Sara Webb, Swinburne University of Technology

What goes up must come down, and earlier this week yet another of SpaceX’s Starships, the biggest and most powerful type of rocket ever built, came back down to Earth in spectacular fashion. In the sky above the Indian Ocean, it exploded.

This was the ninth test flight for the rocket, and the third catastrophic failure in a row, just this year.

Is this what we should expect from the very ship some are counting on to take humans further than we’ve ever been in the solar system? Or does this failure point to deeper concerns within the broader program?

A decade of development

The Starship program from Elon Musk’s space technology company, SpaceX, has been in development for more than a decade now and has undergone many iterations in its overall design and goals.

The Starship concept is based upon the SpaceX Raptor engines to be used in a multistage system. In a multistage rocket system, there are often two or three separate blocks with their own engine and fuel reserves. These are particularly important for leaving Earth’s orbit and travelling to the Moon, Mars and beyond.

With Starship, the key factor is the ability to land and reuse vast amounts of the rocket stages again and again. The company’s Falcon 9 vehicles, which used this model, were fantastically successful.

Initial tests of Starship began in 2018 with two low-altitude flights showing early success. Subsequent flights have faced numerous challenges with now four complete failures, two partial failures and three successes overall.

Just two days ago, during the latest failed attempt, I watched alongside more than 200 other space industry experts at the Australian Space Summit in Sydney. Broadcast live on a giant screen, the launch generated an excited buzz – which soon turned to reserved murmurs.

Of course, designing and launching rockets is hard, and failures are to be expected. However, a third catastrophic failure within six months demands a pause for reflection.

On this particular test flight, as Starship positioned itself for atmospheric re-entry, one of its 13 engines failed to ignite. Shortly after, a booster appeared to explode, leading to a complete loss of control. The rocket ultimately broke apart over the Indian Ocean, which tonnes of debris will now call home.

Polluting Earth in pursuit of space

We don’t know the exact financial cost of each test flight. But Musk has previously said it is about US$50–100 million.

The exact environmental cost of the Starship program – and its repeated failures – is even harder to quantify.

For example, a failed test flight in 2023 left the town of Port Isabel, Texas, which is located beside the launch site, shaking and covered in a thick cloud of dirt. Debris from the exploded rocket smashed cars. Residents told the New York Times they were terrified. They also had to clean up the mess from the flight.

Then, in September 2024, SpaceX was fined by the US Environmental Protection Agency and the Texas Commission on Environmental Quality for 14 separate incidents since 2022 where the launch facilities discharged polluted water into Texas waterways. Musk denied these claims.

That same month, the US Federal Aviation Administration (FAA) proposed a fine of US$633,009 in civil penalties should be issued to SpaceX. This was on the grounds of using an unapproved launch control room and other violations during 2023. Musk denied these claims too and threatened to countersue the FAA for “regulatory overreach”.

It’s unclear if this suit was ever filed.

Two other failed launches in January and March this year also rained rocket debris over the Caribbean, and disrupted hundreds of commercial flights, including 80 which needed to be diverted and more than 400 requiring delayed takeoff to ensure they were entering safe air space.

Success of different space programs

Until last year, the FAA allowed SpaceX to try up to five Starship launches a year. This month, the figure was increased to 25.

A lot can go wrong during a launch of a vehicle to space. And there is a long way to go until we can properly judge whether Starship successfully meets its mission goals.

We can, however, look at past programs to understand typical success rates seen across different rocketry programs.

The Saturn V rocket, the workhorse of the Apollo era, had a total of 13 launches, with only one partial failure. It underwent three full ground tests before flight.

SpaceX’s own Falcon 9 rocket, has had more than 478 successful launches, only two in flight failures, one partial failure and one pre-flight destruction.

The Antares rocket, by Orbital Sciences Corporation (later Orbital ATK and Northrop Grumman) launched a total of 18 times, with one failure.

The Soyuz rocket, originally a Soviet expendable carrier rocket designed in the 1960s, launched a total of 32 times, with two failures.

No sign of caution

Of course, we can’t fairly compare all other rockets with the Starship. Its goals are certainly novel as a reusable heavy-class rocket.

But this latest failure does raise some questions. Will the Starship program ever see success – and if so when? And what are the limits of our tolerance as a society to the pollution of Earth in the pursuit of the goal to space?

For a rocketry program that’s moving so fast, developing novel and complex technology, and experiencing several repeated failures, many people might expect caution from now on. Musk, however, has other plans.

Shortly after the most recent Starship failure, he announced on X (formerly Twitter), that the next test flights would occur at a faster pace: one every three to four weeks.

Sara Webb, Lecturer, Centre for Astrophysics and Supercomputing, Swinburne University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.