A dual rotor system for the next generation of Mars helicopters is tested in the 25-Foot Space Simulator at NASA's Jet Propulsion Laboratory in Southern California on Sept.15, 2023. Over three weeks, the carbon-fiber blades were spun up at ever-higher speeds and greater pitch angles to see if they would remain intact as their tips approached supersonic speeds. Longer and stronger than those used on NASA's Ingenuity Mars Helicopter, the blades reached Mach 0.95 during the test. The simulator's vacuum chamber allows engineers to test spacecraft and components in conditions like those they would face on Mars. The inset at upper right shows the same test from the perspective of a second camera also located inside the chamber. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA26079