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To the moon on a shoestring budget

How to win Xprice100M$ with a vehicle on the moon for 100.000$
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(1). Let a hydrogen balloon carry the launcher to about 80.000 meters.

(2). The launcher is a vertical tube with about 100 ring- formed directed explosives all around it (or plain dynamite would do). The space vehicle is drop shaped construction with a hard solid backend,( the tail of the drop).

(3). The vehicle is squeezed like a bathroom soap as the explosives "in turn" go off, one after the other and synchronized with the accelerating soap/vehicle pushing mainly on the hard solid backend of the vehicle.

(4). A 20 meter tube would easily accelerate the vehicle to escape velocity, (shot through the ballon by the vertical pipe).

(5). Vehicle is accelerated to escape velocity of earth but below velocity for earth+moon, and if it is just vaguely pointed towards the moon, the moon will catch it.

(6). A wire is ejected and by electromagnetic induction (earths magnetic field) and heat radiation, it is slowing the vehicle down until it eventually crashes on the moon. It is made to withstand the crash and to bounce on the surface.

(7). When it has come to a stop a rolling robot is released.

(8). It is an inflatable robot inflated with a tiny helium pressure from a tank.

(9). Each wheel is painted black and white in such a way that the the sunwind and radiation pressure get the wheels rolling, like a Crookes radiometer.

(10). A Ball is inflated, half of it is transparent and half is silver coated. It has a filter coating reacting to the radiation pressure from the blue earth and will start to adjust itself pointing towards the earth by radiation pressure.

(11). The now directed ball will work as an approximate antenna for sending the video signal back to earth (from a small video camera.)

janpeternordin, Sep 25 2013

How does a light-mill work? http://math.ucr.edu...ill/light-mill.html
[spidermother, Sep 25 2013]

N-Prize [FlyingToaster, Sep 25 2013]

Similar idea I had for achieving high velocity projectile Explosively_20confined_20gun_20barrel
I had a similar idea a while ago, posted it originally on one of the n-prize ideas as an option for final-stage propulsion. [Custardguts, Sep 26 2013]

High velocity manhole covers http://nuclearweapo...lumbob.html#PascalB
Didn't hit Mars. Didn't escape Earth. Didn't orbit Earth. Didn't leave the atmosphere. [lurch, Sep 26 2013]

[link]






       What [FlyingToaster] said, except I find that double line-break characters work even better (just hit <enter> twice).
pertinax, Sep 25 2013
  

       Why would you inflate the robot with Helium instead of Hydrogen ?
FlyingToaster, Sep 25 2013
  

       Why would you want to go to the moon anyway ? It's a dump.
8th of 7, Sep 25 2013
  

       party planet.
FlyingToaster, Sep 25 2013
  

       Radiation pressure almost certainly won't be a large enough force to do the alignment thing, and you may be forgetting that the Moon's surface is very dusty, electrostatically dusty, and sticks to everything. The dust will interfere with any attempt to use radiation pressure.
Vernon, Sep 25 2013
  

       Hi, Thanks for the input, I have cleaned it up. I hope it is easier to read now...   

       The robot is filled with helium and the initial lift balloon; hydrogen (for maximal altitude).
janpeternordin, Sep 25 2013
  

       I have some drawings, the "antenna-balloon" is simplified in the description above, the idea was to somehow use the sun-wind to lift it (kite?) while the angle is such that the transparent part is facing earth (to prevent it from tracking the sun.) However, that would require releasing the ballon at a certain moment which I would like to avoid.
janpeternordin, Sep 25 2013
  

       The challenge I played with was to have it autonomous without electronics (except for the video camera).   

       I did most of calculations a year ago and the "soap" seems to be feasible.
janpeternordin, Sep 25 2013
  

       I would guess that radiation pressure would be enough, for a lifted balloon in a string,
janpeternordin, Sep 25 2013
  

       Judging from a Crookes radiometer.
janpeternordin, Sep 25 2013
  

       The wire's an interesting idea for a brake. So's the soap method of initial propulsion.   

       I'm a bit skeptical that you're going to accelerate or decelerate as fast as you want to without totally trashing anything inside the craft, or the craft itself.   

       Problem with high explosives is they can set each other off from shock. So your //20 meter tube// isn't going to work, far as I can tell [edit: oh wait]. And the current balloon altitude record is 53k meters.
FlyingToaster, Sep 25 2013
  

       [+] It may only cost $100k to make the final version, but R&D will likely run into the millions.
the porpoise, Sep 25 2013
  

       I don't see any problem with (2) and (8).
lurch, Sep 25 2013
  

       I'm curious about (5).   

       So, we've narrowly exceeded Earth-escape velocity - I get that part. What, though, is this "Earth+moon -escape velocity"? Presumably, you mean we're not going so fast that the moon's gravity is unable to pull us back in - but how fast that is surely depends on how close to the moon we're heading *before* we start to feel its pull.   

       If our vehicle had just barely enough velocity to escape from Earth, I'm guessing (on the basis of no maths, not even on the back of an envelope), that we'd still have to aim within a fraction of one degree of arc of a direct collision course before the moon had any chance of "catching" us. I doubt that "pointing vaguely" would do it.   

       But, by all means, do the maths and prove me wrong.
pertinax, Sep 25 2013
  

       The depth of the earth+moon gravity well is deeper than the earth-only gravity well in all directions. However, in most directions, the difference would be a helluvalot smaller than the lack of precision in this idea.   

       Beyond that, for the vast majority of that gravity well, the earth is the local minimum, the deepest spot in the gravity well. So you have to go over the ridge into the area where the moon is the local minimum; you'll then have all the potential energy necessary to get back out, unless you stopped at the top of the ridge and slowed down some more on the trip (or pash into the side of the moon, direct, incavate). Remember Apollo? "Free return path", it was called.   

       "Electromagnetic induction" doesn't work with the earth's magnetic field for slowing down in the vicinity of the Moon, because the earth's magnetic field isn't there. "Heat radiation" is an infrared herring.
lurch, Sep 25 2013
  

       A Crookes radiometer isn't driven by radiation pressure (link).
spidermother, Sep 25 2013
  

       I thought that someone around here had shown that explosions are inadequate to propel something to escape velocity. Or is it that the angle coming from the ground is wrong to achieve a stable orbit?   

       The example is usually the legendary manhole cover propelled into orbit by the early H-bomb tests.
bungston, Sep 25 2013
  

       //The example is usually the legendary manhole cover propelled into orbit by the early H-bomb tests.// That manhole cover reached escape velocity, so orbit is not a factor. It's probably on Mars by now. Putting something in actual orbit with explosives would be more difficult and expensive than just using a rocket, but there is no reason why it's impossible.
DIYMatt, Sep 25 2013
  

       // Let a hydrogen balloon carry the launcher to about 80.000 meters.//   

       As a minor point, I think 30km is about the limit for hydrogen balloons that carry useful payloads. Beyond that, the extra mass of the envelope needed starts to outweigh the lifting capacity of the gas. (I see the "53k metres" comment above, but that balloon carried only 4kg of instruments.)   

       [janpeternordin] have you seen the N-Prize?
MaxwellBuchanan, Sep 25 2013
  

       //explosions inadequate ... orbital velocity// true in that high explosives' propogation speed is a tad less than that required for escape velocity... except for the soap thing which translates as "tacking in 3 dimensions" (which I've never heard of before and is extremely cool so [+]).   

       //angle// more true except he's not trying to escape Earth's gravity, just make it as far as the Earth-Moon gravitational null point, at which time the Moon can take over, in the same manner that, if you want to just get the ball into the basket, you can toss it up in the air using a small amount of energy instead of having to kick it sidewards at a bit greater than orbital velocity.   

       No clue personally if the calcs actually work for the above.   

       <N-Prize link added>
FlyingToaster, Sep 25 2013
  

       This is quite a lovely delerium, may I join you?
Alterother, Sep 25 2013
  

       depends... wots a "delerium" ?
FlyingToaster, Sep 25 2013
  

       See [link] for similar idea I had a while ago. The mechanism I was proposing was gas pressure not "squeezing", otherwise essentially the same.   

       Be cool to see if it could actually work.   

       Not sure about the rest of the idea.   

       []
Custardguts, Sep 26 2013
  

       //wots a "delerium"//   

       I think it was one of those giant marsupial ground sloths, extinct about 20,000 years ago.
MaxwellBuchanan, Sep 26 2013
  

       //extinct about 20,000 years ago// right... in that case what's that living under my porch ?   

       "soap" - well mostly what [8/7] said in [Cg]'s idea though they aren't really the same except for the "squish stuff inwards to make other stuff pop out the end".   

       In this case the bullet needs a running start to get up to the velocity where a low-explosive deflagrant as the first explosive takes over. There is a certain amount of inherent self-correction of small errors if there's a gap between the ring (aka "tube'o'boom) and bullet.
FlyingToaster, Sep 26 2013
  

       Not quite, [FT].   

       Initial acceleration of the payload can be achieved using a recoilless mechanism like the Davis gun. That will give you initial translative velocity. The payload then passes into a region where a Lyman-Haskell system takes over, but could use radial implosion to provide longtitudinal impulse.
8th of 7, Sep 26 2013
  

       Unless you've a brace of Davy Crockett heads, I don't see how L-H is going to get you to escape velocity. Though, strict escape velocity is probably not necessary: you only need to get up to the Earth-Moon null point.
FlyingToaster, Sep 26 2013
  

       // a brace of Davy Crockett heads //   

       We only sell them by the dozen.   

       // I don't see how L-H is going to get you to escape velocity //   

       Very long barrel, lots of side chambers. Theoretically ...   

       Ok, so it went pear-shaped for Adolf and Dr. B ... but the theory is sound.
8th of 7, Sep 26 2013
  

       / I don't see any problem with (2) and (8). — lurch, Sep 25 2013 /   

       7 is cool with me. I like 7 a lot.
bungston, Sep 26 2013
  

       okay, I'm feeling better now.   

       //Theoretically// a cylinder which composition transitions smoothly from low-explosive at one end to high-explosive at the other exponentially by velocity (gotta do it that way because the tail isn't shape-variable), resulting in a smooth transfer of energy and minimal delamination of the projectile's surface.   

       Realistically, at the first mixture anomaly the wave goes pear-shaped and stays that way through the rest of the blow and you're apologizing to somebody halfway'cross the continent about their shed.   

       So, as far as I can tell, it has to be a series of wavefronts with enough of a separation mechanism to keep malformations from proliferating, ie: it can't be continuous and you need something between rings to keep the next one from being set off prematurely.   

       Which is what the idea said.   

       I will donate $10 to anybody who promises to accidentally take out an ugly public statue, parked minivan, or telecommunications satellite with great prejudice during testing/operation.   

       $20 if there's live footage.
FlyingToaster, Sep 27 2013
  

       Thanks for all the comments. I agree to the sensitivity of the moon+earth gravity well. To be robust, I'd guess, the magnetic break wire must be released somewhere between the earth and moon to slow the vehicle down enough to avoid a sling shot return to earth. It will then be much more likely to go into mooon orbit
janpeternordin, Oct 06 2013
  

       A cannon start of the flight is an excellent idea.
janpeternordin, Oct 06 2013
  

       It is true that the radiometer does not work by radiation pressure but as an effect in a near vacuum gas. That would potentially make it useful for powering the robots inflated transparent inside i.e. wheel and anything inside robot with the low pressure helium gas. I agree that it would be difficult to use it in the space vacuum i.e. on the moon. On the other hand there the sun wind probably could be used, it should have full force on the moon since it has no magnetic field.
janpeternordin, Oct 06 2013
  

       [[[this was my first posting and I must say I was impressed by the useful high quality feedback...]]]   

       crowd-sourcing? ...anyone...? :)
janpeternordin, Oct 06 2013
  

       The escape velocity is due to the high-pressure and high acceleration of explosives (compared to i.e. gun powder.), Eventhough not all of the energy will be efficinetly spent. The cargo- folded inflatable robot - could be made to withstand the enormous acceleration.   

       Yes, you need high-explosives 9 km/s +   

       "In a high explosive, the gas pressure is strong enough to destroy structures and injure and kill people. If the gas expands faster than the speed of sound, it generates a powerful shock wave. The pressure can also push pieces of solid material outward at great speed, causing them to hit people or structures with a lot of force."
janpeternordin, Oct 06 2013
  

       The solar wind would indeed be as great on the moon as in space. But (copied from Wikipedia):   

       "The [solar] wind exerts a pressure at 1 AU typically in the range of 1–6 nPa (1–6×10^-9 N/m2), although it can readily vary outside that range."   

       and:   

       "Solar radiation pressure ... perfect reflectance: F = 9.08 uN per square metre (9.08 uPa) (normal to surface)"   

       Unfortunately, you would have a very hard time orienting something passively on the moon using the sun's photon pressure directly. Solar wind or light from the Earth exert vastly less pressure again.
spidermother, Oct 06 2013
  

       // you're apologizing to somebody halfway'cross the continent about their shed //   

       Never apologize, never explain ... for a start, they're likely to take it as an admission of liability.   

       // I will donate $10 to anybody who promises to accidentally take out an ugly public statue, parked minivan, or telecommunications satellite with great prejudice during testing/operation ... $20 if there's live footage. //   

       How much will you pay for an anonymous YouTube posting ?
8th of 7, Oct 06 2013
  

       <ponders the Borg insurance racket: "wun't it be a right shame if an asteroid wuz to crash on youse nice planet there">
FlyingToaster, Oct 06 2013
  

       //A 20 meter tube would easily accelerate the vehicle to escape velocity, (shot through the ballon by the vertical pipe).//   

       //The cargo- folded inflatable robot - could be made to withstand the enormous acceleration.//   

       Escape velocity is something like 10000m/s. That means an acceleration of 250,000G. For example, a bolt weighting 1 gram will put a loading of 250kg on the surrounding structure.
MaxwellBuchanan, Oct 06 2013
  
      
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