032.concrete shells

3.3.7. Concrete Shells
Concrete can be manufactured out of Martian regolith and water. It does need however need something acting as a form and inflatable structures could provide it thus allowing big shells with very large spans.

PROS
· Good performance both as compressed (concrete) and tensed (inflatable).
· Continuous surface without joins.
· No need for outer protection to abrasion.
·
CONS
· Inflatable structure will require manufacturing in Earth and therefore small amounts of pressurized spaces will be able to use this system. However unpressurized spaces using this technology will be largely available if the inflatable form can be reused several times.
· Still need for protection for radiation (50cm regolith).

TEC3

031.steel profiles and e glass

3.3.6. Steel profiles and E Glass
Steel plates can also form profiles that can be filled in with E Glass windows in order to get transparent structures needed for the greenhouses.

PROS
· Good performance both as compressed (gravity) and tensed (inner pressure).
· Easy methods for welding testing.
· No need for outer protection to abrasion..
CONS
· Large lengths of continuous welding.

TEC7

030.fiber glass vessel

3.3.5. Fiber glass vessel
Fiber glass can be winded around a cylinder using pressure and resins to manufacture vessels of different diameters depending on the manufacture spaces size.

PROS
· Good performance as tensed due to inner pressure.
· Reduced weight that simplifies construction.
CONS
· Joints and holes have to be previewed and need steel connections.
· Depending on size, main structure will be required in order to stand compression forces due to the weight.
· Low performance in front to abrasion. Will need protection (steel plates or sand projection)
· Need for radiation protection.

TEC2

029.steel plate construction

3.3.4. Steel plate construction
Steel can provide a construction system that both stand the weights of materials due to Mars gravity and the tension due to the interior pressure in conditioned spaces. Steel will be manufactured in the shape of plates and small profiles. By continuous welding small plates of around 30cm together, bigger plates of around 90cm can be manufactured on conditioned spaces and afterwards brought to the construction site where they will be finally welded to achieve bigger surfaces.

PROS
· Good performance both as compressed (gravity) and tensed (inner pressure).
· Easy methods for welding testing.
· No need for outer protection to abrasion.
· All shapes available.
CONS
· Large lengths of continuous welding.
· Still need for radiation protection.

TEC8

028.rigid vessels

3.3.3. Rigid vessels
Rigid vessels built with light materials such as aluminum are the most common technology at the moment for space constructions. It’s a proven technology although its manufacturing might be difficult in Mars. However, it can be brought from Earth in small amounts specially to set up the first conditioned spaces.
PROS
· Proven technology with better shielding against radiation and micrometeoroids.
· Fully tested on Earth.
CONS
· Difficult to manufacture in Mars, would require expensive transport from Earth.
· Lower ratio volume/mass and thus larger launching cost.
· Smaller diameters and volumes due to launching fairing capabilities.

TEC5b

027.inflatable structures and vessels

3.3.2. Inflatable structures and vessels
Inflatable structures are very attractive but it is still a non proved technology and it might be difficult to manufacture it in Mars facilities. It is however a good option to bring in small amounts from Earth.
PROS
· Offer large in-use volume with big launch weight savings, lower packaging volume.
· Offer good ruggedness.
· Easily deploys curved surfaces (optimal for interior pressure requirements).
CONS
· Non proven technology
· Difficult to manufacture in Mars, would require expensive transport from Earth.
· Difficult integration of windows and hatches.
· Difficult protection against radiation and micrometeoroid impacts.

TEC6b

026.masonry structures

3.3.1. Masonry structures
Consisting in arches or vaults structures built from bricks manufactured using regolith.
PROS
· Easily available, simple to produce and extremely durable.
· Easy building operations in site with techniques requiring no support.
CONS
· Difficult to achieve big spans without support.
· No tensile strength capacity. Need for interior tensile structure or 10m regolith covering to balance interior pressure.
· Problems of sealing joints between bricks to avoid decompression.

TEC1

025.building technologies

3.3. Building Technologies
Considering these environmental challenges and the ISRU available on Mars following 4Frontiers Corp. guidelines, some technologies are considered to meet the requirements of a human inhabited set of buildings. 4Frontiers Corp. strongly recommended maximizing the use of different technologies in order to have a wide range of options in case any of them is considered ineffective once deploying the settlement.

To evaluate these technologies it is necessary to consider:
· Maximizing the in situ resource utilization due to the extreme cost of importing materials from Earth. This provides a set of materials such as: bricks and concrete from the Martian regolith, fiber glass and steel.
· The size of the facilities where materials will be manufactured into building elements such as steel plates, steel profiles…
· The building operations in the construction site.