SpaceX has launched the third test flight of it Starship spacecraft, the largest and most powerful rocket ever built, which aims to carry astronauts to the moon and, eventually, to Mars.

The 120-metre system, which weights about 5,000 metic tonnes when fully fuelled, took off from SpaceX’s spaceport, named Starbase, on the Gulf of Mexico in Boca Chica, Texas. It entered space several minutes later.

Two previous attempts ended in the explosion of both the spacecraft’s 33-engine booster, nicknamed Super Heavy, and the cruise vessel, which is designed to eventually carry up to 100 astronauts. Stacked together, they stand at 10 metres taller than the Saturn V rocket that sent humans to the moon in 1969.

SpaceX is much more tolerant of risk than Nasa and has a flight-testing strategy that aims to frequently push its spacecraft prototypes to the limit, and beyond. Its first Starship launch attempt lasted four minutes and the second lasted eight, with the latter reaching space. The company says frequent flight testing will provide valuable data that will help it design and develop a more robust rocket.

“Each of these flight tests continue to be just that: a test,” SpaceX said in a statement before the third launch attempt, in an apparent attempt to manage expectations in case the system exploded. “They aren’t occurring in a lab or on a test stand, but are putting flight hardware in a flight environment to maximize learning.”

The third flight aimed to conduct the first ever re-light of SpaceX’s signature Raptor engine while in space, open a payload door, and make a controlled re-entry of Starship in the Indian Ocean. Both the upper and lower segments of Starship are designed to eventually power themselves safely back to Earth for a soft landing so that they can be reused, which will be significantly cheaper than building entirely new parts for each mission.

Elon Musk, SpaceX’s billionaire founder, hopes Starship will be the first step on a human journey further into space that ever before. He says he developed Starship, previously named the BFR (heavily hinted to mean “big fucking rocket”), so that humans can eventually become a “multiplanetary species”. To do this, Musk intends to begin the colonisation of Mars so that humanity can survive a planet-destroying event on Earth, such as a sentient AI takeover or asteroid strike.

Nasa has contracted SpaceX to land astronauts, including the first woman, on the moon as soon as 2026, although that date is likely to be pushed back. Several other Starship systems are already in production for future tests.

Musk had previously said the total development cost of Starship could be between $2bn and $10bn. Each launch is estimated to cost tens of millions of dollars.

The company makes money by operating smaller rockets to launch satellites as well as sending astronauts to the International Space Station. It has announced longer term plans to use the spacecraft as a shuttle for commercial travel on Earth, promising trips from London to Tokyo in less than an hour.

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