Much work has been done in the last 2 months or so on revamping the structures of Cernan's Promise. Much more than is shown below, actually. As is common, much of my time is spent staring at my monitor, trying to figure out what makes sense on the Moon. This is punctuated by research online, consultations, and occasional deletion of current work to start over. Maybe a third of my time is actually spent building digital models.
To give a sense of the new directions, here are a few images of the Atrium habitat, the first to be occupied at the Lalande Crater colony of Cernan's Promise, which is the second colony constructed, after Inukshuk at the north pole. This is an evolution of the previous version. I rebuilt the entire thing fresh. Even with all the thinking, it still went ten times faster than the last build. May this be a sign of things to come, for it is necessary to move beyond this phase soon, and seek to make this a business. It will all be open-source, and the colonies will always be free. But, to do this will take a considerable amount of labor. It needs revenue.
For now though, i present for your consideration the beginnings. I spent only a day on giving things color, lighting them, and adding a little bit of imagery. With time, these images will look highly realistic.
The first image is of the top window at the south end of the Atrium hab. The glass is 6.5 m across (21 ft) and 10 cm thick (4 in). It maybe doesn't need to be so thick. The windows on the ISS cupola are 7 cm thick because of the amount of debris in orbit. In this case, a consideration is the backscattered spray of particles from collisions of cosmic rays with the ground. Those particles won't have the energy to penetrate too far, but we don't know how far or how many such particles fly around above the Moon's surface. It's really hard to say whether this thickness of glass is a sensible measure for long-term residents, or it's too much, or too little. This is a great example of the sorts of things i fret over - a barely visible detail that nevertheless has a lot of implications for the overall design, as glass is heavy and has to be locally produced in order to build a large colony.
|Finally, a window on the Moon i can get behind.|
The reason this window can see the Earth is it looks onto a shaft lined with mirrors, with the south face of the shaft tilted 45 degrees so it reflects whatever is directly above it into the hab. As this colony is on the equator, and the Moon is tidally locked to the Earth with an orbit inclined only 5 degrees to it, the Earth hangs in the sky near the zenith all the time on the Moon's equator. It should always be in view looking out this window. Okay, it won't actually look that big, that was a bit of license. But it will be 16 times the area of the Moon from our perspective, and 50 times as bright. In fact it might be worth hanging a big lens above the window that magnifies it so it actually does appear this size.
So let's talk stairs. On the Moon, climbing a step as high as steps on Earth would take the effort needed to climb a step an inch high in Earth gravity. It just isn't enough to feel like any kind of exercise at all. I think i'd actually find it annoying after a while. The stairs in the habs are all between 40 and 50 cm high (16 to 20 inches). That requires effort comparable to stairs here at home. But if that was the only difference, there would be two problems. One, that doesn't take into consideration that inertia is the same everywhere. Two, it is absolutely no fun. These problems are actually important to consider together. On the Moon, i think people are going to want to make use of their superhuman capacity to leap great distances a lot. If you are trying to run up oversized Earth-style stairs though, the challenge will be to not fall flat on your face because your forward inertia has not diminished, unlike the pull of gravity. It could be so challenging that one would be obliged to take one's time or risk a nasty spill. No fun at all.
|Low gravity stairs require a lot of thought.|
Thus, i made these stairs in which one hops from side to side to step up or down, and if desired, the pole can be used to aid in balance. Or you could slide down the pole. Or shimmy up it, for that matter - it wouldn't be very hard. As the path one takes is vertical, there is no need to think about inertia. With a little practice, i bet it would be easy to slip up and down these stairs, including jumping multiple steps, hauling yourself up after you've climbed part way, swinging off them from part way down, and generally getting good fun exercise out of them that fits neatly into your day. And yet, if you are carrying a tray of food, for instance, or you have a sprained ankle, or what have you, you can also use them gingerly and still get where you are going.
That's the kitchen in the corner there. I'll leave that for now though.
|The full 35 m height of the hab, showing the planters suspended from the beams, all the levels, and a bit of the crew quarters at left.|
On the left here is a row of crew quarters. This is the first hab on this site, so the quarters are built in a standard modular fashion to save space and time. (This is in contrast to the typical method of building quarters in the colonies, where each couple builds there own however they want, within the large open spaces of the habs.) The hanging planters of the gardens are above the rows of quarters. A fair bit of light still filters through them during the day, providing a soft green lighting like a forest in the area below. The catwalks along the planters for tending the plants will be mesh to minimize reduction of light - i haven't made those yet.
Here you get a sense of how high the hab is. Tall structures are a very good thing on the Moon - or rather, deep structures. They are built in excavated pits. Depth automatically provides good radiation protection and assists with thermal control, especially if the bottom of the habs are in contact mostly with rock instead of regolith. And in lunar gravity it makes sense to organize things much more in 3 dimensions. Reaching something 2 or 3 meters above your head is really no challenge, moving between floors takes very little effort. This allows highly efficient use of space, while providing a sense of openness. This atrium is 35 m high, with 10 levels. The internal structures are mostly suspended from the beams of the roof rather than being supported from below - light and efficient.
|Up close to the beams, a view of the sky. All the hab can see slivers of sky through the beams, and get natural sun from there.|
Between the beams is a view of the sky through glass. The beams are 50 cm wide and there are gaps of 75 cm between them. This is the radiation blind design discussed [here](https://www.moonwards.com/colonies.html#AtriumRadBlind), in which there is a dose of radiation coming from directly above, but to the sides it is blocked, and overall the reduction in radiation is something well over 90%. This is a first stab at representing what that would be like. The light is completely wrong, as is the sky, obviously. Mostly this gets across how much of the sky would be visible. The beams are very tall, to fulfill their radiation-blocking role. They shouldn't be black, i don't know why the cream color of them renders as black. Lighting and transparent materials are a complicated thing in 3d software. I'm still learning the basics.
|The mouth of the tunnel portion of the hab, the surrounding levels, and the 28 m tall gym in the corner|
This shows more of the layout of the levels, the mouth of the large additional section of the hab that is a tunnel, and the gym area in the corner. The curved bottom of the oval tunnel, under the main floor, is an area for all the equipment needed to maintain life support and hab systems. The interior of the gym is 30 m tall.
|Looking down from the top platform of the gym. The ropes, ledges, and rope net for climbing and parkour are shown, and the two trampolines at the bottom.|
This is a view looking down from the platform along the wall at the top of the gym. Jumping from this platform would be a drop of 28 m. And it is intended that people would often to exactly that. Everything is padded so that such a jump is perfectly safe, even if you landed badly. It is equivalent to jumping 4.7 m on Earth. If you hit one of the trampolines shown in light green, you could bounce right back up to the height of the platform. The trip in each direction would last about 6 seconds. Every surface is designed to be climbed on and jumped between. With no need to fear falling, this space is full of possibilities. As it is hard to work up a sweat without there being a big vertical element in your exercise (or else dealing with the awkward matter of inertia vs gravity), lots of vertical space is a good design for a lunar gym.
|Infrastructure stuff - the tanks for the water supply, thermal control, the walk-in fridge and freezer, exterior view of the reflecting window, and structural elements of the atrium.|
There is lots of infrastructure behind the visible things in the hab. This needs lots of work still. The habs make use of a large water supply (thanks to ice mining at the pole) to ease the burden of thermal control. That is what is in the biggest tank. The rest i'll explain later. There is a lot of thinking behind it but it is pretty dry.
|Dry composting toilets on the Moon... these too required a lot of thought...|
Ah toilets... these things took me a week. They are closely based on dry composting toilets on Earth, as all of the residents, um, output is valuable stuff that must be recycled. But it can't smell, and the volume of air in the hab is small enough for that to be a challenge. So the toilets look fairly ordinary above ground, but under the floor are a mass of tanks and tubing and filters. And they feed into larger tanks, and the drums behind them are emptied into a large main composter in such a way as to minimize odor. These things could be a blog post by themselves. But, let's leave that for now...
So this is what i've been doing, in part. Lots more work lies ahead. Videos and new 3d models that can be manipulated should get posted much more often beyond this point.