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Thread: Perseverance Mars Lander

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    I was looking for a meme that closely resembled how I thought about all this Mars stuff...




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    ...they won't be able to fire guns indoors? That would render the US sourced P.D. useless.
    However a bullet shot outside from a normal 0.22 calibre rifle aimed up at 30-45˚ angle could reach well over 100km range and easily hit a dome and pierce it or other random targets.
    Last edited by Uncle Fester; 24-02-21 at 10:38 PM.
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    very interesting what can happen as normal in our lives but on the moon or mars the differences become almost impossible what we know involves the atmosphere and gravity and its hard to get ones head around that when its not there , I wonder what effect it would have on the hidden things like emotions and ethics ???
    reject religion for the planets safety

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    Quote Originally Posted by hinekadon View Post
    very interesting what can happen as normal in our lives but on the moon or mars the differences become almost impossible what we know involves the atmosphere and gravity and its hard to get ones head around that when its not there , I wonder what effect it would have on the hidden things like emotions and ethics ???

    Everything will be about staying alive and surviving and that will only work when everybody works perfectly together.
    So the ethic is: You behave properly or we all die.
    This might eventually lead to a kind dictatorship but initially the colony is a team of flexible and highly skilled people who all know what to do without being commanded too much.
    The main emotion will be a feeling of success that we lived another day and maybe missing something from home like fresh air, water and good food.
    As everyday is an achievement, people should stay in a reasonably good mood.
    I know this feeling when I am 'roughing it' in the bush.
    I feel quite satisfied with achieving basic things that we normally take for granted.
    And some of these things are going to be an incredible achievement on Mars.


    Of course a lot will change dramatically when the colonists can start to procreate.
    Last edited by Uncle Fester; 25-02-21 at 09:34 PM.
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    Quote Originally Posted by Uncle Fester View Post
    Dry ice is quite soft, I can crumble it with my hands.
    Earth dry ice. Not Mars dry ice. There's just a slight difference there.

    BTW I think it is time the stop sending these awkward rovers and just send a bunch of Boston Dynamics "Spots".
    You forgot - power hungry. The advantage of a rover is power efficiency.
    But in general, spot offers no advantages for Mars exploration.

    [qoute]
    Unlike what Trash claims, it sure got there but the lander crashed due to an engine failure in the last seconds before touchdown.
    [/quote]
    I didn't say it was impossible or it had not happened. It's just harder to land there and not because it has anything to do with landing sites.
    It has everything to do with orbital mechanics and the energy required to just get to the landing phase.

    If you approach mars equatorially, you can take advantage of Mars's orbital velocity and subtract that from your spacecraft's velocity for a fuel saving on an orbital insertion. If you try to do that in a polar orbit you do not have that saving so even the orbital approach has to be different which is another fuel consideration.
    Of course you can go for a direct entry which is common, again it requires the right approach and burn. Once in the atmosphere everything is the same except for the approach speeds and angle but those are still able to be factored in. The cost is really about the fuel. Small lander it's not a lot of difference, but a big lander the cost goes up in multiples. At the end of the day they are already picking the low hanging fruit first for life anyway.

    Quote Originally Posted by lsemmens View Post
    There must be an atmosphere on the moon,
    There is an atmosphere but not a lot of it.
    I can't remember the composition. Hydrogen and Helium make up most of it. Pressure is about 2e-12 torr which is what I call a "damn hard vacuum"
    My pumps go down to 1e-7. Which "suck a balling ball through 10ft of garden hose" kind a vacuum.

    Quote Originally Posted by Uncle Fester View Post
    However a bullet shot outside from a normal 0.22 calibre rifle aimed up at 30-45˚ angle could reach well over 100km range and easily hit a dome and pierce it or other random targets.
    I'm kind of surprised it's not further than that, but I suppose it's just a .22. Have you crunched some numbers to see if it is correct?

    I can't help myself, I have to crunch the numbers for fun anyway.
    .22 is about 500m/s and Mars gravity about 3.7m/s/s. which means it's 135 to apogee if shot straight up.
    s=ut+1/2at^2 == 500 - (0.5 * 3.7 * 135^2) = ~34km altitude.

    For 45 degrees we use 354m/s. which gives us 95.5 seconds to apogee at 17km and 191 seconds flight time.
    We'll ignore air friction. 191s x 354m = ~68km.

    Turns out it's less. But that is an average .22 velocity I just picked.
    Of course we can go magnum, hornet or my personal fave, wildcat

    Now did somebody say spot?
    Last edited by trash; 25-02-21 at 09:31 PM.
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    Quote Originally Posted by trash View Post

    You forgot - power hungry. The advantage of a rover is power efficiency.
    But in general, spot offers no advantages for Mars exploration.
    The rover only seems efficient because it is slow but it is also very heavy, so I will question the efficiency to work load ratio here.

    Spot's base weighs 32.5kg (on Earth), lets say 50kg with arm and gun (to fire holes in the ice )
    20 spots could do a hell of a lot more than a single rover and without having to be extremely careful before you consider even moving the rover a single meter. Pretty sure Spot can crawl out of small but unexpected deep craters that would bog or tip over the rover and losing a few spots won't really matter.

    I did say we need to drop a power pack to charge the Spots, better in nuclear form especially for polar expeditions.
    Spot (or two Spots) could also carry expansion battery packs with foldable solar panels to distant locations to increase the accessible range.
    Essentially they would become the first inhabitants and workers.

    Oh did I mention cost: 2.2Billion for the rover. Spot costs $74K, probably cheaper by the dozen. Plenty left for batteries, transceivers, mining tools, test equipment and drones.


    EDIT: just when I was thinking about contacting JPL and Boston dynamics I did a duckduckgo search and :



    I am always too late

    Happened last time when I contacted them with a suggestion to install wipers on the solar panels of the Opportunity rover, kind of like those fine brushes you use to clean vinyl records that self clean themselves when they pass over an edge.
    I was told the idea had merit but I had contacted them TOO LATE to allow for any further additions.
    Opportunity DID fail likely due to dust eventually covering the panels but it lasted way longer than expected as the wind managed to keep them clean which was unexpected at that time.
    Maybe with my wipers it could still be active today.
    Last edited by Uncle Fester; 25-02-21 at 10:53 PM.
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    interesting thread very good participants intelligent conversation well done , I wish all threads were this good
    reject religion for the planets safety

  • #28
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    Quote Originally Posted by hinekadon View Post
    interesting thread very good participants intelligent conversation well done , I wish all threads were this good
    Hey! You forgot about me! I'm not that intelligent!
    I'm out of my mind, but feel free to leave a message...

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    Thumbs up generally

    I was generalising still a quality thread in my opinion
    reject religion for the planets safety

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    Quote Originally Posted by hinekadon View Post
    I was generalising still a quality thread in my opinion
    I dunno...we started talking about Mars Exploration and ended up talking about guns......

    Then again, Perseverance IS American...
    The fact that there's a highway to hell and a stairway to heaven says a lot about the anticipated traffic flow.

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