An asteroid colony

[j05h]

The device I describe uses both a Tunnel Boring Machine (TBM, search: Lovat) and a solar-heater- the main components are the TBM in a "mining platform" and a powerplant "tug". It is really only useful for mining dead comets in the inner solar system - there are a few candidate objects but only one is needed. It won't work on stony or metal asteroids, and might work marginally on C-types - the initial goal is water production. Getting water from mud ice (dead comets) seems much easier than processing hydrated rocks. For some products (breathing gases) , there might be enough extraneous volatiles available on the comet to support local needs. The water , judging by the Deep Impact results, is much easier to get at than from a C-type asteroid. The various asteroids offer other resources, but I'm convinced that water will be the first big extraterrestrial export product (to LEO). Whether it comes from the Lunar poles, 1989VA or Phobos depends on who succeeds first.<br /><br /><br /> <br />The mining system I'm baselining includes a 5m diameter TBM. The mining platform burrows long tunnels into the comet with chambers at the end. The tunnels should be large enough to pass deflated Bigelow Nautilus units into the interior. Alternatively an airlock could be installed at the tunnel entrance and the interior pressurized and sealed with mylar or astrocrete. I'm not sure if there is a direct window into the tunnel, it could very likely just need to heat the TBM to create a bubble of warm water/mud that can be pumped dry. You could easily use several of the tunnels to remove large segments of the comet, or hollow out the interior leaving a "swiss cheese" of tunnels in the outer shell. Once you get to that level of comet engineering, you have sold millions of tons of water throughout the inner solar system. <br /><br />Vast chambers could be hollowed out of the inside while leaving the outer levels largely untouched. Ice and astrocrete would be used to reinforce chambers and seal th <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[chriscdc]

Seems like alot of hardware for the tunnel. <br />How much water is likely to be in these dead comets? Have they spent too much time near the sun and have lost most of their volatiles? Are they in favourable positions?<br /><br />For a C-type you would probably have to mine material to put in the hole.<br /><br />Are there any designs for simple, light airlocks? If you are going to have multiple chambers then you will need a large number of airlocks. What precision do airlock interfaces have to be machined to and can this equipment be portable?

 

[j05h]

Even Near-Earth comets are going to be about 50% water, only the upper layer will be dehydrated. Estimates are in the few meters depth before hitting serious water. Yes, there are some in extremely favorable positions, and according to Dr. John Lewis as many as 1/3 to 1/2 of all NEOs may be dead comet cores. Oceans of water at our doorstep. If they are former comets, Phobos or Deimos will be economic powerhouses if there is a rush for Mars.<br /><br />From my understanding, a lot of C-type asteroids fall into the "rubble pile" category. <br /><br />Simple light airlocks... maybe deep-water diving airlocks. Ideally, the mining platform could leave behind a component that docks and seals an airlock. The tunnel-based lock could be shipped as two pressure doors and astrocreted/iced in place in the tunnel. The doors would have all the pumps and controls for the lock. Another option would be a disc with inflatble ring, when commanded the ring deflates (after depress), the EVA crew pushes door out of way, exits and replaces door. A big inflatable bag jammed at the tunnel entrance might do the trick if you feel lucky. If the lip of the tunnel is built inward, the outer lock door could just be held in place by pressure. I don't see a need for a "module" airlock if the tunnel is a known size and material. I am guessing that in the 'swiss cheese' scenario, many of the tunnels will be sealed or used as light tunnels/gardens/something. Also, I would expect there to be plenty of vaccuum space inside some tunnelled comets, for use in manufacturing and assembly, but sheltered. <br /><br />The tunnelling hardware is being sized on 10 ton robots - the mining platform is 10 and each tug/powerplant is 10 (or several smaller units). The actual hardware should be robust, simple and fairly minimal - lots of frame and accordion tanks. Dr. Zuppero's numbers indicate ice-return craft being able to realistically bring back 100s of times their own mass in water, a 10-ton tug may very well be able to <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[nexium]

I think nearly all these ideas have near term possibilities. The robots first establish whatever type of out post is practical on as many of these near Earth objects as practical. Even a 50 meter object likely has some useful resources and 20 meters of shielding is much better than, the perhaps, one meter which is practical with most other space ideas. If 2000 is the correct number over one kilometer, there may be 100,000 over 50 meters. With outposts in 1% of them, windows of opportunity should occur most weeks. A specialized robot can move to a different object, shortly after it has accomplished as much out post improvement as practical.<br /> A robot low on fuel or with other problems will stay put until another robot or a pair of humans lands at the out post. Repairs and refueling will sometimes (frequently as technology improves) be practical. With improving technology more than a million of these out posts may be practical all the way to the Oort cloud. Each would have zero to ten humans, with larger human colonies rare. Each outpost would have one to a few specilties as it it is unwise to try to do a lot of things. The system can operate without out posts on Mars or big moons. Opportunities for small moons should occur occasionally. My guess is most objects have at least tiny ammouts of nearly every element. Neil

 

[j05h]

Nex- yeah, mining robots as small-settlement precursors is the plan. One dead NEO comet is all it takes for starters. Once you have the resources, those little NEOs (the 20-100m ones) can be directly moved to Earth orbit (or the main comet) for centralized processing. Yes, there should be plenty of extra volatiles, metals and silicates on any of these bodies. Nitrogen may be an issue, but there are plenty of long-chain polymers (essentially oil shales/kerageenan) in C-type asteroids - even if it's a little hard to grow plants there can be a native freespace plastics industry. There should be a source of N somewhere in the NEOs...<br /><br />The "mining platform/tug" architecture I described allows for serious bootstrapping on both the individual robots and whole system levels. Other advantages include low energy needs, non-toxic/cryo product (simple handling) and ready market. Now, I just have to figure out how to build it. 8) <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

Making asteroid mining (then colonization) practical in the near term is going to involve what? here is my list.<br /><br />In-situ bootstrapping: use of available materials in new ways. Water for fuel, atmosphere and vehicle structure. My focus lately has been dead NEO comets, what products would be viable from other asteroidal sources? The radio today described Tempel 1 comet as having the consistency of meringue - separating the water and various volatiles should be fairly simple once the comet can be mined. Should be plenty of volatile rich meteors inside the comets as well. Here are some quick space-made products that could effect nearterm colonization: water, H, O, methane, CO2, plastics (habs and solar reflectors), metals for foil & vapor depositting,<br />sintered products, fiberglass, maybe solar-blown glass. The biggest stumbling block is Nitrogen. Any sources? Perhaps one of the C-types? Nexium's idea on most asteroids having resources from other types has validity. Even relatively small amounts of various elements could have a strong influence on NEO economics. Starting with small NEOs is interesting, as they can be captured in bags and baked for resources. Small "rubble pile" type asteroids could be utilized in a similar manner. A 50m ball would probably lend itself to complete transformation into a much larger object via manufacturing, or consumed to get to the next target. Homesteading the small NEOs, if you had a product to export, has possibilities. <br /><br />Equipment bootstrapping: reuse of rocket stages, tugs and other material. With human technicians on the LEO end, the water tugs I proposed could be repacked and sent back to mining site. Large rocket stages can serve<br />as extra living space in the "tin can" period, water or waste storage.<br /><br />Lifeform bootstrapping: IMHO, the only way development and colonization can succeed is with serious biology. We may end up living inside giant organisms instead of machines, live among giant trees <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

Pretty much the same thing. The objects I was describing are smaller - one or several trees a few km long each, from a central comet. Orion's Arm never ceases to amaze me, very creative effort. <br /><br />I think that biology and "printing" (either inkjet or nano-based) will be the two really big enabling technologies for developing large structures in space.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[nexium]

Deep shaft mining on Earth typically pumps in large quantities of air from the surface to carry away waste heat. A NEO = near earth asteroid may start at 100 degrees k, but will warm one degree per hour, if heat in exceeds heat radiated from the surface by one trillion small calories per hour in a volume of two trillion cubic centimeters assuming an average specific heat of 0.5 Two trillion cubic centimeters = two million cubic meters which is about the volume of a 110 meter asteroid. We will be at 273 k (ice melts) average temperature in 173 hours of operation.We need to operate much smaller scale or cover the surface with heat radiators for waste heat disposal. A large colony population will also melt the asteroid without large area radiators on the surface. <br />Presurizing a billion square inches of interior tunnel surface = three billion pounds of pressure (humans can tolerate 3 psi of 98% oxygen) trying to expand the asteroid. Small asteroids have negligible gravity to oppose this expansion. A billion square inches is 0.645 million square meters. That is why I suggested small population per asteroid. Banding the asteroid may be prudent even for small populations to prevent expansion. Neil

 

[voyager12]

A 'Celestial Titanic' was mapped out over a year ago, that could support a large colony in orbit using a main belt captured asteroid:<br /><br />http://uk.geocities.com/aa_spaceagent/restricted/earth-ring.html<br />