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Thread: Mars in a decade?...

  1. #61
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    Quote Originally Posted by Apollo17 View Post
    As far as your statement "I want space to be profitable, and that means it has to be safe and predictable". That is your opinion and you are welcome to it, i guess we will have to agree to disagree.
    Sure if space becomes profitable then that's great. However i do not believe that we will ever get anywhere in space if we wait until it is 100% safe and predictable. That is just my opinion though.
    Perhaps I should have said I want "manned" spaceflight to be profitable. If you want any civilians to ever go into space then it will have to be safe and predictable. Kill all the astronauts you want, but I'm not getting into that rocket unless I can trust it. If you want to sell manned spaceflight to civilians, you have to sell the idea that they might one day be able to go or will at least be able to reap some material reward.
    Et tu BAUT? Quantum mutatus ab illo.

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    Quote Originally Posted by Ilya View Post
    Short answer -- no. There is simply nothing physical in space so valuable as to be worth bringing back to Earth. Note that the only thing which currenly IS worth bringing back (and is) are bits and bytes. When I wrote "industrialize the Moon without ever setting foot on it" I meant things like mining ice from poles and transporting it to Earth orbit for use by satellites -- mining in support of other space activities.
    Depends on how you calculate costs. The savings from not messing up our own ecosystem in pursuit or minerals might be worth more than the market rate of those minerals alone.
    Et tu BAUT? Quantum mutatus ab illo.

  3. #63
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    Quote Originally Posted by Ara Pacis View Post
    Perhaps I should have said I want "manned" spaceflight to be profitable. If you want any civilians to ever go into space then it will have to be safe and predictable. Kill all the astronauts you want, but I'm not getting into that rocket unless I can trust it. If you want to sell manned spaceflight to civilians, you have to sell the idea that they might one day be able to go or will at least be able to reap some material reward.
    Some people are working on that. I am feeling more and more confident that within 15 years we may finally have made LEO accessible enough for tourism.

  4. #64
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    Quote Originally Posted by danscope View Post
    " ....
    Yes, I know what Lunokhod was. But the delay which is acceptable in driving a slow research rover is not acceptable when driving trucks carrying tons of mined ore. Or operating mining machines. "

    Why ????
    Assume that you are driving a truck and one of your left wheels blocks. The vehicle will start turning left. Normally, after perceiving that the vehicle is turning left, the driver will immediately counter this by steering right, and, if he notices that the vehicle still does not behave normally, he will figure out that he has a problem and stop immediately. Now, if you add in a 2.6 second delay, there's a good chance that the vehicle will be off road before the driver even reacts. For added fun, assume that you are driving up the crater wall on a road like this: http://www.planetware.com/picture/tr...d-n-nor202.htm and guess what happens next.

  5. #65
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    Quote Originally Posted by Apollo17 View Post
    Mars, in a decade?..
    I wouldn't worry about Mars in a decade. It will still be much the same as it is now, out there, and we shall still be down here.

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    Hi Kamaz , Where these vehicles are going, there will be no roads. And they will be going slow.

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    Quote Originally Posted by danscope View Post
    Hi Kamaz , Where these vehicles are going, there will be no roads. And they will be going slow.
    And AI override for this sort of situation is well within current capabilities.

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    Hi, Quite agree. It's not a very complicated logic tree .

    Dan

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    Quote Originally Posted by danscope View Post
    Hi Kamaz , Where these vehicles are going, there will be no roads. And they will be going slow.
    Hi "Road" can mean different things, including "a safe path". But never mind, I see where you are coming from. But if you want an AI override, wouldn't it make more sense to make a vehicle completely autonomous, like a Mars rover?

    That aside, let's build upon the experience from the previous threads about lunar mining. A simple strip mining operation requires three machines: an excavator, a loader and a truck. (I will grant you a (semi-)autonomous truck). In the first approximation, operating an excavator or a loader means controlling the position of a bucket. A human driver essentially does that with a simple feedback control loop: if too much to the right, move to the left, and so on. Let's say that a human driver has the reaction time of 0.3 seconds, i.e. he can perform 3 loop iterations per second. If we throw in 2.6 second delay, then the loop delay is now almost 3 seconds. This still allows one to operate, of course, but the digging performance is going to be 10 times worse then with the driver located in the cabin (or within a sensible (<150ms) distance).

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    Quote Originally Posted by kamaz View Post
    Hi "Road" can mean different things, including "a safe path". But never mind, I see where you are coming from. But if you want an AI override, wouldn't it make more sense to make a vehicle completely autonomous, like a Mars rover?
    Wouldn't it be best to have a group of semi autonomous vehicles with an operator who only gets brought into the loop if the vehicles find themselves in a situation that their programming doesn't deal with? Not exactly wildly exciting for the operator but simpler than sending out a 'field service engineer'.

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    Hi K, Aren't you forgetting the processing of that "ore" . Ten tons of ' ORE ' .... to get 1 ton of Unobtanium ; that sort of thing .
    It simply would not make any sense to boost raw ore off planet and send it back here .
    The whole concept of off world mining is frought with real problems . Amoung these are severe expense .

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    Does Mars direct mean we skip low Earth orbit, and depend on fuel we can make on the surface of Mars (or one of it's moons) for the return trip? Even if we leave Earth with barely enough fuel to return, we probably want ten plus years of essential supplies, in case multiple failures mean we have to (or it is prudent) to wait for a rescue craft. One or both moons can also be a fall back option. For less than the cost of a bare bones manned mission we can land supplies at three or more locations with unmanned supply craft. Perhaps the unmanned supply craft is the first order of development. Can the Russian supply craft used for the ISS, reach Mars if it has a bigger first stage, and minor modifications? What is the probability that the manned craft will land too many kilometers from the supplies delivered in advance? Neil

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    Quote Originally Posted by neilzero View Post
    Does Mars direct mean we skip low Earth orbit, and depend on fuel we can make on the surface of Mars (or one of it's moons) for the return trip? Even if we leave Earth with barely enough fuel to return, we probably want ten plus years of essential supplies, in case multiple failures mean we have to (or it is prudent) to wait for a rescue craft. One or both moons can also be a fall back option. For less than the cost of a bare bones manned mission we can land supplies at three or more locations with unmanned supply craft. Perhaps the unmanned supply craft is the first order of development. Can the Russian supply craft used for the ISS, reach Mars if it has a bigger first stage, and minor modifications? What is the probability that the manned craft will land too many kilometers from the supplies delivered in advance? Neil
    Well from the perspective of a Mars mission you can do good science on Phobos, and possibly find water for conversion into fuel etc, and deploy a small army of robots to build the ISRU infrastructure for a manned base while being close enough to use telepresence to deal with unexpected events. In essence Phobos becomes the forward base for our 'invasion' of Mars.

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    Quote Originally Posted by danscope View Post
    Hi K, Aren't you forgetting the processing of that "ore" .
    Because processing is not relevant to my argument. Ilya has put forward a claim that space (particularly, Moon) can be industrialized solely using AI and teleoperation from Earth. I am pointing out that industrializing Moon implies mining and that the mining operations cannot be performed effectively with teleoperation. In contrast, resource processing is nothing else than chemical processing, and the chemical industry already uses automated process control on a daily basis. So, in principle, a fully automated, teleoperated factory processing lunar regolith can be put together with today's technology (if we ignore the "what if something breaks" problem). It's the extraction, loading and transport of raw materials to that factory that I see as really problematic.

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    Quote Originally Posted by neilzero View Post
    What is the probability that the manned craft will land too many kilometers from the supplies delivered in advance? Neil
    That depends on how you do the landing. But consider, that the Apollo missions from 12 on were able to make precision landing on the Moon (the error was well below 1 km) and that STS can do precision landing on the runway at KSC (in fact, landing outside the runway would end in a disaster). Recently, Soyuz TMA-11 landed 400km off-course, but that was due to an equipment failure.

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    On that note, what about the concept of setting up shop on Phobos before descending into the Martian gravity well?

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    Quote Originally Posted by Glom View Post
    On that note, what about the concept of setting up shop on Phobos before descending into the Martian gravity well?
    I brought that up about 3 posts back. It makes sense as a target worth investigating in its own right as well as a handy base for telepresence operation of ground robots building base/ISRU infrastructure in advance of a landing. Also possible that if there is water on Phobos then that could supply fuel and life support supplies.

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    Quote Originally Posted by Garrison View Post
    I brought that up about 3 posts back.
    There were simultaneity issues due to our relative speed.

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    Quote Originally Posted by Glom View Post
    There were simultaneity issues due to our relative speed.
    You're not using a carrier pigeon are you?

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    What do you think about going to Phobos with a relative velocity differential of some magnitude and ..... no chance of aerobraking ?

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    Quote Originally Posted by danscope View Post
    What do you think about going to Phobos with a relative velocity differential of some magnitude and ..... no chance of aerobraking ?
    Use the Martian atmosphere for aerobraking into an orbit round Phobos. if you can decelerate enough to enter martian orbit or to land, you can decelerate less to achieve a proper transfer orbit for a low delta-v maneuver to Phobos.
    Et tu BAUT? Quantum mutatus ab illo.

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    Quote Originally Posted by kamaz View Post
    Hi "Road" can mean different things, including "a safe path". But never mind, I see where you are coming from. But if you want an AI override, wouldn't it make more sense to make a vehicle completely autonomous, like a Mars rover?
    Not necessarily. An AI self-protection feature would be akin to reflexes on a human.

    That aside, let's build upon the experience from the previous threads about lunar mining. A simple strip mining operation requires three machines: an excavator, a loader and a truck. (I will grant you a (semi-)autonomous truck). In the first approximation, operating an excavator or a loader means controlling the position of a bucket. A human driver essentially does that with a simple feedback control loop: if too much to the right, move to the left, and so on. Let's say that a human driver has the reaction time of 0.3 seconds, i.e. he can perform 3 loop iterations per second. If we throw in 2.6 second delay, then the loop delay is now almost 3 seconds. This still allows one to operate, of course, but the digging performance is going to be 10 times worse then with the driver located in the cabin (or within a sensible (<150ms) distance).
    But is 10 times worse than actual presence, adequate?
    Et tu BAUT? Quantum mutatus ab illo.

  23. #83
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    Hi Ara Pacis ,
    Pretty good idea. You think well ! The power of parallel thinking ... indeed.
    Best regards,
    Dan

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    Quote Originally Posted by Ara Pacis View Post
    Use the Martian atmosphere for aerobraking into an orbit round Phobos. if you can decelerate enough to enter martian orbit or to land, you can decelerate less to achieve a proper transfer orbit for a low delta-v maneuver to Phobos.
    Yes, this can be done. The earth to Mars Hohmann is a hyperbola with regard to Mars, and velocity at this hyperbola's periapsis is about 5.5 km/sec. Periapsis speed for a low Mars orbit to Phobos transfer orbit is about 4.1 km/sec. So about 1.4 km/sec needs to be shed. As you say, much of this 1.4 could be done with aerobraking.

    Upon reaching Phobos orbit, another .5 km/sec would be needed to circularize the orbit and match velocities with Phobos.

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    Teleoperation is all well and good, but it would still require humans to be relatively close at hand or have the machinery operating at a very low speed. At best the communications delay is three minutes each way, at worst 22 minutes!

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    Quote Originally Posted by MikeMcc View Post
    Teleoperation is all well and good, but it would still require humans to be relatively close at hand or have the machinery operating at a very low speed. At best the communications delay is three minutes each way, at worst 22 minutes!
    You seem to be describing teleoperation of vehicles on Mars from earth.

    From earth, Lunar teleperation is 2.7 seconds. From EML1, less than .5 seconds.

    Teleoperation of Mars vehicles from Phobos or Deimos is sometimes suggested. In these cases, light lag is about .13 seconds and .04 seconds when moons enjoy line of sight with teleoperated vehicles.

    Teleoperation would also be possible from bases on the surface of the moon or Mars.

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    So... when it comes to robots, who is in a hurry ? They aren't running out of gas. And they don't need air or vacation.

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    Quote Originally Posted by Hop_David View Post
    Yes, this can be done. The earth to Mars Hohmann is a hyperbola with regard to Mars, and velocity at this hyperbola's periapsis is about 5.5 km/sec. Periapsis speed for a low Mars orbit to Phobos transfer orbit is about 4.1 km/sec. So about 1.4 km/sec needs to be shed. As you say, much of this 1.4 could be done with aerobraking.

    Upon reaching Phobos orbit, another .5 km/sec would be needed to circularize the orbit and match velocities with Phobos.
    Hopefully the Phobos-Grunt mission will answer a lot of questions about Phobos, and provide some solid data for Mars mission profiles. From what I've read Phobos has some water but no one knows how much.

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    Quote Originally Posted by Garrison View Post
    Hopefully the Phobos-Grunt mission will answer a lot of questions about Phobos, and provide some solid data for Mars mission profiles. From what I've read Phobos has some water but no one knows how much.
    I'm also hoping for a good Phobos Grunt mission.

    Recently Mars Express made some close fly bys. It looks like the findings are starting to be released. For example, see this BBC article on Phobos

    A couple of tantalizing paragraphs from the article:

    "We detected for the first time a type of mineral called phyllosilicates on the surface of Phobos, particularly in the areas northeast of Stickney, its largest impact crater," said co-author Dr Marco Giuranna, from the Italian National Institute for Astrophysics in Rome.

    These phyllosilicate rocks are thought to form in the presence of water, and have been found previously on Mars.

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    Quote Originally Posted by Hop_David View Post
    I'm also hoping for a good Phobos Grunt mission.

    Recently Mars Express made some close fly bys. It looks like the findings are starting to be released. For example, see this BBC article on Phobos

    A couple of tantalizing paragraphs from the article:
    I read that article and it just amplifies the fact that Phobos is a worthwhile target of exploration in its own right as well a potential beachhead for manned Martian exploration.

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