News
SpaceX installs full set of car-sized grid fins on second Super Heavy booster
SpaceX appears to have installed a full set of car-sized grid fins on Starship’s second flightworthy Super Heavy booster, leaving the massive rocket just a few steps away from completion.
Measuring ~69m (~225 ft) tall and 9m (~30 ft) wide, Super Heavy Booster 5 (B5) – like B4 before it – will be one of two of the largest rocket boosters ever built once completed. In broad strokes, Super Heavy B4 and B5 are the same. Aside from near-identical dimensions, both have been built to hold up to 29 Raptor engines while Starbase has already begun receiving parts of the first 33-engine Super Heavy. That means that Booster 4 and 5 – while both potentially capable of flight – are also pathfinders for an upgraded version of Super Heavy with similar dimensions but the potential to produce more than 40% more thrust once Raptor 2 production takes over.
While more similar than not, there are significant differences between SpaceX’s first and second flightworthy Super Heavy boosters.
The biggest visible differences are tweaks SpaceX has made to the Super Heavy assembly process. Booster 4 was assembled out of mostly naked steel rings and only had thousands of feet of external plumbing, wiring, raceways, and hardware installed after it was stacked to its full height. That may partially be because CEO Elon Musk had ordered SpaceX to complete the first full-height Starship stack by early August, requiring the build team to prioritize speed above all else.
Regardless, SpaceX appears to be outfitting Super Heavy Booster 5’s exterior before and during the process of stacking the booster to its final height. Most sections of 3-4 steel rings have had partial plumbing and raceways preinstalled, meaning that Booster 5 will be far closer to test readiness than Booster 4 once stacking is complete. Booster 4, on the other hand, required at least several more weeks of outfitting after SpaceX briefly rolled the rocket to the orbital launch pad for a full-stack photo-op and fit check.
On October 12th, after rapidly stacking Super Heavy B5’s upper methane tank to completion, SpaceX began installing the booster’s four car-sized grid fins. Fixed in place and assembled out of welded steel unlike the Falcon family’s deployable, cast titanium fins, Super Heavy grid fins are several times larger and heavier but still serve the same purpose of stabilizing boosters during atmospheric reentry, descent, and landing. Like Booster 4, SpaceX has also installed all four Booster 5 grid fins before stacking the Super Heavy to its full 69-meter height.
Based on B4, that final stack could happen just a few days from now, though there are signs that it might take B5 a fair bit longer. Notably, whereas Booster 4’s aft liquid oxygen (LOx) tank was already fully stacked by the start of grid fin installation, Booster 5’s LOx section is still waiting on its thrust dome. That thrust section was most recently spotted inside a production tent on October 11th – far more thoroughly outfitted than Booster 4’s aft but awaiting installation nonetheless.
That slight difference in timing pales in comparison to a massive tube that may or may not have been installed inside Super Heavy B5 late last month and that definitely wasn’t installed in B4. Without official information, it’s hard to know for sure, but the general community consensus is that this new tube (possibly one of two installed inside Booster 5’s LOx tank) is some kind of header tank or sump meant to collect propellant for Super Heavy’s boostback and/or landing burn.
If SpaceX really is adding header tanks to Super Heavy, it would drastically increase the complexity of booster plumbing, potentially explaining why Super Heavy B5’s thrust section installation is taking longer than B4. Only time (and hopefully a tweet or two from Musk) will tell.
Elon Musk
Elon Musk and Tesla AI Director share insights after empty driver seat Robotaxi rides
The executives’ unoccupied tests hint at the rapid progress of Tesla’s unsupervised Robotaxi efforts.
Tesla CEO Elon Musk and AI Director Ashok Elluswamy celebrated Christmas Eve by sharing personal experiences with Robotaxi vehicles that had no safety monitor or occupant in the driver’s seat. Musk described the system’s “perfect driving” around Austin, while Elluswamy posted video from the back seat, calling it “an amazing experience.”
The executives’ unoccupied tests hint at the rapid progress of Tesla’s unsupervised Robotaxi efforts.
Elon and Ashok’s firsthand Robotaxi insights
Prior to Musk and the Tesla AI Director’s posts, sightings of unmanned Teslas navigating public roads were widely shared on social media. One such vehicle was spotted in Austin, Texas, which Elon Musk acknowleged by stating that “Testing is underway with no occupants in the car.”
Based on his Christmas Eve post, Musk seemed to have tested an unmanned Tesla himself. “A Tesla with no safety monitor in the car and me sitting in the passenger seat took me all around Austin on Sunday with perfect driving,” Musk wrote in his post.
Elluswamy responded with a 2-minute video showing himself in the rear of an unmanned Tesla. The video featured the vehicle’s empty front seats, as well as its smooth handling through real-world traffic. He captioned his video with the words, “It’s an amazing experience!”
Towards Unsupervised operations
During an xAI Hackathon earlier this month, Elon Musk mentioned that Tesla owed be removing Safety Monitors from its Robotaxis in Austin in just three weeks. “Unsupervised is pretty much solved at this point. So there will be Tesla Robotaxis operating in Austin with no one in them. Not even anyone in the passenger seat in about three weeks,” he said. Musk echoed similar estimates at the 2025 Annual Shareholder Meeting and the Q3 2025 earnings call.
Considering the insights that were posted Musk and Elluswamy, it does appear that Tesla is working hard towards operating its Robotaxis with no safety monitors. This is quite impressive considering that the service was launched just earlier this year.
Elon Musk
Starlink passes 9 million active customers just weeks after hitting 8 million
The milestone highlights the accelerating growth of Starlink, which has now been adding over 20,000 new users per day.
SpaceX’s Starlink satellite internet service has continued its rapid global expansion, surpassing 9 million active customers just weeks after crossing the 8 million mark.
The milestone highlights the accelerating growth of Starlink, which has now been adding over 20,000 new users per day.
9 million customers
In a post on X, SpaceX stated that Starlink now serves over 9 million active users across 155 countries, territories, and markets. The company reached 8 million customers in early November, meaning it added roughly 1 million subscribers in under seven weeks, or about 21,275 new users on average per day.
“Starlink is connecting more than 9M active customers with high-speed internet across 155 countries, territories, and many other markets,” Starlink wrote in a post on its official X account. SpaceX President Gwynne Shotwell also celebrated the milestone on X. “A huge thank you to all of our customers and congrats to the Starlink team for such an incredible product,” she wrote.
That growth rate reflects both rising demand for broadband in underserved regions and Starlink’s expanding satellite constellation, which now includes more than 9,000 low-Earth-orbit satellites designed to deliver high-speed, low-latency internet worldwide.
Starlink’s momentum
Starlink’s momentum has been building up. SpaceX reported 4.6 million Starlink customers in December 2024, followed by 7 million by August 2025, and 8 million customers in November. Independent data also suggests Starlink usage is rising sharply, with Cloudflare reporting that global web traffic from Starlink users more than doubled in 2025, as noted in an Insider report.
Starlink’s momentum is increasingly tied to SpaceX’s broader financial outlook. Elon Musk has said the satellite network is “by far” the company’s largest revenue driver, and reports suggest SpaceX may be positioning itself for an initial public offering as soon as next year, with valuations estimated as high as $1.5 trillion. Musk has also suggested in the past that Starlink could have its own IPO in the future.
News
NVIDIA Director of Robotics: Tesla FSD v14 is the first AI to pass the “Physical Turing Test”
After testing FSD v14, Fan stated that his experience with FSD felt magical at first, but it soon started to feel like a routine.
NVIDIA Director of Robotics Jim Fan has praised Tesla’s Full Self-Driving (Supervised) v14 as the first AI to pass what he described as a “Physical Turing Test.”
After testing FSD v14, Fan stated that his experience with FSD felt magical at first, but it soon started to feel like a routine. And just like smartphones today, removing it now would “actively hurt.”
Jim Fan’s hands-on FSD v14 impressions
Fan, a leading researcher in embodied AI who is currently solving Physical AI at NVIDIA and spearheading the company’s Project GR00T initiative, noted that he actually was late to the Tesla game. He was, however, one of the first to try out FSD v14.
“I was very late to own a Tesla but among the earliest to try out FSD v14. It’s perhaps the first time I experience an AI that passes the Physical Turing Test: after a long day at work, you press a button, lay back, and couldn’t tell if a neural net or a human drove you home,” Fan wrote in a post on X.
Fan added: “Despite knowing exactly how robot learning works, I still find it magical watching the steering wheel turn by itself. First it feels surreal, next it becomes routine. Then, like the smartphone, taking it away actively hurts. This is how humanity gets rewired and glued to god-like technologies.”
The Physical Turing Test
The original Turing Test was conceived by Alan Turing in 1950, and it was aimed at determining if a machine could exhibit behavior that is equivalent to or indistinguishable from a human. By focusing on text-based conversations, the original Turing Test set a high bar for natural language processing and machine learning.
This test has been passed by today’s large language models. However, the capability to converse in a humanlike manner is a completely different challenge from performing real-world problem-solving or physical interactions. Thus, Fan introduced the Physical Turing Test, which challenges AI systems to demonstrate intelligence through physical actions.
Based on Fan’s comments, Tesla has demonstrated these intelligent physical actions with FSD v14. Elon Musk agreed with the NVIDIA executive, stating in a post on X that with FSD v14, “you can sense the sentience maturing.” Musk also praised Tesla AI, calling it the best “real-world AI” today.
Elon Musk and Tesla AI Director share insights after empty driver seat Robotaxi rides
Starlink passes 9 million active customers just weeks after hitting 8 million
