SpaceX will attempt a second test flight of the world’s largest rocket on Saturday, with expectations high for a big show after April’s launch, when the spacecraft pulverised the launchpad during lift-off and then exploded at altitude.
The 120-metre Starship rocket system, the most powerful ever built, was due to launch from Texas on Friday but that has been delayed until the weekend after teams found that a component needed replacing.
SpaceX, which also operates smaller rockets to launch satellites as well as human space missions to the International Space Station, gained approval this week from the Federal Aviation Administration for the test to go ahead. Concerns were raised locally after debris was scattered over a wide area during April’s launch.
Elon Musk, SpaceX founder, hopes Starship will be the first step on a human journey to Mars, with the system’s cruise vessel designed to eventually carry up to 100 astronauts. Almost as long as three passenger jets, the mammoth spacecraft stands 10 metres taller than the Saturn V rocket that sent humans to the moon in 1969.
Unlike Nasa, which generally attempts to avoid risk, SpaceX has a record of showing a willingness to have test flights explode, with Musk saying the private venture benefits from understanding what goes wrong.
SpaceX has jokingly referred to April’s explosion as “a rapid unscheduled disassembly” and said the flight, which lasted four minutes, provided vital information on how to improve.
For the second test, the rocket has had several upgrades, including a new heat shield installed on the booster, the lower part of the system that provides thrust from 33 Raptor engines to get the rocket off the ground before detaching from the cruise vessel. During April’s launch, that separation did not happen successfully.
On the launch pad, which was turned into a crater during the first test when the thrusters pulverised the concrete, a new water-cooled steel flame deflector has been installed.
The upper and lower segments of the system are designed to power themselves safely back to Earth for a soft landing so that they can be reused, which is significantly cheaper than building entirely new parts.
Musk said 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, he intends to begin the colonisation of Mars, which he said was needed to preserve humanity in case of a planet-destroying event on Earth, such as an asteroid strike or deadly pandemic.
SpaceX claims that Starship, which has a payload capacity of up to 150 tonnes, will be able to transport dozens of people on long-duration interplanetary flights. Nasa has contracted SpaceX to land astronauts, including the first woman, on the moon as soon as 2025. That date is considered ambitious.
The company 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.
SpaceX built its own spaceport, named Starbase, on the Gulf of Mexico in Boca Chica, Texas, from where it will launch its rockets. Several other starship systems are already in production for future tests.