Iteration on the design of the Falcon 9 grid fins continued into 2017. SpaceX CEO Elon Musk announced in early 2017 that a new version of the Falcon 9 grid fins would improve reusability for the company's vehicles. Falcon 9 Block 5 introduce new cast and cut titanium grid fins. Musk had noted the original Falcon 9 grid fins were made from aluminum. The fins experience temperatures near their maximum survivability limits during reentry and landing, and so the aluminum fins were coated with an ablative thermal protection system. In fact, some aluminum grid fins have actually caught fire during the entry and landing sequence. The new titanium grid fins should introduce greater controllability to the rocket and increase the payload to orbit capability by allowing Falcon 9 to fly at a higher angle of attack.