A team of researchers brought a pair of scale model space capsules to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to try out a rotor system that could be used in place of parachutes on returning spacecraft.
The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation that has been proven repeatedly on helicopters but never tried on spacecraft.
The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or the top of a building. In other words, wherever a helicopter could land, a spacecraft could land, too. Instead of throwing away the stage and its valuable engines, rotors could be built into the booster frame and unfurled as the stage descends to Earth. Just as with the capsule, the stage would be controllable the whole way down and would land softly to save the all-important engines.
One might think the blades would fold up like an umbrella on a windy day the moment they touch the airstream around the capsule, but the airflow around the hinges would be balanced, so the blades would hold strong.
Some bombs have fins that flick open safely at high speed. The returning spacecraft could use a mechanism similar to the fins, with the difference being that the capsule's blades would start spinning almost immediately after opening. Control fins would open on the side of the capsule, too, to keep it from revolving with the blades.
According to the engineers, the testing is extremely simple compared to the high-tech evaluations that must be done before such an experimental system could be flown into space, but the analysis is critical to moving through the early phases of development to convince people it's an idea worth pursuing.
