IN the early years of the 20th century, zeppelins filled with flammable and explosive hydrogen were all the rage in Germany, a reckless infatuation that ended with the eruption and crash of the Hindenburg in 1937. Sometimes, technology is a triumph of wild-eyed enthusiasm over the unpleasant facts of the real world.

Today we are witnessing a similar outburst of enthusiasm over the literally outlandish notion that in the relatively near future, some of us are going to be living, working, thriving and dying on Mars. A Dutch nonprofit venture called Mars One aspires to send four people to Mars by 2026 as the beginning of a permanent human settlement. In the United States, the nonprofit Inspiration One has plans for a two-person team to fly within 100 miles of the planet, launching from Earth in January 2018. And the entrepreneur Elon Musk, who runs a rocket company called SpaceX, has said he hopes to send the first people to Mars in 11 to 12 years.

Unfortunately, this Mars mania reflects an excessively optimistic view of what it actually takes to travel to and live on Mars, papering over many of the harsh realities and bitter truths that underlie the dream.

First, there is the tedious business of getting there. Using current technology and conventional chemical rockets, a trip to Mars would be a grueling, eight- to nine-month-long nightmare for the crew. Nine months is a long time for any group of people to be traveling in a small, closed, packed spacecraft. (We’re not talking about the relatively comfy confines of a habitable satellite like the International Space Station.) Tears, sweat, urine and perhaps even solid waste will be recycled, your personal space is reduced to the size of an S.U.V., and you and your crewmates are floating around sideways, upside down and at other nauseating angles.