 Good afternoon everybody Welcome to today's planet. I'm sorry panel discussion planets in the next sentence Panel discussion lunar and planetary resources are asteroids the moon and Mars really a vital source of useful resources My name is Bill Crossley. I am the J. William Urig and Anastasia Vornas head of the School of Aeronautics and Astronautics I'm pleased to help kick off Today's event in the Purdue gotta get this right Purdue engineering distinguished lecture series Which we obviously make it an acronym because that's what the engineers do so pedals So I know what pedals is that I don't always remember all the words are This series is sponsored by the College of Engineering in conjunction with all the schools and today We get to host as the School of Aeronautics and Astronautics And we've got a visitor today as the title of the panel indicates somebody who's really directly aligned with space exploration So to get things started I have the honor to introduce our panel moderator and he's going to subsequently introduce all the Panelists including our Purdue engineering distinguished lecture series visitor and he's going to give you a little bit about how the panel is going to run today So with that let me introduce our moderator mr. Andrew Cox Andrew is a PhD candidate here in Aeronautics and Astronautics He's a NASA space technology research fellow and in that position He explores the motion of spacecraft affected both by low-thrust propulsion forces and multiple gravity fields, right? So the multi-body problem Falling graduation Andrew plans to continue working in the space sector supporting spacecraft mission design. So with that, please welcome mr. Andrew Cox All right. Thank you professor crossley So to get started I'll introduce our panelists here our distinguished guest is professor Daniel Shears He visits us from the University of Colorado in Boulder He's a distinguished professor the a Richard Seabass endowed chair there Uh joining us from Purdue our remaining panelists we have professor Jay Malosh He is also a distinguished professor in the Department of Earth Atmospheric and Planetary Sciences And of the physical and astronomy Here at Purdue professor Antonio Bombette It's the Edgar B and Hedwig M. Olson professor in civil engineering and Professor Breone Horgan is an assistant professor of planetary science in the Department of Earth Atmospheric and Planetary Sciences So as professor crossley mentioned our topic today is the viability of Gathering resources from places other than earth There's a lot of excitement about colonizing the moon NASA's Big goal right now is to get humans back to the moon and to establish a permanent presence there But also there's lots of excitement about going to Mars. We have multiple missions to asteroids And as we move out from the earth We're obviously obviously going to need a lot of resources So one of the the obvious questions is where are these resources going to come from or we can launch them from earth Which can be very expensive or are we going to gather them in space? And if we're going to try and gather things from space What kind of challenges are we going to have what can we get? So that's what we're going to talk about today. What kinds of resources we can gather And this is going to lead into professor shears talk. That's at 430 where he discusses more about asteroid missions So this is 330. Excuse me. It ends at 430 So yeah, we'll jump right into it The we're going to start with outlining a couple big topics really briefly I think because it's not the most interesting of the questions that we want to talk about is what are these resources and Then we'll talk about how are these resources potentially used in space or perhaps back on earth? And then we'll jump into the the more detailed and interesting topic is what what kinds of challenges do we face both in gathering and using and and What are the challenges in gathering these resources? We're going to do a panel discussion here for about the first 30 minutes and then we'll open it up to audience questions So be thinking as we're as we're talking questions that you want to ask these panelists as we go All right, so to begin with I'd like to get each of the panelists maybe to give just a couple sentences or a few minutes about about your research and how it relates to Space exploration and the resources that we can find there. So I think we'll just go down the line to start with professor shears Okay, thanks very much Andrew so my research area is largely focused on understanding how we can send spacecraft to Explore small bodies in the solar system by small bodies I mean asteroids and comets and the like and and really the maybe the best way of thinking about them and especially in terms of resources are We're going to send we're sending spacecraft out to explore these very primitive bodies in the solar system. These are bodies the materials that they're made of have not been a substantially altered Since the formation of the solar system or if they have they haven't been nearly as processed as they are on the earth and And hence there there might be some, you know, definitely some valuable Species minerals Iron cores what have you that could be available for you know for utilization Although my expertise is certainly not in the area of what these things are made out of I think other Other of our esteemed panel are much much better suited to talk about that I I will say that probably the the most valuable resource That exists in these primitive bodies may in fact be just common everyday water Which actually has many many uses in space for propulsion and for human You know for humans to keep them alive and going and shielded from from radiation and all that so I'll just Okay, my my basic research is impacts Which might not seem to have much to do with resources, but I participated in 2005 in a deep impact mission where we ran a 300 kilogram spacecraft into comet temple one at 10 kilometers per second in order to find out what was inside just like any child Figures out what's inside a strange object by smashing it. We did exactly that to comet temple one and Learned a bit not as much as we had originally hoped but we learned a bit about What was inside the comet since then I participated in the Grail mission with people here at the AE department? with Professor Howell and a number of former PhD students and We worked with the Grail mission to look for Empty lava tubes on the moon and we found them in fact We found rather large empty lava tubes on the moon that we believe would be a great Resource for humans to live inside to get shielded from radiation from meteorite impact and so on how that that bears on resources I'm not sure directly there. There's been some language about water condensed inside lava tubes But we don't know that that is in fact the case maybe sulfur might be from the volcanic eruptions that made them I Certainly agree that the major resource in the inner solar system is water if we were in the outer solar system We'd be up to our necks in it, and we wouldn't think it's a rare resource But there is virtually no element if you look at the tables that Is in abundances in carbonaceous chondrites in the most primitive type of asteroid That is up to the level of an ore deposit on the earth The only exception might be iridium and that's barely barely makes it everything in space is expensive and Bringing things back from space back to earth probably is is not a non-starter or is a non-starter, but You know it once we're in space that Changes the story quite a bit. I'll pass it on to Antonio now. Thank you. My name is Antonio Bobette. I'm a civil engineer And you know the question is maybe what I'm doing on a panel about, you know It's not the rest of the bodies, but the question is very simple What we do once we get there, right? So that's where civil engineering comes into place So I was interested in this topic my years expertise are rock mechanics and tunneling particularly stability of the ground structures seismic stability and it was involved in this topic about Maybe not even three years ago when pressure Milash called me and said well, we have these we think that we have these large Underground structures these large tubes under the moon and we don't know if they are stable or not And my first reaction because of the large size that says you know that that's not possible because a thousand meters or hundreds of meters That's something is uncalled for but then we started looking at those and things begin to make sense because then you have to learn About, you know the different environments. We see engineers have learned a lot about how to design and build and How to be safe here on earth based on the hazards that we know of and we have experiment here on earth But certainly as you get exposed to the hazards that may be possible that certainly are possible Out there you begin to question a lot of things that maybe you have taken for granted, right? so then I was involved with that we had some funding from the Purdue from the Provost office We made I think some progress. We had a lot of fun thinking about that Recently and one of the copy eyes with other faculty on what we call the resilience at the rest of the Institute Here at Purdue where we are going to put forward concepts of civil engineering in particular the concept of resilience this is something that we've learned over decades of designing and observing how our Infrastructure and our constructions behave under unexpected events and guess what? I think we are going to have a lot of those when we go out on the moon on Mars and Maybe other other bodies, right? So again, you know the fundamental question is how we are going to be Living because eventually is going to happen How are we going to be living on the moon Mars and in other places and how we're going to take advantage of the resources that we are going to be finding there for example for construction How are our habitats are going to be looking like there? How are we going to thrive? as Explorers out there when we are going to be exposed to all these hazards that we need to learn and we need to be able to live Great, so I'm dr. Briannie Horgan Planetary geologist and of course if you want to go find a resource on earth you're an engineer running a company What's the first thing you would do you'd hire geologists right you'd hire a geologist to go out in the field and figure out What metals or whatever resource you're looking for is there where they are what the properties of the rocks are? How deep are they right and so we're doing the same thing on the moon Mars asteroids Using mostly satellites as well as landed robots your rovers and things to try to understand What kinds of minerals and water deposits are present on these bodies and it's actually it's a pretty hard problem because it's very Different from doing mining geology on the earth the processes are totally different For water for example right so where do you go look for water? What's the most obvious form you can imagine water being in say on somewhere cold like the moon any ideas? Ice right so ice is a great one we think there's ice on the moon But we're not really sure where it is or how much is there still right even we've sent missions to do this But it's still a big question But we can also go looking for water in other weirder places right we can go looking for Water trapped in volcanic deposits maybe just as oxygen not even water We can go looking for water trapped in minerals that have been formed by water That's a great resource on asteroids that have some of these primitive materials Jay was talking about you know primitive water altered materials in the early solar system on Mars those kinds of minerals are Laying all over the surface huge football fields of water bearing minerals on the surface And so that's one of the things we're doing we can look for other things too right what kind of if you want to go to an Asteroid and mine it you have to figure out what it kind of asteroid it is first Is it the kind you want to go mine that's interesting or is it just a boring rock right and so to do that? We use Spectroscopy from satellites and telescopes to try to figure all that out That's what I do here is trying to understand the mineralogy of places like the moon and Mars from satellites and rovers And that's how it plays in All right, thank you all for those Introductions and talking a little bit about what kinds of resources we have out in space waiting for us Professor Milo you mentioned that a lot of these at least the metallic and elemental resources are Are just sort of lightly sprinkled around could you expand on that a little bit? I know one of the the exciting things is asteroid mining and people think of platinum and gold But you seem to be implying that maybe that's not a very feasible Adventure well Platinum and gold and iridium maybe are one of the few elements that whose abundance in So-called undifferentiated bodies is comparable to that of terrestrial ores You know things like iron certainly they're present, but the abundance is much less than a terrestrial or and no No geologist would would pay to open a mine in some average random rock, but that's what you have to deal with out in space the most Primitive materials are so-called carbonaceous chondrites Which are bodies that condensed early in the solar system and whose elements did not get separated in the process of forming? Planet in the case of our own planet The the constituents that fell onto the surface of our planet were heated in impacts The the denser elements like iron sank to the core That's that's where they are in the center of our earth and the lighter elements floated to the surface and made What we have in the case of earth a differentiated planet That separated all the initial elements that in carbonaceous chondrites were completely mixed up What happened further on earth though to make ores was hydrothermal circulations mainly near volcanoes and And volcanic centers of different kinds that drove circulations of water in the ground that Differentially picked up elements out of the the average crust and concentrated them as far as we know There are no ores of that kind on the moon. There's very little water to form a hydrothermal circulation We don't know about Mars yet, but You know, we we don't know of any ore bodies out there to go in mine so right now our thinking has to focus on the undifferentiated bodies In which there are a few elements that are rare in earth's crust iridium for example is one part in the trillion in earth's crust That's not an ore our ores are one part in a billion But that happens to be about their abundance in a carbonaceous chondrite yet still You know, how do we economically extract something that's one part in a billion We'd be better off doing it on earth where you go to any mine site Lavish use is made of water at every mine site on earth We have to deal with the fact that there's not a lot of water Available to us in the inner solar system that we have to work with and so it requires new technology And some new thinking about what resources are are worthwhile and how to use them Thank you Anybody else have anything to add to that So the concept of resources it would like to take it a little bit further. So it's not only Things that we can take there to bring back to earth which Eventually we need right the resources on earth are finite and we are using them So I'm convinced that humanity is going to survive if we are able to just Leave on other planets. There is no question about that But I would like to expand the concept of resource so resource for me would be a space where Humanity astronauts could leave right? So it's a little bit of an intangible sense of resource. So So what are the resources in that terms that that we can find and and we can explore On the moon and Mars such that all these activities, right? that we need to get these resources right and Do other things and and build infrastructure and and build rockets that are going to allow us to go So these are resources. Okay, we need to look at those also not only metals or water but You know, it's are we looking at resources on the surface Where we are going to be building our resources on the ground like the lunar lava tubes that we can use for Shelter, right? What is the materials are out there that we can use as resource to build to protect against radiation? Which is something that is not completely trivial trivial So so this idea of expanding this concept of resources that is not only very specific about, you know, rare earth that we may Need but all the things that are important. Yeah, you could even ask a simple question like okay Say you want to do some 3d 3d printing to construct stuff on the moon Is the lunar soil the regolith? Is it actually appropriate for that? It is nasty nasty material, right? So you need to think about what are the properties of it? How's that going to affect the mechanics of your process? Can you do it? How do you need to modify it? The only thing I'd add to Jay's comment is that just a plug for the next river That's going to Mars if you really care about trying to find ores and interesting metals and things on another planet We're actually sending a rover to land on one of the biggest impact basins on Mars is to the space in Mars 2020 It's gonna land and look at some of these really ancient really messed up Impact deposits with big hydrothermal veins running through them and all kinds of stuff. So if you ask me in five years Maybe I can tell you whether or not there are gold and platinum and stuff on Mars for us to mine Let me out. I've been pretty negative about some of these resources But I've been I've been thinking when you say resources I like many other people think about You know gold and stuff you might mine out of the ground There are some really abundant resources in space that we don't have on the earth and one of them is abundant solar energy So energy is certainly Something that is easily harvested in open space not on the surface of the moon because it gets dark for two weeks and Storing energy will be a problem there, but we do certainly have a lot of of power available We also have what what many industries consider the resource is vacuum. There's a lot of that out there and You know, it's easily and abundant or easily available. So there are some positives as well Yeah, I think I would really agree that If you take a you know asteroid or a mining Conception to resources it really limits you and really that doesn't make sense in a lot of different ways Whereas, you know, you talk about solar energy. Well, we harvest this with almost every spacecraft now It's completely powered by solar energy. You know the the radiation and the like So even now we're we're utilizing these resources at a very fundamental level and it is important what everyone else was saying about Changing the concept. What is a resource a resource? This is something that you can use and you can't sort of be you can't track yourself into a Traditionalist model necessarily about you know metals or what have you lava tubes could be a Fantastic resource for for a future colonies on the moon Safety is a resource in space Those are awesome some very good points So I think I think that sort of leads us into some of the challenges we could discuss with more conventional resources, what are the challenges with perhaps getting to an asteroid and and Getting resources out whether that be iron or regolith or water ice Or on the moon and Mars What are some of the challenges with with accessing and using those? I think you professor shares maybe talk a little bit about accessing at least the asteroids It's your area of expertise right and probably the most in if you want to have this concept of resource maybe a Useful way of thinking of it is once you get to where you're going and we have a variety of ways of doing that Is there anything there that you can utilize to at the most fundamental level get back, right? this is what the You know people that were off going from Europe to the New World This was the crucial thing they didn't build enough to go to the New World and back again They built enough to get there once they got there they figured well We can use the natural resources to build what we have right now with the space science missions the sample return missions That we have and this is a big issue with Mars sample return. We have to construct something that Takes us to the site and brings us back if there's anything that we can utilize that that lessens the load I think that's crucial. This is where something like if there is an abundant source of water You can turn this into propellant The observation about solar energy is is very cogent because we use this on the way there and on the way back So those are just some thoughts. Yeah a Professor Bobette you've mentioned the stability of the Luna lunar lava tubes and so how feasible is is Setting up a habitat or some sort of operation inside one of those right so Kind of continuing maybe with the with the idea and looking at how we can scale up things right because you know right now What we may be able to do or we think we are able to do is just go there And it's a fantastic very difficult task and maybe get a sample get back You know, but looking ahead right 20 years 50 years whatever our vision is is How we really are going to go to the moon or to an asteroid and really Get used of the resources again with a generic. So the first thing that we need to know is is what's the environment, right? What's the environment where humans and equipment and machines and infrastructure? How is this environment going to affect? how these functions and That's what I've been Looking at with with Jay and others is the first question is what are the hazards that are there because we're going to Send people we're going to send equipment and we expect that for a certain Time not not a matter of days, but maybe weeks We are going to or years we are going to We want to do some operation and we want to have a mission that is going to be successful So the first question is what are they what is the environment? What are the hazards that all this is going to be exposed and that's what we need to learn? And I've been learning and the more that I learn is the more I realize that that the more I don't know So first is look at these hazards What is the intensity and not only looking at those some of those are completely new to us? We don't design Lunching pods or or or habitants. So even we will look at underground that said well, you know, how is this going to? React to moonquakes, right And and and we look at the moonquakes and and we realize that Gosh, they are so different than the earthquakes that he would have here on earth here on earth That we are familiar with right we designed for we have codes building codes But these earthquakes, you know, they may have a significant Intensity, but the duration is about few tens of seconds the frequency content is I don't know maybe one to ten hertz and so then we said well, let's look at the moonquakes and sure enough for the intensities much smaller as expected But then they last an hour Gosh, we've never seen something like this The frequency content we were not able to measure because the equipment Cannot register, you know, high frequency content, but we expect that the frequency is going to be the order of 40 50 or more hertz Gosh, we don't have any experience with that The physics may be the same right and I think that we are going to be able to work on those and Learn and try to understand but what I'm trying to say is that that this is completely new We are we are faced with completely new challenges and questions that simple as a well, you know We design our buildings that maybe has a probability of failure of ten to the minus three ten to the minus five here on earth, right? Are the same concepts going to be applicable when we design on the moon? Because if there's a problem here on earth, you know, we have the resources to go there in a matter of hours We're going to be there trying to help and fix things But maybe the moon is closer, but what about Mars? They're going to be months. If not, maybe a year or more away So these are the challenges the challenges are that we need to look at these things and we need to realize And we need to learn and maybe change the way we think and these are in my mind You know some of the critical challenges That that we are a little bit far away that really need to work on those until we feel that Yes, I think that that we can be ready. I think that there is a lot of work Professor Horgan I'm not sure if this is a 2020 instrument or one that's already launched But I understand one of the rovers has seismic monitoring. So can you comment at all about Martian quakes? Yeah, so I mean Jay probably knows more than I do, but this is the the insight lander which landed last year on Mars So it's been looking for a land that's sort of in the most boring place You could possibly land on Mars flattest place they could find and his goal has been to try to measure Mars quakes right at actually land and do a good job measuring the first earthquakes on another planet beyond the moon And they've they found them they found a couple now They're all you know really small kind of what they expected more or less And so what they're going to be able to do hopefully is use the collection of Mars quakes that they detect over the next year or so To put together a model for the interior of Mars how big is the core? You know how often are impacts hitting it to create these quakes what other things are creating these Mars quakes? So that's an important one. We're sending some other cool instruments to Mars that are helping with Exploration the next river is going to have an actual in situ resource utilization instrument moxie Which is going to attempt to extract oxygen from the co2 in the Martian atmosphere It should be hopefully One and done get there try it out for a few months and then you can show you can do it But then we have you know a very small portable instrument that can extract oxygen from the Martian atmosphere And the last really important one is on the current rover curiosity We actually have an instrument that is measuring radiation and it measured radiation all the way from launch on earth all the way to landing on Mars and our last Oh, you know six years seven years on Mars now And so we know really well what the radiation risk is both in space and also on the ground on Mars And it turns out it's actually a lot worse than we thought Oh good Professor Milosh did you want to comment on that as well on the Mars? Building for earthquakes or any of those resources well those hazards are there and Radiation is one of the main ones that we really don't know how to deal with very well NASA's put a lot of time and effort into it and not really come up with any answers It was just a couple of years ago when the then administrator of NASA came and openly admitted That radiations a problem that they didn't know how to deal with before that NASA had kind of covered over that that aspect At least it's in the open now, and we're talking about it It may be that the only way to get there is to depend upon people here in AE to give us propulsion systems That'll get people to Mars really quick so we can cover up once we get there Because the amount of shielding required for well, there are different kinds of radiation in space There are solar cosmic rays, which are a problem, but you can shield against them or a couple of million electron volts Galactic cosmic rays are much more energetic than that and the amount of shielding needed is measured in meters not in a few centimeters and Really, there's not much you can do except cover up in a lava tube or deep underground in order to get away from them so it is something that we have to deal with and We're making some progress that but that's One of the future challenges Indeed I think we're at about halfway, so we're gonna keep this discussion going, but we're gonna include the audience So there are a couple of microphones Around the room so if you have a question for the panel or as a whole or a panelist individually Go ahead and raise your hand, and you'll get a mic And don't start asking your question before you get the mic because the people that are watching online can only hear you through the mic Hello Thank you for the wonderful conversation so far. I've learned a lot. I had a question for You forget your name. Sorry but you mentioned the That we had several ways of getting to these asteroids and these small bodies in the in the Sort of interspace I guess Could you elaborate on that please? Sure the different technology it was that we take to go visit asteroids There are a few different techniques that we use And in fact the most The the most ancient of all techniques is to wait for them to come to you and this has been happening for Since whenever with the meteorites Meteors that we pick up off of the ground so these are asteroids that have come to us and Actually give us a lot of detail about what is actually out in the solar system Now the atmosphere serves as a screen and keeps out some of the more interesting and actually some of the more primitive asteroids Preferentially and lets other ones in like you know the the heavy metal ones and the like So really that's one way of exploring asteroids In terms of space travel we can Fly by an asteroid that tends to be actually rather simple to do And but it's sort of like if I want to visit Chicago or in the Annapolis or West Lafayette I just drive down the freeway and I take a bunch of pictures as I go through and say okay I've visited West Lafayette. I have all these great pictures. I obviously haven't really experienced the city right? Same way when we have a flyby of an asteroid We take a bunch of pictures as we fly by but we don't stop we don't get dinner You know we don't hang out try the local bruise and all that So then the next level is a rendezvous mission and that's More complex because we not only have to be on a trajectory that flies by The city we have to have propulsion technology to stop once we get there and drive around the streets and you know Observe things and the like usually still from the safety and comfort of our car So even that you can't even get a good meal that way unless you go to the McDonald's or something, right? Or a drive-thru So then the next level is you actually stop get out of the car and wander around And this is really where we're at with asteroid exploration with the right now the Hayabusa 2 mission the Japanese mission It actually has launched several rovers on the surface of their asteroid They're hopping around taking lots of interesting images measurements and the like and even the NASA one the Syringe Rex is gonna come all the way down and touch the surface grab a bunch of material and Eventually bring it back home. So yeah, these are sort of the the different levels of Exploration that we can do everything from just sitting at home waiting for the meteorite to hit all the way to Going out there stopping and essentially getting out of the car touching the surface and interacting with it. Hi I think what a lot of people think of when I think of asteroid mining is they think of more the metallic a chondrite Asteroids out there given their relatively low abundance. Would it be even practical or reasonable to try and mine those bodies? Well, I'd say it depends on what you're after If you're after something that's not abundant in a the chondrite that you know would make no sense at all One point I might get across that you know, not everybody realizes One thing that that is not Under abundant out there is oxygen Most rocks are about 90% oxygen by volume. I mean all oxygen is a big up big I in it about 40% by mass so it's bound and there's a lot of energy needed to unbind it But if energy is cheap oxygen is an abundant item out there Hydrogen to burn with it is something else again. You really need water for that But oxygen itself at least to breathe for us humans is not under abundant But something Dan made Mention you made about meteorites also made me think iron meteorites are in fact something comes from the sky and at least primitive people who could not smelt iron Used iron and space resources in the form of iron as a resource for many thousands of years before our technology I might also add a sort of tangentially to these questions. We've talked about going to meteorites and asteroids and comets So what's the timeline on that from launching? Hayabusa to to landing something and then bringing samples back. How long are we talking for that? Yeah, so sort of the the natural Tempo in the solar system and for solar system exploration if you're going to what we call near-earth asteroids Which are asteroids that are roughly 1 au from the Sun the the natural tempo is actually the year, right? If you launch if you're close to the Earth's orbit it takes you about a year to go around the solar system and and to Do a rendezvous with some other body? So usually for a near-earth asteroid mission, you're talking a few years, okay? Hayabusa I've got the dates in my my next talk But I think it took about two years to get to its body and it'll take about less than a year to get back Just because of the timing and all that Once you start going out into the outer solar system The tempo starts to slow dramatically Because now the orbital time periods become much larger one and a half years Mars five years or more a Jupiter Etc. Etc. So but but yeah, that's that's sort of the quick answer My question is for professor Horgan or maybe professor Milosh So you mentioned that you guys use Spectometry to kind of like, you know identify and study Asteroids, so let's say you guys landed on one and you discovered that there were maybe I don't know gold in there What other techniques can you use to say now that I know that this particular one has gold? are there any like Asteroids that will have the same kind of resource like so that is not more like a trident error But more so like I know that if it has this kind of characteristics, it's gonna have gold or something like that Yeah, well, it's actually I mean it's a good question One of the things we don't really know is what the the spectral signatures of a lot of asteroids really mean right? So we're looking at just you know, this one's more blue than this one You know it's kind of is that level of detail So we really have to do is like you said go to those places either land on them or orbit them see what they're Really made of using other techniques. You can look at the chemistry. You can look at the more detailed mineralogy You can do sample return right you can do all this stuff to really learn about it We are hopefully gonna go visit a metal asteroid The psyche mission is going to go visit an asteroid that's been Hypothesized to be metallic in nature. We'll see if that's true, right? It'll be very exciting and so hopefully after that we'll know more and then once you know that you can go say Okay, I know all of these asteroids kind of look like this one I visited in their spectral signatures and now I can say okay. This is how many of those there are All right, so it's really the spectroscopy is what you do you can look at other wavelengths, right? We do a lot of visible wavelength spectroscopy because it's pretty easy with sunlight But if you can get a little closer you can do other wavelengths like longer wavelengths and get more information So we'll keep working on it. Oh Hi Can you discuss that technology of seismometers that you that you're planning to take to these asteroids to get a better understanding of their Composition You're interested in That we're taking to these asteroids because you want to learn what's they're made out of and can you discuss that a Little further there. Well, there have been a number of interesting proposals involving essentially X-raying asteroids with radio waves The concept hasn't actually been used well it was partly used on on the Rosetta mission where when the Rosetta spacecraft Traveled behind from the point of view of earth traveled behind the comet They tried to detect radio waves passing through the comet and kind of construct a tomographic image That was partly successful not entirely. I was actually a Pia or a Kauai on a early version of that that got cancelled We were supposed to use higher power than than they eventually tried using but that is certainly a theoretical idea that may eventually work is to use radio waves to send the waves entirely through the asteroid and Essentially make a tomographic image of its interior If we could get things calibrated. I Think that would be a good technique. I don't know if is is Possibly The Hayabusa mission doing that with Ryu you they certainly have the capability No, in fact, they're they're they're not trying to do radio tomography on the body There have been proposals again not funded to actually place various seismometer type objects on the surfaces of asteroids as well in order to detect either Micrometeorite impacts or to to to make larger blasts and then measure Basically speed of sound Transmission efficiency and the like these also haven't been funded as of yet I Think the Hayabusa to spacecraft could certainly do this especially the mascot except they didn't put this Specific type of instrument on because they were trying to cram a lot of other things Do you consider burrowing into an asteroid to use it as a radiation shield a viable option for longer distance? missions Like traveling like burrowing into it making a cave and then yeah Propelling the asteroid. Yeah, I think professor Boba is the expert on that aren't you? Well, one of the reasons why we were so excited about the lunar lava tools because it's it's they provide shielding against radiation right right away and And we all even thought about you know if we have to mine an asteroid, you know What's the best way to do that such that then yes, you know, you just Borrow and then that would be a place for shelter But you know things are more complicated than that. So I'm convinced that to do that sort of thing you what you need to some sort of a partnership between Maybe humans and robots at the very beginning You need the some sort of a non-human intervention to be protected against radiation until you know You build something that is going to provide the shelter So that would be a mechanism to do that right how you know You approach this problem and how you come up with something that is efficient It's not clear to me at this point because of all the difficulties associated with that right But if that has to be and now I think that is needed to have some sort of human intervention Right because not we are not there yet in terms of robots at the very beginning You need to provide shelter for the humans while the robots can be exposed, right? And that maybe is a transitional time until you build the shelter and then you get from there So if you look at the man at the moon and on Mars, you know, that would be an initial mechanism You would use these existing underground structures as immediate shelter And of course there is the issue of how to get in and and before we're talking about how to get out But it seems that is a viable way of Doing something that would provide some immediate shelter that you can you can start from The idea is an old one It was proposed as far as I know by Dandridge Cole in the 1950s to hollow out asteroids and make safe habitats Yeah, and just a little factoid So right now we're visiting the asteroid Bennu Based on its meteorite analogs We know what the density of the rocks should be and a little over two grams per centimeter cubed yet The total density of the asteroid is actually more around one gram per centimeter cube meaning that about half of the Space inside of this asteroid is is is porous is empty now We don't know what that looks like is it fine little porous voids to uniformly distributed are there a couple larger voids or not but you know in terms of You know digging a hole bearing yourself in there like a like a ball pit You know already half the space is empty, right? So this could be viable It'd be fun, right? Okay, thank you So you all mentioned the lava tubes on the moon What's the next step in order to explore those and look at the feasibility of them? Well, there's actually a a class that's going on here in the AE department this semester that Is Dave Spencer is running that is designing a radar mission to Probe below the surface of the moon and look for for lava tubes Something we actually had a proposal two years ago now to do something like that with a ground penetrating radar And we didn't get funded but we're gonna go back and talk to NASA about doing that If we consider using lava tubes as a resource, we really need to know More about them exactly how big they are With grail when we detected big empty lava tubes All we detected really was a deficit of gravity there. There's missing mass We don't know the shape of the The missing mass. We don't know whether it's one big volume or a bunch of small volumes All we know is that there's missing mass Some colleagues in Japan used a Kaguya got ground penetrating radar In some of our our candidate sites and they confirmed that there were empty holes in the ground but Kaguya was not designed to measure things underneath the surface and Really other than the confirmation that there were cavities. We don't know too much about them So the obvious next thing to do is go go back to the moon with a global survey, which means an orbiter With a ground penetrating radar flying at low altitude, which thanks to grail gravity we can now do safely and and probe beneath the surface of the moon and define the Shape size and extent of those cavities that we detected with the gravity deficits The other thing you could do is stick a robot in it, right? It's always the solution just throw a robot in there and see what happens And there is actually a very cool concept out of JPL for I forget the name of the rover axle I think it's the rover where it's you know, you land have a little lander That's basically like a tether platform And then the rover is like a two wheels attached to with a central axle that can roll away on the tether And then roll down into a lava tube, right? We know there are lava tubes on the moon not just from grail But also because we see skylights, you know holes where the ceiling has fallen down. We see the black pit We see the rubble at the bottom We think we can see it extending away some of the room places near where J's team has seen these big lava tubes So, you know, you could do that today and people are proposing to do this to go out and Take this tether robot and run it down the side of the skylight and see what the tube ceiling is made out of and then Go on the bottom and kind of check out the inside It's still it's hard right because it's sending a rover under or any kind of robot underground is a challenge for communication and power and everything But it's something we have the technology to do. We just need the money in the world to do it And of course, you know the question is not only Are there how big they are how big they are is also have an assessment of the restability Right, so are they stable now, right? Because we are going to put something inside or Or, you know, there is a nearby meteorite impact or that is going to not that they're going to impact The lava tube that is going to be very unlikely But it's going to create a seismic wave that may create problems with the stability of the order So we need to know not only the geometry and the existence, but we also need to have Engineering properties of that such that we can have an evaluation of the stability And and for that we need geologists There's some further interesting engineering problems with that because if we discover Lava tubes underneath the surface the moon we're going to want to pressurize them so that we can move inside freely Now they may have been stable for you know, three billion years Being empty with no pressure inside. What happens when we pressurize them? Do we blow the the top off? Exactly what what conditions what's going to happen what kind of small earthquakes or moonquakes are going to create? By changing the pressures So there there are a lot of interesting engineering questions to answer if we get there and start working Would it be This is on oh, thank you guys for coming by the way Would it be feasible to create something similar to the Silk Road? Where a network of resources is moving between different planetary objects so that they're used in places where they're needed I Mean almost anything is possible, right? But is it yeah the scale or doesn't even make sense In terms of transit time transportation and and the like Really at this stage we're more focused on Exploration and just bringing back small valuable bits of matter back to earth where we can Study them very extensively I Don't know in based on the conversations. We've had today. It's not clear that there's any breakthrough material or or other sort of resource that would make sense to actually create a more planetary economy bringing stuff from Mars to Triton to you know, what what have you I thought I've certainly read many science fiction books that do this quite well right Yeah, but I was a as I was thinking up here pondering about what what is a resource and Resource is something that we find necessary for life And in this sense we do a lot of resource extraction from space and space exploration Because we feed our knowledge that we feed our Understanding and this turns out to be very important for us as humans to actually understand our place You know how everything came together and the like so and so in that sense we could say that we're actually doing a lot of resource extraction But it's not you know This is not the sort you can you can monopolize or make money Well, you could you could say that low earth orbit is exactly that a clear view of the entire earth. That's a resource I Think that's getting at a really important point though is that you know We're talking about we keep mentioning you know these rare metals and things and how they don't really make sense right now to mine But they might eventually right say you wanted to build Any kind of manufacturing process in space that was manufacturing electronics for example, right? There might become a point where it is cheaper to do that rather than you know keep working on extracting more material here on earth It's probably a long way off, but you can imagine that eventually being the case, right? So that's when that kind of technology will be helpful But coming back to your silk road we we at a couple of years ago. We had a Faculty member Dan Dunbacher who was here. He liked to talk about me He unfortunately well he left to become the executive president of the AIAA So he's he's certainly in contact with us and helping us But he talked a lot about what he called the space Audubon the the idea that rather than making a one-off Going out to some some location as part of a mission, but you know Imagining a highway where we go both directions and you know connect to things out there We at one time it advertised our our breath program as providing the gas stations and motels for that space Audubon Hi, first of all, thank you for coming The main question I was asked or I'm wondering is that you mentioned that we're currently Trying to practice these sample return and rendezvous missions with near-Earth objects Do you think as we become more comfortable with this will continue making risks to more farther out bodies? To just cover bell objects or even like cove in moons. Thank you Yeah, yeah, I think the motivation to do this is extremely strong To go further and further out the with it with our current technologies However, there's a large price to pay which is time With our capabilities now To go further out to do a sample return from a Kuiper belt object would be an extremely long endeavor with our current technology Even if we had you know very effective propulsion systems, you're still talking, you know 20 years And and if you think just about the you know, what's the timeline for Mars sample return now? Which is Arguably, you know next to the moon and maybe some near-Earth asteroids the easiest body to go to to get material and Like six years or something minimum for the whole process right and when is launch Maybe 2026 ask me in 2026 so I have a question here, so The we've I don't know how long we Looked at these lava tubes over a period of time But do we know how like various Geological effects have impacted them such as asteroid impacts or moonquakes and if these lava tubes new ones have been created or old Ones have been closed off to us and like The last like how many every years Well, we have a moderately good idea of the flux of near-Earth asteroids and There's none targeted honest right now that we know up But on the other hand there's small things that come into our atmosphere all the time Professor Shears and I just served on a nrc panel trying to figure out the best way for NASA to find these objects and came to the conclusion that a A moderate aperture infrared telescope at L1 would do the job of finding most 140 meter plus Objects over the next 10 to 20 years There are still many smaller objects that fall into our atmosphere the threat from an asteroid impact depends an awful lot on How big the asteroid is and asteroids come in all sizes, but in general there are a lot more small ones than big ones That that many people have worked to define that hazard And occasionally we get reminded by either a close flyby or something like chilly events Good, you know, we live in a shooting gallery and every now and again we get hit and that's just life on earth This will probably be our last question Thank you so for Professor Shears what challenge have you challenges have you specifically faced in your research and What is the near future of asteroid? exploration Okay, so that's a perfect advertisement for my talk Because there are real challenges, but they're all solvable Okay, the the the interesting thing about being an engineer is you can usually figure out a solution Now I may not be the best solution It may you know it may cost a lot or it may require, you know extra energy and effort But there are ways of always Solving the problem at hand and then over time we like to refine these and become you know sort of optimize the process So we can solve the problems that we're trying to solve do the things we want to do more and more efficiently in terms of the future of asteroid exploration there are Many missions right now. I can name four for or three for sure Maybe four for sure that are being planned by just by NASA that will actually explore various questions related to these To asteroids and primitive bodies, so there's certainly a large future I think there is some push to do more sample return But I also think that as we take more samples and bring them back to earth We'll probably get a better and better context for the meteorites that we have and be able to interpret them more and more Accurately and interpret remote spectrum more accurately So we may actually have a lower requirement for samples from say all asteroids although samples from comets That's a different thing. That would be exciting Okay, thanks everyone for attending. Oh one more question. I'm sorry that we thought we had one more Professor Milash You've made an extraordinary statement That the radio space radiation problem is a lot worse than we thought that we would need Shielding of the order of a few meters Could you comment further on that and what would be the result or consequence of going to Mars without that shielding? Well, I'm referring to galactic cosmic rays which are more energetic and therefore more penetrating and the thing about Galactic cosmic rays. They have so much energy. They're mostly protons But they have so much energy that the high energy proton hitting your shielding Explodes the nucleus. It strikes and makes even more radiation that makes a shower of Ionizing radiation that penetrates into the the surface that it struck In the case of the galactic cosmic rays, you know a little bit of shielding is worse than none at all You know 10 centimeters of aluminum are worse than nothing You need to talk we need to talk about meters in order to fully shield against that That's something that what one of the attractions of lava tubes or either on earth or on Mars We know that they're lava tubes on Mars as well, and they're also large Is that they they have tens of meters of rock? between the cavity and the surface if they didn't have that they wouldn't be stable and As a result, they could easily shield against the cosmic rays and there are other advantages There are also a huge temperature swings that that are shielded against underground and Various other advantages that we have going here, but but galactic cosmic rays are a really tough problem Any structure that you put on the surface, right? We'll need A pile up of stuff could be regular that is going to be mirror stick Just to protect against radiation So so just cannot build something and then hope what that is going to be protected You need to pile up and that's a little bit the idea that is out there the regular is few meters on top of that Which on the other hand would have the advantage of helping the structure because the structures At least the structure on the moon And Mars are going to be working with pressure inside Because we need an atmosphere and that means that most of the materials that we build with They work very well in compression, but not in tension and you have something pressurized Then you are you are working with tension and you put it in the shield on top That's going to be helping but that means that the infrastructure and the work that you need to do To build is this significant Make sure it's safe for me to stand up now Sorry, I had my cues mixed a little bit. Can you join me in thanking our panel today? So Professor Brioni Horrigan Professor Jay Milosh, Professor Dan Shears and Mr. Andrew Cox