40 thoughts on “Why We Need Fusion”

  1. We need an artificial Mars gravity “thing”
    Zubrin thought do it on the way to Mars.
    Let’s do it in Earth orbit.
    What would it take?
    One falcon 9 launch?

    1. Two Falcon9 launches with two Dragons that can dock and tether nose to nose and rotate around each other putting .3g in each capsule while in LEO. With one in each with supplies enough to last a year. One man, one woman in each to stretch life support would be minimum you’d need for a test I’d think.

      1. Not saying Dragon can do that. It’s physically possible but don’t know if Dragon life support can go that long.

        1. Tether and separate a goodly distance so that angular momentum can be kept at a minimum to minimize inner ear coriolis issues while living/moving inside the capsules.

        2. Dragon life support is 20 man-days plus some margin, so two people would last 10 days. It’s also pretty small for long duration flights, about the size of the master bath in my crummy little house. If, instead of cargo in the lower bay, you put additional life support, it’d last longer, but not a lot, maybe a couple of months tops for one or two people.

          You’d be better off making a habitable module out of a Cygnus (which is pretty much a description of the Gateway HALO module), and if that was the sum of available technology, that’d be worth it. But a single Starship offers a fairing volume roughly equal to all of ISS. The intended life support capability of the Mars transport variant is a minimum of 9,000 to 18,000 man-days for the trip over alone.

      2. I would extend the height of falcon 9 second stage by 27.4 meter.
        So second stage is 12.6 meter and + 27.4 meter get total length of
        40 meter. The extension, is just thin metal, have lots of floor [thin metal floor}. No windows.
        But has fair amount air in it. Some solar panels to give some light and bit of power. And weighs about 10,000 kg.
        Falcon 9 with with first stage reuse can lift about 15,000 kg to LEO. So add about 5000 kg of stuff to it. It has no shielding, so
        maybe few tons of water and/or other shielding.
        Anyhow, I think heavier spent second stage falcon 9 would tend to point to Earth. It could have more drag than ISS, and probably want get in something 400 km high orbit. And you cameras and whatever to monitor it, and in couple weeks send up a crew in a dragon. So Dragon has ” Dragon 2 has four windows, and passengers can watch the stunning views of the Earth, Moon, and solar system”, and this thing doesn’t. But you design it so it makes easier to add window, if you want a window- it’s something you might fix up.
        Anyhow with crew, you get near it, and get on it. And then could try spinning. Could tow it to spin it, added the dragon to it spinning.
        I was also thinking you could put say within couple miles of ISS, it crew to see what they do with it. NASA probably wouldn’t like that.
        Anyhow, first crews, might spend a week or so, experimenting with it. And next crew might involve bringing more stuff to it, and get point spending couple months. But I would start with maybe .1 or .2 of a gee. The floors could allow get less spinning motion [in terms getting dizzy] so if much for some crew you can “adjust your dose” also with tons of water, it it you adjust spin rate a bit, bring water more to center of mass, or outward away from it. So it kind like learning ride a bike. And if spend a month on with .1 gee, how does effect you. Is not much difference, than microgravity or is it measurable result. Or even when get to .3 gee, how effect is it.
        It seems we need some experience with artificial gravity to explore Mars.

        1. **The 10,000 kg, thing.**
          This not close to a design, but more of an rough idea.
          It’s got 11 floors.
          The four floors up from spent second stage, are not really easily accessible, but it includes 5 meter high pressure room which would starts with air density of about 5.4 kg per cubic meter {air was 60 C, it would have pressure of about 75 psia.
          All rooms would start with the 14.7 psi of earth pressure and would have more than this say, 5 psi. So in space all has at least about 20 psia.
          One designs it to be able to vent air to space and it has the plumbing to adjust air pressure in all rooms.
          Or for example the top has 8 foot diameter and rest has 12 [same diameter as stage}. The top not count as a floor. To get into “air lock” one vents it’s air out it. Crew enter, and you put air into it to get to next floor, which where put on or remove spacesuit- a mud room, the porch.
          Then equalize pressure to get the top deck where crew would get the most amount of artificial gravity, unless you are counting the mud room or “air lock” above it.
          Top floor is 3 meter high, and doesn’t have a door to next floor which is 2 meter high, and next one down has a door, as all other have doors. In the basement area which about 12 meter up booster, wall and floors are 1 cm thick. And upper decks have wall and floors 5 mm thick- though
          top deck floor {and mud room ceiling is 1 cm thick. And bottom floor of upper area, is 2 meter high room, which I call solar flare shelter. It’s the room I think one should have most radiation shielding in. And second most place to have most shielding is the top floor.
          So, have ways monitoring temperature radiation levels and etc. And from Earth would have ability to vent air from anywhere in it.
          And could control where it’s vented- a have some means of using air to “steer it”.
          Oh there 1 meter tank 7 meter high in basement which has about 250 psi of air in it, which would better to get some degree of thrust. But this air is not intended to provide air needs for crew for weeks or month. But you might also want use high pressure air to power air tools, if needed such tools to do something.

          1. I was thinking, after launching it. One could upgrade it, so it keep it’s orbital height and have thrust to avoid things. Then NASA might allow to within a mile of ISS.
            If within a mile of ISS, in addition to a facility to test artificial gravity. It could be a “lifeboat” for ISS. Though of course ISS could be lifeboat to it, also.

            Now a question, if ISS crew spent a month on it, before returning to Earth, would they then have spend as much time adjusting to Earth’s gravity when return to Earth?
            Also if crew jog over there and spent a couple days there, would they need to do as much exercise while staying at ISS?
            So from lowest floor of it, could get in the Second stage?
            Or spacewalk and access to second stage, and refuel it. Then you would have something to give some thrust.

            And since could make gravity, it in general could more easily refuel anything.

          2. Though in terms of the only space race.
            Bezos or others could also do it. It seems developing ways to deal with artificial gravity in space would be big feather for someone’s hat.

          3. So, the thing will bare aluminum save 2 meter wide strip of thin solar panels on outside of flare shelter room.
            Question if at around 400 km orbit, how hot will air get in the thing?
            Because it tall and relatively narrow, I think, it will tend to cooler.
            So, if all air when launched was 0 C, how much would air warm up?
            Or similar question if launch with air a 60 C, would cool down or heat up hotter.
            Related to this, is all the air could used to keep it cooler or warmer.
            And especially in regards to lower floors [basement} one bring very cold oxygen rather than “air”. And rather bring a ton of water for shielding , could bring a ton of LOX for
            cooling or one part of rocket fuel.
            But was also thinking bring hot air, to keep warm.
            So how warm. There not much power for electronic use, {about 1.2 kw} until more power is added, it does seem it adds much heat from that.

  2. …If one accepts the idea that resources are limited, then all nations are fundamentally enemies, and the only issue is who is going to kill whom in order to claim what’s available.
    The Socialist One-World Government theory in one sentence: The only way to have Peace, Prosperity, and Free Ice Cream For All™ is to have a single all-powerful State lead by Enlightened Technocrats.
    It made for a sappy Science Fiction premise from the 60’s on and a chilling promise today. Like Zubrin asserts ‘With enough cheap power you a Free to do anything’. A premise too optimistic for some people.

    1. I’ve long had a different view of the technocratic future. In my latest sci-fi dabble, I recently wrote the following exchange between two protagonists aboard a sall, private spaceship far from ‘civiliztion.’ (One of the zowie technologies in the story is instantaneous communication.)

      “I was just looking in to ask if you squelched the news feed.”

      “Just the ones from Earth.”

      “Oh? Why, did something happen?”

      “They seem shocked to discover that one or another of their lord high muckymuck assistant deputy mandarins-in-chief isn’t immortal. They won’t have anything else to blather about for at least another half-season.”

      “Was he important?”

      “He was a bureaucrat. They breed ‘em like livestock and let them think they’re in charge.”

      She chuckled at his cynicism. “Who’s in charge if they’re not?”

      “The farmer, who else?”

      The question of who is the farmer is left for later examination.

  3. “No, the reason we need fusion is to destroy the Malthusian belief system”

    It can’t be destroyed. This type of thinking arises naturally in any given population, probably because it is so easy to slip into out of ignorance, sloppy thinking, and psychopathy.

    If/When fusion power plants actually exist, these type of people will just move the goal posts. The beat will shift but the hook remains the same.

    1. “The universe isn’t making new hydrogen, so it would be foolish to try and rely on it as a power source. At least fresh uranium gets forged during neutron star collisions. And what do we do with the waste helium? You know they’ll vent it to the atmosphere. And fusion plants produce enormous waste heat that further destroys the environment.”

      1. Theyll freak out about the neutrons and the tritium. If you want the lighrs to stay on, you have to defeat these people.

    2. It’s worth remembering that Malthus published “An Essay on the Principle of Population” in 1798. It was cutting edge at the time and as far as anyone could tell, correct. The problem as we know it began with the Club of Rome report “The Limits to Growth” in 1972. And the Club of Rome still exists, with its membership of special people. It remains an existential threat to civilization.

  4. “The universe isn’t making new hydrogen…”

    Sure it is. Neutron(s) released by spontaneous fission within that same uranium each decay in 1/4 hour or so into a single proton and electron — that is, into new hydrogen atoms.

      1. All I can do is recount my anecdote about the girlfriend who went into a panic when she saw a hydrogen tanker truck on the highway. Turned out she only associated the word hydrogen as an adjective modifying bomb.

        1. You should have driven her down to Amarillo and shown her the igloos around North 15th Street and Washington Dr.

          1. Nice to see some nearby Windfarms there. It’s good to have diverse forms of energy that are not quite so compact.

          1. I made a sincere effort not to do or say anything that would cut off steady access to the you-know-what. I had male friends I could belittle and sneer at without causing much harm, beyond the occasional snit.

  5. The problem with Zubrin is, he spent his career making kludge solutions to problems within the perceived limitations of the circumstances. His idea of colonizing Mars 4 people at a time is a good example, as is his Shuttle-Z launch vehicle. I was guilty of the same short sightedness, as were most others. The Falcon 9 could have been built at any time after about 1980 (and cruder versions any time after 1960), but instead of a Musk we had “visionaries” like Zubrin (and, sad to say, me). Now, a lot of people are clinging to their old ideas (e.g., “Aldrin Cyclers”) instead of taking a step back, a deep breath, and reaching for a new and grander vision. And this ain’t it. Fusion isn’t a magic bullet that will somehow give us a “killer app for space,” because one doesn’t exist and isn’t needed.

    1. It seems to me that the Internet boom was necessary for reusable rocketships, etc. Nothing else could have put sufficient money in the hands of individual nerds willing to invest it in space stuff.

      1. This is simply “post hoc, ergo propter hoc” reasoning, in that you’re suggesting because something did happen a certain way, that’s the only way it could have happened. There are two counterpoints:

        1. The Space Shuttle is a perfectly good example of a reusable launch vehicle, designed and built in the 1970s, and flown from 1981 to 2011. Had it been built as originally designed, there never would have been a Falcon 9, because it woud have been the exact equivalent of SuperHeavy/Starship 40 years before the fact. The RSRM/droptank kludge that really flew was a bad political decision made for political reasons. And, despite that, it was a successful reusable launch vehicle (the ET doesn’t count against it; aircraft with drop tanks are not “expendable”).

        2. People tend to overestimate how much Musk spent developing Falcon 9. It was in the hundreds of millions of $$ range, and there are thousands of people with that much money. The Internet didn’t create Musk. Indeed, it’s arguable that the Russians created SpaceX, and TRW gave him Tom Mueller.

        1. The Internet didn’t create Musk.
          Well no, his Mom and Dad had a hand in that. But let’s not forget that PayPal was an enabler.

          1. Mom and Dad generated more kids than Elon, but only one Wizard. And Zip2 (Elon and Kimbal) generated the main big payout, leading to X.com and then, after merging with Confinity, PayPal. That’s where the argument attributing it to the Internet comes from. I like that Musk learned to program on a Vic-20, just like me, only he was a little kid, and I was a destitute 30-something single parent.

          2. I like that Musk learned to program on a Vic-20, just like me, only he was a little kid, and I was a destitute 30-something single parent.
            I went from “programming” a Geniac as my first “computer”, to a high level semi-interpreted language on a CDC-6600 and then 6600 assembler, with a smattering of FORTRAN and PL-1 along the way. I could have written off to Popular Electronics for the plans for the COSMAC-ELF, but then the MITS Altair showed up and I eventually moved on to a NorthStar Horizon. And then I got a job. Something to do with a thing called the VAX-11/750….


    2. I would say the obvious that Zubrin had large effect on shaping where we at. Though one might not like where we at.
      Zubrin knew enough about NASA to know we got to do something different.
      Or he shook the box. Though you could say he was a critic of NASA, he helped NASA, probably more than anyone else.
      Though it still is a train wreck:)
      I think we got religion involved in this. And he made a Mars cult.

      1. It’s hard to estimate the cultural influence of someone like Zubrin, though it’s certainly larger than mine, if not enormously so. I am arguably to blame for the existence of the Asteroid Retrieval Mission, and therefore at least partly to blame for the existence of Gateway. I agree with you about the Mars Cult. However, I believe Zubrin’s most important and lasting impact hasn’t happened yet, and will prove to be the nuclear salt-water rocket and the magnetic sail. I thought these were so important and potentially trascendent that I based my novel “Alpha Centauri” on them, hoping to cement the ideas as an SF trope that would carry it forward into the future.

    3. Zubrin has the luxury of being able to be creative without consequences but he has his formula that everything fits into. It doesn’t matter what happens in the future, he will always have a we could have/can do this other thing instead and it would be so easy.

      He is a great cheerleader.

  6. Rand, this is tangential to the discussion, but why are we talking about beaming power from orbit to the surface?
    Shouldn’t we be doing it the other way around?
    I have a couple of theories, backed by very little.
    1: Transmitters are always heavier and more power-hungry than receivers.
    2: Power can be had in the upper midwest section of the U.S for around 12 cents/kwh.
    Instead of lofting fragile, massive, and exotic systems into orbit at around $2700.00/Kg to harness solar power, why not beam power to orbit?
    1: On-orbit microwave receivers would be on the order of a few meters square to a few hundred.
    2: No sheilding would be necessary.
    3: Much less total cost for a workable system. (A LOT less.)
    4: Less mass to lift to orbit.
    5: When fusion is harnessed, this will get very cheap.
    All my uninformed opinion. Feel free to correct my errors. Thanks.

    1. We might beam power to the Moon, if Moon has mineable water.
      Later, we might beam power to the Moon, if Moon has no mineable water.
      Or if the Moon has mineable lunar water, we mine the Moon, sooner.
      But once we mine the Moon and we start making say, Steel, and steel
      become cheaper and making everything on Moon is cheaper, than space will beam, energy to Earth.
      BUT by that time, Earth could have less industry because everything is made in space. And skateboards or cars could be dropped from space to a parking lot. Though maybe a major thing dropped from space could be ocean settlements. And you don’t use cars in ocean settlements, but you could use skateboards in ocean settlements.

      And it’s not Moon or Mars. If something happens on Moon, it leads to something happening on Mars [and/or Venus and Mercury]. It said the Moon is gateway to solar system. BUT if one gets settlement on Mars, it same thing, get stuff happening Moon {and/or Venus and Mercury}.
      The question is which do explore first. The Moon is easiest and we going to determine if the Moon has minable lunar water. Then Mars. What also matters with Mars, is does it have mineable water- mineable Mars water is required for Mars settlements. But there is also other factors, such is can humans live on world with 1/3 the gravity as Earth [and other factors, also]
      Lunar water has nothing to do with lunar settlements, lunar water could take more 50 years mining lunar water, to get lunar water cheap enough for human settlements. But lunar water can quite expensive and support tourism and lunar hotels. The moon is close, we don’t need to live there, to work or play on the Moon.
      And main thing about lunar rocket fuel making, is starts water market in space. Or one could sell 100,000 tons of water gotten from some space rock.
      There no market now, for it.

      1. Btw, I would say, Venus orbit is requirement for Mars settlements.
        Venus orbit, can allow twice as much traffic per year, going from Mars to Earth, and Earth to Mars.
        Plus Venus orbit can be export market for cheap Mars water, if it’s found on Mars. If not, then Moon will need to export to Venus orbit until such time, water can gotten from elsewhere in the solar system {assuming lunar water is mineable}.

    2. There is not currently that much demand for power in space, and when there is, it will be easier to gather it in space than depending on the crazy environmentalists on the planet for it. I don’t know how to answer that question without doing an analysis in which I have no interest in doing. The costs of doing things in space are about to come down dramatically, including the cost of building solar-power satellites.

      1. No sure I agree with this. Infrastructure to build in Space vs cost of infrastructure to build on Earth.
        Remember not everything ground based has to be built in the USA. In fact it might be advantageous to build further South. Building on the ground to reduce complexity in Space is generally a win. I cite Musk’s remarks about Stage 0 and moving recovery to the pad tower.

        1. How about hyloop disguised as wind farm for Hawaii?
          So starting around 135 W and Tropic of Cancer, head in general direction of Hawaii to 15 degree N and 150 W,
          then go toward due south to Equator.
          It seems only thing that really survives sea water is titianium.
          Encase concrete within titianium to make hyperloop 20 meter below the waterline. And every 500 meter, attach wind mill to it.
          Have thousands of wind mills. Transmit their power when closer to Hawaii and then have hundreds more when turn due south.
          “Currently, wind turbines are spaced depending upon the diameter of the rotor; standard turbines have rotor diameters of around 300ft.
          Traditionally, wind turbines are 7 times this distance apart.
          However, results from recent studies state that doubling the distance would prove the turbines to be much more cost-effective.”

          seven times 300′ is 2100 feet, doubling is 4200 feet [1280 meter}. So guess have less of them, so have one every km.

          How many ocean wind mills exist in the world in 2021?
          No one totaled them for me, but wiki list looks like many thousands.
          But something like this would biggest in world.
          And would be part of the road South

Comments are closed.