SFERO is a 3D printing habitat concept on Mars planet that relies on: The alliance of the resources that symbolize two planets (Mars and Earth): iron and water. A burrowing construction mast, equipped with two, independent robotic arms that allow for the additive manufacturing of two resistant shells, and the positioning of an insulation tarp (filled with water or other “Martian” materials)

1. SFERO TEAM – Identification Number: 2015-1- 055
FABULOUS: 3D printing consulting EXCELTEC: 3D Manufacturing Material expert François FORGET: CNRS Senior Research Scientist involved in space exploration, observations analysis, instrument development and
modelling of the environment on other terrrestrial planets Pierre BRISSON: Member of the Board of Association PLANETE MARS (the French branch of the Mars Society); President of the Mars Society Switzerland, Economist
(M.A. University of Virginia). TIRONI ARCHITECTURE: sustainable architecture Charles BEL: 3D Graphic Designer Benoit MOREL: engineering drawnman
Sfero – in French, short for Sphere, Iron and Water – is a habitat concept that relies on:
 The alliance of the resources that symbolize two planets (Mars and Earth): iron and water. The design of our shelter is based on the similarities
between the two planets’ main resources and physical make-up.
 A burrowing construction mast, equipped with two, independent robotic arms that allow for the additive manufacturing of two resistant shells,
and the positioning of an insulation tarp (filled with water or other “Martian” materials)
 A double-sphere construction, which is optimal to provide resistance to pressure and mass. Metal additive manufacturing will be used to build
the outer casing, while water will provide a protective membrane for humans. Iron is a symbol of paternal resistance, whereas water symbolizes
maternal protection.
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2. Heating drilling head
Telescopic (up to 50 ft H.T)
Mast with mobile rings that allow the two arms to turn horizontally
and move up and down.
The mast’s inner volume enables the magnetic selection of iron oxides, the
sorting of materials, energy procurement management for the lasers, and
temporary storage of additive manufacturing materials, pumping and
heating water.
Diameter: 1.6 ft. Folded height: 26 ft.
Main KuKa® arm equipped
with 3 CO2-powered lasers:
- Laser Melting (LM) = Laser melting of the substrata without
additional materials (consolidation, water- and airtightness,
foundations)
- Laser metal deposition manufacturing (LMD) = deposition of
FeO in the form of powder, and melting in the plasma stage
- Deposit of the insulating substrata in conjunction with the
secondary armSecondary KuKa® arm:
substance excavation and management
-Drilling, debris suction
-Removal, re-introduction and clearing materials
-Placing and filling the tarps
-Heavy load handling
®
ADDITIVE MANUFACTURING
OF THE TWO SHELLS
DRILLING
FOUNDATIONS INNER DESIGN INSULATION
Lower shell
Upper
Shell
Aqueous
pocket
permafrost
The mast is the core element in the design. Drilled into the ground, it acts as a pillar
and ensures the shelter’s durability and resistance.CONCEPT

3. 1. Principle of additive manufacturing
Additive manufacturing techniques involve building parts by layers of material, but do not always involve fused
deposit modeling. The material to be used on Mars, iron oxide, is an indigenous metal. The goal is to use
this material with additive manufacturing techniques based on laser welding.
2. Laser welding
The process of laser deposition is known by several names, most of which are trademarks of various machine
manufacturers or research establishments (LMD, DMD, DLD, LENS, etc.). The process involves a laser
beam used to form a melt pool on a metallic substrate, into which powder is fed. The powder melts to form
a deposit that is fusion-bonded to the substrate. Both the laser and nozzle from which the powder is
delivered are manipulated using a CNC robot or gantry system. When the process is correctly controlled a
wide range of material can be deposited.
3. Characteristics
Robotic arms
Several projects currently use a robotic arm equipped with a 3D print head for large-scale metal printing. The
idea of using an industrial robot with a welding machine to sculpt and print metals—stainless steel,
aluminum, bronze and copper—came from the Joris Laarman Lab, which conducts experimental work in
arts and design. MX3D-Metal is still at the design stage but the first pictures look promising. In theory, the
technology could be used for large-scale work using basic welding techniques that do not require support
structures. The nozzle on the end of the robotic arm adds drops of molten metal to produce horizontal,
vertical or spiral lines. The quality of the line depends on pulse time, interval time, thickness of layer, or on
the angle of the machine tool. Of course, all these settings can be adjusted on the initial CAD file.
Direct melting
In our case, the additive manufacturing technology is based on the laser melting of iron molecules:
• with added material for the upper parts: iron oxide powder from drilling is sprayed from a nozzle where the
lasers converge;
• without added material: via direct melting with the material for the lower parts and the underpinning.
Sorting of the raw materials
Raw material extracted from the ground is sorted magnetically with an integrated arm system that extracts
iron particles. The other metal particles (e.g. aluminum) can also be captured, sorted and stored for later
use.
(SOURCES:
- JORIS LAARAMAN LAB http://www.jorislaarman.com/mx3d-metal.html%22%20%5Cl%20%22about
- MX3D http://mx3d.com/projects/metal/)
3D PRINT CONSTRUCTABILITY
2015-1-055 [SFERO] Page 3

4. Materials Estimated presence Benefits Observations Design
Iron oxides
(FeO, Fe2O3)
Symbolize the “Red
Planet”, to which the
color owes its name
The concentration in the Martian soil is estimated to be
around 16.03 percent SOURCE 1
- Iron has strong mechanical
properties
- Resistance to pressure inside the
habitat
- Volume to be dug out and
sorted: 100 cubic feet
- Volume of iron for additive
manufacturing: 15 cubic feet
- Weight (on the ground):
31.5 metric tons
Two iron “bees’ nest” shells:
-An inner self-supporting shell, linked to the
mast and the foundations, guarantees
resistance to inside pressure
-An outside shell protects the insulation tarp
Water
(H20)
Symbol of the Earth
and natural and
material
environments
Numerous possibilities of water extraction, by:
-Heating and evaporation: 1.5 to 3 percent of water
present in the ground and in the atmosphere;
-Drilling: Permafrost is present over hundred of square
miles;
-Recovery: imported water reserves, and hydrogen
passed through a Sabatier reactor SOURCE 2
SOURCE 2
- Protection from the sun’s rays
- Resistance to pressure inside the
habitat
- Transparency, luminosity and
photosynthesis from plants
SOURCE 3
Amount of water to be
recovered: between 16 and 112
cubic feet, depending on the
number of openings in the
overall surface
- If the water proves to be insufficient, the
tarp, made up of different sections, is filled
with other insulating materials
- The areas filled with water will be
concentrated in living areas and windows
SOURCE 1: “The Chemical Composition of Martian Soil and Rocks Returned by the Mobile Alpha Proton X-Ray Spectrometer: Preliminary Results from the X-Ray Mode”, Science, Vol. 278, No. 5344,5 December 1997, pp. 1771-4
SOURCE 2: University of Arizona Phoenix Mars Mission Project. (2008). Mars’ Polar Regions - Leshin, L. A., and 447 colleagues 2013. Volatile, Isotope, and Organic Analysis of Martian Fines with the Mars Curiosity Rover. Science 341, 1238937
SOURCE 3: “Managing Lunar and Mars Mission Radiation Risks: Part I: Cancer Risks, Uncertainties, and Shielding Effectiveness". July 2005.
The design of our additive manufacturing shelter is based on the use of two indigenous materials: iron oxide for resistance, and water for protection.
Iron oxide (FeO):
Iron oxide (FeO) is present in great quantity on Mars and gives the planet its red color when seen from space. Thanks to the Pathfinder rover we can estimate that
the concentration of iron oxide in the Martian soil is around 16.03 percent. More recently, on another site (the Gale crater), Curiosity confirmed an equal concentration of iron,
through CheMin sample analysis (X-ray diffraction), including the Rocknest pile of sand and dust. It appears that the majority of the deposit is made of crystalline of basalt origin
(between 55 and 71 percent). The rest are amorphous materials, mainly iron oxides.
Water (H2O):
The presence of water on Mars has been established for several years. It is present — in ice form — on the planet’s poles. In 2003, the European spacecraft Mars Express confirmed
the presence of ice in the southern sector when it orbited around Mars. Shortly afterwards, the probe also discovered an area of permafrost around the North Pole, covering several
hundred square miles. More recently, and perhaps more surprisingly, the rover Curiosity revealed the presence of water in the soil dust (as well as in the atmosphere): “Take a scoop
of Mars ground dust. Heat the sample to 835°C. The most abundant gas will be... H2O. In other words, the red sand that covers Mars is full of water. That’s the exciting discovery
made by Martian robot Curiosity, with the sample taken at Rocknest, a sandy area in the Gale crater, about 400 yards from where Curiosity landed on 6 August 2012.”
A recent Danish study has revealed the presence of glaciers beneath the dust of Mars at a latitude corresponding to that of Denmark on Earth. The volume of these glaciers is reportedly
about 150 billion cubic meters, which, if it were spread evenly over the planet, would form a layer 3.6 ft thick. (Source: Niels Bohr Institute; Geophysical Research letters, "Volume
of Martian Midlatitude Glaciers from Radar Observations and Ice Flow Modeling"; 27 April 2015.)
MATERIALS
2015-1-055 [SFERO] Page 4

5. Soil analysis FeO Original amount
RANK 2
Post-deployment 16.6 ± 1.7 68.6
Near Yogi 14.4 ± 1.4 78.2
Dark soil near Yogi 17.3 ± 1.7 89.1
“Scooby Doo” 13.4 ± 1.3 99.2
Near Lamb 17.4 ± 1.7 92.9
Mermaid Dune 17.1 ± 1.7 98.9
Stone/Rock FeO Original amount
2
Barnacle Bill 12.9 ± 1.3 92.7
Yogi 13.1 ± 1.3 85.9
Wedge 15.4 ± 1.5 97.1
Shark 11.9 ± 1.2 78.3
Half Dome 13.9 ± 1.4 92.6
Samples without
soil (estimated)
12.0 ± 1.3 —
According to NASA scientists, the proportion of water present in the soil on Mars ranges from 1.5
to 3 percent, as shown on the graph below.
Energy Efficiency
- Power required for construction work: 100 KW
(3 lasers: 32 KW – 2 robotic arms: 4 KW – Drilling: 10 KW – Debris suction: 10 KW – Magnetic
sorting and grinding: 20 KW – Heating and water pumping: 5 KW – Compressor system: 15 KW)
- 2 sources of energy can be used:
- Nuclear (see nuclear reactor, right).
Advantages: low mass, reliable, stable, long-lasting.
Drawbacks: needs to be stored away from the shelter.
- Sabatier reaction (particularly in the field of fuel production)
CO2 + 4 H2 → CH4 + 2 H2O
SOURCES :
- ENAC UE. “Habiter sur Mars”. Dr Pierre André Haldi, Swiss branches of The Mars Society
and Association Planète Mars
- Flyby Mission Powered by Plutonium
- Compact and Lightweight Sabatier Reactor for Carbon Dioxide Reduction – NASA, George C. Marshall Space Flight Center, Huntsville, AL
35812
Data gathered in the fall of 1997 by Alpha/Proton/X-ray
spectrometer (Mars Pathfinder APXS)
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6. 1 – The sphere: ideally shaped
The architectural approach to the SFERO project draws on the work of Richard Buckminster Fuller, an
American architect who worked on the development of geodesic domes.
This is not only aesthetic but practical for construction work (the vertical central mast raises the work as
new elements are being added).
SFERO’s architecture is based on a complete sphere, the lower half of which protects inhabitants from the
outside elements, especially solar radiation.
2 - Verticality
Building part of the shelter underground has several advantages:
- Consolidates the foundations so they can stand up to cyclonic storms;
- Protects inhabitants on lower floors;
- Maximizes construction time for a given surface;
- Increases living space.
3 - Protection
The two metal additive manufactured shells make for a robust shelter structure.
The shells have a honeycomb shape with waves on the self-supporting pressure-resistant inner shell,
and a sinusoidal form for the shock-resistant outer shell.
- Along with the mast and the foundations, the self-supporting inner shell ensures the shelter’s resistance
to the interior atmospheric pressure.
- The protective outer shell is not self-supporting.
A one-foot-thick intermediary envelope between the two iron shells contains a protective insulation against
external, as well as internal, hostile conditions. Water also protects the shelter and enhances resistance to
internal pressure.
4 - Customization
SFERO shelters can be customized for each mission, and in accordance with the astronauts’ individual
needs (e.g. number of floors or furniture).
Michael Najjar, Sands of Mars, 2013
LEVEL -1
Living and sanitation area
LEVEL 0
Technical and research area
LEVEL +1
Food and growing area
LEVEL -2
Environmental Control and Life
Support Systems (ECLSS)
ARCHITECTURAL PRINCIPLES
2015-1-055 [SFERO] Page 6

7. The interior is layered using iron additive manufacturing.
Everyday items (e.g. bulkheads, furniture, beds, tables)
are built at the same time as the shells, working upwards,
from the bottom of the mast set in the ground
to the summit.
ARCHITECTURAL PRINCIPLES

8. DESIGN
PARTITIONS
Using 3D printing technology, the partitions can be
moved around, dismantled or turned into work
surfaces.
They turn the shelter into an adaptable and flexible
environment and make for easy loading and
unloading during missions.
2015-1-055 [SFERO] Page 8

9. DESIGN
STORAGE
Designed to suit the shelter’s spherical shape, the
storage areas maximize floor space.
They can be customized with racks and shelves.
STAIRCASE
The staircase area should be closed off to ensure
optimal protection on the lower floor. The steps can
be moved so as to fill the staircase’s empty spaces.
2015-1-055 [SFERO] Page 9

10. It is essential that the base be set up in one of the lowest areas
on the planet in order to take full advantage of the decrease in velocity
when entering the atmosphere, and have a thicker atmosphere at the
end of the run.
The average pressure on Mars at the “datum” (the equivalent of sea
level) is 611 pascals. It is 30 pascals at the top of Mount Olympus,
and 1,100 pascals at the bottom of the Hellas basin (the lowest point
on the planet, at minus 5.3 miles).
At the equator, climatic conditions are less harsh, with above-zero
daytime temperatures in summer, and average-length winter nights.
The northern hemisphere is mostly lower than the datum. The northern
lowlands are also much flatter and smoother, with fewer craters (as
they are younger and were once covered in cataclysmic ice and rocky
debris or lava). We should therefore look for an area near the equator
in that region.
As mentioned above, water and iron oxide are present all over Mars.
With such concentration levels, the shelter can be built all over the
planet, although it is best to scout for locations where both materials
are available in vast quantities, as building times will be much shorter.
The northern lowlands may include fossil ice fields, the remains
of a time when the planet’s obliquity was different, which was more
conducive to ice concentration. There are also iron oxide mines
in these areas.
Our chosen area: the 93-mile-wide Gale crater, where the
Curiosity rover landed
•It is located at the equator.
•The presence of iron ore deposits has been established.
The peak of Mount Sharp, located at the center of the crater, is
over 3 miles higher than the bottom of the crater. The mountain
is covered with rock strata, including an iron oxide stratum,
as confirmed by Curiosity.
•This crater may well have been underwater at one point.
The orbiters noticed traces of minerals that form in contact
with water in the lower strata on the mountain. The “aqueous
potential” is one of the scientific reasons for choosing this site,
so as to look for traces of life.
•There are equivalents on Earth: in the Gale crater, Curiosity
discovered minerals similar to those that can be found in
Hawaii’s volcanic ground, and in the Mojave Desert. We would
therefore have a training ground on Earth.
LANDING AREA
(SOURCE: http://www.bbc.com/news/science-environment-20151789)
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