Last week, a private Dutch company, Mars One, announced that it hopes to send a four-person crew to Mars by 2023. To keep costs down, it will be a one-way mission. Mars will become the astronauts' permanent home.

It's not clear whether this will be a scientific mission so much as a reality TV show, since the company plans to finance the operation by airing the entire thing live, with commercial sponsors. But the scheme echoes similar plans that bona fide members of the scientific...