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SpaceX’s first orbital Starship engine just breathed fire
Less than three weeks after shipping to Texas, SpaceX says that Starship’s first Raptor Vacuum engine has completed a “full duration test fire” on the march towards orbital test flights.
Known as Raptor Vacuum or RVac, the engine is almost entirely based off of its sea level-optimized cousin, taking all of the complex turbomachinery and combustion chambers that represent the bulk of a rocket engine. Things start to diverge below the throat of the combustion chamber (the narrow part of the central hourglass-like curve), where SpaceX has expanded Raptor’s existing bell nozzle by a factor of five or more.
SpaceX’s reusable Starship spacecraft will use a mix of three sea level Raptors and three Raptor Vacuum engines to give it the thrust it needs to reach orbit and ensure efficient operations both in atmosphere and vacuum.
In simple terms, a rocket engine can benefit from a vacuum-optimized nozzle because the added surface area (more or less) gives the extremely high-pressure gases exiting its combustion chamber even more footholds to push against. Rocket nozzles are at their most efficient when the engine’s exhaust gas finishes expanding to match ambient pressure at the exact moment it exits the bell. Logically, at sea level on Earth, the ambient air pressure is quite high, meaning that rocket exhaust doesn’t have to expand as much to equalize.
In the vacuum of space, however, exhaust gases must expand far more to reach the same pressure as its surroundings. For rocket propulsion, that extra expansion can be exploited to make a more efficient engine, squeezing extra energy out of the same propellant and in a perfect vacuum, the most efficient nozzle would technically be infinite. Engineering and physical infinities don’t exactly get along, unfortunately, so vacuum rocket engineers are forced to settle on a nozzle size at a scale that humans can feasibly manufacture.
In theory, Starship doesn’t need Raptor Vacuum engines to be a functioning orbital spacecraft and CEO Elon Musk himself floated a design with seven sea-level engines just two years ago. Since then, the SpaceX CEO revealed that Raptor was making such good progress that the company undid the removal of vacuum-optimized engines from Starship’s baseline design.
It’s unclear exactly what SpaceX means when it says that Raptor Vacuum SN1 completed a “full duration test fire.” For Starship, a full-duration orbital insertion burn – beginning immediately after Super Heavy booster separate – would likely be no shorter than five or six minutes. Even for SpaceX, going from shipping the very first engine (Raptor Vacuum) produced to a successful several-minute static fire in less than three weeks’ time would be an almost inconceivable feat of engineering. The feat would imply that SpaceX is already extremely comfortable with several-minute Raptor burns – perhaps the single biggest hurdle standing between Starship and orbit.
More likely, “full duration test fire” simply refers to the fact that the pathfinder Raptor Vacuum engine managed to ignite, burn, and shut down on schedule – avoiding a premature shutdown, in other words. For an engine as large and complex as Raptor, even that downgraded interpretation would represent an impressive achievement.
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Tesla gathers Cybercab fleet in Gigafactory Texas
Images and video of the Cybercab fleet were shared by longtime Giga Texas observer Joe Tegtmeyer in posts on social media platform X.
Tesla appears to be assembling a growing number of Cybercabs at Gigafactory Texas as preparations continue for the vehicle’s mass production. Recent footage shared online has shown over 30 Cybercabs being transported by trucks or staged near testing areas at the facility.
The images and video were shared by longtime Giga Texas observer and drone operator Joe Tegtmeyer in posts on social media platform X.
Interestingly enough, Tegtmeyer noted that many of the Cybercabs being loaded onto transport trucks were still equipped with steering wheels. This suggests that the vehicles are likely testing units rather than the final driverless configuration expected for the company’s Robotaxi service.
The vehicles could potentially be headed to testing sites across the United States as Tesla prepares to expand its Robotaxi fleet.
Additional footage captured at Gigafactory Texas also showed the Cybercab’s side and rear camera washer system operating as vehicles were being loaded onto transport trucks.
The growing number of Cybercabs at Giga Texas comes amidst the company’s announcement that the first production Cybercab has been produced at the facility. Full Cybercab production is expected to begin in April.
The vehicle is expected to play a central role in Tesla’s Robotaxi ambitions as the company looks to expand autonomous ride-hailing operations beyond its early deployments using Model Y vehicles.
Tesla has also linked Cybercab production to its proposed Unboxed manufacturing process, which assembles large vehicle modules separately before integrating them. The approach is intended to reduce production costs and accelerate output.
Musk has also noted that the Cybercab’s ramp will likely begin slowly due to the number of new components and manufacturing steps involved. However, he stated that once the process matures, Cybercab production could scale quickly.
Elon Musk
Elon Musk’s xAI, creator of Grok and Grokipedia, celebrates its third birthday
xAI Memphis highlighted several of its milestones over the years in its celebratory post.
Elon Musk’s artificial intelligence startup xAI has marked its third anniversary. The update was shared in a post from the xAI Memphis account on social media platform X.
xAI Memphis highlighted several of its milestones over the years in its celebratory post.
As per xAI, it has built three massive data centers in the city, launched a coherent cluster of 330,000 GBs, created over 3,000 jobs, and paid over $30 million in taxes to local communities.
xAI’s Memphis operation has become a key part of the company’s infrastructure as the company works to train and deploy its Grok artificial intelligence models. Elon Musk has been quite optimistic about Grok’s potential, noting in the past that the large language model might have a shot at achieving artificial general intelligence (AGI).
xAI’s Memphis’ crown jewel is its Colossus supercomputer cluster. The project was announced in 2024 and has since become the home of one of the world’s largest AI compute facilities. The first phase of Colossus reached its initial 100,000 GPU operational milestone in just 122 days, or just about four months.
Industry figures such as Nvidia CEO Jensen Huang have praised the facility, noting that projects of similar scale typically take two to four years to complete.
xAI has cited Memphis’ central location, skilled workforce, and industrial infrastructure as key reasons for selecting the city as the home of its AI training operations. The company has also emphasized plans to expand the site further as it scales compute capacity for Grok and future AI models.
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Tesla Sweden’s Megapack Supercharger near Arlanda continues to aggravate IF Metall union
The charging site, located in Arlandastad outside Stockholm, appears to be operating despite ongoing union blockade measures tied to Tesla’s labor dispute in the country.
Tesla Sweden’s Megapack-powered Supercharger station near Arlanda Airport has continued to aggravate Swedish labor union IF Metall. The charging site, located in Arlandastad outside Stockholm, appears to be operating despite ongoing union blockade measures tied to Tesla’s labor dispute in the country.
Comments about the site were shared by IF Metall representatives in remarks to Swedish publication CarUp.
The Arlandastad location includes eight Tesla Superchargers powered by a Megapack battery system. Unlike traditional charging stations that rely on direct grid connections, the site uses a large battery installation to store electricity and power the chargers.
According to the Swedish publication, the setup allowed the station to come online despite sympathy measures from Sweden’s electricians’ union, which has attempted to prevent companies from cooperating with Tesla as part of the broader labor conflict.
IF Metall press manager Jesper Pettersson indicated that the union was not aware that the Superchargers had already been connected and activated.
“We do not know the details around this. But it is further proof of how Tesla systematically finds loopholes to circumvent the sympathy measures through active strikebreaking. Every time this happens it gives us reason to sharpen our conflict measures,” Pettersson said.
Union representatives also noted that the Megapack appears to be charged using electrical cables routed through nearby terrain, though the exact power source remains under review.
The Megapack-powered site has then prompted questions from Swedish labor unions about how electricity is being supplied to the system.
IF Metall has submitted a report to Sweden’s Energy Market Inspectorate asking the regulator to review whether the electricity supply arrangement complies with national regulations. The Megapack is reportedly charged using electricity from a local company, though the provider has not been publicly identified.
Peter Lydell, an ombudsman at IF Metall, previously stated that Swedish law limits electricity trading to companies with proper authorization.
“The legislation states that only companies that engage in electricity trading may supply electricity to other parties. You may not supply electricity without a permit, then you are engaging in illegal electricity trading. That is why we have reported this…
“This is about a company that helps Tesla circumvent the conflict measures that exist. It is clear that it is troublesome and it can also have consequences,” Lydell said.
IF Metall and Tesla Sweden’s conflict has been going on for over two years now.
Tesla gathers Cybercab fleet in Gigafactory Texas
Elon Musk’s xAI, creator of Grok and Grokipedia, celebrates its third birthday
