In five years, a new class of spacecraft will be heading to the Red Planet. This week, NASA announced the four finalists that will compete for the opportunity to be the first “Mars Scout.” Of the 25 proposals submitted in August, NASA selected these four because of their innovative scientific goals and cost effectiveness. Each mission is designed to answer many unknown questions about the planet’s chemical composition and biological activity. A full-scale model of the ARES Mars airplane NASA / LARC The four finalists are: ARES, Aerial Regional-scale Environmental Survey; Marvel, Mars Volcanic Emission and Life Scout; Phoenix; and SCIM, Sample Collection for Investigation of Mars.