Why NASA & other capable space agencies like ESO don't make their base on Moon (Lunar Surface) instead of floating onboard the ISS?

The main reason is because the Moon is about 940 times farther away than the ISS. The view of the surface of Earth from the distance of the Moon is so lacking in detail as to be almost useless.

Each pound of anything (most notably fuel) costs over a thousand dollars to send into space and many times that to reach the Moon. Much fuel is needed to slow and land on the Moon, and a large additional amount of fuel is needed to get off the Moon and back to Earth.

Yes, it would be easier and more comfortable for the astronauts to perform routine tasks on the surface of the Moon than in space.

The real primary reason is because the ISS is first and foremost a zero gravity research station. All sorts of experiments are conducted there that can only be done in zero G. None of that would be possible on the surface of the Moon because then they wouldn't be under zero G.... Also the ISS became more of a political propaganda (look at all these nations working together) thing than anything to actually benefit manned space exploration. We could've easily built the exact same thing on the surface of the Moon. Yes, easily despite what many people seem to think. We've had the technology to do so since the 1970's. But while it would've been just as easy, it would've cost at least 10 times as much. Actually, it may have been even easier to build it on the Moon since no orbital assembly would've been required. Just bolt everything together on the surface and shovel some regolith over it. Still though, much more expensive. And the ISS is already expensive. And of course you'd lose the whole zero G aspect... I believe we can expect to see a manned research station on the Moon probably before 2040. However, I doubt it will be American. Chinese or Indian probably. Maybe they'll let us visit......

More comfortable for the astronauts? Probably yes.

But:

- much harder to reach

- much, much harder to come back from

- much further away (so more effort needed for terrestrial observations)

- no micro-g environment, so all the experiments that now are done in micro-g on the ISS would have to be done under presumably much more cramped circumstances during transfer

Having a base on the moon would be viable if there was a way to set up a self-sustaining base that would need no (or only very little) in terms of supply from earth. There have been indications for extractable water on the moon, but apart from that, our technology is not yet up to the task to drop a bucket full of von-Neumann-machines http://en.wikipedia.org/wiki/Self-replicating_mach... on the moon and come back a year later to a finished base.

The moon is 384,000 km from earth, and requires a lot of fuel for controlled descent to land on that you would have to take with you. Building a moon base requires hauling all the components there and descending them to the surface - For the mass of the space station that would require an enormous amount of fuel. The space station is 400km up and once in orbit it takes just a tiny bit of fuel to align and dock. Any moon base would be in shadow 2 weeks of every month and sun two weeks of every month meaning power is more difficult to manage as well as longer term temp extremes.

Comfort yes, cost roughly times a thousand, radiation dose lethal over three months.

Bear in mind an Apollo Astronaut that went to the Moon used up their lifetime radiation allowance.

Very little real science is being done on the ISS, there is very very little to be done on the Moon.

Primarily due to the Moon being so far away. It is nearly a quarter million miles away, ISS is only a bit over 200 miles away.