Water on Mars

I just thought I'd bring up the discovery that Mars' northern pole has between 2 - 3 million cubic kilometres of ice (about 95% pure). This is about 100 times the volume of North America's Great Lakes. On Earth there are about 41 million cubic kilometres of freshwater. About 69% is thought to be locked into permanent ice and snow. About 30% is located within soil and aquifers. This leaves about 1% or 0.41 million cubic kilometres to run free on the surface. A large number of people get drinking water from aquifers, but this suggests that with wise management, Mars' water should be able to support a population substantially larger than what now exists on Earth.

Mars Hab Facade Concept

Here is a concept for the facade or a Mars habitat. In this design, there are no pieces that are actually fastened together. Everything is held in place by the interior pressure of the habitat. The Tension anchors (point towards centre) hold the entire structure together. They may be hidden in floors of the habitat. These in return hold in place the steel panel frames. These steel panels hold in place the glass with a layer of cushioning in between. Between each metal panel is another seal (the rectangular black) to prevent atmosphere from escaping. There is a great reduction in overall forces in all pieces, excluding the tension anchors.
The above is a side few of the facade. The same replacement technique can be used for the glass panels as mentioned in my previous post.
From the back, it is easier to see the black cushioning. This design has a lot of drawbacks and would likely be impractical. It would be difficult to fashion the tension anchors to one centre point. It is possible there could be a ring structure in the centre with each tension anchor attaching to it like to a key chain. The top would still need to be weighed down with regolith. It would be difficult to construct and ensure that no leaks were present. With all seals dependent on the interior being pressurized, the structure would have to be pressurized very quickly at a rate faster than it initially leaks.

It may be more practical to use this idea along with others, as opposed to applying it to all components.

Mars Bean Can Facade

The above picture is a 'detailed' look at the facade for the Bean Can Hab. The main vertical and horizontal structural members can be clearly seen. The metal ridges that support the glass can also be seen, covered with cushioning at the edge. The panels are then placed on the cushioning.

When a panel needs to be replaced, a seal (temporary panel behind glass, made of steel) is put against the main structural members on the inside (with cushioning if necessary). The original panel is then removed from the outside (possibly shattered). Since the panels are smaller than the area between the frames, a new panel can be brought through the outer frame on an angle. The panel can them be moved into place and held there while the inside steel seal is removed. A plug may be removed from the steel panel allowing pressurized atmosphere to enter between the clear panel and temporary seal. The new panel would be locked into place by the pressure, and the temporary steel panel could be easily removed.

Mars Bean Can Hab

One of the first concepts that I developed for a mars habitat is a 'Bean Can'. This takes the so-called tuna can design to a more permanent level. The majority of the structure is constructed of steel, with solid transparent panels used as the skin. Inside, there are several stories to house colonizers, scientific equipment, greenhouses, etc. The metal frame has a cushion onto which the panels are placed. Once the habitat is pressurized, the force exerted on the panels pushes them against the cushion, creating an airtight seal.

To replace a panel, a seal (larger than the panel) is placed on the inside in contact with the horizontal and vertical steel supports. There is an extra metal frame welded to the supports to hold in the panels (not shown in renders). The old panel is destroyed from the outside and removed. A new panel is slid in at an angle and rotated. When it is appropriately fixed into place, the inside seal is removed and pressure reseals the panel.

In the picture above, you can see the main support columns inside the structure. These serve two major purposes, to hold up the floors and also to hold up the large mass of soil on the roof during construction. The lower portion of the structure is used as green/public space. The space between the outer frame and interior structure allows for panels to be easily replaced, and allows for better air flow. Sensors will be located throughout to constantly monitor the outer frame.

















The roof of this habitat has many useful features. First of all, it greatly reduces the strength requirements of the vertical members. The pressure inside this hab is about 50kPa. This means that for each square metre of roofing area, about 50KN or soil is required to be placed on the roof to prevent it from flying off (about 6m depth assuming density of concrete). It may not be practical to place enough to entirely counteract the pressure, but it will definitely be helpful to have some. The rest of the force would be carried by the vertical members. This would however require bedrock anchors to transfer the force into the ground. The soil also helps to shield residents from radiation. The roof may also act as a solar collection area, or eventually sprout antennaes.

This last picture is just a side view. The floors five metres apart and the radius of the habitat is about 16m. The plant silhouettes are a bit taller than the average human (of course we, especially future children, may be taller with the reduction of gravity)

Water

Unfortunately, Mars appears to have very little water. This means that it will be a treasured resource on the planet. Although there is the possibility of trade with Earth, or more likely mining of the asteroid belt, the available water must be used wisely. I have seen many suggestions for the use of plastic/kevlar domes. I have also seen people suggest Martian concrete be used in colonies. This strikes me as a waste of a pressure resource. Water should not be locked up into construction materials. Nor should it be broken down for use in plastics.

The following elements are available on Mars in plentiful supply:

Silicon
Aluminum
Iron
Calcium
Magnesium
Titanium
Oxygen
Carbon

These elements exist lesser amounts:

Sodium
Sulphur
Chlorine
Potassium
Nickel
Zinc
Argon

The iron on Mars mainly exists as FeO. All that is required to free this iron is the addition of carbon monoxide. As such the steel industry on Mars will flourish. Major alloying materials are also available in plentiful supply. I believe that glass will also be a major building material. Silicon dioxide makes up the majority of the crust. New methods will be required to make the glass ductile to prevent unexpected failures in dome/habitat structures.

Martian Apartments

I have been thinking for a long time about the different ways to live on mars. I don't like the idea of subterranean dwellings. I would need to be on the surface with a view of the landscape. I do find domes to be alternative, however from an engineering point of view there are many technical problems to overcome. I'm sure they will eventually be constructed, but until then another solution may be in order. For this reason I developed the concept of a Martian apartment.

All parts would be prefabricated, transferred to site, and then assembled. After the outer skin is sealed, construction could be continued without environmental suites. Proper radiation coatings/precautions on the skin may allow plants to be grown hydroponically under Martian sunlight (with supplemental lighting for dust storm season if necessary). Sheet could be drawn over the apartments at times when large solar flares are approaching the planet.

The reason the apartments are on 'posts' is to eliminate problems from accumulating dust (although the tops may collect some). Posts also reduce the need to excavate the frozen regolith.

This 'pill' apartment could comfortably house about 160 people. They should be able to grow about 30% (conservative) of their food on the roof hydroponically.

Here are three different concept shapes in a complex together. It would make more sense for them all to be linked.