make sure you play in story mode, mars is only in story mode. As for 3 days i just did it, so it's not all that hard to do, took me 3 attempts. 6 days 5 days 3 days. My record flight is 30 minutes 95000 feet 14.647 million(without the gravity reduction)
Dementedlord, switch the fuel of your garbage fleet to natural gass or ethanol, and use geothermal or wind turbines instead of coal planets, it'll drop your smog to 0
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