[HN Gopher] Powering the lunar base, version 2
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       Powering the lunar base, version 2
        
       Author : 6177c40f
       Score  : 27 points
       Date   : 2022-12-31 19:24 UTC (3 hours ago)
        
 (HTM) web link (caseyhandmer.wordpress.com)
 (TXT) w3m dump (caseyhandmer.wordpress.com)
        
       | Nomentatus wrote:
       | Good but it should probably be mentioned that solar power
       | production and transmission from geostationary orbit (where the
       | sunlight is nearly constant) would work better and have the same
       | positional advantage. Costs have to be considered, of course.
       | 
       | I still kinda like the idea of dropping a few nukes on crater
       | rims at one of the poles to reduce the height necessary to get to
       | perpetual sunlight though.
        
       | bob1029 wrote:
       | How infeasible would it be to deploy an HVDC cable that actually
       | connects opposite sides of the moon and sidesteps most of the
       | storage issue? The longest one on earth is 2500km so it seems
       | within the realm.
       | 
       | You could hypothetically split the conductors east/west,
       | eliminating the need for most insulation. Conductors could
       | potentially be deployed from space and stitched together with
       | robots or something.
        
         | yyyk wrote:
         | Just about every solution you can think of is _feasible_ with
         | enough engineering effort. We need to think about what we want
         | to optimize.
         | 
         | We need a solution which involves a logistical tail to Earth as
         | tiny as we can, being very light on the mission [ = don't cost
         | much weight/fuel ], and dealing as little as possible with
         | lunar, and in general non-terrestrial, surfaces [ = less
         | uncertainty, easier to fix] . Your suggestion fails the last
         | two, and probably the first if we ever need to replace the
         | cable (unless someone does come up with those ultra-special
         | robots half of these proposals suggest).
         | 
         | These considerations strongly lean towards external power
         | supply solutions. I hadn't considered the variant the article
         | suggested. Neat, but I suspect it's politically infeasible -
         | all nations on Earth will demand a vote, and just look at
         | climate negotiations to see how long this takes and how
         | expensive this will get.
         | 
         | IMHO, the obvious solution given our tech level involves
         | geostationary satellites, requires no tech beyond our current
         | capabilities, covers 100% of the surface and involves
         | relatively little burden on the mission itself or dealing with
         | non-terrestrial surfaces. If we think anything is at risk of
         | going wrong, we can just launch more satellites.
        
         | WalterBright wrote:
         | The weight of it would be fantastic.
        
         | vlovich123 wrote:
         | The temperature on the dark side of the moon is -130 degrees
         | Celsius. The hottest super conductor we've build is ~-140
         | degrees Celsius which isn't too far away. I wonder if you can
         | use HVDC to transfer the energy from the light side to the dark
         | side over a shorter distance and then use super conductors to
         | transfer it "for free" all over the dark side...
        
       | [deleted]
        
       | nynx wrote:
       | Apologies to Casey if this was in the article and I missed it,
       | but what about nuclear power?
        
         | WalterBright wrote:
         | It was in the article.
        
       | [deleted]
        
       | clort wrote:
       | Well, in The Moon is a Harsh Mistress, they had a bit of a
       | revolution on the moon and started throwing rocks. Having the
       | power generators situated on earth would keep that scenario at
       | bay.
        
         | m4rtink wrote:
         | Still, a good space navy & sufficient sensor coverage is the
         | only real mitigation against people playing with KEWs.
         | 
         | Still I wonder how dangerous a mass driver launched rock from
         | the Moon is as long as the mass driver is originally configured
         | for cargo launch, so "just" a few km/s.
         | 
         | Still could do quite a bit of damage if it hits something but
         | if it does not do any.manuevers &could be detected, then there
         | should be ~days for arranging something to collide with it and
         | turn it to plasma or dust.
         | 
         | But I guess if they could spam it & be creative with the
         | resulting trajectories. Still the mass driver is fixed on the
         | Moon surface, so it might not survive for long until it is
         | itself hit by something in retaliation.
        
       | choeger wrote:
       | Come to think of it, the tidally locked orbit kind of makes such
       | a supply seem obvious, doesn't it? I mean it's like a big fat
       | "send power here" sign.
        
         | idlewords wrote:
         | Too bad it's not also in geosynchronous orbit, or we could just
         | use an extension cord.
        
       | gigel82 wrote:
       | I'm not an expert or anything, but is this making the assumption
       | that there is 0 loss? You put 1Kw into a microwave transmitter on
       | earth and expect to get 1Kw out of the receiver on the moon?
       | 
       | That's preposterous - I would be surprised if you get more than
       | 5% of the power considering the losses in the transmitter,
       | receiver (and related circuitry), not to mention the atmosphere
       | itself plus whatever little bits get in the way (like, I don't
       | know, the thousands of Starlink satellites and other space junk).
        
         | georgeoliver wrote:
         | I think the assumption is that Earth power is much cheaper than
         | lunar, so the inefficiency doesn't matter.
        
       | rippercushions wrote:
       | > _Current space hardware development costs range from $100,000
       | /kg for basic, boring LEO hardware up to >$1m/kg for deep space
       | robots such as the Mars Science Laboratory rover. A 50 T lunar
       | power system would then cost between $5b and $50b_
       | 
       | This assumption seems highly dubious. Nearly all of that 50T will
       | be solar panels and batteries that only need to be designed once,
       | meaning the development costs will scale sub-linearly.
        
       | SoftTalker wrote:
       | This is one of those late-night-dorm-conversation topics that is
       | fun but pretty much hypothetical. We will not have any bases on
       | the moon for a long, long time. We can't even manage powering our
       | society here on earth.
        
         | WalterBright wrote:
         | > We can't even manage powering our society here on earth.
         | 
         | Those are political problems, not engineering ones.
        
         | Dylan16807 wrote:
         | > We can't even manage powering our society here on earth.
         | 
         | It's orders of magnitude less power so that doesn't matter.
        
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       (page generated 2022-12-31 23:00 UTC)