6 ms·

Link to Canva presentation for the winning entry https://www.canva.com/design/DAGmr3ubC8E/LHHAeeAIGGQe_TkZVs-PXA/view https://www.canva.com/design/DAGmr3ubC8E/

Link to Canva presentation for the winning entry https://www.canva.com/design/DAGmr3ubC8E/LHHAeeAIGGQe_TkZVs-PXA/view https://www.canva.com/design/DAGmr3ubC8E/LHHAeeAIGGQe_TkZVs-...

virgildotcodes 1y ago
Reading through this in detail just cements that we are never leaving this solar system unless we discover some new physics to get around our speed limitations.
- kylecordes 1y ago
  c appears to be the speed limit of the propagation of information in the universe - never say never, but so far it appears quite unlikely any new physics will overturn this.
  - VagabundoP 1y ago
    If we manage to get anywhere near 0.1c and slow biological ageing we can get nearly anywhere with the right engineering.
- JumpCrisscross 1y ago
  > we are never leaving this solar system unless we discover some new physics to get around our speed limitations The winning proposal coasts at 0.01c. Propulsion systems--not the speed of light--and thus engineering, not phsyics, are the relevant limitors.
  - jvanderbot 1y ago
    We're one good new religion away from colonizing the solar system. Cathedrals were built over 100s of years. Imaging just living in a massive one and your whole holy purpose is to survive and thrive and spread. It's entirely reasonable we'd have the will to make it happen, and pretty reasonable we'd be able to build it with planet scale effort, but sadly quite difficult to imagine it surviving even dust impacts for 400 years.
    - JumpCrisscross 1y ago
      > quite difficult to imagine it surviving even dust impacts for 400 years Whipple shields [1]. [1] https://en.wikipedia.org/wiki/Whipple_shield https://en.wikipedia.org/wiki/Whipple_shield
      - privatelypublic 1y ago
        Whipple shields are consumed by impacts.
        JumpCrisscross 1y ago
        > Whipple shields are consumed by impacts Everything is consumed on such a voyage. If we can send a generation ship at 0.01c, we can send replacement parts quicker and probes ahead to verify our estimates even faster.
        jvanderbot 1y ago
        Are you just casually handwaving away sending a dockable resupply ship at 0.01c to somewhere in interstellar space, then doing some kind of rendesvous with it at 0.01c with a spaceship measured kilometers in length? There's no free lunch. Every gram of mass that you want to get to interstellar space requires exactly as much fuel to get there as you'd have to add to the original spacecraft to just carry it. (thought experiment - have them fly side by side, then connect them by string, then shorten the string until they touch, then weld them together - the fuel required doesn't change at any point). And a shield + a resupply ship has a lot more grams than just adding the shield to the original thing.
      - jvanderbot 1y ago
        > up to 18km/s Vs > 0.1c Off by quite a bit
        JumpCrisscross 1y ago
        Where are you getting either of these figures?
  - os2warpman 1y ago
    If you can build and maintain a system capable of sustaining the lives of 1,000 humans for 400 years, why do you care about interstellar travel anymore? “The indefatigable spirit of exploration” isn’t the answer. People, as a mass, only explore to find new resources due to scarcity. There are exceptions, but they tend to be thrill seekers or publicity hounds seeking to capitalize on a measure of fame upon their return and dying on a spacecraft 1/5th of the way through its journey isn’t thrilling and no ticker tape parades await your return. If you can build a spacecraft capable of sustaining 1,000 human lives for multiple centuries, you’ve solved all local resource scarcity problems. You could just mine the solar system and build billions of habitats that lazily circle the sun. Hell, you wouldn’t even care about habitable planets anymore and a likely endpoint for any interstellar efforts would likely be a long-lived star with large orbiting gas giants you could turn into solid materials in order to build trillions of habitats orbiting that star, not an insignificant earth-like boulder. Imagine turning all of the methane in a gas giant into carbon strands, using its hydrogen to do it and building a near-infinite number of habitats, each perfectly suited to human existence. An earth-like planet with its quakes and tsunamis and seasonal cycles would seem pathetic.
    - JumpCrisscross 1y ago
      > People, as a mass, only explore to find new resources due to scarcity Empirically totally untrue as to be trivially disproven by like half of wealthy social media. > thrill seekers or publicity hounds seeking to capitalize on a measure of fame upon their return Everyone on these ships would be a celebrity on Earth. (Ideally, if they so chose.) Again, a simple reading of one-way trip settler-explorers across history similarly rejects this notion. > If you can build a spacecraft capable of sustaining 1,000 human lives for multiple centuries, you’ve solved all local resource scarcity problems The first several of these ships are likely to end in catastrophe. The first to succeed will be breaking down on arrival. If we learn to build luxurious space habitats it will be through these endeavours.
      - os2warpman 1y ago
        > Empirically totally untrue as to be trivially disproven by like half of wealthy social media. A week in Bali is not the same thing as interstellar travel…
  - munificent 1y ago
    I am increasingly certain that culture is by far the biggest limiting factor when it comes to large-scale problem solving now and in the future. We couldn't even reliably get people to put a piece of fabric over their face to stop killing their own relatives. Even if we could build a generation ship, it would turn into an Event Horizon hellscape if we don't figure out better cultural, communication, and sociological tools to enable us to get along and work together effectively.
    - deleted 1y ago
      [deleted]
    - JumpCrisscross 1y ago
      > We couldn't even reliably get people to put a piece of fabric over their face Rural Americans couldn’t. But I don’t see anyone proposing we put high school dropouts and polio patients in space. China, India and Japan managed to pass that test just fine. I imagine one of the former two will be the first to colonise deep space.
      - kryogen1c 1y ago
        >> kill their relatives > Rural Americans > high school dropouts Lol HN you really are too much sometimes. Covid went really well in all the intellectual bastions of liberal democracy right? NYC, SF? California famously no downsides from their policy choices at all. And then to top it off, you compare response to China - the government that lied through it's teeth about covid from the beginning, jailed journalists and destroyed evidence. Unreal
        JumpCrisscross 1y ago
        Oh, nobody managed Covid well. The question was capacity to sacrifice for the common good. New York is a bad example to call out since it was one of the first places to get hit, locked down hard after a delay, and yet came out with lower per-capita deaths and a stronger economy than most red states. (Speaking as someone who lives in one of the reddest states in the union.) > jailed journalists and destroyed evidence Not sure we can call anyone out on this anymore.
  - scythe 1y ago
    Relativity isn't the problem. The problem is that hitting a grain of sand at 0.1 c delivers the energy of several tonnes of TNT. My guess is that we will colonize the asteroid belt (Palladium! So much palladium!) and send lots of interstellar probes long before we try to send humans outside the solar system. Right now we're like a village that lives by a river and has never reached the mouth talking about sailing across the ocean. There are a lot of intermediate stages.
    - pmontra 1y ago
      It's not only about palladium or any other kind of ore. It's that you can launch from there to Earth orbit and spare most of the costs of lifting mass from the surface of our planet. Then you build habitats and ships with that stuff because it's much cheaper. Too bad we don't have neither mining nor factories in space yet. Two not trivial technologies to develop. The book Delta V [1] explores that scenario, with an asteroid on an orbit close to Earth to minimize the delta v to ship things back home. [1] https://daniel-suarez.com/Delta-v_synopsis.html https://daniel-suarez.com/Delta-v_synopsis.html
    - Someone 1y ago
      > Right now we're like a village that lives by a river and has never reached the mouth talking about sailing across the ocean And that’s an enormous understatement. Let’s say the villagers have travelled a meager 10 km of the river. Then, the ocean is, ballpark, at most 1,000 times as wide as the distance to the sea. A thousand times the distance between earth and moon (the farthest humans have travelled) gets you, ballpark, to mars. A lightyear is ~50,000 times the distance to mars or 50,000,000 times as far as humans have travelled. And yet, in interstellar travel, a lightyear gets you nowhere.
      - m4rtink 1y ago
        Sure, but the speeds you can realistically reach on the surface of a planet for any lenght of time is also many orders of magnitude less than you can reach in space & you also don't really loose speed by friction. That at least partially compensates for the mindboggling distances in space.
  - andrewflnr 1y ago
    I read their comment as saying that current physics doesn't allow the kind of propulsion systems we need, even with optimal engineering and well below the lightspeed limit.
    - JumpCrisscross 1y ago
      > current physics doesn't allow the kind of propulsion systems we need Which is wrong. Direct-drive fusion fits the bill. It’s also easier than terrestrial power-generating fusion since you don’t need to convert to electricity.
  - Ekaros 1y ago
    Energy is the limit. If used Wolfram Alpha right for reasonable comparison that is largest cruise ship with mass of 248663000 kg to speed up to 0.01c mentioned the kinetic energy would be 2.9 times the worlds fossil fuel reserves... Then double that to slow down. And remember efficiency and that well you need to spend some to keep people alive... Seems like energy in general is one of the true problems.
    - WithinReason 1y ago
      You wouldn't be burning coal for propulsion, you would fuse atoms: https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
      - Ekaros 1y ago
        I didn't coal would be used. Just that involved amount of energy would be truly massive. Even with fusion.
      - m4rtink 1y ago
        Or even better - ride a continuous fission detonation powered by the worlds biggest super-soaker! :) https://en.wikipedia.org/wiki/Nuclear_salt-water_rocket https://en.wikipedia.org/wiki/Nuclear_salt-water_rocket
    - JumpCrisscross 1y ago
      > If used Wolfram Alpha right for reasonable comparison that is largest cruise ship with mass of 248663000 kg to speed up to 0.01c mentioned the kinetic energy would be 2.9 times the worlds fossil fuel reserves This math is wrong. Back of the envelope: accelerating 250 x 10^6 kg to 1% of c over one year is about 310,000 TWh. That’s like half of current annual energy production. Even at like 10g, which would accelerate that mass to 1% c in less than half a day, you’d only use like a tenth of our 10^22 joules of fossil fuel reserves. > double that to slow down Why the asymmetry? 1x to accelerate, 1x to decelerate. (Less if you can aerobrake and/or use gravity assists.) Taking the 310k TWh from earlier and doubling it, and assuming 18 MeV for D-T direct-drive fusion, and you need 6,600 kg fuel for the journey. (Plus propellant.) 100x that to account for inefficiency and cooling and you have 660 metric tonnes of hydrogen. That, if kept in its bastard liquid form, takes up about 3 Olympic-size swimming pools in volume.
- qingcharles 1y ago
  Adding to the issue that it is relative pointless (IMO) to send meat popsicles all that way when a robot can make the journey about a million times easier and just send us some postcards. I hate to be a Debbie Downer, but it's kinda boring out there. We'd certainly not want to make the trek until the robots had scoured the galaxy looking for a fun place to visit. And by that time we'll all be living in some post-Singularity holodeck and won't give a hoot about some empty rock 600 light years away. Send the bots. I'll watch the highlight reel from my pod.
  - philistine 1y ago
    Said like a true citizen of the Culture. And I mean that as a compliment!
  - arethuza 1y ago
    My own view is that the most likely form of interstellar travel will be something like that used in Greg Egan's Diaspora - with upload communities sending themselves in relatively small ships and choosing whether to experience the journey or not.
  - lanfeust6 1y ago
    I expect a kind of leapfrogging. Scout ahead, build a gate and/or infrastructure/terraforming, then a small fraction will decide it's worth migrating. Repeat. Expansion will only go as quickly as travel time allows. Even the speed of light seems insufficient beyond a certain point. We will want to manipulate space.
- WithinReason 1y ago
  We had the technology to do it in 44 years 60 years ago: An atomic (fission) Orion can achieve perhaps 9–11% of the speed of light. [...] At 0.1 c, Orion thermonuclear starships would require a flight time of at least 44 years to reach Alpha Centauri, not counting time needed to reach that speed (about 36 days at constant acceleration of 1 g or 9.8 m/s2). https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
  - notahacker 1y ago
    Tbf we had nuclear [fission] pulsed propulsion technology in the 1960s in roughly the same way we had nuclear fusion in the 1960s: we had an understanding of some basic principles of physics and some calculations that looked broadly plausible The problem with using thermonuclear explosions to produce that level of thrust are more "but can we actually do it safely" than "but can we do it in a way that generates more that it takes to produce", but that's a not inconsiderable problem even without all the international agreements about where we shouldn't be exploding nuclear bombs...
  - slightwinder 1y ago
    > We had the technology to do it in 44 years 60 years ago: No, we had not. That was only theoretical work, no real technology, not even a prototype.
    - m4rtink 1y ago
      IIRC there were sub-scale test done with chemical explosives. Also Feynman said it should work. :)
- konart 1y ago
  Speed is one thing. Surviving space is another.
- FuriouslyAdrift 1y ago
  Speed isn't the problem... time is. Long term travel in space will destroy the body. Even with artificial gravity, cancer is nearly inevitable. I am ignoring the mental and emotional issues. Astronauts are extremely tough individuals. Now, if we can figure out some form of suspended animation, that fixes many problems for long range travel. I am much more convinced that our best way to leave our solar system will be without our physical bodies. Some form of synthetic or uploaded consciousness would be much easier to move around. After constructing a network, they could even be transmitted instead of shipped. This is obviously in the range of science fiction but if we exist long enough, who knows. The show, Pantheon, did a fairly decent fictional take on the idea.
  - zdragnar 1y ago
    > Now, if we can figure out some form of suspended animation You'll still need someone awake to pilot the ship, otherwise you'll end up crash landed on a planet with Riddick running loose.
    - m4rtink 1y ago
      Yep, it is always a good idea to have a flight crew[0] when most of the passengers are in hibernation. It might take them some time but they will always sort thing out in the end! :) [0] https://revelationspace.fandom.com/wiki/Galactic_North_(short_story) https://revelationspace.fandom.com/wiki/Galactic_North_(shor...
    - random_is_rando 1y ago
      Some sort of AI algorithm? Don't think anyone pilots the SpaceX Dragon.
      - m4rtink 1y ago
        Looks like it is x86 + Linux and C++: https://hackaday.com/2024/02/10/the-usage-of-embedded-linux-in-spacecraft/ https://hackaday.com/2024/02/10/the-usage-of-embedded-linux-...
jvanderbot 1y ago
Pretty awesome. I feel like Paul Chadeisson should do a reward render of the assembly/flight. Nobody does space "big stuff" like he does.
AtlasBarfed 1y ago
Where is the propulsion system design? Are all of these handwaving propulsion? They seem to all be habitat designs. Ok I'll take my shot at propulsion: Pulse nuclear BUT: For acceleration, we have a launch gun that fires more fuel at the ship, and the ship catches the fuel, imparting momentum from the catch, and more fuel for acceleration. For deceleration, we have pellets that it catches up to and uses the catching to slow down with, AND gains fuel to decelerate. If the catch can be done like an ion drive in efficiency, then you get ion drive efficiencies while gaining fuel for the pulse nuclear accelerations/decelerations. The real problem would be timing the deceleration "catches", and a HELL of a railgun. We aren't really doing this in current physics without a massive and functional orbital/planetary economy that gives cheap nuclear fuel and materials. We'll probably need solar wind antimatter harvesters as well, if those are actually a thing.
- vl 1y ago
  The drive in this design is not yet invented Helium 3 - Deuterium Direct Fusion Drive. In your design how is it going to catch up to pellets if it's decelerating? I.e. pellets need to be pre-decelerated for this. Which raises the question, would it be cheaper just to bring all deceleration fuel onboard.
  - amenhotep 1y ago
    You'd spend years firing pellets in advance of the voyage, on the same trajectory but moving a little slower than the ship you plan to launch. Time it all so you catch up with the first of them just as you want to start decelerating.
    - WithinReason 1y ago
      But then the whole project takes thousands instead of hundreds of years
      - vl 1y ago
        And also it requires extraordinary navigation precision. These launches are going to be spread in time, which means that they don't happen from the same place (all celestial bodies move relative to each other). Which in turn means that when you approach the pellet there is going to be perpendicular velocity component. Even without taking this into account all systems are going to need active guidance - there is no way you do single burn and end up in the same place in the same time few light years away. The best schema is probably launching all fuels containers that should be picked up for retro burn at the same time with much higher acceleration (orbital rail gun and then a burner), and with very slightly smaller final speed. Then on the main craft you do short retro burn to match speed to fuels containers, attach them and do full retro burn for orbital insertion. Benefit of this schema is that you don't need to accelerate everything slowly using main engine, so your original booster can be way smaller. (Energy-wise it only works if you have stationary means to accelerate high-g-capable payloads, i.e. orbital railgun, in this case you don't have to accelerate extra fuel required for initial burn)
fuckinpuppers 1y ago
Reminds me of the probe from Star Trek IV
vl 1y ago
Cool concept, but some things are just strange: Power provided by toroidal nuclear fusion reactors in the outer shell of the living module, but why do you need such reactors if your primary propulsion is provided by Helium 3 - Deuterium Direct Fusion Drive? If you have direct fusion technology, you don't need toroidal reactors. Rotating inner shells mechanically for 400 years is terrible design, it's much easier just to rotate entire structure. Once it's going it keeps rotating inertially! Another comment points to error in speed calculation - at declared acceleration they should go at 0.1c, not 0.01c! And what is missing of course is the calculation of how many years of current world's GDP is required to complete such project event if all yet-to-be invented technologies exist.
- nn3 1y ago
  If you would spin the whole structure you couldn't have multiple shells all with 1G on their surface. The required spin speed for 1G depends on the diameter. But their whole concept is built around multiple shells, which is clear from the name. Regarding the GDP needed once you have a working "mine from the moon and send to orbit" economy it doesn't seem to be too bad. The assumption would be that a lot of technology is already developed for other projects. Launching it all from earth obviously wouldn't be possible even with vastly cheaper launch. That's why they put the build into the moon-earth L1 lagrange point to be easily reachable from the moon. For propulsion and reactors, but there are multiple projects today working on all of this. Building a life support system for 400 years is still an unsolved problem however.
  - vl 1y ago
    Re: orbital assembly. L1 point is bad in every respect. If most materials come from Moon, then the best assembly point is low Moon orbit (as benefit you get a boot to your launch speed to escape Earth gravity), if most material comes from Earth, then best assembly point is low Earth orbit. Hauling all material to L1 is going to be more expensive in either case (unless the ratio of materials is very exact, which is unlikely). Re: spin. I still claim that the best design is to rotate entire living module as one. Most of the activity is going to be on the outer shell. Warehouses, etc will be in the lower gravity inside. No moving parts. The only question is what to do with fuel and retro engines. Rotate them as well? Fuel tanks need to be stronger. Do not rotate? Then maybe living module can undock for the flight and rotate separately.
forgingahead 1y ago
Perhaps I'm being mean (haven't read the full presentation) - but the winning team is made up of 2 actresses/artists, 1 social innovator, 1 designer, and 1 astrophysicist?
- riffraff 1y ago
  One of the artist is also an environmental engineer, the other is also a psychologist, the designer is an architect. But yes, it's a work of design more than a blueprint.
dirkc 1y ago
Thanks for sharing the presentation. I wish I could download it to look at it in a few years from now. I hope durable file formats regain popularity before humanity starts embarking on interstellar voyages :)
deleted 1y ago
[deleted]

Link to Canva presentation for the winning entry https://www.canva.com/design/DAGmr3ubC8E/LHHAeeAIGGQe_TkZVs-PXA/view https://www.canva.com/design/DAGmr3ubC8E/LHHAeeAIGGQe_TkZVs-...

virgildotcodes 1y ago

Reading through this in detail just cements that we are never leaving this solar system unless we discover some new physics to get around our speed limitations.

kylecordes 1y ago
c appears to be the speed limit of the propagation of information in the universe - never say never, but so far it appears quite unlikely any new physics will overturn this.
- VagabundoP 1y ago
  If we manage to get anywhere near 0.1c and slow biological ageing we can get nearly anywhere with the right engineering.
JumpCrisscross 1y ago
> we are never leaving this solar system unless we discover some new physics to get around our speed limitations The winning proposal coasts at 0.01c. Propulsion systems--not the speed of light--and thus engineering, not phsyics, are the relevant limitors.
- jvanderbot 1y ago
  We're one good new religion away from colonizing the solar system. Cathedrals were built over 100s of years. Imaging just living in a massive one and your whole holy purpose is to survive and thrive and spread. It's entirely reasonable we'd have the will to make it happen, and pretty reasonable we'd be able to build it with planet scale effort, but sadly quite difficult to imagine it surviving even dust impacts for 400 years.
  - JumpCrisscross 1y ago
    > quite difficult to imagine it surviving even dust impacts for 400 years Whipple shields [1]. [1] https://en.wikipedia.org/wiki/Whipple_shield https://en.wikipedia.org/wiki/Whipple_shield
    - privatelypublic 1y ago
      Whipple shields are consumed by impacts.
      - JumpCrisscross 1y ago
        > Whipple shields are consumed by impacts Everything is consumed on such a voyage. If we can send a generation ship at 0.01c, we can send replacement parts quicker and probes ahead to verify our estimates even faster.
        jvanderbot 1y ago
        Are you just casually handwaving away sending a dockable resupply ship at 0.01c to somewhere in interstellar space, then doing some kind of rendesvous with it at 0.01c with a spaceship measured kilometers in length? There's no free lunch. Every gram of mass that you want to get to interstellar space requires exactly as much fuel to get there as you'd have to add to the original spacecraft to just carry it. (thought experiment - have them fly side by side, then connect them by string, then shorten the string until they touch, then weld them together - the fuel required doesn't change at any point). And a shield + a resupply ship has a lot more grams than just adding the shield to the original thing.
    - jvanderbot 1y ago
      > up to 18km/s Vs > 0.1c Off by quite a bit
      - JumpCrisscross 1y ago
        Where are you getting either of these figures?
- os2warpman 1y ago
  If you can build and maintain a system capable of sustaining the lives of 1,000 humans for 400 years, why do you care about interstellar travel anymore? “The indefatigable spirit of exploration” isn’t the answer. People, as a mass, only explore to find new resources due to scarcity. There are exceptions, but they tend to be thrill seekers or publicity hounds seeking to capitalize on a measure of fame upon their return and dying on a spacecraft 1/5th of the way through its journey isn’t thrilling and no ticker tape parades await your return. If you can build a spacecraft capable of sustaining 1,000 human lives for multiple centuries, you’ve solved all local resource scarcity problems. You could just mine the solar system and build billions of habitats that lazily circle the sun. Hell, you wouldn’t even care about habitable planets anymore and a likely endpoint for any interstellar efforts would likely be a long-lived star with large orbiting gas giants you could turn into solid materials in order to build trillions of habitats orbiting that star, not an insignificant earth-like boulder. Imagine turning all of the methane in a gas giant into carbon strands, using its hydrogen to do it and building a near-infinite number of habitats, each perfectly suited to human existence. An earth-like planet with its quakes and tsunamis and seasonal cycles would seem pathetic.
  - JumpCrisscross 1y ago
    > People, as a mass, only explore to find new resources due to scarcity Empirically totally untrue as to be trivially disproven by like half of wealthy social media. > thrill seekers or publicity hounds seeking to capitalize on a measure of fame upon their return Everyone on these ships would be a celebrity on Earth. (Ideally, if they so chose.) Again, a simple reading of one-way trip settler-explorers across history similarly rejects this notion. > If you can build a spacecraft capable of sustaining 1,000 human lives for multiple centuries, you’ve solved all local resource scarcity problems The first several of these ships are likely to end in catastrophe. The first to succeed will be breaking down on arrival. If we learn to build luxurious space habitats it will be through these endeavours.
    - os2warpman 1y ago
      > Empirically totally untrue as to be trivially disproven by like half of wealthy social media. A week in Bali is not the same thing as interstellar travel…
- munificent 1y ago
  I am increasingly certain that culture is by far the biggest limiting factor when it comes to large-scale problem solving now and in the future. We couldn't even reliably get people to put a piece of fabric over their face to stop killing their own relatives. Even if we could build a generation ship, it would turn into an Event Horizon hellscape if we don't figure out better cultural, communication, and sociological tools to enable us to get along and work together effectively.
  - deleted 1y ago
    [deleted]
  - JumpCrisscross 1y ago
    > We couldn't even reliably get people to put a piece of fabric over their face Rural Americans couldn’t. But I don’t see anyone proposing we put high school dropouts and polio patients in space. China, India and Japan managed to pass that test just fine. I imagine one of the former two will be the first to colonise deep space.
    - kryogen1c 1y ago
      >> kill their relatives > Rural Americans > high school dropouts Lol HN you really are too much sometimes. Covid went really well in all the intellectual bastions of liberal democracy right? NYC, SF? California famously no downsides from their policy choices at all. And then to top it off, you compare response to China - the government that lied through it's teeth about covid from the beginning, jailed journalists and destroyed evidence. Unreal
      - JumpCrisscross 1y ago
        Oh, nobody managed Covid well. The question was capacity to sacrifice for the common good. New York is a bad example to call out since it was one of the first places to get hit, locked down hard after a delay, and yet came out with lower per-capita deaths and a stronger economy than most red states. (Speaking as someone who lives in one of the reddest states in the union.) > jailed journalists and destroyed evidence Not sure we can call anyone out on this anymore.
- scythe 1y ago
  Relativity isn't the problem. The problem is that hitting a grain of sand at 0.1 c delivers the energy of several tonnes of TNT. My guess is that we will colonize the asteroid belt (Palladium! So much palladium!) and send lots of interstellar probes long before we try to send humans outside the solar system. Right now we're like a village that lives by a river and has never reached the mouth talking about sailing across the ocean. There are a lot of intermediate stages.
  - pmontra 1y ago
    It's not only about palladium or any other kind of ore. It's that you can launch from there to Earth orbit and spare most of the costs of lifting mass from the surface of our planet. Then you build habitats and ships with that stuff because it's much cheaper. Too bad we don't have neither mining nor factories in space yet. Two not trivial technologies to develop. The book Delta V [1] explores that scenario, with an asteroid on an orbit close to Earth to minimize the delta v to ship things back home. [1] https://daniel-suarez.com/Delta-v_synopsis.html https://daniel-suarez.com/Delta-v_synopsis.html
  - Someone 1y ago
    > Right now we're like a village that lives by a river and has never reached the mouth talking about sailing across the ocean And that’s an enormous understatement. Let’s say the villagers have travelled a meager 10 km of the river. Then, the ocean is, ballpark, at most 1,000 times as wide as the distance to the sea. A thousand times the distance between earth and moon (the farthest humans have travelled) gets you, ballpark, to mars. A lightyear is ~50,000 times the distance to mars or 50,000,000 times as far as humans have travelled. And yet, in interstellar travel, a lightyear gets you nowhere.
    - m4rtink 1y ago
      Sure, but the speeds you can realistically reach on the surface of a planet for any lenght of time is also many orders of magnitude less than you can reach in space & you also don't really loose speed by friction. That at least partially compensates for the mindboggling distances in space.
- andrewflnr 1y ago
  I read their comment as saying that current physics doesn't allow the kind of propulsion systems we need, even with optimal engineering and well below the lightspeed limit.
  - JumpCrisscross 1y ago
    > current physics doesn't allow the kind of propulsion systems we need Which is wrong. Direct-drive fusion fits the bill. It’s also easier than terrestrial power-generating fusion since you don’t need to convert to electricity.
- Ekaros 1y ago
  Energy is the limit. If used Wolfram Alpha right for reasonable comparison that is largest cruise ship with mass of 248663000 kg to speed up to 0.01c mentioned the kinetic energy would be 2.9 times the worlds fossil fuel reserves... Then double that to slow down. And remember efficiency and that well you need to spend some to keep people alive... Seems like energy in general is one of the true problems.
  - WithinReason 1y ago
    You wouldn't be burning coal for propulsion, you would fuse atoms: https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
    - Ekaros 1y ago
      I didn't coal would be used. Just that involved amount of energy would be truly massive. Even with fusion.
    - m4rtink 1y ago
      Or even better - ride a continuous fission detonation powered by the worlds biggest super-soaker! :) https://en.wikipedia.org/wiki/Nuclear_salt-water_rocket https://en.wikipedia.org/wiki/Nuclear_salt-water_rocket
  - JumpCrisscross 1y ago
    > If used Wolfram Alpha right for reasonable comparison that is largest cruise ship with mass of 248663000 kg to speed up to 0.01c mentioned the kinetic energy would be 2.9 times the worlds fossil fuel reserves This math is wrong. Back of the envelope: accelerating 250 x 10^6 kg to 1% of c over one year is about 310,000 TWh. That’s like half of current annual energy production. Even at like 10g, which would accelerate that mass to 1% c in less than half a day, you’d only use like a tenth of our 10^22 joules of fossil fuel reserves. > double that to slow down Why the asymmetry? 1x to accelerate, 1x to decelerate. (Less if you can aerobrake and/or use gravity assists.) Taking the 310k TWh from earlier and doubling it, and assuming 18 MeV for D-T direct-drive fusion, and you need 6,600 kg fuel for the journey. (Plus propellant.) 100x that to account for inefficiency and cooling and you have 660 metric tonnes of hydrogen. That, if kept in its bastard liquid form, takes up about 3 Olympic-size swimming pools in volume.
qingcharles 1y ago
Adding to the issue that it is relative pointless (IMO) to send meat popsicles all that way when a robot can make the journey about a million times easier and just send us some postcards. I hate to be a Debbie Downer, but it's kinda boring out there. We'd certainly not want to make the trek until the robots had scoured the galaxy looking for a fun place to visit. And by that time we'll all be living in some post-Singularity holodeck and won't give a hoot about some empty rock 600 light years away. Send the bots. I'll watch the highlight reel from my pod.
- philistine 1y ago
  Said like a true citizen of the Culture. And I mean that as a compliment!
- arethuza 1y ago
  My own view is that the most likely form of interstellar travel will be something like that used in Greg Egan's Diaspora - with upload communities sending themselves in relatively small ships and choosing whether to experience the journey or not.
- lanfeust6 1y ago
  I expect a kind of leapfrogging. Scout ahead, build a gate and/or infrastructure/terraforming, then a small fraction will decide it's worth migrating. Repeat. Expansion will only go as quickly as travel time allows. Even the speed of light seems insufficient beyond a certain point. We will want to manipulate space.
WithinReason 1y ago
We had the technology to do it in 44 years 60 years ago: An atomic (fission) Orion can achieve perhaps 9–11% of the speed of light. [...] At 0.1 c, Orion thermonuclear starships would require a flight time of at least 44 years to reach Alpha Centauri, not counting time needed to reach that speed (about 36 days at constant acceleration of 1 g or 9.8 m/s2). https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
- notahacker 1y ago
  Tbf we had nuclear [fission] pulsed propulsion technology in the 1960s in roughly the same way we had nuclear fusion in the 1960s: we had an understanding of some basic principles of physics and some calculations that looked broadly plausible The problem with using thermonuclear explosions to produce that level of thrust are more "but can we actually do it safely" than "but can we do it in a way that generates more that it takes to produce", but that's a not inconsiderable problem even without all the international agreements about where we shouldn't be exploding nuclear bombs...
- slightwinder 1y ago
  > We had the technology to do it in 44 years 60 years ago: No, we had not. That was only theoretical work, no real technology, not even a prototype.
  - m4rtink 1y ago
    IIRC there were sub-scale test done with chemical explosives. Also Feynman said it should work. :)
konart 1y ago
Speed is one thing. Surviving space is another.
FuriouslyAdrift 1y ago
Speed isn't the problem... time is. Long term travel in space will destroy the body. Even with artificial gravity, cancer is nearly inevitable. I am ignoring the mental and emotional issues. Astronauts are extremely tough individuals. Now, if we can figure out some form of suspended animation, that fixes many problems for long range travel. I am much more convinced that our best way to leave our solar system will be without our physical bodies. Some form of synthetic or uploaded consciousness would be much easier to move around. After constructing a network, they could even be transmitted instead of shipped. This is obviously in the range of science fiction but if we exist long enough, who knows. The show, Pantheon, did a fairly decent fictional take on the idea.
- zdragnar 1y ago
  > Now, if we can figure out some form of suspended animation You'll still need someone awake to pilot the ship, otherwise you'll end up crash landed on a planet with Riddick running loose.
  - m4rtink 1y ago
    Yep, it is always a good idea to have a flight crew[0] when most of the passengers are in hibernation. It might take them some time but they will always sort thing out in the end! :) [0] https://revelationspace.fandom.com/wiki/Galactic_North_(short_story) https://revelationspace.fandom.com/wiki/Galactic_North_(shor...
  - random_is_rando 1y ago
    Some sort of AI algorithm? Don't think anyone pilots the SpaceX Dragon.
    - m4rtink 1y ago
      Looks like it is x86 + Linux and C++: https://hackaday.com/2024/02/10/the-usage-of-embedded-linux-in-spacecraft/ https://hackaday.com/2024/02/10/the-usage-of-embedded-linux-...

jvanderbot 1y ago

Pretty awesome. I feel like Paul Chadeisson should do a reward render of the assembly/flight. Nobody does space "big stuff" like he does.

AtlasBarfed 1y ago

Where is the propulsion system design? Are all of these handwaving propulsion? They seem to all be habitat designs. Ok I'll take my shot at propulsion: Pulse nuclear BUT: For acceleration, we have a launch gun that fires more fuel at the ship, and the ship catches the fuel, imparting momentum from the catch, and more fuel for acceleration. For deceleration, we have pellets that it catches up to and uses the catching to slow down with, AND gains fuel to decelerate. If the catch can be done like an ion drive in efficiency, then you get ion drive efficiencies while gaining fuel for the pulse nuclear accelerations/decelerations. The real problem would be timing the deceleration "catches", and a HELL of a railgun. We aren't really doing this in current physics without a massive and functional orbital/planetary economy that gives cheap nuclear fuel and materials. We'll probably need solar wind antimatter harvesters as well, if those are actually a thing.

vl 1y ago
The drive in this design is not yet invented Helium 3 - Deuterium Direct Fusion Drive. In your design how is it going to catch up to pellets if it's decelerating? I.e. pellets need to be pre-decelerated for this. Which raises the question, would it be cheaper just to bring all deceleration fuel onboard.
- amenhotep 1y ago
  You'd spend years firing pellets in advance of the voyage, on the same trajectory but moving a little slower than the ship you plan to launch. Time it all so you catch up with the first of them just as you want to start decelerating.
  - WithinReason 1y ago
    But then the whole project takes thousands instead of hundreds of years
    - vl 1y ago
      And also it requires extraordinary navigation precision. These launches are going to be spread in time, which means that they don't happen from the same place (all celestial bodies move relative to each other). Which in turn means that when you approach the pellet there is going to be perpendicular velocity component. Even without taking this into account all systems are going to need active guidance - there is no way you do single burn and end up in the same place in the same time few light years away. The best schema is probably launching all fuels containers that should be picked up for retro burn at the same time with much higher acceleration (orbital rail gun and then a burner), and with very slightly smaller final speed. Then on the main craft you do short retro burn to match speed to fuels containers, attach them and do full retro burn for orbital insertion. Benefit of this schema is that you don't need to accelerate everything slowly using main engine, so your original booster can be way smaller. (Energy-wise it only works if you have stationary means to accelerate high-g-capable payloads, i.e. orbital railgun, in this case you don't have to accelerate extra fuel required for initial burn)

fuckinpuppers 1y ago

Reminds me of the probe from Star Trek IV

vl 1y ago

Cool concept, but some things are just strange: Power provided by toroidal nuclear fusion reactors in the outer shell of the living module, but why do you need such reactors if your primary propulsion is provided by Helium 3 - Deuterium Direct Fusion Drive? If you have direct fusion technology, you don't need toroidal reactors. Rotating inner shells mechanically for 400 years is terrible design, it's much easier just to rotate entire structure. Once it's going it keeps rotating inertially! Another comment points to error in speed calculation - at declared acceleration they should go at 0.1c, not 0.01c! And what is missing of course is the calculation of how many years of current world's GDP is required to complete such project event if all yet-to-be invented technologies exist.

nn3 1y ago
If you would spin the whole structure you couldn't have multiple shells all with 1G on their surface. The required spin speed for 1G depends on the diameter. But their whole concept is built around multiple shells, which is clear from the name. Regarding the GDP needed once you have a working "mine from the moon and send to orbit" economy it doesn't seem to be too bad. The assumption would be that a lot of technology is already developed for other projects. Launching it all from earth obviously wouldn't be possible even with vastly cheaper launch. That's why they put the build into the moon-earth L1 lagrange point to be easily reachable from the moon. For propulsion and reactors, but there are multiple projects today working on all of this. Building a life support system for 400 years is still an unsolved problem however.
- vl 1y ago
  Re: orbital assembly. L1 point is bad in every respect. If most materials come from Moon, then the best assembly point is low Moon orbit (as benefit you get a boot to your launch speed to escape Earth gravity), if most material comes from Earth, then best assembly point is low Earth orbit. Hauling all material to L1 is going to be more expensive in either case (unless the ratio of materials is very exact, which is unlikely). Re: spin. I still claim that the best design is to rotate entire living module as one. Most of the activity is going to be on the outer shell. Warehouses, etc will be in the lower gravity inside. No moving parts. The only question is what to do with fuel and retro engines. Rotate them as well? Fuel tanks need to be stronger. Do not rotate? Then maybe living module can undock for the flight and rotate separately.

forgingahead 1y ago

Perhaps I'm being mean (haven't read the full presentation) - but the winning team is made up of 2 actresses/artists, 1 social innovator, 1 designer, and 1 astrophysicist?

riffraff 1y ago
One of the artist is also an environmental engineer, the other is also a psychologist, the designer is an architect. But yes, it's a work of design more than a blueprint.

dirkc 1y ago

Thanks for sharing the presentation. I wish I could download it to look at it in a few years from now. I hope durable file formats regain popularity before humanity starts embarking on interstellar voyages :)

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