Washington: SpaceX CEO Elon Musk lashed out at NASA’s acting administrator Sean Duffy on Tuesday after the space agency opened its lunar programme to new bidders, seeking alternatives to SpaceX’s delayed Starship project.

Taking to X (formerly Twitter), Musk wrote, “Sean Dummy is trying to kill NASA!” — a direct swipe at Duffy, who also serves as the US Transportation Secretary. The billionaire’s outburst came shortly after NASA invited other aerospace companies to support its goal of returning humans to the Moon, citing concerns over Starship’s timeline and progress.

NASA opens new bids amid Starship delays

On Monday, Duffy announced that NASA would seek new proposals to accelerate its Artemis programme, which aims to land astronauts on the Moon for the first time since 1972. He said the move was prompted by delays in SpaceX’s Starship development, as China pushes ahead with its own lunar mission plans.

“I love SpaceX. It’s an amazing company. The problem is, they’re behind. They pushed their timelines out and we’re in a race against China,” Duffy said in an interview with Fox News.

NASA’s Artemis 3 mission, initially targeted for 2025, has been pushed back to mid-2027 due to multiple technical and regulatory hurdles. The US space agency is counting on SpaceX’s Starship system to serve as the lunar lander for astronauts, but the project has yet to complete key orbital milestones.

Musk’s fiery response on X

In response to Duffy’s comments, Musk defended SpaceX’s progress and criticised NASA’s move to bring in competitors such as Blue Origin, founded by Jeff Bezos.

“SpaceX is moving like lightning compared to the rest of the space industry. Starship will end up doing the whole Moon mission. Mark my words,” Musk posted on X.

Duffy, for his part, maintained that the US must act quickly to stay ahead of China. “We’re in a race against China, so we need the best companies to operate at a speed that gets us to the Moon FIRST,” he said in a follow-up post.

Political tension clouds NASA leadership

The latest exchange adds to mounting uncertainty over NASA’s leadership. Former US President Donald Trump had previously nominated businessman Jared Isaacman, a close Musk associate, to lead the agency permanently. However, the White House abruptly withdrew the nomination in May 2025, shortly after Trump and Musk reportedly fell out.

Media reports now suggest Trump may reconsider Isaacman for the position, while Duffy hopes to remain in charge as acting administrator. The leadership tussle has become yet another flashpoint in the escalating political and commercial space rivalry between the US, China, and private industry giants.

What’s next for the Artemis programme

Despite internal tensions, NASA remains committed to its Artemis timeline, targeting a crewed Moon landing by 2027. China, meanwhile, has announced plans to send astronauts to the lunar surface by 2030, intensifying the competition for technological and geopolitical dominance in space exploration.

As SpaceX continues to refine its Starship design following multiple test flight anomalies, experts say NASA’s decision to diversify partners could both mitigate risk and increase pressure on Musk’s company to meet deadlines.