The need to conserve

A good thing about travel on our planet is that it does not as a whole lose mass each time people travel in a jet from London to Shanghai. In Space Habs on the other hand the situation will be dramatically different. Any movement, any thruster firing will result in a loss of mass from the composite system - irrevocably lost. Slimming down will be no problem in Space Habs : - )

Based on this rather unpalatable fact we can arrive at some dos and don'ts for an aspiring space based civilization.

1. Conserve, conserve, conserve. Recycle, Recycle, Recycle.
2. Invest in technologies to achieve max exhaust velocities in all thruster and rocket propulsion systems. Energy from the sun is limitless, but mass lying around in non-gravity-wells is not.
3. Don't make the same mistake we made on our planet. Plan for a modest population in Space Habs. There have been projections of a trillion people living in space habs. Let's keep the number more manageable. Ten billion let us say.
4. If there is to be trade between two civilizations separated by large distances, it should be kept modest and focus only on high value goods.
5. Basically it would be wiser for populations which move out to simply forget about their home country, to devise their own civilizations and not look back. Just the way it used to be in earlier times on Earth.

Globalization is space is actually as meaningless as it is on our own planet (for other reasons).

Based on this limitation we need to rethink some of our present ideas on space colonization in the NEAR future:

1. Habs on / near Moon: Joe rightly pointed out that hydrogen, which is not available on the Moon can as well be taken from Earth. And carbon too, since we are not too fond of it at the moment. The fact that we are living in a gravity well is one aspect of the problem. But the advantage is we can go on firing as many LOX / hydrogen propulsion rockets as we wish to.

2. There have been some discussions on going to the Moon before going to Mars. Now I too am wondering, why not go to Mars directly if we plan to go there: with support facilities (modestly sized rotating space habs?) in orbit around Earth.

3. The enabling thing will be cheap and giant sized LOX / hydrogen propulsion rockets. Plenty of them.

Selvaraj