Starship explosion raises questions about risk to public, environment

The latest disintegration of a SpaceX test flight was a spectacular sight, as broken-up rocket parts streaked like jellyfish tendrils across the Caribbean sky on Thursday evening.

But some experts say focusing on that dazzling light show, as many people and media outlets did, highlights a lack of understanding of the environmental aftermath of these spacecraft failures.

Moriba Jah, professor of aerospace engineering at the University of Texas Austin, compares it to marvelling at the beauty of a nuclear bomb's mushroom cloud.

"Being mesmerized by the magic of the debris [means] not realizing what it implies," Jah said. "This stuff can harm ecosystems, can affect populations."

There is also the more immediate threat, illustrated by this incident, posed by several tonnes of flaming wreckage raining down on the waters and, though the odds are slim, maybe even on some unlucky patch of land.

Thursday's test of Starship — which was made up of two parts, the upper stage Starship (in this case, Ship 33) and the lower stage Super Heavy Booster — lasted about eight and half minutes. In that time, audiences saw the most powerful rocket ever made successfully separate both stages, and an impressive "chopstick" catch of the Super Heavy booster.

But soon after, SpaceX says it lost its connection to the upper stage. Eventually, confused and awe-struck people in Turks and Caicos saw their evening sky ablaze with the debris of Ship 33.

Elon Musk, the billionaire CEO of SpaceX, suggested the cause was "an oxygen/fuel leak in the cavity above the ship engine firewall." SpaceX says it's looking into what went wrong in co-ordination with the U.S. Federal Aviation Administration (FAA), which requires a "mishap investigation," as it did when a 2023 Starship test flight also exploded.

The trajectory for the flight started from Boca Chica, Texas, and headed east over the Caribbean Sea. Spaceflights like this make airspace warnings ahead of time, but the loss of communication spurred another, more urgent one.

The FAA said in a statement that it "briefly slowed and diverted aircraft" where the debris was falling. The result was flights being delayed, circling in place or turning back.

Some pilots could even see the fireworks from their cockpits.

And for Jah, the risks, even if small, aren't being fully communicated to air travellers.

"If you and I were going into an airplane and somebody said, 'Hey, there's a one in 10,000 chance you won't make it,' I'm not going to get on the plane," Jah told CBC News from Austin, offering some hypothetical odds.

Aaron Boley, co-director at the Outer Space Institute and an expert in space sustainability, agreed, saying the risks and costs of the spaceflight industry are being exported to the aviation industry.