Natural tariffs

Launching stuff from Earth into space is a costly affair because in order to launch a kilogram of payload, a multiple amount of mass of fuel is needed. Even if we would have a working non-rocket space launch system it will still take 34.84 kWh of energy to accelerate a 1 kg pay load to the escape velocity of our planet [1]. There is no way around this since it is the bare minimum [2].

Let us assume that the price of 1 kWh is 0.10 USD, this would mean that in order to launch 1 kg of payload will cost at least 3.48 USD (this ignores the mass of the spacecraft). So the costs of exported goods from Earth is increased with 3.48 USD per kilogram.

Obviously this will be an impediment for future space settlements in importing goods from Earth. In fact the required energy cost serves as a natural tariff with the result that in most cases it would be cheaper for space settlers to produce their own goods.

It seems that future trade between Earth and Space Settlements will be shifted towards export from Settlements to Earth. At first this seem beneficial for Space Settlements but Terrestrial governments might react by imposing formal tariffs in order to “equalize” trade advantages.


[1] The terrestrial escape velocity is 11.2 km/s and assuming that a non-rocket space launch system will accelerate the payload from rest, we can use the following equation:

T = ½mv² (i)

With T the kinetic energy, m the mass of the payload and v the escape velocity. Substituting m=1 kg and v=11.2 km, we get for T a value of 125.44 MJ. And 1 kWh = 3.6 MJ gives T=34.84 KWh.

[2] In reality the figures are even worse, as the above calculation assume a non-rocket space launch system with a 100% efficiency, which is impossible due to the second law of thermodynamics. Hence the actual energy required will be higher.




4 thoughts on “Natural tariffs”

    1. My cost estimate is very, very optimistic but even in that unlikely case, it shows importing stuff from Earth will be prohibitive. Let alone if actual costs would turn out to be much higher.

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