A one-way ticket to Mars sounds like a suicide mission, but a lot of people are interested in getting one. Two years ago, a Dutch group called Mars One created a competition to find applicants and more than 200,000 people signed up. Now the selection process has narrowed the field to 100 candidates, 38 of whom are from the United States. Mars One says it ultimately plans to send a team of four to the red planet in 2024. And to raise the $6 billion it's projected to cost, the group plans to televise the rest of the competition.