Modular stations on the Moon and Mars

[willpittenger]

There has been debate on how to design permanent stations for Mars and the Moon. One school of thought uses inflatable modules. They are small prior to inflation and don't mass much. However, they provide little shielding without help. Other people want to bury the modules. Unfortunately, such modules of a solid construction would make an ISS module look like light weight designs. You need a lot of structure to support the cover. That is heavy. A conventional design would also have to be shipped in one bulky piece.<br /><br />So I thought for a while on how to combine the two concepts. The result uses a foldable or collapsible version of the solid structure to support the cover while an inflatable liner provides the airtight layer. The "solid" shell comes disassembled. It needs no seals or, in most cases, connections stronger than a simple snap-together connection system. You start by laying out the floor. This prevents the liner from being damaged by the regolith. (That would be especially important on Mars where the regolith material will be corrosive).<br /><br />You then spread out the liner onto the shell floor and partially inflate it. The inflation allows you to check one last time for leaks and, hopefully, fix them. Now you put the dome part of the shell up and finish inflating the liner. That module is done.<br /><br />One thing I did not know how it would be done was the interconnection of modules and any docking system for rovers. Please reply for your ideas on that and your concepts for the overall system. Also, which of the following systems to bury the module is better?<br /><li>Place the module straight on the surface and dig material up from elsewhere<li>Dig a hole and put the module in that<li>Use a crater for the module's hole</li></li></li> <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[bitbanger]

Another possibility is to take an inflatable like the BA330 and land it. Over inflate the bladder to provide strength then fill a bladder on the outside of the module with water and let it freeze. Then reduce the internal pressure to normal and inhabit. <br /><br />The water provides both shielding and structural rigidity.<br /><br />

 

[docm]

Bigelow already has a way, and it's made for irregular terrain (below) <div class="Discussion_UserSignature"> </div>

 

[bpfeifer]

I hadn't heard of the ice bladder before. It's an elegant solution. Here are two other possibilities using lunar regolith:<br /><br />Put a lightweight frame over your inflatible module. then fill sandbags with regolith, and pile them over the frame. The biggest advantage is that the system makes use of in situ resources without requiring any heavy machinery.<br /><br />When you microwave lunar regolith it forms a hard glassy material. You could build a device to maufacture regolith bricks, and build a nice dome over your inflatibles. <div class="Discussion_UserSignature"> Brian J. Pfeifer http://sabletower.wordpress.com<br /> The Dogsoldier Codex http://www.lulu.com/sabletower<br /> </div>

 

[willpittenger]

Both of your solutions require lifting some relatively heavy weights over the structure. So you still need something like a forklift or crane. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[thereiwas]

Bigelow's design includes <i>internal</i> water shielding already.

 

[Boris_Badenov]

Heres a little info straight from the horses mouth.<br /><br /> BIGELOW SHOOTS FOR THE MOON <br />Posted: Thursday, February 22, 2007 6:36 PM by Alan Boyle<br />Getting all that right is "Job One," Bigelow told me. But by 2012, the focus could start shifting from low Earth orbit, or LEO, farther out into space. One of the key places in Bigelow's plan is a point about 200,000 miles (323,000 kilometers) out from Earth in the moon's direction, where the pulls of terrestrial and lunar gravity balance each other.<br /><br />Bigelow would turn that region of space, called L1, into a construction zone. Inflatable modules would be linked up with propulsion/power systems and support structures, and then the completed base would be lowered down to the moon's surface, all in one piece.<br /><br />Once the moon base has been set down, dirt would be piled on top, using a technique that Bigelow plans to start testing later this year at his Las Vegas headquarters. The moon dirt, more technically known as regolith, would serve to shield the base's occupants from the harsh radiation hitting the lunar surface.<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>

 

[docm]

Yup, one of this years more interesting interviews even though it's short. <br /><br /><font color="yellow">Both of your solutions require lifting some relatively heavy weights over the structure. So you still need something like a forklift or crane.</font><br /><br />See those retaining arms on the crawler? IMO they double as cranes. <div class="Discussion_UserSignature"> </div>

 

[windnwar]

I always wondered if it would be possible to bring processing equipment to powder the regolith material, and then mix it with a small amount of an epoxy resin to use it almost like a stucco material over an exposed frame, with say the inflatable module inside of it. Basically using it as a sprayable building material to create shielding. either that or use it to fill a special bladder on the outside of an inflatable so it's self contained simply fills the outside form of the structure. It should provide good protection against micrometeorite impacts as well. <div class="Discussion_UserSignature"> <p> </p><p><font size="2" color="#0000ff">""Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." --Albert Einstein"</font></p> </div>

 

[docm]

The Cosmic Log interview addressed that (fluff edited & reordered for continuity);<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>>>(this para out of order)<br /><br />B: <b>our concept of lunar base construction would be to assemble various modules and propulsion/power buses in L1, and that would constitute the base. Those propulsion systems are full of fuel, and they are integrated into the overall structure in such a way that the entire structure lands as a unified base – which essentially was once a spaceship in L1, but is landed on the surface of the moon.</b><br /> />><br />CL: Once the moon base has been set down, dirt would be piled on top, using a technique that Bigelow plans to start testing later this year at his Las Vegas headquarters. The moon dirt, more technically known as regolith, would serve to shield the base's occupants from the harsh radiation hitting the lunar surface.<br /><br />B: "We’ve had some discussions with NASA regarding lunar activities using these structures, and we’ve presented NASA with two concepts for our approach as a private company to creating a lunar base and also providing the regolith insulation protection"<br /><br />B: "Our concepts are completely different from all the other concepts that have been kicked around about how to deploy the regolith. We have our own approach about how to create the base and the provision for gathering that lunar material and placing it over the modules. And that’s been the focus of our discussions with NASA, on just that particular subject of lunar interes"<br /><br />B: "Now, all the architectures for deploying the regolith involve some kind of conveyor belt, or a tractor or some other kind of large equipment that rolls around the surface, scoops up the material and transports it like you see on construction sites terrestrially. "<br /><br />B: "The last thing you want to do is handcuff yourself to an Earth solution for moving material – a strategy that would</p></blockquote> <div class="Discussion_UserSignature"> </div>

 

[kelvinzero]

Frustrating that they feel they have to be so mysterious about their techniques.<br /><br />As for epoxy, It might be easier than that. I read somewhere that the jagged nature of regolith particles can make them interlock quite firmly if compacted the right way, also a low power microwave can be used for sintering (making the regolith particles stick together by heating) because the microwave would heat just the tiny specs of iron that are common within the regolith.

 

[docm]

Microwave makes more sense than epoxy because you only have to ship the emitter instead of tons of resin and whatever you need to mix and apply it by the ton. <br /><br />You wouldn't necessarily have to heat it through either, just enough to form a crust thick enough to retain the rest. Of course this presumes the hab structure can take the heat that reaches it.<br /><br />Whatever means Bigelow intends to test should be interesting given he thinks it can be done by 2 men without significant equipment.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[windnwar]

I'm curious as well because I can't see any easy way to move the amount of material around without having some sort of excavation equipment there. The upside is, it doesn't need to have near the power of earth based equipment since its such a low gravity environment. I would imagine the biggest challenge would be it would need to be all electrically actuated, as traditional hydraulics I would think wouldn't be suited there. <br /><br />What I had in mind for the outer bladder of the hab would be a bladder that is say 12-18 inches wide with a central opening at the top of the structure, then basically powder the regolith an fill it from the top down. You could even do it using lightwieght carbon fiber or aluminum panels that assemble around the outside of the hab with spares attatched to the hab to position it and basically snap them together, fill it near the top and then snap on another row, until you reach the top. You just need something to contain it. Wieght really won't be much of an issue in the low gravity there. <div class="Discussion_UserSignature"> <p> </p><p><font size="2" color="#0000ff">""Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." --Albert Einstein"</font></p> </div>

 

[docm]

Maybe he has a compact battery powered lunar "snowblower", which when you think about it isn't such a bad idea if you can get the stuff to stick where you put it. Using lightweight "catchers" as you described might just work for retention. You might just need it over the top 30-40 degrees or so, minimizing the mass at launch.<br /><br />Whatever it is it'll apparently work in 1G too since he plans on testing it in Nevada, presumably with sand. <div class="Discussion_UserSignature"> </div>

 

[windnwar]

Anything beats getting out with a shovel to do it so hopefully he's got a pretty cool way to do it. If it will work with sand here, it ought to work there i'd figure. <div class="Discussion_UserSignature"> <p> </p><p><font size="2" color="#0000ff">""Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." --Albert Einstein"</font></p> </div>

 

[bitbanger]

I understand that lunar fines are magnetic due to nano scale iron particles. If that is the case, then a magnetic vacuum may be usable. Sort of like a linear accelerator in a tube that transports the fines via magnetic fields.<br /><br />I also wonder if magnetic fields can be used in a habitat's mud room to remove lunar dust? <br /><br />

 

[willpittenger]

The explosives would probably require astronauts whose primary (and only non-emergency duty) would be the safe handling of the explosives. Everyone else would probably be told to stay clear. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>I also wonder if magnetic fields can be used in a habitat's mud room to remove lunar dust?<p><hr /></p></p></blockquote><br />Perhaps the best option there would be a deguasser combined with a vacuum. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[h2ouniverse]

Or another solution:<br />1) find a cave<br />2) inflate the modules in the cave.

 

[thereiwas]

That crawler thing does not look like a Bigelow design to me.<br /><br />The Bigelow modules are intended to be assembled in lunar orbit, and landed already assembled, in a prepared location. He doesn't want to have to move them around on the surface. And even if that was needed, they still have the rocket engines that slowed their landing in the first place, which could be used for a short hop or position adjustment.

 

[crix]

Yeah. I'd like to know where that image came from. I doesn't seem to look like anything that Bigelow was describing. It's exactly the opposite in fact... multiple mechanical joints, plenty of failure points.<br /><br />

 

[docm]

It dates from 2001, BA being founded in 1999, so it's an early concept. Something like it would make sense for moving modules around as would have to be done to replace one. <br /><br />The moon base concept does use assembling several in space and landing them with those modded power busses I posted images of previously. Those images are from last year.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[crix]

I think Bigelow has got the right idea with pre-assembly in space, as opposed to an uneven surface with gravity.<br /><br />

 

[docm]

I agree, especially after reading that the landing feet include what amounts to leveling jacks. <div class="Discussion_UserSignature"> </div>

 

[thereiwas]

Yes, the Power Busses are what they are called. I forgot the name. Possibly with some refueling, those could be used to lift the station off the surface and moved a short distance. Beats using a crane. If the guidance system is good enough to land it in the first place, unmanned, it should be good enough for some careful hops if really necessary.<br /><br />I would not want to be standing too close.