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SpaceX delays Starhopper’s first flight a few days despite Raptor preburner test success
SpaceX has (partially) ignited Starhopper’s freshly-installed Raptor engine, successfully verifying that the engine is ready for its next major test: a full ignition and static firing. Although successful, SpaceX still has some work to do before the vehicle is ready for its first untethered flight(s).
July 15th’s progress is just the latest in a several day-series of preflight tests designed to reduce the likelihood that Starhopper is destroyed over the coming days and (hopefully) weeks. If all goes planned during the awkward Starship prototype’s first foray into hover tests, SpaceX CEO Elon Musk has stated that he will provide an official presentation updating the public on the status of the company’s ever-changing next-generation rocket.
The past week or so of Starhopper preflight testing began with Raptor serial number 6 (SN06) completing the last of a series of acceptance test fires in McGregor, Texas on June 10th. Even on its own, this was a major milestone for the new SpaceX engine: Raptor SN06 was the first of the new, full-scale engines to pass the acceptance test program with flying colors. According to Musk, for the engine to complete those tests so successfully, SpaceX had to solve a challenging bug in which some sort of mechanical resonance (i.e. vibration) damaged or destroyed Raptors SN01-05.
Hours later, the engine began a short ~450 mi (720 km) journey south to Starhopper, located in Boca Chica, Texas. The engine arrived on July 11th and was fully installed on Starhopper by the following evening (July 12th), at which point SpaceX put Starhopper and Raptor through some mild but valuable thrust vector controller (TVC) tests, wiggling the car-sized engine to ensure it can accurately steer the prototype rocket.
Around two days after the above ‘wiggle’ test was successfully completed, SpaceX moved into the next stage, partially fueling Starhopper with liquid methane and oxygen propellant and helium pressurant in what is known in rocketry as a wet dress rehearsal (WDR). The (implicitly) successful WDR was capped off with a duo of what can now safely be concluded were some sort of Raptor test preceding even pre-ignition operations. Whatever the tests were, they appear to have been completed successfully.
That appears to be the case because less than 24 hours after their completion, on July 15th, SpaceX once again began loading Starhopper with propellant and pressurant for a second round of wet testing. This time around, SpaceX got right into more critical Raptor tests once enough propellant was loaded, igniting the engine’s interwoven oxygen and methane preburners.
Previously discussed 24 hours ago in a Teslarati article focused on Raptor wiggles and other miscellaneous tests, Raptor is an extremely advanced rocket engine based on a cycle (i.e. how propellant is turned into thrust) known as full-flow staged combustion.
“In a staged-combustion engine like Raptor, getting from the supercool liquid oxygen and methane propellant to 200+ tons of thrust is quite literally staged, meaning that the ignition doesn’t happen all at once. Rather, the preburners – essentially their own, unique combustion chambers – ignite an oxygen- or methane-rich mixture, the burning of which produces the gas and pressure that powers the turbines that bring fuel into the main combustion chamber. That fuel then ignites, producing thrust as they exit the engine’s bell-shaped nozzle.
Unintuitively, conditions inside the preburner – hidden away from view – are actually far more intense than the iconic blue, purple, and pink flame that visibly exists Raptor’s nozzle. Much like hot water will cool while traveling through pipes, the superheated gaseous propellant that Raptor ignites to produce thrust will also cool (and thus lose pressure) as it travels from Raptor’s preburner to its main combustion chamber. If the pressure produced in the preburners is too low, Raptor’s thrust will be (roughly speaking) proportionally limited at best. At worst, low pressure in the preburners can trigger a “hard start” or shutdown that could destroy the engine. According to Elon Musk, Raptor’s oxygen preburner thus has the worst of it, operating at pressures as high or higher than 800 bar (11,600 psi, 80 megapascals).”
In full-flow staged combustion (FFSC), even more complexity is added as all propellant that touches the engine must necessarily end up traveling through the main combustion chamber to eke every last ounce of thrust out of the finite propellant a rocket lifts off with. As such, FFSC engines can be about as efficient as the laws of physics allow any given chemical rocket engine to be, at the cost of exceptional complexity and brutally difficult development.
Additionally, FFSC physically requires two separate preburners and then makes things even harder by making each separate preburner (methane and oxygen) depend on each other’s operation for the engine to fully ignite. This means that no individual preburner can be used to kickstart Raptor – instead, SpaceX must somehow spin the turbopumps that feed propellant into each preburner with some separate system. This is all just to emphasize the fact that Raptor’s ignition sequence is a spectacularly complex orchestra of valves, spark plugs, sensors, and magic. This is why it’s valuable for Raptor to test its preburner system independently of an actual ignition test, at least as long as the engine is still in the development stages.
According to NASASpaceflight.com managing editor Chris Bergin, what this practically translates to is a minor Starhopper hover test delay of 1-2 days, while the static fire has also been pushed roughly 24 hours from July 15th to July 16th. If that full static fire produces lots of happy data, Starhopper could be cleared for a hover test debut attempt as early as Wednesday or Thursday (July 17/18).
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Tesla Model Y dominated China’s NEV sales in December 2025
As per sales data from China, the all-electric crossover finished first among the country’s best-selling EVs and plug-in hybrids.
The Tesla Model Y ranked as China’s top-selling new energy vehicle in December, leading an intensely competitive market packed with strong domestic brands.
As per sales data from China, the all-electric crossover finished first among the country’s best-selling EVs and plug-in hybrids. The Model 3 also placed within the country’s top ten vehicles.
Model Y leads China’s NEV rankings
The graphic, shared on X and sourced from Chinese auto industry data aggregator Yiche, listed the top 20 best-selling new energy vehicles in China for December. Tesla’s Model Y claimed the No. 1 position with roughly 65,874 units sold, finishing well ahead of a field dominated by domestic manufacturers such as BYD, SAIC-GM-Wuling, and Xiaomi.
The chart also showed strong performances from other high-volume models, including BYD’s Qin Plus, which sold 46,837 units during the month. Tesla’s Model 3 ranked eighth overall, with just under 28,000 units sold, placing it ahead of numerous locally produced competitors despite its rather premium price.
Tesla China’s strong December
Tesla China had a stellar December 2025. During the month, Tesla sold 97,171 vehicles wholesale in China, as per data from the China Passenger Car Association (CPCA). The result marked Tesla China’s second-highest monthly total on record, trailing only November 2022’s peak of 100,291 units.
December’s wholesale figure represented a 3.63% increase from the same month a year earlier and a 12.08% jump from November. Industry watchers have suggested that part of the surge was driven by Tesla pulling deliveries forward to allow customers to benefit from more favorable purchase tax policies before year-end.
Despite this, December’s results suggest that Tesla’s Model Y and Model 3 remain highly competitive offerings in China, which is extremely impressive considering the competition from domestic players and their still premium price.
Elon Musk
Elon Musk’s net worth is nearing $800 billion, and it’s no small part due to xAI
A newly confirmed $20 billion xAI funding round valued the business at $250 billion, adding an estimated $62 billion to Musk’s fortune.
Elon Musk moved within reach of an unprecedented $800 billion net worth after private investors sharply increased the valuation of xAI Holdings, his artificial intelligence and social media company.
A newly confirmed $20 billion funding round valued the business at $250 billion, adding an estimated $62 billion to Musk’s fortune and widening his lead as the world’s wealthiest individual.
xAI’s valuation jump
Forbes confirmed that xAI Holdings was valued at $250 billion following its $20 billion funding round. That’s more than double the $113 billion valuation Musk cited when he merged his AI startup xAI with social media platform X last year. Musk owned roughly 49% of the combined company, which Forbes estimated was worth about $122 billion after the deal closed.
xAI’s recent valuation increase pushed Musk’s total net worth to approximately $780 billion, as per Forbes’ Real-Time Billionaires List. The jump represented one of the single largest wealth gains ever recorded in a private funding round.
Interestingly enough, xAI’s funding round also boosted the AI startup’s other billionaire investors. Saudi investor Prince Alwaleed Bin Talal Alsaud held an estimated 1.6% stake in xAI worth about $4 billion, so the recent funding round boosted his net worth to $19.4 billion. Twitter co-founder Jack Dorsey and Oracle co-founder Larry Ellison each owned roughly 0.8% stakes that are now valued at about $2.1 billion, increasing their net worths to $6 billion and $241 billion, respectively.
The backbone of Musk’s net worth
Despite xAI’s rapid rise, Musk’s net worth is still primarily anchored by SpaceX and Tesla. SpaceX represents Musk’s single most valuable asset, with his 42% stake in the private space company estimated at roughly $336 billion.
Tesla ranks second among Musk’s holdings, as he owns about 12% of the EV maker’s common stock, which is worth approximately $307 billion.
Over the past year, Musk crossed a series of historic milestones, becoming the first person ever worth $500 billion, $600 billion, and $700 billion. He also widened his lead over the world’s second-richest individual, Larry Page, by more than $500 billion.
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Tesla Cybercab sighting confirms one highly requested feature
The feature will likely allow the Cybercab to continue operating even in conditions when its cameras could be covered with dust, mud, or road grime.
A recent sighting of Tesla’s Cybercab prototype in Chicago appears to confirm a long-requested feature for the autonomous two-seater.
The feature will likely allow the Cybercab to continue operating even in conditions when its cameras could be covered with dust, mud, or road grime.
The Cybercab’s camera washer
The Cybercab prototype in question was sighted in Chicago, and its image was shared widely on social media. While the autonomous two-seater itself was visibly dirty, its rear camera area stood out as noticeably cleaner than the rest of the car. Traces of water were also visible on the trunk. This suggested that the Cybercab is equipped with a rear camera washer.
As noted by Model Y owner and industry watcher Sawyer Merritt, a rear camera washer is a feature many Tesla owners have requested for years, particularly in snowy or wet regions where camera obstruction can affect visibility and the performance of systems like Full Self-Driving (FSD).
While only the rear camera washer was clearly visible, the sighting raises the possibility that Tesla may equip the Cybercab’s other external cameras with similar cleaning systems. Given the vehicle’s fully autonomous design, redundant visibility safeguards would be a logical inclusion.
The Cybercab in Tesla’s autonomous world
The Cybercab is Tesla’s first purpose-built autonomous ride-hailing vehicle, and it is expected to enter production later this year. The vehicle was unveiled in October 2024 at the “We, Robot” event in Los Angeles, and it is expected to be a major growth driver for Tesla as it continues its transition toward an AI- and robotics-focused company. The Cybercab will not include a steering wheel or pedals and is intended to carry one or two passengers per trip, a decision Tesla says reflects real-world ride-hailing usage data.
The Cybercab is also expected to feature in-vehicle entertainment through its center touchscreen, wireless charging, and other rider-focused amenities. Musk has also hinted that the vehicle includes far more innovation than is immediately apparent, stating on X that “there is so much to this car that is not obvious on the surface.”
Tesla Model Y dominated China’s NEV sales in December 2025
Elon Musk’s net worth is nearing $800 billion, and it’s no small part due to xAI
