Next-gen Mars helicopter rotor blades exceed Mach 1

The rotor blades that will carry NASA's next-generation helicopters to new Martian heights broke the sound barrier during March tests at NASA's Jet Propulsion Laboratory in Southern California. Data from the tests, which took place in a special chamber that can simulate environmental conditions on the Red Planet, indicate that the fastest traveling part of the rotor blade, the tips, can be accelerated beyond Mach 1 without breaking apart. Data gathered from 137 test runs will enable engi...