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Space China

China Researching Challenges of Kilometer-Scale Ultra-large Spacecraft (spacenews.com) 98

Posted by BeauHD from the planning-ahead dept.
Hmmmmmm shares a report from SpaceNews: The National Natural Science Foundation of China has outlined a five-year project for researchers to study the assembly of ultra-large spacecraft. Scientists are being directed to meet the "urgent need" for the construction of ultra-large spacecraft. Preliminary research is to include studying the challenges of developing lightweight structures and subsequent on-orbit assembly and control. Though vague, the project would have practical applications for potential megaprojects including colossal space-based solar power stations. Such facilities would be based in geostationary orbit and span kilometers. These stations would collect solar energy and transmitting power to Earth through microwaves.

Kilometer-scale, ultra-large spacecraft are described as "major strategic aerospace equipment for the future use of space resources, exploration of the mysteries of the universe, and long-term habitation in orbit," according to the project outline within the mathematical and physical sciences attachment to the released document. The plan, if approved, would aim for commercial, on-orbit gigawatt-level power generation by 2050. This would require more than 100 super heavy-lift Long March 9 launches and around 10,000 tons of infrastructure, assembled in orbit, according to Long Lehao, a chief designer of China's Long March rocket series.
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China Researching Challenges of Kilometer-Scale Ultra-large Spacecraft More

China Researching Challenges of Kilometer-Scale Ultra-large Spacecraft

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  • Somebody needs to do this. If the West doesn't want space to be Chinese, then we need to stop fiddling around. Otherwise, time to learn a new language.

    • Re:Go China! (Score:5, Funny)

      by Opportunist ( 166417 ) on Saturday August 28, 2021 @06:48AM (#61738077)

      "In German oder English I know how to count down,
      Und I'm learning Chinese!" says Wernher von Braun.

      --Tom Lehrer

    • ni hao. wo de zhong wen bu hao.

      Now we just gotta get /. to support Unicode.

      • A question for you in Chinese: " ?"

        The answer is, apparently not.

        • Questions use the character "ma", but fuck my life and tones, least you call your mother a horse.

          I simply said, "Hello. My Chinese is bad." There is no question there -- I am making making a clear reply about how hard learning this new language is and continue by pointing out that \. doesn't even support the language.

    • Re: (Score:2)

      by noodler ( 724788 )

      [quote]If the West doesn't want space to be Chinese, then we need to stop fiddling around.[/quote]
      The us has lost the space race against china over half a century ago.

      • The us has lost the space race against china over half a century ago.

        So you're saying all those silver discs, black triangles, white cylinders and invisible ovoids ("tic tacs" to the idiots) are powered by poodle dumplings?? I'm going to go out on a limb and choose to doubt that.

        • Re: (Score:2)

          by noodler ( 724788 )

          I never said anything about tic tacs.
          I was talking about the fact that china has more people and money than the us.

    • Somebody needs to do this.

      . . . and that somebody will be . . . Jeff Bezos!

      He will now sue China and demand that he be given the contract to build this ship.

  • Variety of problems include: (Score:4, Interesting)

    by Antique Geekmeister ( 740220 ) on Saturday August 28, 2021 @06:18AM (#61738039)

    Tidal forces locking the structure in a vertical alignment
    Electrical currents due to magnetic coupling
    Mechanical resonances in unexpected frequencies

    • Re:Variety of problems include: (Score:5, Insightful)

      by Jarik C-Bol ( 894741 ) on Saturday August 28, 2021 @09:09AM (#61738221)
      Yep, the mechanical resonance thing is a huge one. I always laugh at the ‘spinning space station to simulate gravity’ thing, knowing that they had to build a super special isolated exercise bike for the ISS to keep the person pedaling the bike from shaking the entire space station violently. Movement in space is *complicated*
      • Great story on resonance, A friend of mine had just built a 60lb robot to compete with at BattleBots. Problem was, it would start violently shaking itself every time the drive motors were used. It was pretty bad to the point of not keeping all the wheels solidly on the ground, damaging components, and ruining electrical connectors. Turned out the pwm frequency was a close match to the resonant frequency of the frame + components and the small high frequency mechanical vibrations from the magnetic stres

      • Not because it would break the ISS... (Score:5, Insightful)

        by Akardam ( 186995 ) on Saturday August 28, 2021 @10:05AM (#61738299)

        The treadmills (and other excercise equipment, like the ergometers and the resistive excercise machines) are to varying degrees isolated from the ISS structure foremost because the ISS is a micro-gravity research facility. Since the crew must excercise regularly, and they do not all do so at once (equipment availability, task scheduling, etc), if the equipment was not isolated there would be a significant portion of each day when micro-gravity experiments could not be performed, as their environment would be disrupted by the transient accelerations associated with excercise equipment use. This would somewhat defeat the idea of having the station in the first place.

        A structure being rotated in free space (essentially in an environment with no significant outside accellerations being applied) at a constant rate does not experience resonance due to said rotation. Resonance results from a periodically applied force (i.e. accelleration), whereas the constant rate rotation produces a constant force.

        • Rotating a 5 kilometer structure seems unwise. I'd expect it to be oriented towards Earth, tidally locked on its long axis. Any other orientation would cost energy to maintain and be likely to fail at some point, causing chaos throughout the systems.

      • Re: (Score:2)

        by AmiMoJo ( 196126 )

        Also it wouldn't be very pleasant to live on. It would have to spin slowly to avoid problems with centrifugal forces making it hard to do everyday tasks, and even then experiments have shown that humans don't adapt well to it.

        • Why bother with spinning it? There are some profound medical consequences of living in zero gee, especially when returning to Earth, but the awkwardness and expense of maintaining any significant replacement for gravity is quite large. I suppose if you're building a structure 5 kilometers long, an isolated exercise area might be worth it. Especially if there are ever to be children borne in space, I strongly expect that fetuses require something like gravity to develop normally: those will be fascinating ex

          • Especially if there are ever to be children borne in space, I strongly expect that fetuses require something like gravity to develop normally: those will be fascinating experiments some day.

            True. And it'll be necessary to find out just how much gravity is sufficient. If 1/3 of Earth normal isn't sufficient, you can forget about any permanent colonies on Mars.

            • Or 1/6 G, for the much more feasible colony proposals for Luna. The big difficulty for Lunar colonization is the lack of water. But if you're working in space at that kind of scale, solar sails to bring icy objects from Saturn's or Jupiter's ring and mine them for water and space manufacture iron becomes much more feasible. Mars would seem an expensive rathole of a project by comparison.

        • I believe you are thinking of the Coriolis force that affects moving objects in rotating systems.

        • Re: (Score:2)

          by suss ( 158993 )

          And "You spin me round" by Dead or Alive would be playing on repeat the entire time...

        • Re: (Score:2)

          by HiThere ( 15173 )

          Got any references for that, because I find your claim a bit unbelievable. I can much more easily believe that load balancing would be a problem.

          I suspect that your references involve spinning in much smaller circles where the difference between the head and the feet would be quite noticeable. And yes, that would be hard to adapt to. As the diameter of the wheel gets larger, however, that becomes increasingly less significant. (Another advantage is that the needed speed or rotation becomes smaller.)

          OTOH

  • So, that's what we're going with, for the CCP Space Force cover story? Solar energy farming? MMMkaaay.

    I guess it's better than nicknaming it something vague. Like "The Star Wars program".

    https://en.wikipedia.org/wiki/... [wikipedia.org]

    • Re: (Score:2)

      by sxpert ( 139117 )

      you mean, "Giant Space Lasers" ?

      • I believe you mean "Giant Nuclear X-Ray Space Lasers". The design was called "Project Excalibur", and relied on using atom bombs to generate X-Ray lasers for missile defense.

        https://en.wikipedia.org/wiki/... [wikipedia.org]

        There was never any hint that any aspect of the project was feasible or was ever tested. This is fortunate: such designs were far more suitable for offense than for missile defense.

    • Most likely military applications are only a small part of the overall goal.

      Energy is civilization, and the amount of energy that could be harvested in space is immense. Furthermore, even though they are building coal power plants, the Chinese know full well that they need to move to cleaner energy sources in the long term. They just don't care so much about the short-term.

      In addition, large-scale structures allow large-scale habitation. Space may be a hostile environment, but economy of scale applies t

      • It's very expensive & resource intensive to put stuff up into space & maintain it, you know, like solar arrays. Enough viable radiation comes through the atmosphere to support our massively abundant ecosystem (and we're doing our best to make it overheat). If we want solar energy, there's plenty down here & it's probably cheaper & less risky & problematic than 100 mega-rocket launches.

        Space habitation only makes sense if those people have a very good reason to be there, i.e. scientific.

  • I really, deeply dislike the Chinese government's brainwashing, genocidal, totalitarian ways. But their civilian scientific pursuits, from space exploration to Thorium-based nuclear energy production, their recent focus on curbing commercial algorithmic BSery, and the speed at which they're reducing extreme poverty, make my heart warm up a little to them. Up from absolute zero halfway towards frostbite, but at least that's something.

    • Re:The good, the bad, and the ugly (Score:4, Insightful)

      by sxpert ( 139117 ) on Saturday August 28, 2021 @06:29AM (#61738049)

      there's nothing civilian about this project. anything of this magnitude has the PLA behind it.

      • there's nothing civilian about this project. anything of this magnitude has the PLA behind it.

        Of course, but it also has, at least officially, civilian aims. Look at it this way: from a military perspective, this is an orbital gigawatt laser they can reposition to perforate and vaporize anything on the surface with pinpoint accuracy; from a civilian one, it's an energy source when pointed at a suitable receptor. So it works both ways, and I like it the civilian angle of the thing.

        It may also have a geopolitical and diplomatic side, mind. If this proves successful, and China manages to lower the cost

        • Re: (Score:2)

          by HiThere ( 15173 )

          A powerful orbital laser can only be a first strike weapon. You could take it out with a brick, if the brick were in the correct orbit. And that could easily be disguised as a mistake by someone else.

          I don't see that as a realistic threat. And you couldn't use it multiple times in rapid succession, because of heating problems, which are bad enough on the surface.

          OTOH, I expect the US, and probably Europe, to effectively become satellite states of China. It we're *very* lucky this won't involve a major w

          • And you couldn't use it multiple times in rapid succession, because of heating problems, which are bad enough on the surface.

            That depends on how it's engineered. If they're going for an energy source, those 1 GW would be a sustained output, not short pulses with long cool downs in between. I have done no calculation, but my wild guess is that glassing a large city is quite feasible if one were to sweep it with a sustained 1 GW laser.

            I expect the US, and probably Europe, to effectively become satellite states of China.

            The major problem I see with this isn't even China being authoritarian. It's that due to its totalitarianism it completely kills new ideas. For good and for bad the West has been quite creative over t

            • People forget china had a constant leadership change. Every ten years. Sure it was party chosen but still new leadership every ten years. That's enough for government. Xi changed all that and made him president for life. The next will also be president for life. And china will begin to collapse as all monarchy's due. As china's own monarchy's have done.

              Leaders for life. Sound great as one person can push for specific goals. Except you stop changing. Which stifles creativity.

              I expect china will have

    • This is what happens when you allow profitable businesses to operate in your country, yet still regulate them to the point they actually comply with your rules. Over here in the West it seems the government is more like a moderator than an administrator allowing anyone with enough money to do as they please and negotiate an apology after. In essence unregulated industries in the west have very little interest in appeasing the government or the general public. Unless you are an investor with a investment l

      • I do not want to become China but I do want to live in a Country where rules matter for everyone.

        Interestingly enough, this is more or less what the economic system Germany adopted, Ordoliberalism [wikipedia.org], is all about. It's characterized by the idea of having and enforcing clear but generic rules, so that the government can incentivize certain economic sectors while not benefiting specific incumbent company, as the rules for each sector are neutral and designed for the benefit of the citizens.

        Not that Germany follows this strictly in every instance, its government also has its "too big to fail" beneficiaries,

  • It may be useful around other planets or the moon, because we'd have to get stuff up there anyway, but the only reasonable reason to put solar panels in earth orbit is to have electricity for things you need to do in earth orbit. Lifting panels up there into one of the most hostile environments just so you can (mostly) avoid earth's shadow and then beam the energy back to earth is ludicrous.

    • Lifting panels up there into one of the most hostile environments just so you can (mostly) avoid earth's shadow and then beam the energy back to earth is ludicrous.

      Earth's shadow? That's a benefit, but you also avoid the shadows of Earth's weather. Solar panels not only don't function when in Earth's shadow, they barely function when there's visible water vapor in the atmosphere. But you can use radio frequencies which interact less with water than light does in order to cut through that when beaming power to the ground.

      Ultimately what a solar power satellite ought to look like is just a ribbon or sheet designed to have holes torn in it and still function.

      • Are there really people who are so stupid that they would believe cloud cover is a big enough problem for solar power to justify shooting the panels into space and beaming energy to earth with microwaves? The proverbial bridge might be an easier sale.

        • Space-based solar is not going to be economically viable for people on Earth any time soon, but it will be viable eventually if AGW doesn't destroy our societies. Why not start thinking about it now?

        • Re:No way this will be economical in earth orbit (Score:5, Insightful)

          by bradley13 ( 1118935 ) on Saturday August 28, 2021 @07:58AM (#61738151) Homepage

          Are there really people who are so stupid that they would believe cloud cover is a big enough problem for solar power to justify shooting the panels into space

          Yes, and they aren't stupid. Various groups have run these numbers, and come up with it being a viable option. Sending stuff into space isn't *that* expensive, at least, if you don't have NASA and US government contractors build your rockets. The efficiency gain is huge: between day/night cycles, lack of weather, lack of atmosphere, etc.. Also, you would have the option of working with wavelengths that are blocked by the atmosphere.

          AFAIK, the biggest resistance has come - not from people thinking this is infeasible - but from people worried about the microwave beams being used as weapons. Which is actually not a big concern, because the beams would be unfocused, meaning the energy density is fairly low.

          • The biggest resistance is the fact that the cost of launch needs to come down to less than $200/kg, so nearly 10 fold, and the fact that the antenna array for sufficiently de-columnated beamed power, such that the beam is not a danger to aircraft, people, animals, and vegetation under or near the array, results in a receiver array 10 kilometers across, which suffers from the very real nightmare of convincing NIMBY that it is *not* a space laser that will get loose and fry their house. Also, the fact that so

          • Re: (Score:1)

            by AmiMoJo ( 196126 )

            I wonder if they are thinking about shade too. Dropping the account of light that reaches Earth even by a small amount would have a big effect on global temperature.

            Would need a lot of 1km ships but if they could be mass produced...

            • It wouldn't need ships, merely solar sails correctly piloted. It would seriously _anger_ astronomers, and might profoundly anger farmers, to interfere with weather on such a scale. It could also be used maliciously. "Afghanistan will no longer grow opium, because they will not have sunlight" could become a credible threat.

              • Re: (Score:2)

                by BranMan ( 29917 )

                This is not an alien saucer ship hovering over a city putting it in shadow. Even in orbit, these would still be small enough that they allow light to flow around them - they block some percentage, but are WAY too far away to cast a shadow.

                And the best place to do that would not be in orbit anyway, but at the L1 point between the Sun and the Earth. Block a few percent of light - that would be uniformly "dimmed" across the entire planet - and you get rid of - even reverse! - global warming.

                Which is in fact

                • > And the best place to do that would not be in orbit anyway, but at the L1 point between the Sun and the Earth

                  Then the wrong side of the mirror is facing the Earth. That point is also more than one million miles from Earth. that makes it _much_ more difficult to keep well aligned.

          • "The beams would be unfocused" until a design with the feature to focus the beam at whim is used. As much as I advocate the project, even I share the concern that the microwave transmission array, _or the solar mirror itself_, could be focused at a political target.

  • Oh ya? I'm working on a spacecraft that's a MILE long!
  • I can not believe that solar panels in space are the right thing to do. Ok, it has benefits: eternal sunshine, higher efficiency, no clouds, but the cost is orders of magnitude higher. You can do a lot with that money here on earth. Also, 1 gigawatt is not that impressive for a country as China. So... I don't buy it. If you would just use all the energy to put the platform in space to generate electricity, I can imagine you would be able to generate a gigawatt for quite a while. Sounds like a prestige pro

  • They must be reading Douglas Adams. The real question is what color it should be.

  • How do you say Death Star in Mandarin?

  • Calling something that's just 5 furlongs long "ultra large" will one day be amusing to people who have already been born, never mind those who ride on the first space-elevators.

    • It doesn't look like space elevators are going to happen. The tensile strength requirements are too large. Substances like single-rystalgraphene have the raw strength, but can't be assembled in large enough lengths without fatally fraying.

      • Re: (Score:2)

        by nagora ( 177841 )

        It doesn't look like space elevators are going to happen. The tensile strength requirements are too large. Substances like single-rystalgraphene have the raw strength, but can't be assembled in large enough lengths without fatally fraying.

        Clearly they need wrapped in duct tape.

        • Duct tape typically comes in rolls only 20 yards long, or we might simply use one strand reaching all the way up. Just stick the end on the ground, with another piece across it to hold it down.

  • No matter how bad it will get on earth, it is still by far the most habitable piece of real-estate within reach and will remain so at least for the next few centuries. On the other hand, claiming something is "needed urgently" is a tried and true method to motivate those that cannot or dare not think for themselves.

  • Not a good idea. It would effectively increase the surface area of the Earth for the interception of Sun energy and add to global warming.

  • China isn't satisfied with just poisoning their own country and covering it in a 1km thick layer of garbage - they want to trash the Moon and fill Earth orbit with space garbage as well.

  • "Such facilities would be based in geostationary orbit and span kilometers. These stations would collect solar energy and transmitting power to Earth through microwaves."

    Also known as death ray.
    They could melt snow in stadiums or melt some glaciers in enemy countries or grill their soldiers in their tanks and planes.

  • I may not like much about how China achieves their goals at a governmental level, but unlike my countries (native and adopted), China has beauty of long term leadership that can not only make decisions, but see them through. If they say they want to run a 10 year project, the leader can start it and keep it going for 10 years without having some opposition party boot them out of office and cancel their projects.

    If China says they're going to make a city in the sky... I'm pretty sure that's exactly what they
  • Isn't gathering solar energy in space (energy that was destined for deep space, not energy already coming to Earth) and beaming it to Earth just going to increase global warming?

    • It would really depend on whether it's replacing fossil-fuel use on Earth. If it results in a decrease in atmospheric CO2 then Earth will lose more heat by radiation than it gains from the microwaves.

      In any case it's doubtful that solar power satellites would actually be economical. Constructing them would be orders of magnitude more expensive than paving the nearest desert with solar panels, and the efficiency gain from being in space is not significant enough to compensate for the expense.

  • A very large space vessel with rotation-based artificial gravity could be launched on existing rockets, at relatively low cost already.

    On Earth, we build structures to withstand gravity, the weight we put upon them, and the weather. In such cases, force is directed mostly downward on them. Therefore, rigid dense materials are generally ideal. However in space, there is no down and force is mostly directed outward from them, into the vacuum. The pressure is inside, instead of outside. Consequently, dens

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