Starship prototype tests can generally be classified into three main types. In proof pressure tests, the vehicle's tanks are pressurized with either gases or liquids to test their strength—sometimes deliberately until they burst. The vehicle then performs mission rehearsals, with or without fuel, to check the vehicle and ground infrastructure. Before a test flight, SpaceX loads the vehicle prototype with propellant and briefly fires its engines in a static fire test. Alternatively, the engines' turbopump spinning can be tested without firing the engines, referred to as a spin prime test.
