Near Earth Objects: Ice bearing?

[spacester]

Given the discoveries and observations of the last couple of years, do you think it likely that Near Earth Objects contain significant quantities of water ice?<br /><br />Is it likely that we can find bodies with a relatively thin crust with mostly water ice beneath? Dirty snowballs? Snowy dirtballs? Or just piles of rocks with minimal ice?<br /><br />It seems clear that the population is very diverse, so any answer would be stochastic.<br /><br />I am interested in exploiting them as sources of water for space projects. Do we even know more about them than we did say, 3 years ago?<br /> <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

It seems to me that "asteroids and comets" cover a continuum between rock and ices (I use ices, since water is not the only ice involved).<br />Hence, there should be exploitable NEO's.<br />However, the more time it spends inside 4AU, the less ices will remain after multiple orbits.<br />The trick is figuring out which would be economical, escpecially since the more elliptical ones (hence more likely to have ices) are moving at a higher relative speed to the earth and will require more fuel for a matching orbit.<br />But once we get there, should be plenty of fuel! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[spacester]

Thanks for the response. That reflects my understanding as of 3 years ago. Do we know more now? AFAIK the only thing that has changed is that Uplink is now blessed with more people with relevant knowledge. <img src="/images/icons/laugh.gif" /><br /><br />The economical tradeoff is inded very tricky: those with low eccentricity and semi-major axes near 1 AU have very close to the same orbital energy and velocity as Earth, so require very low delta V, but one needs to wait a long time for them to be in the correct position to take advantage of that. So on an operational basis it is very tricky: you want to be able to go there, mine it for a while, and then return.<br /><br />Do you think the supposition that objects could be found with a relatively thin skin of crust but mostly ice inside is reasonable?<br /><br />And what about the Arjunas (completely inside Earth's orbit)? Would there be any chance (once we finally start looking for them in earnest) of them retaining lots of volatiles? <div class="Discussion_UserSignature"> </div>

 

[Boris_Badenov]

Take a look at this website,<br /><br />http://www.permanent.com/index.htm<br /> <br /> & this page in particular,<br /><br />http://www.permanent.com/a-meteor.htm#compose<br /><br /> I have found this subject to be fascinating & have even tried to get a thread going on what it would take to move an asteroid into a stable Earth orbit. (not too much luck there<img src="/images/icons/frown.gif" />)<br /> I certainly hope to live long enough to see the first successful asteroid mining mission succeed. <img src="/images/icons/smile.gif" /><br /><br /> <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[spacester]

Nice links. (I myself have been there read that many times but hopefully others will catch the asteroid fever.)<br /><br /><font color="yellow">. . . tried to get a thread going . . . </font><br />(Tell me about it. I've been trying for years here. But back to this latest attempt . . . <img src="/images/icons/laugh.gif" /> ) What I'm wondering here on this <i>science forum</i> is what we can expect when we get there, how many C1 / C2 types we can expect to prospect before hitting the mother lode. I was hoping that Deep Impact and other stuff might have spurred some thoughts along these lines.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[Boris_Badenov]

What’s really needed IMO is a real spaceship that can go out & prospect an NEO, come back, then turn around & do it again. IMO that is the only way in the near future we will be able to spur interest & gain knowledge. Space Dev is working on the Near Earth Asteroid Prospector mission, but it is unmanned & probably not very well funded. Only manned missions will really get the investments coming in in the near term, IMO. <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[spacester]

Well this discussion prolly belongs in M&L but what the heck. I'm already known as a trouble-maker anyway, right? <img src="/images/icons/wink.gif" /><br /><br />I pretty much agree but IMO <i>manned</i> missions to asteroids are a little bit nuts. They might make sense for a government-financed science mission, but the costs of keeping those folks alive would seem to blow the economics of a non-subsidized entrepreneurial prospecting and mining effort. Don't get me wrong, if such a thing was in the works I would be thrilled and heartily endorse it. It's just that it seems to add a LOT of extra cost for not all that much more benefit.<br /><br />I agree completely that (if it can be made to work economically) it would be a fantastic way to 'spur interest and gain knowledge'.<br /><br />The logistics are going to be difficult. I would be happy just to see a scholarly treatment of the available targets and mission design choices, based on having a true spaceship with re-propellanting <img src="/images/icons/wink.gif" /> capability. Everything I've seen is quite dated and also based on the minimum-mass mentality as opposed to a maximum capability mentality.<br /> <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

We can probably tell which ones have a high probability of having water ice. Those those are carbonaceous in character and/or show comet like affinities.<br /><br />I suggest the real challenge is to develop a efficient way of exploring beneath the surface. Especially given we don't know the amount of ice, it's depth in the body, whether it occurs uniformly or irregularly. Perhaps a series of Deep Impact type missions to prospective NEOs, followed by detailed orbital reconnaissance of the select few that show water signals? You would need technologies that can explore the subsurface like radar, neutron beams, electromagnetics.<br /><br />Of course developing the technology to extract the water on a NEO is a whole different ball game. Maybe this is something that should be done on Phobos and Deimos first? Propellant extraction on these moons would transform Mars mission logistics and they are also much more accessible. There is also a Phobos sample return slated within the next decade as well.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[spacester]

Hi Jon,<br /><br />Thanks for the reply. Prolly more than I deserve.<br /><br />I guess this is my specific question: is the model of a relatively thin (~1 meter) crust encasing a big ball of ice at all realistic?<br /><br />I'm thinking about a high-risk, high-reward prospector mission with a lot of dV capability which would go visit maybe a dozen candidate NEOs in search of one ore body. If found, it could drill thru the crust and extract a big bag of ice and return to cis-lunar space. It would not have a whole bunch of science instruments, that mass would be allocated to the drill/extractor unit instead. Maybe just cameras and sampling, do the science on the samples when you get home. It would take pictures and land and drill and if it doesn't hit ice after a meter or so of drilling, it would move on to the next NEO. But if it does, it becomes a mining mission first and a science mission second.<br /><br />The Phobos sample return is very exciting but this would be about the NEOs. The science yield would still be high because you would perform a survey of objects which we can expect to be quite diverse based on what we've seen at Eros, Itokawa, etc. Barring malfunction, if you don't get the survey done, you get a big bag of ice instead, and that would have monetary value.<br /> <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

Hi spacester<br /><br />If you are looking for a thin crust over ice then you would be looking for dead or near dead comets, I would guess. Not asteroids. That makes target selection much easier. I am not sure if you could count on a crust less than a metre thick though.<br /><br />I guess it would depend on which was more cost effective, lots of small cheap missions or one complex mission that visits several.<br /><br />The trouble is most comets as I recall have high dV to visit. Don't have figures to hand, sorry.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[spacester]

Oh hey, I'll take care of the dV calcs, no worries there. With any luck, I can get a grad student to do it for me. That's the usual tactic, right? <img src="/images/icons/wink.gif" /> Part of the reason for talking about this on S S & A is to point out that the reason you'll not find dV figures to hand is that they are not out there, at least not current ones and certainly not ones that use Lambert's Solution (quicker than Hohmann, direct no-tangent trajectories), which is what I mean by a maximum capability mentality as opposed to a minimum mass mentality. I can do the calcs myself if it comes to that.<br /><br />But how do I tell the difference beforehand between a pile of rocks ("Asteroid") and an ice ball with a crust ("dead comet")? They both have a low albedo. This is why I've used the word "Object" instead of "Asteroid" in all these posts.<br /><br />I want low eccentricity, but what I understand to be the hallmarks of a dead comet is high eccentricity. I'm looking for that one ore body with low eccentricity, and if high eccentricity is my only guide to telling the difference between a pile of rocks and a disguised chunk of ice then I am working at cross-purposes. What I wonder is if the last three years have done anything to help me out here. I know that results have been somewhat unexpected, and it seems like there has been enough time to analyze and publish.<br /><br />I envision a wildcat prospector craft (not just a "probe") to go find just one ore body and if found, we start exploiting it immediately. You know me, I'm always looking for shortcuts that are actually feasible. <img src="/images/icons/laugh.gif" /> I won't go so far as to say it will be simple, but I see another road between lots of small cheap missions and one large complex mission. I would describe my idea as a medium-sized mission that visits several obje <div class="Discussion_UserSignature"> </div>

 

[torino10]

I think the main problem with the asteroid moving concept is that if it takes more energy to move the asteroid to the earth than it would take to launch a similar mass of useful resources from the earth then it kinda makes it uneconomical to do so. <br /><br />Of course if we listened to been counters we wouldn't be in space at all.

 

[mikeemmert]

Nice pictures of space colonies on that site. Reminds me of the old L-5 Society and the Space Studies Institute. Does anybody remember those? I was one of two members in San Antonio, Texas. The other guy wasn't very active.<br /><br />I've noticed that there aren't a lot of theads on space colonies, solar power satellites, moon and astroid mining, and things like that. So, I have decided to be real frank about what scared me off.<br /><br />The L-5 Society wanted to put a colony at the Earth/Moon L5 point. They said it was stable. You can solve the three body problem for all time.<br /><br />One day I received through snail mail (remember that ancient concept?) a map of the Sun/Earth Lagrange stability zones. That was pretty interesting. Nice, tadpole-shaped orbits. The longest of these met at the Sun/Earth L3 point on the other side of the Sun. I looked at the points of closest approach to Earth and thought, "Gee. What if it hit the Earth?"<br /><br />Then I thought, "Well the Moon might get in the way. What if it hit the Moon?"<br /><br />...<br /><br />~~!@**__ <img src="/images/icons/crazy.gif" /> ~~~<br /><br />"What if it IS the Moon?"<br /><br />If the Moon formed at the Lagrange points, then, since there are Lagrange points throughout the Solar System, there should be evidence of other Lagrange point objects. Instantly, I flashed on Caloris Basin on Mercury, Pluto, and Neptune's strange, backwards orbiting moon, Triton.<br /><br />Was I elated at this stunning scientific discovery? Hell, no! I felt kind of queasy. It meant that I would have to inform the L-5 Society and the Space Studies Institute that the location they had selected for their space colony was not, in fact, stable. What would they think of me saying such a thing? And it wasn't based on some obscure mathematical theory, but rather solid observational evidence.<br /><br />Worse than that, the Voyagers were on the way, and if Lagrange objects did indeed form and were in fact unstable, then there wo