As part of the Mars Inspiration announcement, the foundation released a white paper that goes into great detail about the feasibility of such a mission. From the paper: A manned Mars free-return mission is a useful precursor mission to other planned Mars missions. It will develop and demonstrate many critical technologies and capabilities needed for manned Mars orbit and landing missions. Investments in pursuing this development now would not be wasted even if this mission were to miss its launch date. Working on this mission will also be a means to train the skilled workforce needed for the future manned Mars missions.