SpaceX has launched Starship, the largest rocket ever built, at the International Space Station.

The liftoff happened on Thursday in Boca Chica, Texas, United States of America. The entire stack, being the most powerful in the world, was made of silvery stainless steel and is as tall as a 40-story structure.

The Federal Aviation Administration, United States of America’s aviation regulator, had certified that the rocket ticked all boxes and approved a five-year license for it.

In a statement, it said, “After a comprehensive license evaluation process, the FAA determined SpaceX met all safety, environmental, policy, payload, airspace integration and financial responsibility requirements. The license is valid for five years.”

While addressing a private Twitter audience, Elon Musk, the CEO of SpaceX, expressed uncertainty about the success flight. “Success is not what should be expected. Probably, tomorrow will not be successful. It is just a very fundamentally difficult thing.”

The rocket represents a strong paradigm shift from others before it. The capsule is a reusable one and could travel beyond Mars if refueled in space.

A report by the Agence France-Presse quoted Musk as saying, “In the long run – long-run meaning, I don’t know, two or three years – we should achieve full and rapid reusability.”