[Amezarak]

> Sending a few people to Mars will be the first steps in becoming a multi-planetary civilization,

I think there is immense value in continued unmanned Mars missions and yes, even in manned missions, but I don't think that a trip to Mars would be a step towards becoming a multi-planetary civilization beyond "we can ferry humans between planets." Mars is not and most likely never will be colonizable. We might have an outpost or a station like the ISS, but Mars' extremely thin atmosphere and low surface gravity (a third of Earth's) means that long-term habitation will never be practical barring extraordinary technological developments in planetary engineering, the medical field, and/or artificial gravity.

Personally I suspect the only long term colonization prospect in the Solar System is Venus - thick atmosphere and near-Earth surface gravity - but for obvious reasons we'd still need extensive terraforming to cool the planet and make the atmosphere breathable - seeding the clouds with oxygen-producing bacteria would be a first step towards both, I suppose.

[danielweber]

Why do you think humans won't be able to live in 3/8g?

[gambiting]

Oh I think we would. But at the moment I think that living on Mars would be almost the same as living on the bottom of the ocean - both would require spending all of the time inside pressurized containers, looking outside through glass. Yet the perspective of looking at the ocean floor is incredibly boring, but perspective of looking at Mars' surface is exciting? Don't get me wrong, it would be AMAZING if we got humans to Mars. But if we are to live inside plastic structures, we can do it just as well on the Moon, which is much easier to reach.

[Amezarak]

> Oh I think we would.

We could. But there are serious health issues associated with living long-term in low-g environments and anyone who spent their whole life there would probably never be able to visit Earth.