The top priorities of the Falcon 9 are reliability and reusability. The rocket is equipped with three redundant navigation and flight computers in case of failure. It is capable of flight with only 7 of the 9 main engines operational. In 2012, when one engine failed midflight, the rocket was still able to deploy the payload to the correct orbit despite a loss in thrust, proving its reliability. The launch of the Falcon 9 includes a hold-down procedure which performs a system check after engine ignition before releasing the rocket. The check will allow for an early abort if there is any problem, which can save the lives of astronauts on future missions. SpaceX has reduced the weight and strengthened the rocket by creating an alloy of lithium
