Author Topic: NASA's lunar landing pad project, built in Hawaii  (Read 4727 times)

Offline TrevorMonty

Re: NASA's lunar landing pad project, built in Hawaii
« Reply #20 on: 01/08/2017 05:50 PM »
Alternative is design lander so main engine is not used for landing takeoff stages. Use main engine for high DV deorbit burn. While landing is handled by multiple small pressure fed thrusters high up on lander facing outwards at slight angle.

There are some other benefits to this design.
Redundancy, can afford to lose a thruster at critical landing/takeoff phase. With main engine this would be fatal for lander and cargo.
Can land on regolith and not kick up rocks so they will damage lander.

Online savuporo

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Re: NASA's lunar landing pad project, built in Hawaii
« Reply #21 on: 01/08/2017 06:29 PM »
Two layers of interleaved tiles, with rods/nails through the edges. Use 3d interlocking pattern between top and bottom layers, instead of 2d in one layer.

EDIT: like this
http://i.imgur.com/QCDrRbM.png
http://i.imgur.com/veVMjlP.png

Red pegs can simply be part of the mold or print you use to make either top or bottom layer bricks, with matching holes on other side. If the bricks are thick enough, it'll be really hard to gases to blow the layers apart.

There are probably way better 3d interlock patterns possible, but principle would be the same - its only possible to unlock the pattern with a straight up or down motion, because of vertically aligning surfaces between two layers.
« Last Edit: 01/08/2017 07:25 PM by savuporo »
Orion - the first and only manned not-too-deep-space craft

Offline Arch Admiral

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Re: NASA's lunar landing pad project, built in Hawaii
« Reply #22 on: 01/08/2017 09:17 PM »
The surface erosion problem is even more severe with jet-lift VTOL aircraft on Earth because the dirt, grass, stones etc. thrown up by the exhaust gets sucked back into the turbojets and wrecks them. The solution is a landing pad made of lightweight aluminum sheeting, the same kind used to make temporary runways for conventional aircraft. The idea of building a pad on the Moon out of local materials is silly. This bogus experiment was just a free vacation for some favored NASA employees.

Offline RocketmanUS

Re: NASA's lunar landing pad project, built in Hawaii
« Reply #23 on: 01/09/2017 04:58 AM »
Very interesting, thanks for finding this.  I fear sintered regolith might not be thick enough, but that really requires tests in place to determine.  As a non in situ solution, might it be possible to stake down some kind of high temperature thermal cloth, such as these?
http://www.thermalproductsco.com/high-temperature-products.html

Light metal stakes could be used to fix the blanket in place.  At 1/2 lb per ft square (1/2 inch thick), 20x20 would weigh 200 lbs.  Perhaps 1/4 inch thick could work for 100 lbs, plus 10-20 lbs of stakes.
This should be easy to test, anywhere in the world...
Using a landing pad like the one you have for mars with a deflector trench lined with thermal cloth. Pad made from interlocking cut large Lunar rock or large interlocking bricks made from Lunar soil.
The second image.
https://forum.nasaspaceflight.com/index.php?topic=41427.msg1626990#msg1626990
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Offline zodiacchris

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Re: NASA's lunar landing pad project, built in Hawaii
« Reply #24 on: 01/09/2017 05:26 AM »
How about sintering the surface of the pad by exploding a nuclear warhead with proximity fuse? We have the technology for that..  8)

Offline Chris_Pi

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Re: NASA's lunar landing pad project, built in Hawaii
« Reply #25 on: 01/25/2017 05:53 AM »
How about sintering the surface of the pad by exploding a nuclear warhead with proximity fuse? We have the technology for that..  8)

And it it saves fuel by not needing to be soft-landed on the surface. Use two, One groundburst and then one at altitude and you can even dig down to solid rock, build a berm around the landing site, and clear any loose debris from the surface. Looking at weight, simplicity (Well-demonstrated complex stuff anyways), reliability and speed of operation this might actually be worth a look at. (No really. Stop laughing, I'm serious. Slightly.)

Offline KelvinZero

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Re: NASA's lunar landing pad project, built in Hawaii
« Reply #26 on: 02/09/2017 10:28 AM »
And it it saves fuel by not needing to be soft-landed on the surface. Use two, One groundburst and then one at altitude and you can even dig down to solid rock, build a berm around the landing site, and clear any loose debris from the surface. Looking at weight, simplicity (Well-demonstrated complex stuff anyways), reliability and speed of operation this might actually be worth a look at. (No really. Stop laughing, I'm serious. Slightly.)
This might sound like a silly question, but would a nuclear explosion need to be particularly violent?

What I mean is, would there be much of a shock wave, or would it just suddenly raise the temperature of the ground to a predictable temperature? There is no air or anything, only the material of the bomb itself would definitely become a fast expanding ball of vapour.

If it just instantly raises say the top meter of rock to molten temperature over a few hundred meters then there is not any huge amount of material that is vaporised and expands violently, despite the vast energy that has been absorbed.

I wonder if an impact of fine dust would have a similar result. Imagine you grabbed a fast moving 1000 ton rock with a SEP tug and set in on a course that it hits some other object a while before impact, so it is a spread out cloud of grit before it hits the ground. (You can grab a fast moving rock because you don't need to bring it into orbit, just nudge it's trajectory)

I personally prefer the idea of some big inflatable lens though. You could have the thing trundling around for a year. You could make roads. You could do primitive 3d printing.

Offline Chris_Pi

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Re: NASA's lunar landing pad project, built in Hawaii
« Reply #27 on: 02/09/2017 10:29 PM »
I'm not terribly familiar with how nukes work, Either in vacuum or atmosphere, So if anyone else wants to hop in and tell me how it really works feel free, I'll probably be a bit (or badly) off with this:

Heating from X-ray absorption of atmosphere (if present) makes a large part of the bang. Not going to heat uniformly down a meter. Materials heating from the radiation output will depend on what that stuff is. Mostly very rapid surface heating that can vaporize a thin layer if close enough and that can set up a shockwave in what's left and give it a good shove. Lots of energy, But dumped out too fast for conduction to move it around much. Look up Project Orion for some idea of what a bit of distance does. Plan was for hundreds of bombs set off <1km from a steel pusher plate as a propulsion system.  :o but  8)


Offline whitelancer64

Re: NASA's lunar landing pad project, built in Hawaii
« Reply #28 on: 02/09/2017 11:11 PM »
I doubt anyone here is a nuclear physicist specializing in the construction of nuclear bombs, and if they were, they certainly would not be able to talk about it.

However, there's some unclassified information available from various "peaceful use of nuclear weapons" projects, from which I know nuclear material in bombs can be shaped so that the explosion goes more in one direction than another, and our nuclear weapons have been "dial-a-yield" since the 1960s so the power of the blast can be varied, and the composition of the materials in the bomb can be varied to produce blasts of greater or lesser intensity of the radiation produced so desirable portions of the EM spectrum could likely be coaxed to greater intensity.

However, for earth-moving projects involving nuclear detonations, there's a lot less control of how the ground is shaped. You get basically one result - a crater.

Just a quick correction, it was much less than 1 km from the spacecraft for Project Orion. They were planning on a detonation distance of about 60 meters, ~200 ft.
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