News
SpaceX fires up Starship rocket twice in 30 hours ahead of next big tests
SpaceX has successfully fired up a full-scale Starship rocket for the second time in barely 30 hours and removed the ship’s Raptor engine to perform an additional suite of “cryo testing”.
Around 7pm CDT on May 6th, SpaceX technicians began loading the fourth full-scale Starship with liquid oxygen and methane, filling up a large portion of its massive propellant tanks. Just the latest in a line of several tests involving wet dress rehearsals (WDR) completed in the days prior, this test would soon become exceptional. About an hour and a half after work began, Starship SN4’s lone Raptor engine ignited and burned for ~3 seconds, marking the first time in history a next-generation SpaceX rocket truly came alive with one of the engines designed to take it all the way to orbit.
In line with tests performed with Starhopper – a low-fidelity, subscale tested that flew twice with Raptor – last year, it would have been business as usual if SpaceX had called it a day and moved on to something else with Starship SN4. Instead, Starship performed another WDR and fired up its Raptor engine for a second time in just 30 hours after SpaceX teams inspected the rocket and cleared it for another round. It’s unknown why two back-to-back static fires were performed but, to be clear, every step Starship SN4 takes forward is a step into uncharted territory. Already, the ship’s next steps could come as soon as Friday, May 8th.
According to CEO Elon Musk, SpaceX’s second Starship SN4 static fire test was completed successfully and actually marked the operational debut of a critical aspect of the next-generation launch vehicle and spacecraft. Known as header tanks, Starship needs two smaller secondary propellant tanks to complement its main tanks, a need driven mainly by the challenges of landing such a large and mobile spacecraft. Smaller header tanks will also make it dramatically easier for SpaceX to insulate cryogenic propellant and ensure it remains liquid over long-duration cruises in space, but safe and reliable landings are a more pressing concern for these early prototypes.
During landing operations, the main benefits smaller header tanks offer are relative ease of pressurization (needed to safely feed Raptor engines) and a much lower risk of issues from sloshing, which can introduce bubbles and voids that can obliterate rocket engines if ingested. Impressively, per Musk, Starship SN4 completed its second static fire test using its internal liquid methane header tank – a sort of bubble attached to the bottom of the main methane tank dome.


Starship’s liquid oxygen header tank is situated at the tip of the conical nose section, a part that all full-scale ships have been tested without thus far. However, the use of the fuel header tank on May 7th means that Starship SN4 already has a functional, plumbed header tank installed, verifying the partial functionality of a critical part of the next-generation launch vehicle. A second static fire will have also provided SpaceX a wealth of extra data about Raptor’s performance while installed on Starship, invaluable at such an early stage of integrated testing.
Two Starship static fires now under its belt, SpaceX removed SN4’s Raptor engine around 12 hours after its second test and returned it to storage at the company’s nearby factory facilities. According to public notices provided by Cameron County, Texas officials, SpaceX’s next Starship SN4 activity is expected to occur on May 8th with backup windows on the 9th and 10th and will involve “cryo testing”.


The most obvious conclusion is that SpaceX – having completed enough static fire testing to verify Starship SN4’s performance – now wants to really put the rocket through its paces with another cryogenic test. Completed on April 26th, the ship’s first cryogenic ‘proof’ test maxed out at around 4.9 bar (70 psi), enough for low-stress hop tests but well short of the sustained pressure needed for orbital spaceflight. While testing singular propellant tanks in the first few months of 2020, Musk revealed that SpaceX was targeting a minimum of 6 bar (~90 psi) for orbital Starship flights – ~8 bar (115 psi) with a 25% safety factor.

The company actually achieved 8.4 bar with one of its Starship test tanks, the same processes of which were used to build Starship SN4, but a full-scale ship has yet to demonstrate those pressures. Now, SpaceX already has a fifth full-scale prototype (Starship SN5) likely just a week or so away from pad readiness, meaning that Starship SN4’s potential destruction during pressure testing wouldn’t have a big impact on plans for a series of imminent flight tests. If SN4 survives pressure testing, it would likely have its Raptor engine reinstalled and move on to a 150m (500 ft) hop test.
Lifestyle
Tesla Cybercab and Robotaxi’s real advantage won’t be the ride service
For a century, the car has asked the same thing of its owner, which is basically to pay attention. Even the best ride-hailing app like Uber or Lyft only moved the problem into someone else’s hands. You stopped driving, but you still sat in a stranger’s car, while half listening, and wondering whether to take a phone call in the car without being rude. The Cybercab has no wheel, no pedals and no driver. With Grok @bot now live inside it, it becomes something else entirely, and I think that matters more than the fleet count that everyone is tracking.
Grok @bot is an agent, not a voice assistant. A rider signs in once, and from then on can say what they need and watch it happen. Order dinner from a favorite restaurant. Fill the grocery cart. Move money, answer email, adjust a calendar, push a work project forward. Tesla engineer Yun-Ta Tsai confirmed it is enabled across every Cybercab and the rest of the Model Y fleet, and Tesla’s own pitch is that Full Self-Driving handles the commute while Grok handles the errands.
Think about what that does to a thirty minute ride. Uber sells you a trip, while Waymo sells you the same trip in a more private setting. Tesla is selling the thirty minutes themselves, returned to you with an assistant attached. Errands that used to eat a Saturday get done between pickup and drop off. The ride stops being dead time between two places and becomes a place of its own.
Tesla integrates Grok Bot into its vehicles for the ultimate personal assistant
Best of all, your Bots follow you into any Cybercab, and presumably your own Tesla, then logs you out automatically when you step out. Anyone can bolt a chatbot onto a screen, but much harder to own the vehicle, the autonomy stack and the assistant at once. It also quietly ties SpaceX’s Super Intelligence business to Tesla’s fleet, after Tesla converted its xAI stake into SpaceX equity. The relationship between those two companies is getting harder to describe as separate.
This is also where the hard questions start, because an agent that can spend your money in a vehicle other people also ride in needs some answers. How does it handle a voice it shouldn’t trust? What gets recorded, who can see it, and for how long? What happens when a rider leaves halfway through a task?
If Tesla gets those answers right, the scoreboard changes. We have been counting Cybercabs and wait times. The more telling number may be what riders accomplish per trip. That is data almost no one else will ever have, and it is the real reason to watch Grok @bot.
What do you think? Leave me a comment.
News
Why Elon Musk’s target date for buying an Optimus robot is harder than it sounds
Musk says China’s magnet export ban cost Optimus months, and robot hands remain shockingly hard.
Elon Musk says China’s export curbs on magnets used in electric motors set back Tesla’s Optimus program by two to three months, and that the robot’s hands remain the hardest part of the project. He made the comments Saturday during a live interview with Tesla Owners Silicon Valley at the X Takeover event at Giga Texas, in front of roughly 2,000 attendees. The Optimus discussion begins around the 49 minute mark of the stream.
On the hands, Musk was blunt and noted that a general purpose humanoid needs fine motor skills that are “incredibly difficult to get right. Shockingly difficult,” he said in the interview. He pointed to a problem he says no one has demonstrated yet: “One of the hardest things also generally is to do precision and force at the same time,” such as driving a small self tapping screw into wood. Touch sensors add another layer, since it is “actually kind of hard to get touch sensors that elastically deform and can handle high cycle life and it won’t just break after a few thousand cycles.”
He also took aim at rival robot videos. “Any complicated looking robot demo, it’s a canned demo. It’s not real,” Musk said, adding that real AI means showing a robot something it has never seen and watching it still cope, the way FSD handles a city it has never driven.
Musk expects the Optimus ramp to be slower than a new vehicle production ramp. “The initial part of that S curve of production ramp is going to be very slow at the beginning,” Musk said, partly because “unlike cars, there’s no pre existing supply chain for robot stuff.” That echoes his July reply on X that Optimus production “will be extremely slow at first, as everything is new.”
The magnet disclosure puts a number on a problem Musk first raised in 2025. He said China “prevented the export of magnets for use in electric motors” and that it “set back the Optimus program by like two or three months.” Then he added: “We had robots with no arms.” Tesla’s fix is to bring the supply chain home. “You’ve got to be able to make all the parts domestically,” he said. Teslarati reported in April 2025 that Musk tied the issue to permanent magnets in the arm actuators, where motors have to be as small as possible.
Tesla Optimus V3 hand and arm details revealed in new patents
Production is moving regardless, with a reported internal goal of more than 1,000 a week by the end of 2026. Teslarati recently covered how Tesla is certifying supply partners in China for Optimus parts, while the company’s hand design has been the subject of new patent filings.
Musk has said he wants Optimus available to the public by late 2027, though Tesla has not confirmed that date or published updated production figures.
Investor's Corner
Elon Musk drops a Thanksgiving hint about Starship’s biggest test yet
Elon Musk says Starship Flight 15 will try to catch the ship itself, a first.
Elon Musk says SpaceX’s next Starship flight will try something nobody has done before, by catching the ship itself. Speaking to roughly 2,000 people at the X Takeover event at Giga Texas on Saturday, Musk said Flight 15 is about four to six weeks away and “probably launches a little bit before Thanksgiving, is my guess.”
That is a slip from earlier reporting, which had pointed to a launch as early as October 19. Musk explained why the date keeps moving. “We’re making a bunch of improvements to the rocket between every flight,” he said, adding that there are often hundreds, sometimes thousands, of small changes. This time the list is short, “but some of them take a fair bit of work and we’ve got to go inside the tank to make some of these changes.”
“We’re going to try to catch the ship, which is a super big deal,” Musk said. “If we do so, that’ll be the first time that there’s been full recovery of an orbital class rocket.” SpaceX has already caught the Super Heavy booster with the tower’s mechanical arms, and has talked about catching the ship since late 2025, but the upper stage has never been caught.
Musk also laid out what comes after. “The next big milestone would be to refly both the booster and the ship,” he said, describing a Flight 16 where “all parts of an orbital rocket are reflown.”
The reason SpaceX wants this comes down to cost and cadence. Every Starship ship so far has ended its flight in the ocean, and SpaceX expects most of those water landings to end in fireballs. A ship that returns to Starbase intact can be inspected and flown again. SpaceX’s IPO filing, says Starship V3 is designed to deliver 100 metric tons to orbit in a fully reusable configuration, that SpaceX aims to cut the cost to reach orbit by 99% or more versus the historical average, and that tower catches should allow “multiple launches per day.”
The payoff goes beyond cheaper launches. The next generation Starlink V3 satellites are too large for Falcon 9 and can only fly on Starship, which can carry up to 60 per flight. Flight 14 on September 28 deployed the first 26 of them after Starship reached orbit despite an early engine shutdown, as Teslarati reported. Musk blamed engine computer software, and said the heat shield “was extremely robust,” which he claimed in August had solved Starship’s biggest challenge.
NASA’s Moon plans depend on the same capability. NASA’s inspector general has described a lander mission that needs a propellant depot in low Earth orbit and more than 10 tanker flights, with SpaceX targeting one tanker launch every six days. That schedule only works if ships and boosters come back fast and fly again. Also, ship to ship propellant transfer has not been attempted yet.
One interesting hurdle yet to be explored is bringing the ship back to the launch site, with reentry over land, which will undoubtedly come with a lot of aviation safety reviews.