Over the next several years, Elon Musk aims to take astronauts to the moon using a 123-metre rocket, launch a
fleet of autonomous vehicles that lack a steering wheel or pedals, and turn millions of existing Teslas into self-driving cars overnight.

Musk has acknowledged his ambitions require overcoming regulatory hurdles, roadblocks presented by Nasa, the US Department of Transportation, Federal Aviation Administration and the National Highway Traffic Safety Administration.

Throwing caution to the wind, Musk took aim at the man overseeing each one of those agencies in X posts this week – Transportation Secretary and acting Nasa administrator Sean Duffy – igniting a new public feud with the Trump administration.

“Having a NASA Administrator who knows literally ZERO about rockets & spacecraft undermines the American space program and endangers our astronauts,” Musk said in an X post on Wednesday (Thursday NZT).

Behind the scenes, his business decisions appear to express even more defiance.

In recent days, Tesla has launched a new mode, dubbed “Mad Max”, a version of its advanced driver assistance intended to allow vehicles to weave through traffic and maneuver more confidently, but which has been reported to roll through stop signs and exceed the speed limit.

The Biden administration took a hard line against similar aggressive maneuvers, leading Tesla in 2022 to issue an update eliminating a “rolling-stop” function, which sent cars through intersections without coming to a complete halt, and a recall of more than 50,000 vehicles. (Tesla said it was not aware of any collisions, injuries or deaths related to the issue at the time.)

The new Mad Max feature, rolled out quietly during the US Government shutdown, reprises the type of driving behaviour previously rejected by regulators for pushing cars afoul of traffic laws.

NHTSA, the federal traffic safety regulator Duffy oversees, disclosed for the first time to The Washington Post that it has now made an inquiry into the Mad Max mode.

A NHTSA spokesman said on Tuesday the agency “is in contact with [Tesla] to gather additional information” on the feature. The agency opened a probe earlier this month into reports of traffic violations while Full Self-Driving was active, including running red lights and crossing into opposing lanes of traffic.

Musk’s persistent feuding with Trump officials marks a stark contrast to early this year, when he was a key adviser to the president after aiding in his election with hundreds of millions in campaign contributions. At the time, Wall Street expected Musk’s cosy relationship with Trump – Musk proclaimed himself “first buddy” – to benefit his businesses, helping clear a regulatory pathway for some of his biggest bets.

Tesla’s quiet addition of features similar to previously scrutinised capabilities and Musk’s skirmishes with people in the Trump administration have caused longtime Musk observers and backers of his companies to say he’s putting his businesses at risk. Musk’s sparring goes beyond Duffy; he has exchanged barbs with trade adviser Peter Navarro, Treasury Secretary Scott Bessent and even Trump himself.

“You’re essentially fighting with the guy in charge,” said Tesla investor Ross Gerber, who has become a prominent Musk detractor in recent years. “It’s so much self-sabotage.”

The Department of Transportation did not respond to an inquiry regarding whether Duffy had any response to Musk’s criticisms or how they might impact the agency’s work; a DOT spokesperson referred a reporter to Nasa. Tesla, SpaceX and Musk did not respond to requests for comment.

Tesla has long aimed to deploy a more aggressive version of its driver-assistance system, Full Self-Driving. But rolling out a feature that includes humanlike driving characteristics is complicated by the fact that such programming often causes vehicles to run afoul of traffic laws.

“When you take an AI-driven system like Tesla’s … and you say, ‘Well let’s take away a little of its guardrails,’” said Gerber, “This can only make it more dangerous.

“It’s more confidently making the mistake,” he added.

During Tesla’s quarterly earnings call on Wednesday, Musk described a new wave of innovations he expects the company to fulfil, echoing promises he has made for years. “We’re really just at the beginning of scaling, quite massively, Full Self-Driving and Robotaxi and fundamentally changing the nature of transport,” Musk said. “There are millions of cars out there that with a software update become full self-driving cars.”

Still, Musk said, Tesla’s ability to expand its Robotaxi ride-hailing service to around 10 metro areas by year’s end hinges on “various regulatory approvals”.

Meanwhile, Musk has berated Duffy in a smattering of posts on X more than 36 hours after making his opening jab.

Musk took umbrage with Duffy’s suggestion that Artemis III, a Nasa mission to land a crewed rocket on the Moon, would be opened to vendors besides Musk’s rocket company SpaceX. After initially being awarded the $2.89 billion (NZ$5b) contract, SpaceX has faced numerous setbacks and delays in its effort to deliver a functional moon lander.

Potential competitors include Blue Origin, founded by Washington Post owner Jeff Bezos.

Nasa spokeswoman Bethany Stevens said on Wednesday that the agency is giving both Blue Origin and SpaceX the opportunity to present “acceleration approaches”, while also asking other companies for proposals to speed up the moon mission. “At the President’s direction, Sean has focused the agency on one clear goal – making sure America gets back to the moon before China,” she said.

The agency’s current plan requires SpaceX’s Starship to be refuelled in space, a feat that has never been accomplished by any company or government agency.

“A lot of people have questions on that and they haven’t got into orbit to even demonstrate [the refuelling],” said a Nasa employee familiar with the matter, speaking on the condition of anonymity. “If we had five more years, there would be less concern.”

Nasa had planned the Artemis III launch for 2024 before delaying it to 2027, but many experts believe that timeline, too, is unrealistic. Duffy, in an appearance on Fox & Friends, seemed to suggest the timeline would slip another year. “We’re going to beat the Chinese and do it in President Trump’s term … so, before 2029 January,” he said.

SpaceX has tested Starship 11 times with a mixed record of success. The first, in 2023, saw the rocket lift off successfully before exploding, sending debris hurtling onto a nearby beach. A major breakthrough last October, with a system successfully catching a returning rocket booster, proved short-lived after four subsequent tests ended in explosive failures.

Using Starship for the moon mission will require it to reach complex milestones, causing experts to worry the system won’t be ready in time for the maneuvers required by Nasa’s Artemis III plan.

“SpaceX is far behind in meeting all of the progress milestones it must meet before [Artemis III],” Todd Harrison, a space policy analyst with the American Enterprise Institute, said in an email.

There are numerous other companies working on moon landers. The defence contractor Lockheed Martin has been working on technical and programmatic analysis for lunar landers that would provide more options to Nasa, according to an emailed statement from Bob Behnken, the company’s vice president of exploration and technology strategy. Texas-based Firefly Aerospace and Japan’s iSpace both sent uncrewed landers to the moon earlier this year.

Musk’s tirade against Duffy came after the latter singled out SpaceX in comments to CNBC.

“I love SpaceX; it’s an amazing company,” Duffy said on CNBC’s Squawk Box. “The problem is they’re behind. They pushed their timelines out and we’re in a race against China. The President and I want to get to the moon in this President’s term, so I’m going to open up the contract.”

Musk responded to Duffy directly – with a juvenile meme. Later, he settled on a nickname, “Sean Dummy is trying to kill NASA!” he wrote.

The fraught dynamic is complicated by mutual dependence. Musk’s SpaceX has received billions of dollars in US government contracts, while Nasa is dependent on SpaceX’s equipment and ability to propel people into orbit.

While Duffy, as Nasa’s acting administrator, seeks to consolidate power over the space programme, Musk has pushed for his preferred candidate, Jared Isaacman, to lead the space agency. Trump withdrew Isaacman’s nomination in May over his Musk ties and alleged Democratic leanings, though Isaacman responded that he has “been relatively apolitical”.

Meanwhile, Musk drew criticism from fans who said he was playing with fire by picking a fight with the person overseeing the Department of Transportation and Nasa.

“It’s not a smart idea to [upset] the DoT when you need them for [Full Self-Driving] and Robotaxi Elon,” one X user responded, referring to Tesla’s plans for an autonomous vehicle ride-hailing service.

That hasn’t stopped Tesla from enthusiastically touting its new mode.

“If you are running late, this is the mode for you,” another person said on X, a testimonial reposted by Tesla with two words: “Mad Max.”