I wouldn't recommend traveling with a human payload at all. I'm an astronomer, and I saw something during a public star watch this summer, and it made me a true believer. A large with ship that was black at first suddenly appeared like they flicked the lights on. It was a equilateral triangle, or delta shape, I screamed in front of 70 or more people including colleagues. I am with a group as an educator, and we work with a very prestigious museum, and that's what I see!?! I'm not happy, I'm afraid. They have ben here for 1,000's of years and our gov. is the only one who won't disclose the information. Our Astronauts are telling all about what they saw during the 1st lunar landing and it wasn't good. The gov, sent them with an olive branch and a coin from Kennedy and Neil or buzz said that there were ships right next to them and they were watching them...WTH!?! No Mars, the god of war, just stay here because it's real.
A visit to the Mars would be dangerous due to the years-long return trip. Astronauts have not yet been to the red planet due to several safety reasons. Unlike earth, mars doesn't have magnetosphere shielding it from galactic radiation.
According to some of the documentaries I have seen on discovery, NASA is planning an expedition by 2030. They said they chopped the shuttle and the shuttle replacement program in order to save money for the development and construction of a craft capable of reaching Mars.