President Obama recently said that he wanted to have a space mission to land on Mars. There were, as usual, no specifics, just generalities, no mention of cost or length of stay.
This from the president who canceled the entire space shuttle program and had nothing to replace the space shuttle with. He showed terrible foresight, proven by the crisis in Crimea, when he decided to oppose Russian aims.
Someone who was high up in the Russian government said, "If America wants to go into space, she can jump on a trampoline," or similar words.
To go on a six-month journey, stay for a very limited period of time, then hopefully return after another six-month journey is pushing it to say the least.
Instead of calling for permanent stations on the moon, which is only three days' travel and actually has been done, he proposes to go on a six-month voyage that has not been done.
We have to take baby steps. Set up stations on the moon, do an in-depth development of the moon, then start sending temporary voyages to Mars. The much lower gravity on the moon will greatly reduce the cost of a voyage to Mars, and will enable the astronauts to carry many more supplies than could be carried from a launch from Earth.