anyone who has read the book or seen the movie knows how they did it, make a station that goes from Kerbin (Earth) to Duna (Mars) and have a base already set up on Duna/Mars then send the crew via the station
RULES:
1. You must have a station that goes from Kerbin to Duna that carries only the crew
2. You must land the Duna base before the crew even leaves Kerbin
3. You must have 2 rovers on Duna that is sent with the Duna base
4. You must have an ascent vehicle that is not your lander and has to be on Duna before the crew leaves Kerbin
If you are unsure about anything feel free to ask!