With one of these planes they found a way to put it into a stall at a 70° angle towards the Earth, They found that in this configuration, it falls reasonably slowly, rather like a parachute. The plan was to add thrusters for a vertical soft landing on the Martian surface.NASA's Langley Research Center Artist's concept of the Mars Airplane - one of many ideas - this is a tiny plane with five foot wingspan which folds to fit into an aeroshell for entry into the Mars atmosphere.