An explosion knocks out the Anduril rocket engine testing site in Mississippi

A rocket motor exploded during a test at an Anduril facility in Mississippi last Friday, marking another setback in the startup’s hopes of becoming a major supplier of missile propulsion systems to the defense industry. Anduril publicly confirmed the incident after an inquiry by WIRED.

No one was injured in the blast that damaged Anduril’s test bench, the company’s chief operating officer, Matt Grimm, said in a social media post on Tuesday, hours after WIRED contacted the company about the incident.

Three people familiar with Anduril’s operations, who spoke on the condition of anonymity to discuss a sensitive situation, told WIRED that they could not recall another time such a test resulted in an explosion in the past few years, and did not know what might have caused last week’s mishap. The accident halted a key step in prototype testing work that generates revenue for Anduril’s rocket engine, and it could take up to several months to restore the setup, one of the people said.

Grimm wrote in his post, which included photos of smoldering equipment, that Anduril expects to resume testing within weeks. « Anduril continues to build and test rocket engines every week, and the production facility remains on schedule, » he said. « Disciplined iteration breeds steady progress, and we’re already assembling the pieces of our test bench for the next test. »

Shannon Prior, a spokeswoman for Anduril, did not respond to a request for comment for this story, other than to point to Grimm’s post.

Anduril plans to begin mass production of rocket engines on July 1, 2025, but a year later has yet to do so, four people familiar with the matter said, disputing Grimm’s claim that the effort is on schedule. A former Pentagon official who helped land Anduril’s multimillion-dollar grant previously told WIRED that he expected years of delays despite the company’s promises to deliver the complex technology on time. Production of solid-fuel rocket engines in the U.S. is largely controlled by just a few companies, leading to a shortage that the Pentagon is trying to overcome by supporting start-ups.

Anduril is valued at $61 billion by investors and has fulfilled billions of dollars in government contracts around the world by developing drones, submarines and surveillance equipment, but its rocket engine, based in McHenry, Miss., has faced repeated challenges. In March, WIRED reported on a series of safety and technology issues at the McHenry facility, including accidentally burning an employee’s hand with a lighter and buying expensive equipment that didn’t work as intended.

On social media, Anduril founder Palmer Luckey framed some of the incidents described in earlier WIRED reports as « whining about … pointless stuff. » The company’s chairman, Trey Stevens, wrote in a separate post that Anduril is « scaling faster than anyone else in this industry » and « fixing problems when we find them. »

Before it could begin mass production of rocket engines at McHenry, Anduril generated revenue by designing, building and testing prototype engines for customers such as the U.S. Navy. That business earned the company tens of millions of dollars in revenue last year, according to a person familiar with the figure. Even critics of the unit say the test business has performed well. After the prototypes are built, Anduril measures how well the designs perform, including how long the fuel burns. Customers receive the data to inform their plans. This job can now be stopped.