They should play KSP. They would find out the "hard" way!

An excellent novel on that topic is "Pushing ice" by Alastair Reynolds. But it's not on a natural asteroid... It's on a spaceship asteroid that is set to travel both n deep space and in deep time...

To gently land on something, you have to match its speed.

And we thought Callisto was a dead, boring world. Now we know it has auroras. And perhaps an undercrust salty ocean. Oh, and it might be the place receiving the least amount of radiation that we could potentially reach and colonize (compared to Mars, Ceres, Europa and Ganymede).

The most badass (and probably feasible) design, in my opinion, is Zubrin's nuclear salt water rocket.

https://en.m.wikipedia.org/wiki/Nuclear_salt-water_rocket#:~:text=A%20nuclear%20salt%2Dwater%20rocket,or%2020%20percent%20enriched%20uranium.

If we manage to land equipment and the first modules and habitats by 2027 to 2030, then I'd say 2035.

Probably not. But if SpaceX can land an autonomous habitat (unmanned), or at least a first base module by 2027, that would be a big achievement.

The logistic of a Mars mission are super complex and we will certainly not send a monolithic mission there. We need advance missions to set up the site.

Why did Shackleton organize an expedition to Antarctica? Some people are natural explorers and are willing to take huge risks for science, adventure, country, or glory.