UPDATE - I wrote this answer some time ago. Since then I’ve written Case For Moon First and was surprised to find out that the Moon wins out against Mars in just about every comparison. It seems a good place to set up a base such as the ESA village and to explore human settlement. I think it is far too soon to think about colonization. If we had the technology to colonize the Moon or Mars or anywhere else, we’d be able to colonize the seas of Earth with sea cities using only the air and sea water as resources - that’s far easier than “colonizing” Mars. We could get all our living requirements from those floating sea cities plus asteroid resources, if we used the same technology suggested for Mars “colonization” - which we don’t have yet.

Original answer:

Could be, but for interplanetary missions, I think a better precursor is the L2 position on far side of the Moon.

First, though, I don't think we should colonize Mars and not sure about the Moon but definitely not Mars, at this stage.

WHY WE SHOULDN'T COLONIZE MARS AT LEAST NOT NOW

That's because the one thing that makes Mars most interesting is the possibility of biologically interesting life on the planet - both ancient traces and possibly today also. That's also the thing that makes it most vulnerable to contamination by humans. We shouldn't have humans anywhere near the surface of Mars - unless we are totally sure that they won't contaminate it. It's hard to see how we could be so sure though, because there are thought to be possible habitats on Mars, and there's a definite risk of a hard landing, which would be an immediate fail of planetary protection. That's not to mention problems with spacesuits and airlocks that would leak microbes all the time onto the surface.

Anyway, neither the Moon nor Mars are of much use as a place for humans to live in their present form, you'd die immediately. Even after an asteroid strike or nuclear war, the best place to terraform would be Earth, not Mars or the Moon.

SO YOU GO TO EXPLORE AND DESIGN YOUR SETTLEMENT ACCORDINGLY

So you go there to explore, like Antarctica. But if you do that, you build your colony as a settlement rather, like the Antarctic research stations, wherever they are most needed for the research.

That might not be on the surface, it might be in orbit, maybe in case of Moon some on the surface. But in the case of Mars, most likely, in orbit around the planet, controlling robots on the surface by telepresence.

For now at least. Later on I think we could have colonies in space perhaps - and if so - makes most sense to make them out of materials from the asteroids and NEOs. Because - your colony has to be shielded from solar radiation and cosmic radiation by tons per square meter of shielding. Do that on a planetary surface and you have to live a basically trologdyte existence.

But in free space, with Stanford torus habitats and so forth, you can make your habitats large and spacious inside, as technology improves, and with full gravity or whatever level you need. And there's enough material in the asteroid belt for habitats with a thousand times the land area of the Earth's continents.

UNPROVEN TECHNOLOGY FOR INTERPLANETARY FLIGHT

But - so far we haven't yet flown a single spacecraft with a closed self contained habitat making its own oxygen and recycling everything without tons of supply from Earth every few months and disposing of tons of waste back to our atmosphere every few months. We also haven't really cracked the issue of radiation shielding, just make sure nobody spends too long in the ISS. And haven't even begun to test artificial gravity in space. In that situation - then before we do anything else we need to test an interplanetary flight somewhere close to hand.

I think the L2 position, far side of the Moon, is ideal for that. Close enough to Earth so you can get back in a couple of days. Far enough away, also with the Moon between you and Earth to have a real sense of psychological isolation, and need for some independent decisions. Useful because you can use it for telerobotic exploration of the lunar poles and far side, and to build far side long wave radio telescopes (just spooling out cables basically) using telerobots on the surface.

Would be an interesting mission for the astronauts. If you don't find the idea of such a mission interesting you are probably not cut out for space exploration.

NEXT STEP AFTER THAT - MARS EXPLORATION FROM ORBIT

Mars exploration from orbit would be amazing - with an orbit that takes you close to Mars every 12 hours - continually changing in the sky, and explore any part of Mars by telepresence. No need to go to the surface. Just as humans like being in the ISS, they'd enjoy orbit around Mars also I think, so long as we can crack the health issues, find a way to do it safely without contaminating Mars.

I don't think we absolutely have to do this. It might cost less to send rovers and gradually work on making them more and more autonomous. But humans in orbit with telepresence could probably explore better and faster.

And they'd out do humans on the surface also in my view, even without the contamination issue, because not restricted by clumsy spacesuits, able to control robots anywhere on the surface, no need for life support on the surface, lightweight robots instead able to explore in dangerous places no humans can go to.

But biggest plus of all is that robots can be sterilized. Humans, currently, can't be sterilized and no spacesuit been designed or spacecraft to guarantee to keep the Earth microbes within the human habitat.

LESSON FROM APOLLO - DO ONE STEP AT A TIME, A BOLD EXPEDITION THAT'S BASED ON MANY PRIOR SPACE MISSIONS AND A STEP BY STEP PROGRESS.

But - one step at a time. With Apollo they did many flights closer to home before they went to the Moon, testing all the things they needed. If they had launched straight to the Moon from Earth without the Gemini missions for instance, and the fly by of the Moon and the docking tests and the Apollo 10 that flew there and did a test landing but came back again before reaching the surface - then the astronauts would surely have died.

Those who suggest going straight to Mars in one go with unproven spaceships are ignoring the lessons learnt with Apollo (it doesn't count as proof of fitness for humans to send the spaceship to Mars without humans in it). And if you not only go to Mars but land on the surface, you are doing a pointless thing that will make it almost impossible for future biologists to have any confidence in their findings about Martian biology especially since we now have instruments that could detect a single amino acid or a single DNA molecule in a sample,

That's my view on it anyway - just presenting it as I see it.

See also

• Let's Plan For Exploration and Discovery of Space with no End Date - NOT Escape from Earth - Opinion Piece
• Why No Disaster Could Make Earth as Uninhabitable as Mars
• Why Mars is NOT a Great Place to Live - Amazing to Explore From Orbit - with RC Rovers, and Nature Inspired Avatars
• Asteroid Resources Could Create Space Habs For Trillions; Land Area Of A Thousand Earths
• Ten Reasons NOT To Live On Mars - Great Place To Explore

and many other articles at Robert Walker's blog