Sources and Details

https://www.best-chem.co.uk/dust-supression/what-is-foam-dust-suppression/

In order to prevent dust particles from getting airborne, foam is introduced in controlled measures at transfer points, immediately prior to the crushers or directly in to the crushers. This ensures that all the material is fully coated in Foam.

https://dura-foam.com/resources/foam-roofing/nasa-shuttle-fuel-tank/

Already used in mining industry, but in liquid form;

Deposition systems - external water sprays;

(Taking experiences from the field, industrial applications of dust management are largely used)

Polyurethane foam typologies (for our evaluation):

• Low density polyurethane,

180 [kg/m³]

• Medium density polyurethane,

350 [kg/m³]

• Medium density rigid structural polyurethane,

450 [kg/m³]

POLYURETHANES - Main applications:

- Rigid foams

- Thermal insulation products for buildings - Industrial refrigeration, commercial and domestic - Temperature controlled transport - systems Aeraulic

- Structural rigid foams

- Furniture - Sailing

Polyurethane rigid foam has a useful life of 50 years and more;

Density ranging between 30 [kg/m³] and 450 [kg/m³];

Depending on the density, typical tensile stress values for PUR/PIR lie between 40 and 900 [kPa], and shear strengths values between 120 and 450 [kPa].

Furthermore, a number of special polyurethane products can be installed as insulation under poured-asphalt floor screed and can withstand temperatures of +200 [°C] without additional heat protection, or can be used for cold-temperature applications down to -180 [°C]. (Used by NASA to screen the SpaceShuttle).

Considering the development of a material with density average values around 50 [kg/m³] and assuming a thickness of 5 [cm]:

=> 2,5 [kg/m2]

Assuming a development of the surface of the lunar city of 100x100 [m] (we assume that we need to pave about 50% of the surfaces) (the rest being occupied by structures does not need them) therefore for 5.000 [m2] are necessary 12250 [kg] (smaller volumes, because expansion carried out on site).

At the costs indicated by spacex website https://www.spacex.com/about/capabilities the cost per kg with use of Falcon Heavy: 26,000 [kg] cost $ 90M, 3500 [$/kg], 10500 [$/m2], around $ 43M.

- MoonSwepeers Technical Report.