27 thoughts on “Elon And Mars”

  1. I do fear that Mar’s gravity might be too low for a proper human colony. But I figure it would be due to bone loss not gestation problems.

  2. Not everyone living at Mars has to stay on surface. Mars has two small moons which fairly near to Mars. It’s easier to get to Mars orbit from Mars surface. Transport across Mars surface would suborbital travel. Going 1/2 way across the planet with suborbital travel takes longer than compared to Earth and one might do suborbital travel by going to orbit, dock at station and then leave station to get to a surface destination.
    Or for every 1000 people living on Mars surface there could be couple artificial gravity space stations in Mars orbit.
    Though not sure one would want 1 gee, maybe 1/2 or 3/4 gee.

    One could even use space stations as part of Mars Exploration- I would not use space station instead of landing on Mars surface, but rather I have both space station and bases on Mars surface.

    1. Or for every 1000 people living on Mars surface there could be couple artificial gravity space stations in Mars orbit.
      Though not sure one would want 1 gee, maybe 1/2 or 3/4 gee.

      Who knows but that capability would be good for lunar operations and also help enable trips to the asteroid belt, Jupiter, and Saturn. Mars and the Moon are both great destinations but the bulk of the resources are further out.

    1. I’ve always liked Hellas Planitia myself. Lots of reasons to favor it.


      Lowest elevation on Mars. That combined with its location in Southern Hemisphere means Hellas during summer has the highest air pressure at Mars, as the larger Southern icecap evaporates and increases the planetary atmosphere.

      That higher pressure is useful for landing a spacecraft, as well as ISRU exploitation of the atmosphere. (And that’s just a couple of the many reasons Hellas might be a good destination)

      Of course the best places for exploiting Martian resources are the polar regions. Lots of surface ice is a good thing. Burrowing into polar glaciers might be the easiest way to craft a human colony on Mars.

      1. A polar base would have to rely on nuclear. At 42°S, would the same apply to Hellas during winter?

        1. Hellas is BIG. The interesting NW corner of the crater which is really deep is only about 33 degrees South.

          As for solar vs nuclear power, that gets real tricky. NASA pretty much assumes nuclear power no matter where you land on Mars. But lets look at that polar situation.

          Geoffrey Landis made a very interesting proposal which touted the advantage of surface solar power at a polar base during the summer.


          1. Thanks for the link to that interesting article. While it does address summer-only temporary mission to the poles, much of what it says could apply to a more permanent base which hunkers down to winter over with the help of a few small nuclear powered generators. I suppose that a less extreme seasonal approach at Hellas might work where large solar power fields would allow high propellant production rates during the summer with their reduced winter output still sufficient to sustain the base.

            Still, I’m intrigued but that 2013 Geomorphology paper.

          2. For solar on Mars, solar power satellites are a tempting option. The rectenna receiver would have a much lower area density than solar panels. But that advantage only works for a system above a certain scale. And as I hear it, a stationary orbit over Mars has a problem being perturbed by Phobos.

    2. A clue to what NASA thinks is important are the locations where high resolution photos have been taken. BTB always has those nifty pics for us to look at with all the red being where the hi-res photos are from. It is a little surprising that more of the surface hasn’t been surveyed like this.

    3. Large amount of fossil ice possibly suggests finding ground water at depth.

      If find a large amount ground water, it easy to mine and is sort of harvesting geothermal energy on Mars- or ice requires a lot of energy to melt.
      In terms exploration, you can afford the high cost of ice mining as it’s compared to cost of water that is thousands of dollars per kg, or water at cost of mining at $500 per kg is a cost savings.
      And in terms of beginning exploration, I could favor idea of extracting water from Mars air- or a costly way to get water. Though that is not a way to get water for settlement purposes.

      So having base in region having of lots of fossil ice and having possibility of finding ground water seems like favorable site location.

      And such a base might start with extracting water from air and then once base gets more established transitioning to mining ice for water, and with a longer term goal of searching ground water which could allow extracting large amounts [billions of tonnes] of water at a low cost of, say, $1 per kg, which would an asset for future human settlements.

  3. Attendees are being asked to not publicize the workshop or their attendance.

    Is this because it will be a lot of woo woo that will invite derision from normal people?

    I wonder if the topic of ability to gestate in partial gravity will be a topic?

    There are a lot of human factors that we don’t/won’t know anything about. I’m partial to a variable gravity station to investigate some of these but just going has its own appeal too. Of course, we could do both. It doesn’t have to be one or the other. It would be very tragic to spend trillions and trillions of dollars and decades on setting up shop on Mars only to find out it is a horrible place to live because of the effects on the human body.

    We probably don’t even need to worry about it because the environmentalists are going to prevent humans on Mars anyway.

    1. The good news is, if BFR works out, it won’t cost trillions to go, and if Mars is a bust for anything longer than a 3-year mission, BFR will get you to Ceres just as easily.

      1. If you get BFR operational, there should be sufficient lifting capability to get a PuFF prototype to orbit. Then you have the potential to shorten transit times beyond what even NTP can offer.

          1. Pulsed Fusion-Fission. Dr. Adams at Marshall’s Advanced Concepts Office is developing the concept.

      2. The Moon will always be cheaper to land people on than Mars.
        Mercury is easier to land people on then Ceres.

        Mercury and Moon might have minable water.
        The poles of both the Moon and Mercury are most desirable locations- both could have solar power grid network which provides solar energy on a constant basis. And the thermal environment can be benign and/or controllable. Level surfaces are always cold/cool and vertical structure/surface can be hot.

        If Moon and Mercury is cheap to get to, then one get cheaper electrical power. And can get cheap solar thermal energy.
        If cheap enough one get unlimited oxygen from their rocky surface- or even if there is not minable water, one make rocket fuel- get oxygen from rock and get Hydrogen which implanted in in surface regolith.
        If you buy rocket fuel at lunar or Mercury surface, both become viable places to go to. Both have a pretty good vacuum and fairly good vacuum environment are made on Earth in order to manufacture things.
        Without considering making rocket fuel on Moon and/or Mercury if there is cheap enough rocket fuel at high earth orbit- this makes the Moon and Mercury viable destinations.
        So lunar water mining main value is making rocket fuel in high Earth orbit, cheap- it allows you to go to Moon or anywhere else.
        And it can shipped to LEO and make it easier to leave Earth or even travel from point to point upon Earth.

        And the ultimate goal of going to anywhere- Mars, etc would be getting to the point of making electrical power cheap enough at high earth orbits. If electrical power in GEO is cheap enough then one transmit it to Earth surface.
        Or we get SPS when their is enough markets in Space.
        Our global satellite market is about 250 billion dollar per year, if it could grow to say 10 trillion dollars per year, we probably get SPS, but it only growing at about 5% per year, so that market by itself would take awhile. A global satellite market plus people living on Mars probably require less than 10 trillion dollar market if including them both.
        But having just a Mars settlements is unlikely and quite silly- or silly as imagining Earth satellite market could grow to 10 trillion without something else happening- I think before the global satellite market could grow to 1 trillion per year, other things going to happen. Other things include suborbital travel.
        A lunar water mining and rocket fuel making business on the Moon is about 20 billion dollar industry which enable a 200 billion lunar market- a decade of doing that is unlikely give Earth SPS. It’s more likely to first give Mars SPS. Mars settlements probably more than happy to get electrical power at $1 per kw hour and Earthlings have cheaper electrical power

        1. Mercury is not easy to get to at all. To reach the surface of Mercury from the Earth requires 23.5 km/s of delta vee. From Earth to the surface of Ceres is 17.2 km/s of delta vee. That’s an enormous difference.

          1. “Ed Minchau
            August 7, 2018 At 10:04 AM
            Mercury is not easy to get to at all. To reach the surface of Mercury from the Earth requires 23.5 km/s of delta vee. From Earth to the surface of Ceres is 17.2 km/s of delta vee. That’s an enormous difference.”

            If we assume you use that amount of rocket delta-v, you will get there in 105 days and if want get to Mars in 105 days, one might determine it require more rocket delta-v- than 23.5 km/s and is certainly the case if you want to get to Ceres in 105 days.
            If you don’t care about the time it takes and use gravity assist, Mercury Messenger use a lot less rocket delta-v to reach Mercury orbit.

            Though I have in the past mentioned my crazy ideas of how to get to Mars in 3 to 4 months [ and using much less than 23.5 km/s].
            So, around 8 km/sec if starting from Earth high orbit.
            I think getting to Mars in less than 4 month is something NASA should plan on. And I think it’s possible to get to Mars in 2 months- using chemical rockets- and needless to say, using a non hohmann transfer.

            I think NASA should plan on it, because NASA is bureaucracy and it will worry about radiation levels of it’s employees.
            Mercury better in terms of GCR radiation than going to Mars- even if talking same time periods.
            Of course with sending non human stuff, one sends things using hohmann transfers [cheapest way in terms of delta-v to send non living stuff to Mars].
            Other than radiation, a fast transit to Mars requires less mass in terms of life support and less physical damage form micro gravity effects- and better for crew morale- and I think 3 crew would do ok with a shorter travel time. Or some think 6 crew better because of the long duration of flighttime

          2. Sure, you could get anywhere faster, using for instance a brachistochrone trajectory. But that is a lot more delta vee. The number I gave was for the Hohmann transfer.

          3. –Ed Minchau
            August 8, 2018 At 3:12 PM
            Sure, you could get anywhere faster, using for instance a brachistochrone trajectory. But that is a lot more delta vee. The number I gave was for the Hohmann transfer.–

            I wasn’t familiar with brachistochrone trajectory. So I googled it:
            “What exactly is a Brachistochrone anyway?

            A Hohmann orbit is the maximum transit time / minimum deltaV mission. Weak spacecraft use this because they do not have a lot of deltaV. …”

            It’s not a good definite, but I like how they defined Hohmann- roughly speaking it is maximum transit time and minimum delta-v.

            Mercury not easy to get to due to the planet’s orbital inclination, Mercury distance from the Sun [or 57.9 million km from sun] is quite easy to get to and requires least amount of time with hohmann transfer as compared any other distance that a object/planet is from the sun.
            So if Mercury had object at it’s L-4 or 5 [or L-3] which orbited the sun with same year as Mercury and was at the solar plane, it would be less delta-v to get to it as compared to needing to change your inclination to orbit or land on Mercury.
            But it seems to me the inclination of Mercury is not much problem in terms leaving Mercury.
            Leaving Mercury allows fastest transit time with hohman transfer to any planet compared any planet to any other planet.

            And it’s the different inclination of Earth’s quasi moons which makes it hard to get to them but likewise from this these quasi moon is seems to me, that getting to Earth should not be much problem due this difference of inclination.

            Anyhow, brachistochrone trajectory does not seem like it’s term which is useful, though it’s not a lot different than using the term of a non-hohmann transfer trajectory. Though it useful in sense of specifically expressing the idea of shortest distance traveled, which what is the main aspect I am referring to by using the term “non-hohmann”.

  4. Depot or robotic space station

    Whatever you want to call it, you need them to commercially mine lunar water.
    And need them for human Mars exploration.
    And NASA should build a depot or robotic space station to transfer LOX at a LEO orbit. And use it for robotic and later manned missions to the Moon.
    The robotic space station
    …. Commercial robotic systems in Earth orbit will appear in the near future. One of the first will be the Robotic Servicing of Geosynchronous Satellites (RSGS) servicer, a joint project of DARPA and SSL, a leading manufacturer of GEO satellites. Working toward a launch date of 2021, RSGS is designed to fulfil several specific capabilities:

    Automated docking to a customer spacecraft’s launch adapter
    Close inspection of external customer features
    Mechanical manipulation, for missions such as correcting deployment anomalies
    Attachment of modules with new capabilities to the exterior of customer satellites
    Refueling through the customer satellite’s propellant fill and drain valves
    Repositioning a customer satellite using the servicer’s thrusters

  5. How about this for a mars colony: Elon sends up a Boring tunnel maker and digs a hole 100 km straight down. Normal atmospheric pressure given by gravity!

    Perhaps that is why the Boring company is at SpaceX headquarters!

    1. Well Mars pressure is 100,000 feet above earth or about 33 km, and 100 km down would give 1 atm.

      Of course one might hit a Mars water table.
      Earth is something like 25 C per km, what is Mars?
      Say it’s 10 K per km- so it be warm down 100 km also.

      One thing which is fairly certain, it would one most important exploration project to ever be done.

  6. –Ed Minchau
    August 7, 2018 At 10:04 AM
    Mercury is not easy to get to at all. To reach the surface of Mercury from the Earth requires 23.5 km/s of delta vee. From Earth to the surface of Ceres is 17.2 km/s of delta vee. That’s an enormous difference.–
    I been thinking about it and I want to give it another go.
    Going from Earth surface to Mercury surface would be basically impossible with chemical rocket. Though from Earth surface to Ceres surface would also be rather hard to do, assuming your numbers are correct.
    And sending humans with their needed life support mass would probably impossible for both.
    With a single rocket we went to the Moon with crew and returned them safely to Earth- and that is close to impossible to do in terms of landing Mars and return crew to earth safely with a single rocket launch.
    We have Zurbin plan of sending hydrogen to mars surface and making rocket fuel for the return to Earth. But there are problems landing large payloads on Mars surface if you are expecting to use a parachute.
    Mars is commonly said to cost 6 km/sec of delta-v- and that’s from LEO to low Mars orbit, ie:
    Synodic Period: 2.1354 Years
    Trip Time: 0.7087 Years
    Perihelion DV: 2.9448 km/sec
    Aphelion DV: 2.6490 km/sec
    Total DV: 5.5937 km/sec
    And look at LEO to Mercury orbit
    which is Total DV: 17.1452 km/sec
    And btw, it’s Synodic Period: 0.3172 Years

    I would think it’s better to stage for Mars trip from high earth orbit rather the LEO.

    Hop discusses it:
    Briefly, he says from capture orbits to capture orbits earth to Mars is about 1.2 km/sec. But his list only includes planets with atmospheres- as he likes idea of using them.
    I would think it might ok to just go from capture point to surface directly- and lacking atmosphere one could do that with Mercury.
    Or with crew I would think one could want to get them to surface fairly quickly.
    And like Hop, I am fan of using depots to refuel.

    And do same with going to Mercury- would going from Earth high orbit, to a capture orbit at Mercury which I tend to pick as ending up at Mercury L-2.

    Before you sending crew, one would establish a refueling depot in Mercury L-2. And if not sending crew, a way to refuel at L-2 for robotic craft landing on Mercury surface.

Comments are closed.