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SpaceX Super Heavy tank prototype survives crush testing
A tank prototype similar to SpaceX’s next-generation Super Heavy rocket booster has survived a series of tests that repeatedly attempted to destroy it.
Known as Booster 7.1 or B7.1, the tank is the latest in a long line of ‘test tanks’ designed to verify the performance of Starship and Super Heavy and qualify new designs and manufacturing techniques without risking an entire upper stage or booster. In general, that means that test tanks are as minimal as possible and much shorter than either Starship stage, but they’re also assembled out of nine-meter-wide (30 ft) steel barrels and domes almost identical to the sections that make up Starship and Super Heavy.
For most of the duration of SpaceX’s steel Starship program, ‘test tank’ work has followed a fairly consistent and linear development path, where tanks were used to verify design changes before those changes were implemented on more expensive prototypes. B7.1 firmly ignored that norm.
While it’s not an exact match, the tank – built out of two stacked rings and dome sections and measuring about 11 meters (~36 ft) tall – has a Super Heavy thrust structure (where Raptor engines would attach) and external stiffeners known as stringers that are (mostly) exclusive to Starship boosters.
As its name suggests, B7.1 shares many of the significant design changes that SpaceX had already implemented on Super Heavy Booster 7 (B7). The company began testing B7 months before B7.1, subjecting the full-size booster to multiple cryogenic proof tests and Raptor thrust simulation testing to qualify its new thrust ‘puck’ and several other structural changes. SpaceX began testing B7.1 in late June, shortly before Super Heavy Booster 7 was damaged by an unplanned explosion that halted its first Raptor engine test campaign. B7.1 testing then restarted in mid-July and was completed by the end of the month.
For unknown reasons, SpaceX’s decision to build and test Booster 7 before B7.1 meant that any significant issues discovered during subsequent B7.1 testing could disqualify the booster for flight testing, potentially wasting the months of work and tens of millions of dollars already invested in the prototype. Ultimately, though, B7.1 appeared to sail through multiple cryogenic proofs and crush tests without any catastrophic issues. Only on the last crush test did any part of the test tank finally give way, and the resulting damage was minor.
B7.1’s testing made use of a relatively new two-piece stand. The tank was first installed on a sturdy base using clamps similar to those on the Starbase orbital launch site’s (OLS) launch mount. Then, a hat-like structure was placed on top of the tank, resting on the surface that a Starship upper stage would sit on during launch. Massive ropes were finally dropped down to attach to hydraulic cylinders on the base. Once B7.1 was loaded with benign cryogenic liquid nitrogen (LN2), replicating most of the thermal and mechanical stresses of real oxygen/methane propellant, the hydraulic cylinders retracted, pulling the cap down to evenly exert massive crushing forces down the vertical axis of the test tank. Simultaneously, additional rams installed underneath B7.1 may have simulated the thrust of 13 central Raptor engines.
It’s unclear what exactly SpaceX was testing. The goal of the test could have been as simple as verifying that Super Heavy Booster 7 can withstand the weight of a fully-fueled Starship (~1350 tons / ~3M lb) sitting on top of it. It could have also been used to simulate an entire orbital launch from Super Heavy’s perspective, replicating many of the forces Starship boosters will experience between liftoff and landing. Given that Booster 7’s upgraded thrust puck had already made it through stress testing, B7.1 didn’t have much to add there, but it may have been useful for estimating the compressive strength of the current Super Heavy booster design.
Regardless of what B7.1 did or didn’t prove, it did so with very little drama. After four long days of testing, at least two of which involved attempting to crush the tank, the only truly noteworthy visual event was evidence of a slight buckle near the top of the tank during its last crush test. A few days later, with the test stand ‘cap’ removed, B7.1 survived one final test in which SpaceX likely attempted to pressurize the tank until it burst. Instead, the tank didn’t so much as develop a leak, reiterating – contrary to their occasional tin-can-like appearances – just how sturdy Starship and Super Heavy really are.
With nothing more to give, SpaceX will likely scrap B7.1. Meanwhile, Super Heavy Booster 7 remains stuck inside one of SpaceX’s Starbase assembly bays after being forced back to the factory by unintentionally explosive testing. The fate of that booster is unclear but SpaceX has removed all or most of its 33 Raptor engines over the last few weeks while simultaneously expediting work on Booster 8, which may ultimately take B7’s place.
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Tesla confirms that it finally solved its 4680 battery’s dry cathode process
The suggests the company has finally resolved one of the most challenging aspects of its next-generation battery cells.
Tesla has confirmed that it is now producing both the anode and cathode of its 4680 battery cells using a dry-electrode process, marking a key breakthrough in a technology the company has been working to industrialize for years.
The update, disclosed in Tesla’s Q4 and FY 2025 update letter, suggests the company has finally resolved one of the most challenging aspects of its next-generation battery cells.
Dry cathode 4680 cells
In its Q4 and FY 2025 update letter, Tesla stated that it is now producing 4680 cells whose anode and cathode were produced during the dry electrode process. The confirmation addresses long-standing questions around whether Tesla could bring its dry cathode process into sustained production.
The disclosure was highlighted on X by Bonne Eggleston, Tesla’s Vice President of 4680 batteries, who wrote that “both electrodes use our dry process.”
Tesla first introduced the dry-electrode concept during its Battery Day presentation in 2020, pitching it as a way to simplify production, reduce factory footprint, lower costs, and improve energy density. While Tesla has been producing 4680 cells for some time, the company had previously relied on more conventional approaches for parts of the process, leading to questions about whether a full dry-electrode process could even be achieved.
4680 packs for Model Y
Tesla also revealed in its Q4 and FY 2025 Update Letter that it has begun producing battery packs for certain Model Y vehicles using its in-house 4680 cells. As per Tesla:
“We have begun to produce battery packs for certain Model Ys with our 4680 cells, unlocking an additional vector of supply to help navigate increasingly complex supply chain challenges caused by trade barriers and tariff risks.”
The timing is notable. With Tesla preparing to wind down Model S and Model X production, the Model Y and Model 3 are expected to account for an even larger share of the company’s vehicle output. Ensuring that the Model Y can be equipped with domestically produced 4680 battery packs gives Tesla greater flexibility to maintain production volumes in the United States, even as global battery supply chains face increasing complexity.
Elon Musk
Tesla Giga Texas to feature massive Optimus V4 production line
This suggests that while the first Optimus line will be set up in the Fremont Factory, the real ramp of Optimus’ production will happen in Giga Texas.
Tesla will build Optimus 4 in Giga Texas, and its production line will be massive. This was, at least, as per recent comments by CEO Elon Musk on social media platform X.
Optimus 4 production
In response to a post on X which expressed surprise that Optimus will be produced in California, Musk stated that “Optimus 4 will be built in Texas at much higher volume.” This suggests that while the first Optimus line will be set up in the Fremont Factory, and while the line itself will be capable of producing 1 million humanoid robots per year, the real ramp of Optimus’ production will happen in Giga Texas.
This was not the first time that Elon Musk shared his plans for Optimus’ production at Gigafactory Texas. During the 2025 Annual Shareholder Meeting, he stated that Giga Texas’ Optimus line will produce 10 million units of the humanoid robot per year. He did not, however, state at the time that Giga Texas would produce Optimus V4.
“So we’re going to launch on the fastest production ramp of any product of any large complex manufactured product ever, starting with building a one-million-unit production line in Fremont. And that’s Line one. And then a ten million unit per year production line here,” Musk stated.
How big Optimus could become
During Tesla’s Q4 and FY 2025 earnings call, Musk offered additional context on the potential of Optimus. While he stated that the ramp of Optimus’ production will be deliberate at first, the humanoid robot itself will have the potential to change the world.
“Optimus really will be a general-purpose robot that can learn by observing human behavior. You can demonstrate a task or verbally describe a task or show it a task. Even show it a video, it will be able to do that task. It’s going to be a very capable robot. I think long-term Optimus will have a very significant impact on the US GDP.
“It will actually move the needle on US GDP significantly. In conclusion, there are still many who doubt our ambitions for creating amazing abundance. We are confident it can be done, and we are making the right moves technologically to ensure that it does. Tesla, Inc. has never been a company to shy away from solving the hardest problems,” Musk stated.
Elon Musk
Rumored SpaceX-xAI merger gets apparent confirmation from Elon Musk
The comment follows reports that the rocket maker is weighing a transaction that could further consolidate Musk’s space and AI ventures.
Elon Musk appeared to confirm reports that SpaceX is exploring a potential merger with artificial intelligence startup xAI by responding positively to a post about the reported transaction on X.
Musk’s comment follows reports that the rocket maker is weighing a transaction that could further consolidate his space and AI ventures.
SpaceX xAI merger
As per a recent Reuters report, SpaceX has held discussions about merging with xAI, with the proposed structure potentially involving an exchange of xAI shares for SpaceX stock. The value, structure, and timing of any deal have not been finalized, and no agreement has been signed.
Musk appeared to acknowledge the report in a brief reply on X, responding “Yeah” to a post that described SpaceX as a future “Dyson Swarm company.” The comment references a Dyson Swarm, a sci-fi megastructure concept that consists of a massive network of satellites or structures that orbit a celestial body to harness its energy.
Reuters noted that two entities were formed in Nevada on January 21 to facilitate a potential transaction for the possible SpaceX-xAI merger. The discussions remain ongoing, and a transaction is not yet guaranteed, however.
AI and space infrastructure
A potential merger with xAI would align with Musk’s stated strategy of integrating artificial intelligence development with space-based systems. Musk has previously said that space-based infrastructure could support large-scale computing by leveraging continuous solar energy, an approach he has framed as economically scalable over time.
xAI already has operational ties to Musk’s other companies. The startup develops Grok, a large language model that holds a U.S. Department of Defense contract valued at up to $200 million. AI also plays a central role in SpaceX’s Starlink and Starshield satellite programs, which rely on automation and machine learning for network management and national security applications.
Musk has previously consolidated his businesses through share-based transactions, including Tesla’s acquisition of SolarCity in 2016 and xAI’s acquisition of X last year. Bloomberg has also claimed that Musk is considering a merger between SpaceX and Tesla in the future.
Tesla confirms that it finally solved its 4680 battery’s dry cathode process
Tesla Giga Texas to feature massive Optimus V4 production line
