Crewed or uncrewed space missions

I can see how that will be a problem.

But it's probably solvable. We already have good ideas on how to divert asteroids and comets to safe trajectories: wrapping them in a blanket (so they don't fragment) and then slowly tugging them off course with a solar sail for example.

We're less than a century into the space age. After a billion more years of research and development we should be able to handle the problem OK -- especially if humans keep going deeper into space. If there is a regular human presence all the way out to the edge of the solar system by then, there will be plenty of people around to divert asteroids and comets as they pass through the solar system.

The first and the most important- is to broaden space exploration area and to take some samples we couldn`t take before with robotic mission. The question about Mars colonization, it`s really difficult and for me usefull. That is not the planet we need to colonize with such a harch environment.

We didn't need to colonize the world outside of Africa either.

A thing we have to consider too, if we wanna make a living on mars, would also be the irreversible consequences on our human biology. We can mimic a lot in closed facilities: atmosphere, ecosystems, probably even social live if we manage to get enough people there - but there's one thing we can't mimic and that's gravity. Mars only has a third of earth's gravity. Great for earthborns on mars probably, not so much for marsborns on earth. If you were born on mars or even spend a lot of time there, a return to earth might be fatal for you.
All I wanna say is, that if we - humans - colonize mars, our paths will split. An earth human can live on mars, but a mars human probably can't live on earth due to its high gravity. A great motivational factor if you are already there, but if you're still undecided, you have to keep in mind, that a stay on mars for at least ten years might be a one-way trip. No return, no familiy visits

If you really want humans to go to the stars, the place to start is to consider what technologies are required and work on them now rather than try to send people to Mars before we are ready. If you said "we're going to take 1000 years and develop the technologies we need for space", the top on the list would be extremely cheap, near infinite energy. Energy keeps people warm, scrubs the atmosphere, allows us to send large weights out of large gravity wells and propel them where we want them, etc. Right now, that means fusion, solar and battery storage. If you want to pump billions into something, that is where I would go with it.

Talking about technology we need to to have to make even crewed journey to Mars (not even taking into consideration colonizatin) we need to have more advanced technology because at that point technology we have is too weak and we must make a wast development to achieve our goal and not to lose the crew.

That's a good consideration. We will want to think long and hard before we do something that splits us into separate species.

My suggestion that we eventually go to Mars wasn't intended to mean that we go before we are ready.

I think our next step in human spaceflight should be an international base on the Moon.

That is a good point. I consider that building ISS in orbit of Mars is the best option to so called ``Mars colonization`` and further exploration of this planet. But as I have already mentioned it seems not really possible in the next decade I guess.