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Many people say that a Mars colony is economically unsustainable as goods from Earth will be considerably cheaper for the foreseeable future and Mars won't have anything to trade in return. This got me thinking, that due to Mars' lower gravity and lower density atmosphere launching satellites into Earth orbit might be cheaper to do from Mars rather then from Earth, despite the need for a much longer journey. Is this correct from the point of view of orbital mechanics?

If feasible this would also require the satellites to be manufactured on Mars. What sort of level of development (colony size, equipment) would be needed on the surface of Mars before the Martian satellite industry can be cost competitive with the Terran one?

Are there any other examples of industries where this could be the case?

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    $\begingroup$ Why not from the Moon instead? $\endgroup$ – kim holder Mar 24 '16 at 16:46
  • $\begingroup$ I haven't thought about it since most of the colony talk is about Mars. I guess the Moon would be even better but I have a feeling Mars has a higher diversity of raw materials (just a guess) $\endgroup$ – Michal Mar 24 '16 at 17:11
  • $\begingroup$ The gravity on the Moon is just 1/2 of that on Mars and it's much closer. That means it's much cheaper to ship to and from the Moon and the communications are instant. The Moon is also better for science - no atmosphere means no dust storms and on the far side you are shielded from RF interference from Earth too. $\endgroup$ – ventsyv Mar 24 '16 at 19:56
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In theory if you used aerobraking when you arrived at Earth then you could just about get there with less fuel (or more payload) than you would with launching from Earth (I haven given my calculations and source of figures below). Of course this is assuming you had the exact same infrastructure on Mars as you do on Earth, for example SpaceX employs around 5,000 people, the satellite company would be another thousand or so.

Youve also got to have all the supporting industry on Mars before you start launching satellites, from the rocket fuel to micro-chip manufacturers and farmers to cooks, you cant build a rocket without fuel, and you cant use employees without fuel (food) either. So I'd say you need at least 10'000 people to start your colony, but that's even neglecting tertiary support sectors like police, teachers, Martian bus drivers etc.

If you didn't achieve all of this and were to import any supplies from Earth it would make the whole proposal unavailable due to the huge cost of launching supplies from Earth.

Note: I based my Delta-V calculations on the below map, taken from Wikipedia. I assumed the Mars Transfer -GTO stage could be made with aerobraking, hence why I got the value of 8 for the Mars-GEO Delta-V, lower than that required from Earth (~12-14).

enter image description here

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  • $\begingroup$ Perhaps it since microchips are quite light they could be shipped from earth and only the bulk of the satellite (metal, fuel) would be made on Mars. Getting purified metals and fuel would be quite a bit easier then the whole chip making process and it could still come out cheaper $\endgroup$ – Michal Mar 24 '16 at 14:57
  • $\begingroup$ Yeah you could do that, but unless you had robots that made all your components on Mars you would need a large food industry set up to feed your workers though, that's probably a bigger challenge than making rocket fuel and metals on Mars. $\endgroup$ – Dean Mar 24 '16 at 16:22

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