Last month, scientists confirmed the widespread presence of small amounts of water on the moon. This landmark finding was followed by NASA's crashing its LCROSS probe into a crater in the lunar south pole, generating data which is currently being analyzed to determine the extent of water present around the impact site. Water extracted from the lunar soil could be used to sustain life and to generate rocket propellant. PopSci.com spoke to Ed Ethridge of NASA's Marshall Space Flight Center, who has been studying how microwaves could be used to extract water from lunar soil.
Why use microwaves?
The thermal conductivity of the moon's soil is very low, which was something that the Apollo astronauts found. So we can't heat the soil just by shining the sun's rays on it, they would just get reflected. The advantage of microwaves is that they penetrate and heat the soil from the inside.
How do you then extract the water?
The microwaves don't actually heat the ice, they heat the soil. But the water molecules get hot, and at around -60 Fahrenheit the water turns directly from ice to vapor. We could use a cold trap above the soil to turn the vapor back into liquid water and collect it.
And you tested this experimentally?
Yes, along with Bill Kaukler of the University of Alabama-Huntsville. We were trying to get funding for a vacuum chamber, which is really expensive, when Bill pointed out that we didn't really need something that large. So we just put cryogenically cooled lunar soil simulant in a vacuum vessel, and put it in a regular microwave that we modified. And just as we expected the soil heated up, the water turned to vapor, and we were able to collect the water using a cold trap.
How have you followed up that research?
Well, to use more powerful microwaves in the megahertz or gigahertz range would require tens of thousands of dollars. The hardware is available, but it is very expensive. NASA's In-Situ Research Utilization (ISRU) project has a minuscule budget, so it's hard to build prototype hardware like that. So instead we've been using the Comsol multiphysics modeling tool, to model the many variables. Comsol can give us pretty reasonable calculations about how deep microwaves can penetrate at different wavelengths, and the rate at which the water will come out when we heat it up. Once we have more theoretical data, we can build a prototype to target a specific purpose. We're also hoping to get actual lunar soil to test it on; right now we create lunar soil simulants that mimic the soil from different parts of the moon.
How do NASA's recent findings impact your research?
Apart from the fact that there's water on the moon, the data will help us find out where the water is. NASA's lunar prospector showed us some subtle data aspects, like indicating that the top surface of the poles, anywhere from 4 to 40 inches of the soil, is water depleted. So we may need the microwaves to penetrate 40 inches into the soil. More data could help us find out exactly how deep the water is. Also, what's its concentration? Some estimates indicate that water may form 1-2 percent of the soil. But others say it's as high as 40 percent, in which case the water would fill up all the interstices of the soil. This would make mining it very tough, since the soil would be as hard as granite at the temperatures found on the moon. Microwaves would have many advantages: they're simple, and we can heat the water in situ to extract it.
Cool, all you would need is roaming harvesters with massive solar cells coupled with robotic collectors ferrying the water to a moon base in a constant stream. Use solar powered lasers to extract the hydrogen from the water to fuel the collectors and the robotic freight army. Once the fuel and the water and in place, Habitation would be possible and manufacturing could begin on more massive spaceships that would use less power to take off from the moons gravity. We will be to the stars in no time. Just keep sending out robotic water collecting armies ahead of each colony, and move out of the solar system piece by piece.
Get too it NASA. I'm sure we will find Earth 2.0
That sound's great Scrumpulate, but Nasa lacks the money to do that anytime soon. Nasa need's a budget increase, or the private sector (companies and large corporations) need to step up and help.
hey cookiees, how come we got all the ressources needed to do it, but all we lacking is ''money'', if its just money, maybe NASA asking too mutch for what they can offer, what about asking other people to do it for less?
Because always thinking the way you do ''we lack the money for science'' those newly out of 3rd world country like China and India are going surpass us cause they got the ressources and they dont care about the ''money''.
Mark Jannot, from Bonnier corp, was making reference to the fact that NASA can't possibly fund our human expansion to space on the mere 18 billion a year it gets, citing costs of maintaining ISS, and continuing to use the shuttles. This is in the new PopSci. I contend that a private concern could be subcontracted to get people and hardware to space for 18 bil a year, and maintain the ISS, and get a hab up and running on the moon inside 3 yrs, with a manned hab on Mars inside 10. As much as NASA has done for us as a species, it has become way too topheavy in a financial sense. Sooner or later we will have to wake up to the fact that private businesses will begin to outperform our space program. Along with the performance is risk, in human lives and equipment, but the can is open now, and NASA will begin to feel the pressure as more and more contracts go private. We need to demand that NASA adapt to the coming storm now, or it's function will truly become obsolete.
Or is it too late? Is NASA already too far down the road to becoming obsolete?
If our intent is really as we say for the betterment of all humanity, NASA could be helping these startups that have cash and facilities, but little hands on outside their engineering backgrounds, by trimming the waste of craft blowing up on the pad-telling them what works, and why. Technical advice, training, key personnel, and the unmatched ability to get large systems up and running; all of these things have a quantitative value, and are commodities that they will be forced to begin trading in anyway, not to mention facility use here on the ground to prove new designs. Nasa could be self sufficient. Nasa could show a profit. Now there's a scary thought.
sorry, Mark Jannot is Editor for PopSci, which is owned by Bonnier.
This is incredibly good news. Being able to extract water has been a major hurdle for building a self sustaining moon colony (besides the obvious funding and transportation issues we have with getting there). Now what we need is to find (or pretend to have found) something valuable up on the moon or on Mars that gives the private sector a very good reason to invest. When explorers were sent to check out the "new world" there was always the assumption that there would be gold to find. We need to figure out what our "space gold" will be. This could be anything from pharmaceuticals that can only be manufactured in zero g to actually finding something like gold in plentiful quantities on the Moon or Mars. Exploration and science are good reasons to push our reach into space, but are not enough to draw in lots of venture capitol.
I like your point Forest. The technological challenges that large corporations have presented to the private sector (like the X Prize) are advancing some of our technologies by leaps and bounds, but it's somewhat counter-productive in the sense that we're paying them very well to do so. If the private companies were to undertake these projects on their own, simply because they wanted something on another celestial body, I bet we'd be a lot farther along by now.
That aside, I think the only use we're going to find the moon has for us is as a refueling station for farther reaching missions. It's a main focus of our societies attention right now, but would you really want to live their? It's new, but its not BETTER then earth. I can see the novelty wearing out very quickly once we actually have people living their.
we have the technology to extract hydrogen and oxygen now, the system listed here is awesome, too. the multibillion dollar answer is how much content is there in the regolith to mine? we still don't know till NASA releases their findings. long wait with the world wondering and projects ready to go to planning.
John F. Winnick, Sr.
There already is a RF-UV patented dis-resonance method that takes one third of the energy (compared to electrolysis) to extract from steam: hydrogen, oxygen, and pure drinking water.
Space travel to the Moon and Mars would be much easier with feedstock converted by microwave in situ extracting ice impregated soil to convert usable hydrogen fuel, oxygen, and drinking water.
NASA has already merged with the DOD and will morph into a branch for
R & D of long range space transportation development with targets such as the Moon and Mars. In the mean time, commercial companies will take over suborbital and orbital launch vehicle systems. Over time, the commercial vehicles will dominate the landscape for all space access, as demand increases for space tourism in the next decade.