accelerating a human
             | being to acceptable speeds to reach another star, the next
             | closest star is 4 light years away. That means light takes
             | 4 years to reach. Even if you could average half the speed
             | of light, that 's 8 years, one way. Anything you send is
             | gone.
        
               | Sanzig wrote:
               | It's 2025. The first heavier than air flight was barely
               | more than a century ago. The first human in space was
               | less than 70 years ago.
               | 
               | These enabling technologies are very, very hard. No doubt
               | about it. That's why we can't do this today, or even a
               | century from now.
               | 
               | But the physics show it's possible and suggest a natural
               | evolution of capabilities to get there. We are a curious
               | species that is never happy to keep our present station
               | in life and always pushes our limits. If colonizing the
               | solar system is technically possible, we'll do it, sooner
               | or later, even if it takes hundreds or even thousands of
               | years to get there.
               | 
               | > I like how you treat "the fusion problem" with a
               | throwaway, "Yeah, we'd have to solve that" as if we just
               | haven't sufficiently applied ourselves yet.
               | 
               | If you'd read my comment, you'd see I _didn 't_ say that.
               | Fusion rockets would help, but we don't need them.
               | Nuclear pulse propulsion or fission fragment rockets
               | could conceivably get us to the 0.01-0.05c range, and the
               | physics is well understood.
               | 
               | > And even if we solve the issue of accelerating a human
               | being to acceptable speeds to reach another star, the
               | next closest star is 4 light years away. That means light
               | takes 4 years to reach. Even if you could average half
               | the speed of light, that's 8 years, one way. Anything you
               | send is gone.
               | 
               | Getting to 0.5c is essentially impossible without
               | antimatter, and we have no idea how to make it in any
               | useful quantity. Realistically, we're going there at less
               | than 0.1c, probably less then 0.05c. Nobody who leaves is
               | ever coming back, and barring huge leaps in life
               | sciences, they probably aren't going to be alive at the
               | destination either. It'd be robotic probes and subsequent
               | generation ships to establish colonies. But if you get to
               | the point where you are turning the asteroid belt into
               | O'Neill cylinders, a multi-century generation ship starts
               | to sound feasible.
        
               | bena wrote:
               | First, what's the return on that?
               | 
               | You are talking about massive investments to shoot off
               | into space never to return. Who's paying for that? The
               | only way you do that is if you're so fucked, it's your
               | only option and the profit in it _is_ the leaving.
               | 
               | Not to mention, we need to solve the problems of living
               | in space. Which we haven't yet. According to NASA. The
               | space people.
               | 
               | And it very well could be an insurmountable problem. We
               | do not know. We do know that living in microgravity fucks
               | you up. We know that radiation fucks you up. But we don't
               | even know all the types of radiation one might encounter.
               | 
               | > But if you get to the point where you are turning the
               | asteroid belt into O'Neill cylinders
               | 
               | That right there is an example of "solve this impossibly
               | hard problem and the rest is easy". We are nowhere near
               | doing anything close to that.
        
               | looofooo0 wrote:
               | Class 1 civilization has a lot of resources
        
               | octaane wrote:
               | My response to the money aspect of this it's just like
               | any other business: money needs to be invested, and then
               | a return will be realized. Resource extraction (i.e,
               | asteroid mining) is one obvious example.
               | 
               | The human compatibility issues with microgravity are well
               | known, as is the solution, which has even been proposed
               | by NASA: centripetal force to create 1G for the
               | astronauts.
               | 
               | As far the the radiation goes, we do indeed know exactly
               | what kinds of radiation they would encounter. And the
               | easiest way to shield humans from it in space is lots of
               | water, or metal. We know this from extensive real work
               | done on earth re: nuclear power plants.
               | 
               | The real issue is money, not technical feasibility. Once
               | the dough rolls in from asteroid mining, it bootstraps
               | the financing issue and pays for itself many times over.
        
               | bena wrote:
               | https://www.nasa.gov/humans-in-space/the-human-body-in-
               | space...
               | 
               | NASA seems less sure than you do. And considering we have
               | to _get_ to the asteroids before we even start to think
               | about mining them, talking about the money from asteroid
               | mining is putting the cart before the horse.
        
               | vlovich123 wrote:
               | Asteroid mining is one thing. Exploring the nearest star
               | system is science expedition where the payback is in
               | societal scientific knowledge and subsidizing technology
               | development that is then made available here for various
               | things (eg a lot of the space exploration tech in the 60s
               | made its way into consumer tech)
        
             | throwway120385 wrote:
             | The other thing we could do to explore the galaxy is to
             | become biologically something we would no longer recognize.
             | We're viewing this from the lens of "humanity must remain
             | biologically static" but I want to point out that that's
             | not physically necessary here and that there is life on
             | Earth that can stop its metabolism for decades and things
             | like that.
        
               | stickfigure wrote:
               | Or even explore with something nonbiological.
               | 
               | Humans evolved to live on earth. Our bodies fare poorly
               | in low gravity, not to mention vacuum. Given sufficiently
               | advanced technology, I'm pretty sure we could evolve some
               | form of intelligence better suited to the environment.
        
             | TheOtherHobbes wrote:
             | Nuclear pulse and fission fragment designs require no new
             | physics in the same way that a Saturn 5 didn't require new
             | physics when compared to a Goddard toy rocket.
             | 
             | It's easy until you try to actually build the damn thing.
             | Then you discover it's not easy at all, and there's
             | actually quite a bit of new physics required.
             | 
             | It's not New Physics(tm) in the warp drive and wormhole
             | sense, but any practical interstellar design is going to
             | need some wild and extreme advances in materials science
             | and manufacturing, never mind politics, psychology, and the
             | design of stable life support ecologies.
             | 
             | The same applies to the rest. Napkin sketches and
             | attractive vintage art from the 70s are a long way from a
             | practical design.
             | 
             | We've all been brainwashed by Hollywood. Unfortunately CGI
             | and balsa models are not reality. Building very large
             | objects that don't deform and break under extremes of
             | radiation, temperature changes, and all kinds of physical
             | stresses is not remotely trivial. And we are nowhere close
             | to approaching it.
        
               | Sanzig wrote:
               | I thought I was pretty clear that I don't see this
               | happening for hundreds of years at least.
               | 
               | The engineering problem is insurmountable today. But
               | there doesn't seem to be any reason it couldn't be done
               | _eventually_ , given our technological trajectory, unless
               | we believe we are truly on the precipice of severe
               | diminishing returns in most science and engineering
               | fields, and I just don't see that right now.
               | 
               | George Cayley figured out how to build an airplane in
               | 1799, but it wasn't for another century until materials
               | science and high power-to-weight ratio engines made the
               | Wright Flyer possible.
               | 
               | There are plenty of depths to plumb in space systems
               | engineering that we haven't even really had a proper look
               | at yet. A Mars mission with chemical propulsion is hard,
               | but could be made substantially easier with nuclear
               | thermal propulsion - something we _know_ should work,
               | given the successful test fires on the NERVA program back
               | in the 60s. First stage reusability was fantasy 15 years
               | ago, today it 's routine.
               | 
               | Obviously, I'm extrapolating a long way out, and maybe at
               | some point we'll run against an unexpected wall. But
               | we'll never know until we get there.
        
             | rishabhaiover wrote:
             | The child within me likes to dream and this is the dream I
             | have!
        
           | yawpitch wrote:
           | I think it literally every day... and with literally every
           | day the odds of our surpassing ourselves on this one gets,
           | again very literally, further away.
        
         | wkat4242 wrote:
         | Well, the voyager power source is still pretty good. But as I
         | understand it the thermocouple that converts heat to
         | electricity has degraded. Because the Pu-238 half life is 87
         | years so they wouldn't even be down to half yet..
        
         | looofooo0 wrote:
         | Americium battery could last a lot longer.
        
         | georgefrowny wrote:
         | My intuition is that the extra mass for the receivers would be
         | a large negative in terms of travel time (1/sqrt(m) penalty
         | assuming you can give each probe fixed kinetic energy).
         | 
         | Plus keeping a probe as active part of a relay is a major power
         | drain, since it will have to be active for a substantial
         | percentage of the whole multi-decade journey and there's
         | basically no accessible energy in interstellar space.
         | 
         | Then again, it's still far from clear to me that sending any
         | signal from a probe only a few grams in size can be received at
         | Earth with _any_ plausible receiver, lasers or not.
        
           | glenstein wrote:
           | Thoughtful intuitions all around. My understanding is that
           | lasers don't necessitate the big reception dish, but instead
           | have a 1m or smaller reflective telescope. The laser setup is
           | lighter, lower power and gas precedent in modern space
           | missions.
           | 
           | Probes I suspect would realistically have to be large enough
           | to send strong signals over long distances, so weightier than
           | a few grams.
           | 
           | I think 99% downtime is an existing paradigm for lots of
           | space stuff, e.g. NASA's DSOC and KRUSTY, so room for
           | optimism there.
           | 
           | Though I think I agree with you that an energy payload as
           | well as general hardware reliability are probably the
           | bottlenecks over long distances. I have more thoughts on this
           | that probably deserve a seperate post (e.g. periodic zipper-
           | style replacements that cascade through the whole relay line)
           | but to keep this on honoring the Voyager, I will say for the
           | Voyager is at least for me huge for opening my imagination
           | for next steps inspired by it.
        
             | georgefrowny wrote:
             | I also spend far too much time wondering about sending out
             | swarms of probes and if you could somehow rendezvous them
             | and add fuel midjourney and so on!
             | 
             | The problem I see is that lasers are still subject to
             | diffraction, and this is worse the smaller the aperture is
             | relative to wavelength. Due to the small probe mass which
             | you need to split with observation equipment, support
             | systems and presumably some microscale nuclear power
             | supply, you could maybe with a few breakthroughs in
             | engineering manage a wispy affair on the order of a metre
             | at most. It it scales with diameter and mass scales with
             | diameter squared.
             | 
             | So the beam divergence of a visible light laser end with a
             | diameter of over 18 million km over 4 light years. With
             | 100W of transmission power, that's 0.1pW per square
             | kilometer of receiver. Which isn't nothing, but it's not
             | huge either.
             | 
             | I really don't see how the Starwisp type microprobes will
             | actually work on a practical level at any time in the
             | foreseeable future, even if the propulsion works. Not only
             | is the communications a problem, but so is power,
             | computational resources, observation equipment, radiation
             | shielding and everything in between. But anything massier
             | than that requires mindboggling amounts of fuel. And the
             | problem is so much worse if you want to stop at the
             | destination rather than scream past at a modest fraction of
             | c and hope to snap a photo on the way past.
             | 
             | It really seems (sadly, in a way) that building gigantic
             | telescopes will be a lot more instructive than any
             | plausible probe for quite some time. An gravitational lens
             | telescope would be a far better, and probably almost as
             | challenging, project for learning about exoplanets. Not
             | least it would be about 3 times further from Earth than
             | Voyagers.
        
       | elashri wrote:
       | Wow, this gives a reflection about our future. The nearest
       | potentially habitable planet known is Proxima Centauri b, which
       | orbits the red dwarf star Proxima Centauri about 4 light-years
       | from Earth (at least it is in a habitable zone of its star) [1].
       | So we don't have a choice actually except protecting and make
       | sure our planet survives. That's regardless if it really would be
       | able to support life as we know or not (probably not).
       | 
       | [1] https://science.nasa.gov/resource/proxima-b-3d-model/
        
         | onethought wrote:
         | Or we learn how to make uninhabitable planets habitable. Would
         | also help us "save" this one.
         | 
         | (Funny how we say "save the planet" when we really mean "save
         | people/complex life").
        
           | mindslight wrote:
           | Given that there is very little interest in developing
           | commons here on earth (especially new types of commons from
           | whole cloth), the shape that "making uninhabitable planets
           | habitable" would likely take is that of living in bubbles
           | rather than some kind of broad-scale terraforming. This would
           | intrinsically shape society towards top-down authoritarian
           | control, rather than allowing for distributed individual
           | liberty. In this light, Earth's bountiful distributed air,
           | water, and wildlife should be viewed as a technological-
           | society-bootstrapping resource similar to easily-accessible
           | oil and coil stored energy deposits.
        
         | nixpulvis wrote:
         | Space is cool, and I support the scientific work some of its
         | pioneers discover. But the category of people who believe space
         | travel is somehow the solution to problems on Earth give me
         | headaches.
        
           | udev4096 wrote:
           | Whoever is currently alive won't live to see the absolute
           | worse that earth is going to be in upcoming centuries, if the
           | human civilization even survives until then
        
             | nixpulvis wrote:
             | I try not to succumb to this attitude. Humans are
             | remarkably able to build systems and technology to solve
             | complex problems. The fact that we aren't making the needed
             | changes now fast enough doesn't rule out that we might as
             | it becomes more apparently necessary, or that some new plan
             | will emerge which helps dramatically.
             | 
             | But we also cannot get complacent thinking that it's future
             | generations problem. We need a breakthrough yesterday.
        
           | dylan604 wrote:
           | Even if we find another habitable planet, figure out how to
           | get there, start a colony, what in the world makes us think
           | we won't fuck up that planet like we've fucked up this one?
        
         | godshatter wrote:
         | In my opinion, if we really want a presence off of earth we'd
         | be better off building larger and larger space habitats and
         | bootstrapping a mining industry in space.
        
           | Night_Thastus wrote:
           | Agreed. Once it becomes commercially viable to start building
           | things in space, it'll take off on its own. There will be
           | constant pressure to build faster, safer, more capable craft.
           | Whether that will lead to something like FTL isn't possible
           | to know, but at the very least it's a step towards a space-
           | faring civilization.
        
           | JumpCrisscross wrote:
           | > _if we really want a presence off of earth we 'd be better
           | off building larger and larger space habitats and
           | bootstrapping a mining industry in space_
           | 
           | This turns entirely on how human biology works in zero versus
           | low gravity. (Same for spin versus natural, or linear,
           | gravity.)
           | 
           | The experiments we need to be doing is building and launching
           | space stations and planetary bases for mice.
        
             | airstrike wrote:
             | I can't wait for all the studies making the news that end
             | with "in mice in space"
        
           | Iolaum wrote:
           | Daniel Suarez [1] has written a book where he imagined how
           | this could happen (Delta-v)
           | 
           | [1]: https://en.wikipedia.org/wiki/Daniel_Suarez_(author)
           | 
           | P.S. Read a lot of his book, great author
        
         | Tepix wrote:
         | Yes, the distances are mind-boggling. There are a few somewhat
         | realistic solutions for making such a trip in the forseeable
         | future. If you send something of significant mass, it is
         | certain to take a long time. So we're either talking generation
         | ships(SS), embryo space colonization (growing into adults en
         | route or at destination) or hibernation. That or a breakthrough
         | in fundamental physics.
         | 
         | --
         | 
         | (SS) Something like O'Neill cylinders with fusion as energy
         | source could work
        
           | vee-kay wrote:
           | This old video is a beautiful and astounding demonstration of
           | just how vastly, hugely, mind-bogglingly big the Universe is,
           | and where in all this endless space our dear favourite little
           | Pale Blue Dot (Earth) resides:
           | 
           | https://m.youtube.com/watch?v=X-3Oq_82XNA
           | 
           | We all Earthlings are extremely lucky to be alive and
           | thriving (or trying to) in such a beautiful bountiful rarest-
           | of-rare ecosystem that somehow survived and thrived despite
           | all the vagaries and vastness of spacetime.
        
             | vee-kay wrote:
             | I think the video I have linked above is Google's tribute
             | to this Power Of Ten video (linked below, thanks to user
             | dtgriscom for sharing the link in another comment), a
             | classic video that demonstrates the scale of the Universe
             | from the micro to the macro perspectives in a scaling
             | increase by a factor of ten for each scene.
             | 
             | Power of 10: https://www.youtube.com/watch?v=0fKBhvDjuy0
             | 
             | Another relevant video (thanks to user christev for sharing
             | the link): A Brief History of Geologic Time:
             | https://youtu.be/rWp5ZpJAIAE
             | 
             | Absolutely humbling to realise how infinitesimally small
             | and irrelevant our existence is, in the grand scheme of
             | theme. Nature and science are amazing.
        
         | ferguess_k wrote:
         | I have an optimistic view that building underground facilities
         | on Mars/Lunar might not be a far-stretched idea. But I have
         | never done any research into the idea so not whether it works
         | or not.
         | 
         | Basically, reducing costs and tech requirements by going
         | underground (since it is underground we do not need to
         | terraform the planet, and it is less likely to leak oxygen to
         | external environment). Digging dirts and stones is a solvable
         | problem. So optimistically I believe this is just an
         | engineering/cost problem.
        
           | prmoustache wrote:
           | Mars is less habitable than the least habitable state we
           | could let the earth in without being extinct. This is silly.
        
             | jquery wrote:
             | Almost understating the point if anything. Mars is less
             | habitable than the bottom of the Marina trench. An
             | environment that could kill every person on earth in a
             | millisecond.
        
             | ferguess_k wrote:
             | Yeah it is a silly thought. But one can hope. I wish I
             | could work in the space, or anything related.
        
         | ozim wrote:
         | Well I guess real end of the world will come around when we
         | crash with Andromeda.
        
           | s_dev wrote:
           | When Andromeda and the Milky Way collide there will be no
           | planets or solar systems that collide from either system. A
           | fascinating fact in in own right, it's simply due to the
           | scale of the galaxies and that they are mostly composed of
           | empty space.
        
             | generic92034 wrote:
             | Unless we find the means to manipulate our own star or the
             | orbit of Earth we most likely will not be around at that
             | time. The sun's increased luminosity will boil us way
             | earlier.
        
         | yogsototh wrote:
         | I think there are a few movies that made me realize how much
         | the space is vast, empty and adverse to life.
         | 
         | I think it would be nice for people to take a look at them:
         | 
         | - Aniara (2018)
         | 
         | - High Life (2018)
         | 
         | and maybe in a less artistic view:
         | 
         | - Powers of Ten (1977) yt:
         | https://www.youtube.com/watch?v=0fKBhvDjuy0
        
           | theoldgreybeard wrote:
           | I showed my 6 year old son Powers of Ten a few nights ago and
           | I think I accidentally gave him an existential crisis.
        
             | thangalin wrote:
             | https://www.youtube.com/watch?v=KEHCCsFFIuY
             | 
             | Try that to give him a sense of awe. Watch it on a big
             | screen, all the way to the end.
        
         | phkahler wrote:
         | Gliese 710 will pass 0.17 light years from us in a bit over 1M
         | years. If we can colonize mars and build some infrastructure in
         | the solar system by then, we should have an OK shot at getting
         | _something_ there to stay. It 'll be 62 light days away.
        
         | vidarh wrote:
         | Proxima flares and bathes Proxima Centauri b in radiation when
         | it does, so it seems unlikely to be particularly habitable. But
         | it's still tantalising...
        
         | layer8 wrote:
         | Note that a journey to a star a 100 light years away where you
         | accelerate and decelerate with a constant 1 g for each half of
         | the journey only takes 9 years of subjective time for the
         | traveller (hence the twin paradox). To Proxima Centauri (4.24
         | ly) the gain isn't as dramatic, it would take 3.5 years of
         | subjective time.
         | 
         | Of course, we aren't anywhere near having the technology for
         | that, and there may not be any suitable planets in that
         | vicinity, but it also doesn't seem completely impossible.
        
       | zkmon wrote:
       | How is the link with earth maintained at this distance? Is it
       | really a powerful transmitter that sends signals without
       | attenuation?
        
       | ferguess_k wrote:
       | I hope the Voyagers are not the furthest man-made item that we
       | send into the universe in the whole civilization.
        
         | gattr wrote:
         | Once we develop more efficient propulsion (fission, fusion,
         | light sails, etc.), would you like for someone to catch the
         | Voyagers and bring them back into a museum? I myself am not
         | sure. (Perhaps a "live museum" instead, keep them on their
         | trajectories, but surround with a big space habitat with
         | visitor center and whatnot.)
        
       | firefoxd wrote:
       | Now the question is, what time is it in voyager 1? With time
       | dilation, the "now" on Voyager is out of sync with our now. I was
       | watching star wars recently and when Han Solo casually say "we
       | should be in Alderaan at 0200 hours", I paused for a second. What
       | does that even mean [0]? Traveling through space is challenging
       | today, but after we figure that out, we will have to face the
       | problem of time keeping across the galaxy.
       | 
       | [0]: https://idiallo.com/blog/galactic-timekeeping
        
         | JumpCrisscross wrote:
         | > _With time dilation, the "now" on Voyager is out of sync with
         | our now_
         | 
         | A couple minutes [1].
         | 
         | > _we will have to face the problem of time keeping across the
         | galaxy_
         | 
         | Not really. Barring relativistic travel, it's not dissimilar
         | from the problem seagoing voyagers faced on long trade routes.
         | Ship time is set based on the convenience of the passengers and
         | the route.
         | 
         | [1] https://space.stackexchange.com/questions/56055/if-
         | voyager-1...
        
           | chistev wrote:
           | Why a couple minutes?
        
             | JumpCrisscross wrote:
             | > _Why a couple minutes?_
             | 
             | ...because that's what the math says? Based on Voyager's
             | relative velocity it's expected to be about 2 seconds
             | younger than it would have been had it stayed on Earth.
        
       | udev4096 wrote:
       | The article points that by 2030, we will lose comms with voyager.
       | Is there a way to avoid it?
        
       | dgrin91 wrote:
       | Here is a funny thought experiment - the distance from Voyager to
       | Earth varies by approximately 16 light minutes throughout the
       | year. Why? Because it takes ~8 minutes for light to go from the
       | Sun to the Earth, so presuming the Voyager is roughly planar with
       | the Sun/Earth (I'm just assuming yes), that gives a variance of
       | ~16 minutes depending on where the earth is on its orbit.
       | 
       | Now I'm presuming they aren't using the actual Earth position,
       | but rather an average Earth position (which is basically just the
       | Sun's position). Since Voyager is ~30 light minutes away from
       | being 1 light-day away, that means this ~16 minute change can
       | affect our 1 light-day mark by up to ~6 months!
        
       | jamesgill wrote:
       | If Voyager could stay operational and keep its speed of ~61,000
       | km/hr, it would reach the nearest star (Proxima Centauri) in
       | about 72,000 years.
       | 
       | My mind understands the numbers, but can't grasp them.
        
         | generic92034 wrote:
         | No, it would no reach that star. It is not aimed at it but at
         | the constellation Ophiuchus.
        
           | jamesgill wrote:
           | You're right; I was thinking of distance traveled, not
           | direction.
        
         | ksymph wrote:
         | For reference, the oldest cave drawings we know of were made by
         | neanderthals around ~70,000 years ago [0].
         | 
         | [0] https://www.southampton.ac.uk/news/2018/02/neanderthals-
         | art....
        
           | trenning wrote:
           | Proxima Centauri is about 250 million years older than our
           | sun. Makes it not-impossible their earth like planet had
           | advanced entities capable of sending their own voyager
           | towards earth. Possibly it flew by while we were still in our
           | Mesozoic Era and all they saw were dinosaurs.
        
             | chistev wrote:
             | I love thinking about things like this, but we will never
             | know!
             | 
             | Sometimes I close my eyes and imagine I traveled back in
             | time to the days of the Dinosaurs and just observed how the
             | world was back then.
             | 
             | But I wonder if I'd be able to survive. The atmosphere,
             | environment, microbes, etc, would be drastically different
             | from what we've evolved to handle. Millions of years ago is
             | a very long time!
             | 
             | Edit: Apparently microbes from millions of years ago would
             | be so evolutionary distant that they might not regard me as
             | host.
        
               | ebbi wrote:
               | I always do this too - imagine being just an observer, in
               | first person, at random points in time in history.
               | 
               | I'm hoping VR will help with this.
        
       | sgt wrote:
       | Trump will turn this into "American spaceships, the best in the
       | world, world class probes, now light years away from Earth to
       | find who knows what treasures lie there."
        
       | throwaw12 wrote:
       | What happens if Voyager decides to go back home?
        
       | _trampeltier wrote:
       | We are flying "faster" on earth.
       | 
       | You often hear about the fatality rate per 100 million or 1
       | billion passenger miles in transportation statistics, but over
       | the last 15 years, U.S. airlines have averaged less than 1
       | fatality per passenger _light-year_ traveled
       | 
       | https://x.com/RyanRadia/status/1764868263903723874
        
         | jquery wrote:
         | Technically when tweeted for the given selective timespan, but
         | no longer true since the crash this year in DC.
         | 
         | Still, mind blowing. When fact checking this I learned we went
         | over 2 passenger light years worth of airline travel with no
         | fatalities during that time frame. Incredible safety record.
         | Real shame this year has been so terrible for our reputation.
        
           | _trampeltier wrote:
           | Yes, when I saw the tweet, I thought the next crash might be
           | near, and then happened DC soon after.
        
           | Vinnl wrote:
           | I'm kinda interesting in the same statistics for trains,
           | although I wouldn't be surprised if we don't travel near that
           | distance with trains.
        
       | AbraKdabra wrote:
       | "is about"
       | 
       | "On November 2026"
       | 
       | I know it's like a nanosecond in astronomical time, but come
       | on...
        
       | theoldgreybeard wrote:
       | We're never getting out of this solar system, are we?
        
         | chistev wrote:
         | Haha, never doubt science! You never know. Centuries ago,
         | humans then would have regarded today's technological feats as
         | impossible.
         | 
         | But, yeah, I don't think we are ever leaving the Milky Way. Lol
        
         | redox99 wrote:
         | Unless we go extinct, I would assume eventually it will happen.
         | Maybe in tens of thousands of years.
        
       | GMoromisato wrote:
       | The Voyagers are just the beginning.
       | 
       | We can't see it yet, stuck as we are, in the present moment,
       | filled with strife, failure, and disappointment. But the years
       | and centuries to come will see us colonize the solar system,
       | bringing new opportunities for millions, while easing the drain
       | on Earth's ecosystem.
       | 
       | How can I be so sure? Because in the long arc of history that is
       | what we've always done. We went from Africa to Asia to Europe and
       | all the way to the Americas, founding cities and developing
       | technology every step of the way. We launched into the Pacific,
       | exploring island after island, eventually finding a new world in
       | Australia. We have outposts on Antarctica and in low-Earth orbit.
       | And I'm certain that, this decade, humans (Americans, Chinese, or
       | both) will once again walk on the moon.
       | 
       | The people who launched the Voyagers believed that the future
       | would come--they built a machine that would last for decades,
       | knowing that people would benefit from its discoveries. Without
       | that belief, they would have never tried it.
       | 
       | That's my lesson from the Voyagers: we have to believe the future
       | will be better than the past, so that we can build that future.
       | That what we've always done. We are all voyagers, and always have
       | been.
        
         | GalaxyNova wrote:
         | That colonization was primarily driven by the need to obtain
         | resources. Today and in the future, there is no reason to
         | should send humans to gather resources when we can send robots
         | to do it instead.
        
           | GMoromisato wrote:
           | Past colonization happened because individuals made choices
           | they felt would benefit them.
           | 
           | Even if the only goal of colonization is getting resources
           | (which I dispute), some individuals will risk colonization to
           | get resources that they can't obtain at home. Resources are
           | not evenly distributed across a population and, and every
           | piece of land is owned by someone, but not everyone owns
           | land.
           | 
           | The cost of space travel will continue to drop, and at some
           | point it will make sense for people to seek their fortune
           | there.
           | 
           | Moreover, we didn't land on the moon in 1969 to get
           | resources, and we're not going to land in the 2020s for
           | resources. The reasons are complex, and not always logical,
           | but they are definitely not about resources. I don't see any
           | reason why that would change in a hundred years.
        
           | octaane wrote:
           | There's plenty of resources to be extracted from space.
           | Metals, for one. Also, zero-G drug development and
           | manufacturing is promising too.
        
       | j_walter wrote:
       | > Commands now take about a day to arrive, with another day for
       | confirmation. Compare that to the Moon (1.3 seconds), Mars (up to
       | 4 minutes), and Pluto (nearly 7 hours).
       | 
       | These numbers aren't right...Mars is 4 minutes MINIMUM, but could
       | be up to 22-ish minutes at the maximum distance between Earth and
       | Mars. This is also one way, double that for communication and a
       | response.
        
       | danishSuri1994 wrote:
       | It's wild how Voyager forces two truths to sit together:
       | 
       | Technically, what we've done is almost boringly modest.
       | 
       | ~17 km/s
       | 
       | ~1 light-day in ~50 years
       | 
       | No realistic way to steer it anywhere meaningful now On cosmic
       | scales it's... basically still on our doorstep.
       | 
       | Psychologically, it's still one of the most ambitious things
       | we've ever done.
       | 
       | We built something meant to work for decades, knowing the people
       | who launched it would never see the end of the story.
       | 
       | We pointed a metal box into the dark with the assumption that the
       | future would exist and might care.
       | 
       | I keep coming back to this: Voyager isn't proof that interstellar
       | travel is around the corner. It's proof that humans will build
       | absurdly long-horizon projects anyway, even when the ROI is
       | almost entirely knowledge and perspective.
       | 
       | Whether we ever leave the solar system in a serious way probably
       | depends less on physics and more on whether we ever build a
       | civilization stable enough to think in centuries without
       | collapsing every few decades.
       | 
       | Voyager is the test run for that mindset more than for the tech.
        
         | ricardo81 wrote:
         | Agree. Voyager is probably considered by many to be one of our
         | greatest achievements.
         | 
         | It makes me wonder when we'll have anything set foot in another
         | star system. I would guess realistically after 2100, but then
         | we went from the Wright brothers to landing on the moon in
         | under 70 years... so I may be proven wrong.
        
           | jonhohle wrote:
           | Space is so ridiculously big that I don't think it will ever
           | happen.
           | 
           | Back of the envelope math - 4.2 light years to the nearest
           | star that's not the sun, current vehicles traveling about 10x
           | the speed of voyager (e.g. 1 light day in 5 years). If
           | something was launched today it would get to the nearest star
           | system in about 7,660 years (assuming that star system also a
           | radius of 1 light day).
           | 
           | 100x faster than current (1,000km/s) would still take 76
           | years.
           | 
           | Definitely not before 2100 and almost certainly so long after
           | that we will seem like a primitive civilization compared to
           | those that do it.
        
             | alexose wrote:
             | Just spitballing, but maybe it would be possible with
             | relatively modest advances in ion thrusters, and one
             | (admittedly less-than-modest) breakthrough with fusion.
             | 
             | It's maybe too speculative to even matter, but I don't
             | think it's _crazy_ to imagine a handful of AI-fueled
             | advances in materials discovery during the next decade or
             | two. Possibly enough to unlock laser fusion, or something
             | that could be crammed onto a spacecraft.
        
               | Forgeties79 wrote:
               | > AI-fueled advances
               | 
               | There is no amount of money in the world that would get
               | me on the ChatGPT rocket
        
               | setopt wrote:
               | By "AI" they probably aren't thinking about LLMs in this
               | context.
        
             | api wrote:
             | Humans might one day have settlements around the solar
             | system and in free space (large stations, etc.), but I have
             | doubts about whether we'll ever go to the stars.
             | 
             | For machine intelligence, though, it would be easy. Just
             | switch yourself off for a few thousand years.
             | 
             | It's likely that our "children" will go to the stars, not
             | us.
        
               | LarsDu88 wrote:
               | Unfortunately at the current trajectory, it will be Grok
               | that reaches the next star system first. Just imagine
               | interplanetary immortal AI sycophantic towards a very
               | specific billionaire
        
             | polski-g wrote:
             | Getting the travel time down to 500 years would be a
             | reasonable goal.
             | 
             | You'd ship embryos and caregiver robots, start
             | breeding/raising people 30 years before you'd arrive.
        
               | pyrolistical wrote:
               | Imagine being born and told your life has been determined
               | by some other humans living a comfortable life with
               | unlimited air and water.
               | 
               | You are told you are to about make the great achievement
               | humankind has ever made but all you want is a little bit
               | more food and to take a shower.
        
               | immibis wrote:
               | Isn't that already all of us?
        
             | grvbck wrote:
             | > current vehicles traveling about 10x the speed of voyager
             | 
             | As I understand it, not really. Parker Solar Probe is crazy
             | fast, but only because it has that trajectory, and is
             | unable to just change course and keep that speed in other
             | directions.
             | 
             | If you want to launch something for deep space, the
             | Jupiter-Saturn slingshot is still the most powerful
             | trajectory we know of.
             | 
             | Today's rocket engines would give the probe a higher
             | initial speed, but the final velocity would not differ
             | dramatically. A fair bit higher, but not orders of
             | magnitude.
        
               | georgefrowny wrote:
               | You can do a Sun-diving Oberth maneuver too. Project Lyra
               | was a proposal for an `Oumuamua flyby that got over
               | 50km/s: http://orbitsimulator.com/BA/lyra.gif
        
             | fooker wrote:
             | > Space is so ridiculously big that I don't think it will
             | ever happen
             | 
             | You are underestimating acceleration. To travel and come to
             | a stop at 4.2 light years, a spaceship with 1g acceleration
             | barely needs 3.5 years in relativistic ship time (~6 years
             | earth time).
             | 
             | The technology to sustain 1g acceleration through 3.5 years
             | is a different story, but very much within our
             | understanding of physics (and not warp drives, etc). 20-50
             | years of engineering can get us there.
        
               | stickfigure wrote:
               | > 20-50 years of engineering can get us there.
               | 
               | What energy source do you think is merely 20-50 years of
               | engineering effort away from being able to power that
               | kind of journey?
        
               | brookman64k wrote:
               | I think you are way too optimistic. Even with an
               | antimatter drive and 100% conversion efficiency, such
               | rocket would have a fuel to payload ratio of >1000.
        
               | georgefrowny wrote:
               | > 20-50 years of engineering can get us there.
               | 
               | I want to believe, but I think it'll be a lot more than
               | that. The rocket equation is a stone cold bitch in this
               | case.
               | 
               | Sustaining the thrust that accelerates a probe at 1g is
               | very different to sustaining the thrust to move the probe
               | and all the fuel. And it's much worse if you want to stop
               | and not just fly past into deep space.
        
               | christkv wrote:
               | You got the shielding problem how to protect the ship
               | from disintegrating when it hits the first pebble at
               | massive speed
        
               | mvkel wrote:
               | Whatever speed advancements we make on earth, they pale
               | in comparison to sling shotting off of a planet. to make
               | an engine that can go significantly faster, we would need
               | the energy of a planet.
        
               | beAbU wrote:
               | Is there enough reaction mass on earth to construct a
               | rocket capable of accelerating at 1g for 3.5 years?
        
         | itake wrote:
         | The feat, from the perspective you describe, isn't that
         | remarkable. Humanity has tons of projects that meet these exact
         | standards throughout our history:
         | 
         | > We built something meant to work for decades, knowing the
         | people who launched it would never see the end of the story.
         | 
         | > We pointed a metal box into the dark with the assumption that
         | the future would exist and might care.
         | 
         | > It's proof that humans will build absurdly long-horizon
         | projects anyway, even when the ROI is almost entirely knowledge
         | and perspective.
         | 
         | The pyramids, the Bible, governments, or even businesses [0]
         | are all human constructs that last way beyond their creators
         | (and their intention), with and without their creator's
         | intention.
         | 
         | > we ever build a civilization stable enough to think in
         | centuries without collapsing every few decades.
         | 
         | This is a valid point though
         | 
         | [0] - https://en.wikipedia.org/wiki/List_of_oldest_companies
        
           | kristianc wrote:
           | The challenges to even get close seem insurmountable. At that
           | speed, microscopic grains of dust hit like bullets. It's not
           | like the nearest is much of a prize - we know that the
           | Centauri system is likely inhospitable and that Tau Ceti has
           | an enormous debris field.
        
         | DrBazza wrote:
         | I like to think the Plumbob bore cap overtook Voyager 1 quite
         | some time ago.
         | 
         | https://en.wikipedia.org/wiki/Operation_Plumbbob
        
           | pandemic_region wrote:
           | This made me laugh, cheers mate.
        
         | dheera wrote:
         | > It's proof that humans will build absurdly long-horizon
         | projects anyway
         | 
         | They used to. But these days the people who control the economy
         | and funding for things like this are either politicians
         | interested in 4 year cycles or VCs interested in 5-10 year
         | cycles.
         | 
         | Nobody gives a damn about long horizon stuff anymore. We landed
         | humans on the moon half a century ago, and we _still_ haven 't
         | reached Mars. Instead we're building some stupid apps for
         | people who are forced to work 7 days a week in the office on
         | some boring ads optimization algorithm to have someone to walk
         | their dog for them and deliver their groceries for them and
         | monitor their health because they can't get enough exercise
         | (that would solve their health problem the way the body
         | intended) and don't get time to leave the confines of their
         | <strike>jail</strike> office.
        
           | moron4hire wrote:
           | To be fair to our generation, people didn't build so much
           | stupid shit in the 60s not because they weren't interested in
           | stupid shit but because the whole world was too _poor_ to be
           | able to afford it. Our generation created the economic
           | conditions in which people could have the spare cash to spend
           | on stupid shit.
           | 
           | I would put good money on a bet that there are more people
           | _today_ who deeply care about the long-term horizon than did
           | in the 60s. I don 't think we spent money on long-shots in
           | the 60s because people cared more. I think we did it because
           | it was relatively low-hanging fruit in a gigantic culture war
           | between US-centric Western powers and USSR-centric Eastern
           | powers. We don't have that kind of "most people agree it's an
           | existential threat" level of cultural difference anymore.
           | China? They sell us most of our stuff. We don't hate China,
           | not really. But we _hated_ the Soviets.
        
         | jjk166 wrote:
         | This is not an example of nor even an attempt at long horizon
         | thinking. Voyager wasn't built with the intention that it would
         | last for decades. It was a rush job to take advantage of a very
         | rare planetary alignment and it's primary mission was completed
         | 12 years after it started.
         | 
         | It is a testament to the ingenuity of the engineers who have
         | worked and are still working on the project that they've
         | managed to keep it to some degree functioning for so much
         | longer than it was intended to last.
        
           | neilfrndes wrote:
           | I loved watching "It's quieter in the twilight", a
           | documentary about how a dedicated team of engineers (mostly
           | retired) are fighting to keep the Voyager mission alive.
           | 
           | https://m.imdb.com/title/tt17658964/
        
           | isolli wrote:
           | Also a testament to their foresight that it managed to send
           | back useful data decades after the end of the mission, for
           | instance when it crossed the heliosphere.
        
             | p-e-w wrote:
             | This wasn't foresight. As the comment you responded to
             | stated, the Voyager probes were built to explore the outer
             | planets, nothing less and nothing more. The fact that they
             | are still working is essentially a fortunate coincidence,
             | helped by there not being much that can damage a spacecraft
             | in outer space.
             | 
             | Just like _Opportunity_ lasted for 15 years, while its
             | identical twin _Spirit_ only lasted for 6. The Voyager
             | probes could easily have failed long ago, they just didn't.
             | But not because of planning or foresight. Sometimes things
             | simply work out well.
        
           | raincole wrote:
           | Given JavaScript, my headcannon is our galaxy is actually
           | full of "rush jobs" probes from different species.
        
         | micromacrofoot wrote:
         | I'm kind of upset that we haven't done much on the equivalent
         | level in the time since... sure we have done some very cool
         | things, but none of it quite feels like it's on the Voyager
         | level of duration
        
         | jwpapi wrote:
         | U made me cry on HN
        
           | thebruce87m wrote:
           | The comment wasn't made by a human.
        
             | alexose wrote:
             | Well now _I 'm_ crying too
        
         | jacksondc wrote:
         | This is a strange comment. The author claims to be a
         | human--"what _we 've_ done", " _we_ built something ", " _we_
         | pointed a metal box into the dark "--but nearly every sentence
         | sounds distinctly AI-writen.
         | 
         | (Examples: "I keep coming back to this:", "Voyager isn't ...
         | It's ...", "the assumption that the future would exist and
         | might care", "on our doorstep", "see the end of the story",
         | "depends less on ... and more on ...", etc.)
        
           | averageRoyalty wrote:
           | Or it's just their writing style. There's nothing distinctly
           | AI that I can see in there, and many of the common AI tropes
           | come from commonalities in human writing.
        
             | gjm11 wrote:
             | Nah, look at their posting history. In the last hour
             | they've posted a whole slew of comments with the same sort
             | of tone and the same AI-ish stylistic quirks, all in quite
             | surprisingly quick succession if the author is actually
             | reading the things they're commenting on and thinking about
             | them before posting. (And their comments before this
             | posting spree are quite different in style.) I won't say
             | it's _impossible_ for this to be human work, but it sure
             | doesn 't look like it.
        
               | averageRoyalty wrote:
               | Yeah you're right. I wanted to give them the benefit of
               | the doubt, but the comment history makes it pretty
               | obvious.
        
           | switchbak wrote:
           | I don't think so. I wouldn't expect an AI to say " It's proof
           | that humans will build absurdly long-horizon projects anyway,
           | even when the ROI is almost entirely knowledge and
           | perspective"
           | 
           | "the ROI is almost entirely knowledge and perspective" - this
           | isn't a way I've ever heard an AI talk.
           | 
           | And at a meta-level, accusing someone of being an AI is
           | getting very boring and repetitive (admittedly, I've done it
           | once), and I expect we'll have to get used to that too.
        
             | brandon272 wrote:
             | I think we _should_ be vigilant against AI generated
             | content. And I find it does read similar to the output of
             | some locally hosted LLMs.
        
               | anomaly_ wrote:
               | This sounds a lot like AI.
        
               | brandon272 wrote:
               | Mine? Not really
        
           | brandon272 wrote:
           | The account's comment history today is all the same style.
           | Almost certainly AI.
        
           | AstroBen wrote:
           | It's almost certainly an AI account
        
         | kakacik wrote:
         | That plate with info about us, where to find us... not smart,
         | naive. I get that 70s were probably way more enthusiastic and
         | open minded re space space exploration compared to rather bleak
         | times now when greed often takes prime and Star Trek TOS
         | probably had its effect too, but next time we should do better.
         | 
         | Dark forest theory sounds more rational conclusion on long
         | enough timescale than Star trekkish utopias. Although, in next
         | million years, if intercepted it should be trivial to pinpoint
         | where it came from just from trajectory.
        
         | johnwheeler wrote:
         | When I was around five years old, I was surprised to learn that
         | all of our tax dollars weren't going to space exploration. For
         | some reason, I intuited that was man's highest aspiration and
         | we'd be throwing everything at it. Come to find it's all
         | defense spending and printing money.
        
         | mvkel wrote:
         | The Voyager project itself has long ended and it's just cute to
         | keep monitoring it and getting data from it. If nothing else,
         | it serves well as a perpetual PR vehicle for NASA. The core of
         | the project I would not say represents long-term thinking of
         | NASA or civilization. I'm not convinced that we're biologically
         | wired to think long-term. It's extremely rare when someone pops
         | up, and they usually end up becoming extremely impactful in
         | society (Lincoln; Jobs; Elon)
        
         | UncleOxidant wrote:
         | But the thing is, the Voyager project came about in a much more
         | stable period for the US - and in a more optimistic cultural
         | climate (we could say similar for the Apollo project which
         | wasn't _that_ much earlier). When we used to prioritize
         | spending on basic science and projects like this that basically
         | had no ROI (NASA didn 't even much think in those terms back in
         | the 70s). Now we're in a very different place where, in the US
         | anyway, we're very pessimistic about the future. To create a
         | Voyager project you have to have some hope, like you said "with
         | the assumption that that future would exist and might care" -
         | now we're in a very different place where people don't have a
         | lot of hope about the future. And it's also different in that
         | we now ask "what's the payback going to be?" - everything now
         | seems to need to pay it's way.
         | 
         | Not saying that other countries won't be able to do stuff like
         | this - probably China is going to take the position that the US
         | used to hold for this kind of exploration. It seems to be a
         | more optimistic culture at this point, but hard to say how long
         | that lasts.
        
       | rncode wrote:
       | voyager isn't proof we can reach the stars, it's proof we can't
       | and we launched it anyway. that's the most human thing we've ever
       | done
        
       | pfdietz wrote:
       | Musk is now talking about near term putting servers in space,
       | because that's where power will be cheapest.
       | 
       | Should this happen, we'll see many gigawatts of power in space. A
       | spinoff of this would be large solar-electric spacecraft, or even
       | large lasers for beam powered spacecraft. Either case should
       | allow considerably higher delta-V than chemical rockets.
        
       | ck2 wrote:
       | moon ping time 2.6 seconds
       | 
       | voyager ping time 172,800 seconds
       | 
       | 1000+ years from now a ship will take off from earth or orbit and
       | pass Voyager in a few hours (assuming the planet is not turned
       | into one huge radioactive, forever-checmical ocean before then)
        
       | Crontab wrote:
       | If obtaining speed was the only goal, how fast could we get
       | something traveling in space with our current technology? That
       | would include using gravity assists.
        
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