There are as many ideas for getting people to Mars as there are ways of getting people across an ocean, from Kon-Tiki concepts up to supersonic airplane concepts.

The mission will have to be wrapped around the technology available, and a mission around many low-cost small launches will look completely different from a mission depending on one or two huge expensive launches.

It's educational to look back at how most scientists and engineers thought we would reach the Moon back in the 1950s. Based on hundreds of low-cost reusable orbital launches, a large orbiting space station, and a robust space construction capability, it bore no relation to the eventual Apollo program. But unlike Apollo, it would have resulted in a permanent space infrastructure.

Then you have to decide what the mission actually is. Land people on Mars right away and bring them back? Land them and set up permanent colonies? Build orbital stations around Mars (maybe on one of the Martian moons) and work up to a landing later (my personal favorite)? There are many possibilities, all with different requirements and different timelines. Again, the available technology is a major driver. For example, it may be possible for current robotic technology to have a safe working habitat waiting for astronauts when we get there.

Key to any mission in space is lowering the cost of space transportation. You don't need large cargoes if you can ship a lot of them, and you don't need fancy life support for a colony if you have a reliable, redundant supply flow. The entire city of Honolulu was built by stuff that would fit on boats. But it was a LOT of boats.

Remember there's a lot going on outside of NASA. When the Orion capsule landed this week, SpaceX had already launched and recovered their Dragon capsule six times, and it too is designed for high-speed re-entries from lunar or planetary trajectories.