Engineers design motorless sailplanes for Mars exploration

Eight active spacecraft, including three operated by NASA, orbit Mars, gathering imagery of the planet's surface at a resolution of about 1 foot per pixel. Three rovers traverse the ground, mapping small areas of the planet with greater precision. But what lies in the hundreds of kilometers between the rovers and the orbiters—including atmospheric climate processes and geological features like volcanoes and canyons—is often of most interest to planetary scientists.