Hybrid rockets on Mars

[whitelancer64]

I just had what may be an interesting idea, since Mars is known to have perchlorates on its surface, would it be useful for Martian settlers to develop hybrid rockets with a solid oxidizer (perchlorate) with a liquid fuel? Presumably the fuel would be methane.

What types of perchlorates are on Mars, and are they useful for such an application? I have no idea how efficient such a hybrid rocket would be, but it would eliminate the need for liquid oxygen.

I imagine it would probably be very difficult to get stable combustion, and the combustion byproducts might be hazardous to human health thanks to that chlorine atom.

[Slarty1080]

I just had what may be an interesting idea, since Mars is known to have perchlorates on its surface, would it be useful for Martian settlers to develop hybrid rockets with a solid oxidizer (perchlorate) with a liquid fuel? Presumably the fuel would be methane.

What types of perchlorates are on Mars, and are they useful for such an application? I have no idea how efficient such a hybrid rocket would be, but it would eliminate the need for liquid oxygen.

I imagine it would probably be very difficult to get stable combustion, and the combustion byproducts might be hazardous to human health thanks to that chlorine atom.

I don't think this would be a practical proposition. Extracting the hydrogen that is needed to manufacture methane would also produce a lot of the oxygen needed as a bi-product.

Not only that but extracting and purifying the perchlorates from Martin regolith would be a nightmare. IIRC Mostly Calcium perchlorate but also other perchlorates and other salts and compounds mixed in and in relatively low concentration. Sound like a whole lot of extensive wet chemistry involving filtration and fractional crystallization, drying, milling and then mixing with binders (and the rest) to make suitable propellant.

Not sure there would be any problems with the combustion products however as on Mars everyone would be inside in pressurised habitats.