Any long-term base camp on Mars will need to be powered by renewable energy. A proposal developed in response to a competition run by the European Space Agency suggests using a giant kite flown by robots to harness high Martian wind speeds, which could provide enough energy to sustain several astronauts in their everyday work. Producing and storing renewable energy on Mars is difficult. It is further from the sun than Earth, so it only gets 43 per cent of the sunlight Earth does, making solar power less effective.

SpaceX is developing a reusable rocket-spaceship system called the BFR to help make Mars settlement economically feasible. Humanity's brutal and bellicose past provides ample justification for pursuing settlements on the moon and Mars, Elon Musk says. The billionaire entrepreneur has long stressed that he founded SpaceX in 2002 primarily to help make humanity a multiplanet species -- a giant leap that would render us much less vulnerable to extinction. Human civilization faces many grave threats over the long haul, from asteroid strikes and climate change to artificial intelligence run amok, Musk has said over the years. And he recently highlighted our well-documented inability to get along with each other as another frightening factor.

If it wasn't already clear that Elon Musk has considered virtually every aspect of what it would take to colonize Mars, it is now. As part of his Reddit AMA session, the SpaceX founder has revealed that his vision of a permanent colony would entail a huge number of "miner/tunneling droids." The robots would build large volumes of underground pressurized space for industrial activity, leaving geodesic domes (made of carbon fiber and glass) for everyday living. As a resident, you might never see the'ugly' side of settling the Red Planet. Musk also explained how his colony would get to the point where it can reliably refuel spacecraft all by itself.