A drone start-up backed by the US tech billionaire Peter Thiel has conducted two trials with British and German armed forces that were branded a “disaster”, raising questions about its bold public claims and its hopes of winning government contracts.
Attack drones produced by Berlin-based Stark failed to hit a single target during four attempts at two separate exercises this month with the British army in Kenya and the German army near the town of Munster, in Lower Saxony, according to four people familiar with the trials.
At one point during the German test, one of its unmanned Virtus drones lost control, landing in a wooded area. On another occasion, after an attempted strike in Kenya, a drone’s battery caught fire upon impact.
“It was a disaster for Stark,” said one person briefed on the German trial, adding: “They have been overselling [their capabilities] and now they are paying the price.”
Stark, which is due to open a factory in the UK town of Swindon in November, said in a statement: “We did not crash once or twice, we have crashed a hundred times. That is how we test, develop, and ultimately continue to deliver defence technology like Virtus to the front lines in Ukraine.”
Stark was founded just 15 months ago but has grown rapidly. The start-up has won the backing not only of Thiel’s investment firm but also of Silicon Valley venture capital giant, Sequoia Capital, and the Nato Innovation Fund.
The German company was recently provisionally chosen as one of three winners of a contract worth €300mn each to supply armed autonomous drones to the Bundeswehr, the German armed forces — although a person familiar with the plan said it was contingent on performance during ongoing trials as well as parliamentary approval.
Earlier this month the company, which was valued at $500mn in its last funding round, unveiled its new chief executive Uwe Horstmann. Horstmann is also a partner at venture capital firm Project A, which is a Stark backer, and had played a role in building up the company after its founding last year.
European governments are pouring billions of euros into defence technologies as drones prove to be a decisive capability in the war in Ukraine. German defence minister Boris Pistorius said this month that his nation alone would invest €10bn in drones in the coming years. But the rush of interest and money has also prompted concerns of a drone sector bubble.
At the time of his appointment as Stark chief, Horstmann trumpeted the performance of the company’s Virtus drone. “We’re getting feedback that Virtus is among the absolute top performers,” he told the German broadcaster NTV, prior to the latest trials.
He also told the Financial Times that his company would be ready to produce “thousands” of drones from January 2026 onwards.
A few days later, at a base in Kenya, Stark joined two other German start-ups — Helsing and ARX Robotics — for testing. The exercise, named “Haraka Storm” was designed to test, train and evaluate the kamikaze drones.
The company told soldiers at the trial that it was only willing to crash two of its four drones, according to two people familiar with the testing. The weapons were to be used without warheads and instead simply flown into their target to simulate a real strike. Stark would not let the soldiers operate them.
Stark’s website says that its Virtus drone can “track and engage precise targets up to 100km away” and “can go from cruising at a steady speed of 120km/h to performing rapid, high velocity dives at up to 250km/h”.
When the company attempted two strikes in Kenya, they missed on both occasions, with one attempt culminating in a drone landing in a smouldering heap after a battery caught fire.
Stark also gave some troops a special “challenge coin” as a souvenir from the trip, according to one person familiar with the exercise. It featured the company logo over a black and white map of Europe — which was missing the British Isles.
Stark’s rival Helsing — which has previously faced harsh criticism of its predecessor drone, the HF-1 — performed five successful strikes with its newer model, the HX-2. ARX Robotics, which makes small unmanned vehicles for use on the battlefield but also software systems, used its Mithra technology to help guide Helsing’s drones to their targets.
A British army spokesperson said: “The British Army routinely tests and evaluates the latest cutting edge technology to contribute to the defence of the nation and Army modernisation. As part of this, we work with a range of suppliers and companies to evaluate their capability and suitability for integration with the British Army.”
One western official familiar with the exercise said that it was “not an either or” choice between Stark and Helsing. “It was an experiment. The army wants all industry partners to play a role because it is advantageous for us.”
In Germany, Stark also undertook a separate trial with the country’s armed forces, according to three people familiar with the details. In front of a large audience of soldiers and defence industry representatives, it failed on both of its two strike attempts, with one of the drones unable to be retrieved after crashing. Helsing, which was also present, struck their targets 17 times, according to two of the people.
One of Stark’s financial backers, who asked not to be named, stressed the importance of “testing and experimenting” as “necessary parts of building and innovating at the frontier”.
That was echoed by a senior Bundeswehr officer who was not involved in either of the tests, who said that soldiers generally enjoyed working with start-ups, which were “much quicker to adapt to our wishes than the larger companies”.
The German Bundeswehr declined to comment, as did Helsing, Sequoia and Project A. Thiel Capital and Nato Innovation Fund did not respond to requests for comment.
ARX chief executive Marc Wietfeld said that the company “successfully tested” its integrated systems together with Helsing in Kenya.