Insulation

Sheets of foamed polystyrene for insulation of houses.

Insulation is needed to keep a colony warm and reduces the consumption of energy for heating. Aerogel or plastic foam may be utilized for insulation. Regolith may be heaped over buildings to keep in heat. Mineral wools, spun from local resources, may provide a lower tech alternative insulation. Fiberglass, a type of mineral wool, is commonly used as insulation on Earth. Arsenic is a mineral that can be used as a heat tolerant insulation, but is toxic to life.

The glass body of a vacuum flask.

The thin Martian atmosphere has a reduced capability for a convective flow of heat. More important is the heat radiation, which can be effectively reduced by choosing the material of the building's surface. A smooth bright metallic surface emits much less heat radiation than a rough black one. A simple aluminium coated foil wrapped around the settlement modules provides excellent insulation. Multi-layer insulation of the same type of foil can reduce heat loss to very low numbers and is commonly used for satellites.

Foam glass is another form or insulation than can be produced locally and should have superior insulation properties,as well as good structural properties.

A block of ice wrapped in aluminium foil to prevent melting.

Insulation table

The following table shows some insulation values for materials on Mars. The exact value will need to be tested on Mars, and will vary significantly if the material is used inside a habitat at Earth atmospheric pressure or outside the habitat at martian atmospheric pressure.

Table of insulation materials
Material	Thermal conductivity (W/m/C)	Density kg/m3	Specific heat (kJ/kg/°C)	Embodied energy (MJ/kg)	Notes
Multi layer insulation					This insulation's effectiveness varies with the number of layers
Foam glass					Might be produced in-situ
Fiber glass
Foam					Might have problems from outgassing
Mineral wool
Aerogel
Regolith

Tank insulation

Insulation of fuel tanks on Mars may be a requirement to prevent accumulation of frozen CO2 on tanks. CO₂ freezes a little bellow -67C and could accumulate significant mass on a fuel tank. Tank insulation needs to have a vapor barrier, or be composed of closed cells to avoid the risk of condensation in the insulation and the accumulation of water or CO₂ ice in the material.

Oxygen

Methane

Hydrogen

Production

Insulation can be produced in-situ. The very low atmospheric pressure of Mars already provides a good insulation, reducing heat transfer from convection.

Foam glass would be an interesting type of insulation to produce on Mars. The resources, mainly silica oxide, are available in large quantities. An adequate foaming agent would need to be identified and mined and the production process refined to create a viable product.