Only time will tell. To be specific, what we are talking about here is not in respect of some future date, but the time it takes to go all the way to Mars and come back safely. And precisely it is this travel time which will have a telling effect on such a space mission.
Although the data obtained by unmanned space missions so far have shown Mars to be a planet with a harsh and hostile environment, this is not a serious obstacle to sending an expedition to the planet. Special spacesuits would ensure man’s safety and working capacity in the Martine environment. A soft landing and subsequent take-off would also not be a major problem. After all, there have been six moon missions during which these maneuvers were successfully executed. The main obstacle to an expedition to Mars arises from the flight duration. Earth and Mars have to be aligned properly when distance between the two planets is at a minimum. Such alignment, or launch window, occurs only a few days in every two to two-and-a-half years.
With our present limitation in rocket technology, the trip to mars would take 259 days and the return flight just as long. In between the crew must await 450 days until the two planets are lined up again so that the spacecraft can return to Earth on the same orbit. The expedition to mars will last 968 days – about three years. One crucial problem is developing life-support systems for such a prolonged flight. An immense quantity of food, water and oxygen would have to be carried aboard. New fail-safe system of control and automation, capable of long-duration functioning will be required. Numerous medical and psychological problems must be surmounted. It may be necessary to create artificial gravity on board, and even this may not be enough to simulate Earth’s gravity. Until such problems are solved, manned-mission to Mars will remain an unfulfilled dream.
Human spaceflight (Wikipedia)
Manned mission to Mars (Wikipedia)