13 thoughts on “Tomorrow’s Mars Hearing”

  1. The topic is humans to Mars. It didn’t saying anything about live or dead. SLS with the proper upper stage configuration could probably send cadavers to impact on Mars.

    On the other hand, the SLS with its LOX/LH configuration is too much of a producer of water vapor at high altitudes in the atmosphere and hence to be launched in the numbers required to start a Mars colony would be a significant driver of climate change because of it being a significant source of GHG emissions and should be rejected on that basis alone….*

    Dave

    *smirk…

  2. One day I may try to summarize some of the Mars Societies collection of papers which includes some good stuff mixed in with a lot of crap. While there is a limit to planning we need to consider as many risks and mitigations as we can w/o being paralyzed by them.

    I don’t believe any plan will get all things right. The only safe strategy is to presupply such an over abundance; which will include a lot of the wrong stuff so that contingencies are covered. I estimate it will take about ten years of presupply to just one site before sending any humans. Musk seems to think MCT (I’m sticking with that acronym for now) has the capacity to bring enough supplies with a limited crew. If people die because of miscalculation that would teach the wrong lessons.

    1. I estimate it will take about ten years of presupply to just one site before sending any humans.

      Why would it take that long? I see four years myself (assuming that presupply includes some automated ISRU like methane production). First, launch all the presupply the outpost will need. It lands on Mars almost two years later (assuming Hohmann transfer orbits, not anything fancy with propulsion). If there are problems with anything significant (like too many failed landings or methane processing fails to work), then you can try again with a two or more year delay.

      But if it works, then you let the automated ISRU work for a couple of years to verify it’s functional and then launch people. That’s about all the time you need for a successful deployment.

      If you’re not doing anything other than dropping supplies, then you don’t need even that. Just verify your presupply dropped successfully and within landing window tolerances and then you’re good to go.

      1. To answer Dave, I consider return an entirely separate issue.

        Karl,

        I’m considering ISRU just for colony use with methane, water and power being just the basics. Although they can make UV protected plastic ISRU, I believe they should be presupplied with enough for about ten of Zubrin’s 50 meter hobby farms which should fully feed about 3 dozen (with only one dz. crew the first 26 months.) 2kg per day per person of emergency backup food should be available if food production has any problems which should be topped off every window until food production is deemed more than a safe rate.

        I assume a single lander can get 2mt to the surface of mars. MCT is supposed to do much greater than that, but even with Musk announcement next week I don’t think it can be added to the critical path yet.

        I also think presupply should include tools and equipment even though anything made from iron should be relatively trivial on mars assuming enough power to melt iron oxide. A machinist with a starter set of tools can make any other tool they need (including lathes, presses, mills, extruders, etc.) progressively scaling up. Mud and iron scale very well.

        They talk about the MCT being 100 crew and 100mt, but just consumables in transit would be 2mt per crew and another mt to the surface. Water recycling probably allows one mt less per crew.

        They also need not quite so heavy (1 mt ea.) equipment. 2 tractor for landscaping at a minimum. Plus things like augers, although those would be easy to make if they get their machine shop operational.

        Probably the main reason for ten years is so somebody has time to point out… “what about… which seems to have been forgotten?”

        We need to really err on over supply which I can’t stress enough. Whatever power requirements we think they need we should triple.

        If we send too much we can send less with later colonists but then we will know from experience.

    2. Would that contingency include an emergency return scenario using pre-supplied fuel stocks in case in-situ refueling fails because of some unforeseeable reason or catastrophe?

      That would seem at least possible if the initial number of colonists is small. And if not needed then that’s because in-situ has already boot-strapped and more colonists can now be accommodated.

  3. How would you test the success of automated ISRU? Just curious about plausible test scenarios. Always willing to learn new things…

    1. You test the products ? Like, if you are making methane, fire a rocket with it. A rocket that goes to orbit and comes back down.
      Or if you are making bricks, build a structure, and stick a dosimeter inside.

    2. A pressure gauge on the tank and something to detect the presence of CH4? At worst you could vent some and ignite it to see if it burns.
      The oil and gas industry should have something usable.

  4. If I were Chris Cadbury, I’d be lobbying Congress to get a gravity lab in orbit, like as soon as possible. The only acceptable sooner than possible scenario would be having them fund it yesterday.

  5. David Spain wrote:
    “If I were Chris Cadbury…”

    Carbury. Egads, chocolate starved, Freudian fingers! Sorry…

  6. I still have weird ISRU thoughts.

    1) Gather an acre of ‘soil’.
    2) Separate everything ferromagnetic out with an electromagnet.
    3) Separate both piles by conductivity with an -AC- electromagnet.
    Bonus points if performed as sorts across a spectrum.

    So far, the vital ‘must ship’ gear is energy and wire. I’m quite curious what the makeup of the piles would be. Next up would be separating by particle size andor density via a fluidized column of nitrogen or cyclonic separator. Recover the nitrogen.

    Now. Are any of these piles something worth either electrolyzing or directly smelting for use? Even getting to ‘pot metal’ that can make fairly crude pipes and wires leads to dramatic reductions in what needs shipping.

    Separation processes for ore that make absolutely no sense for terrestrial mining would seem much more useful if you’re stuck into a specific spot for some other resource. Nothing here is half as fancy as attempting CVD solar cell growth. Skip all that, make pipes for heat cycle power. Use a trench as your “cooling tower” and smooth rock as the solar concentrators….

    1. …ore that make absolutely no sense for terrestrial mining would seem much more useful…

      That’s martian thinking. Thomas Sowell would point out the same thing.

  7. That list is like a who’s who on SLS. They could at least have ONE outsider. Unless the NASA guy is the outsider. Oh wait he’s the moderator. So much for that.

    Like the folks here said any mission to Mars is going to require precursor robotic missions to build supply depots on Mars. I don’t know where to begin with the reasons why SLS/Orion are a bad idea. I’ll try. Regarding SLS:
    – crappy 2nd stage from Delta IV, which nerfs the payload, making the whole exercise of the “heavy rocket” pointless. why even waste time and resources on this thing? to do a Potemkin launch?
    – cancelling the J-2X which means the decent 2nd stage which could potentially make the rocket viable will probably never happen. time wasted developing J-2X, an engine with about the same power as the Vulcain 2 engine on Ariane 5 srsly, could have been used instead on RL-60 which could have been reused in the EELVs and other rockets.
    – segmented solids. boom.
    – RS-25 engine wasn’t designed to be expendable and any idea to use it in an expendable is nonsense.

    If they redesigned SLS to use LOX/Hydrocarbon in the first stage and made a proper second stage from the start maybe it would be a half decent rocket. It would probably still be too expensive but at least it would make sense from a design perspective.

    Regarding Orion:
    – the Orion capsule is overweight. The whole idea for it to support a large mission duration never made sense IMO. IMO the capsule is only necessary to go to/from orbit and all the transits should be made with a separate vehicle. So anything with more mission duration than a Gemini is pointless.
    – a case could be made for integrating the LAS with the Orion, like in Dragon V2.0, so that it would support soft touchdowns and possibly be reused as a Mars/Lunar lander vehicle with little modification.

    Anyway that would be if we wanted SLS to succeed as a vehicle which does not seem to be the case even for those invested in it…

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