The atmosphere of Mars is not thick enough to support a parachute landing, so that's out. Balloons do not work well on Mars either; landing heavy payloads with

The atmosphere of Mars is not thick enough to support a parachute landing, so that's out. Balloons do not work well on Mars either; landing heavy payloads with balloons result in a lot of bouncing, which is bad for both equipment and for humans. There are also no artificial ponds on Mars. Additionally, water is not good for the rocket parts (salt water is terrible, but I think even fresh water is not good). SpaceX is iterating on technology that will eventually be used to land millions of people on Mars. Before they get to that stage, they are working on perfecting rapid, full reusability of rockets to 1) achieve lower launch costs to win the market, and 2) have a ready-to-go system for landing people on Mars. The primary design principles of the landing system must work on Mars as well as they do on Earth.