We do not already do life support and in situ resource allocation to the sophistication and extent that would be needed. See my previous comment about resupply for the former and the one before that regarding industry not existing in isolation for the latter (for extra clarity consider this: how feasible would it be to leave the ISS for a period of years [2-5] and expect the astronauts to not only maintain the station and survive but also perform continuous experiments?). I'm not convinced that propulsion is a simple matter of scale unless you are suggesting on using chemical rockers (in which case that's one expensive trip!).We already do all of the highlighted things. In fact, the propulsion part will scale very nicely. If you bring a space ship up to low earth orbit and assemble it there, you can take tremendous advantage of the fact that you will start your voyage without regard for the atmosphere. This frees up the design of the spaceship considerably. I've known that since I was 9 years old. It was in a book called 'The First Book of Space Travel", by Jeanne Bendick. Did anyone else here read the 'First Book" series as kids? The psycho stuff may well doom the project once it gets to Mars, but it wouldn't prevent them from getting there. The people on the ISS are a relatively small group isolated for relatively long periods.
Also the people on the ISS, whilst isolated in a confined period, are only like that for a period of months and they have the practical advantage of only being a few hundred kilometres from the ground with all the psychological benefits that brings.
It's not. Off the top of my head we do not have the technology to;I think its more a problem of cost and/or will than of knowledge
- Recruit a counterweight
- Construct a cable strong and long enough
- Power a climber up said cable