NASA Spinoff: Controlled Propulsion for Gentle Landings A valve designed for NASA rover landings enables aerospace companies to fly safely

That required a reliable pyrovalve — a Y-shaped pipe with a pair of leak-proof solid metal barriers that prevent propellant flow until the valve is employed in the descent. The valve contains a pyrotechnic charge that’s fired to activate a piston called a flying ram, which shears off the barriers, carrying them to the bottom of the valve and allowing fuel to flow.