"It would take six months to get to Mars if you go there slowly, with optimal energy cost. Then it would take eighteen months for the planets to realign. Then it would take six months to get back, though I can see getting the travel time down to three months pretty quickly if America has the will."

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The reality is gas prices should be much more expensive then they are because we're not incorporating the true damage to the environment and the hidden costs of mining oil and transporting it to the U.S. Whenever you have an unpriced externality, you have a bit of a market failure, to the degree that eternality remains unpriced.

— Elon Musk