National Geographic : 1967 Dec
Real flying saucer: A conical metal aeroshell such as this may shield an instrumented package entering Mars' thin atmosphere. A Martin Marietta Corporation technician at Denver inspects riveting on the aluminum cone. Inhaling helium through two ducts, the world's largest balloon lifts its head at Walker Air Force Base, New Mexico. As the plastic balloon rises in the rarefying air, the gas expands to fill the main body-here a bright streak on the ground-to a 410-foot bubble. It carries an aeroshell 25 miles into an atmosphere as thin as that 71/ miles above the Martian surface. There the aeroshell, fired by rock ets, will test a parachute's ability to slow descent in a Mars landing.