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SpaceX begins installing new ‘Raptor 2’ engines on Super Heavy booster
SpaceX has begun installing new ‘Raptor 2’ engines on Super Heavy Booster 7 after the prototype completed a range of tests and returned to the company’s South Texas ‘Starbase’ rocket factory.
Earlier this month, SpaceX transported Booster 7 (B7) in the opposite direction, returning the 67-meter (~220 ft) tall rocket to Starbase’s orbital launch site (OLS) for the second time after it was forced to head back to the factory for repairs. Repairs completed, SpaceX dove headfirst into the process of verifying that the booster had been returned to full health and immediately filled its tanks to the brim with at least 3000 tons (>6.5M lb) of liquid nitrogen and oxygen – better known as a cryogenic proof test.
Less than 48 hours after completing its first post-repair test, Booster 7 sailed through another full cryoproof test without losing a beat. On May 13th, two days later, SpaceX attached a crane to Super Heavy B7 and removed it from the orbital launch mount before rolling the rocket back to Starbase’s build site on May 14th. Without official confirmation, which is increasingly rare, it was impossible to determine the results of the testing with certainty, but the speed of the process and Booster 7’s rapid launch mount removal made the two most extreme outcomes the most likely.
A quick return to the build site could have been explained by a significant vehicle failure or a major issue with SpaceX’s repair job – no point in continuing to test a vehicle that can’t be fully tested. On the exact opposite hand, a near-perfect test campaign in which all objectives were more or less achieved without major hiccups could also explain the quick return. In general, the evidence was in favor of the more optimistic explanation. Had a major issue been uncovered during the first post-repair cryoproof, it’s difficult to imagine that SpaceX would have completed the exact same test – in full less than 48 hours later.
However, SpaceX moved an in-situ Raptor engine installation stand towards Booster 7 and the orbital launch mount shortly before testing restarted, hinting – for the moment – that the company wanted to begin installing Raptor engines immediately after cryoproof testing. But mid-way through testing, the stand was moved back to its storage area and Super Heavy was instead removed from the mount and returned to the factory, adding a little uncertainty.

Concerns were immediately assuaged on May 17th when SpaceX was spotted moving Raptor engines from a production tent to the ‘megabay’ assembly building containing Booster 7. While the location of the new bay makes it difficult to peek inside from public viewpoints, preventing direct confirmation, it’s very likely SpaceX has begun installing new Raptor 2 engines on Super Heavy B7.
Additionally, confirming some of the more optimistic speculation about SpaceX’s decision to move Booster 7 back to build site, two of the three Raptor engines spotted on May 17th were also labeled “E26” and “E28.” Unless SpaceX’s engine numbering conventions have changed, the labels identify the engines as three of 20 ‘Raptor Boost’ engines that will ultimately populate the outer ring of Super Heavy B7’s aft end. More importantly, the installation of any Raptor Boost 2 (RB2) engines likely indicates that SpaceX has decided to install a full set of 33 Raptors on the booster before kicking off static fire testing.


To limit risk, SpaceX could have begun test-firing Booster 7 with just 1-3 Raptor engines installed and gradually added more as confidence grew. Instead, SpaceX appears to have accepted the added risk of losing 33 brand-new Raptor 2 engines in one fell swoop in return for the possibility of a much faster test campaign. If there are no major surprises during static fire testing, in other words, Booster 7 could be ready for flight far more quickly if the process begins with all 33 engines already installed. Installing Booster 7’s Raptors, heat shield, and aerocovers will be easier back at the build site.
Doing it all at once should also help prevent Booster 7 from suffering Booster 4’s fate and wallowing, unfinished, for months without completing a single useful test. If the gamble works, the first stage of a two-stage Starship could be ready for an orbital launch attempt in just a few months. If the gamble fails and Booster 7 is damaged, destroyed, or otherwise unable to pass the necessary tests, SpaceX will simply move on to Booster 8 sooner than later, having wasted less time on a more cautious Booster 7 test campaign.
It’s unclear how long it will take SpaceX to install all 33 Raptors, construct a heat shield around those engines, and finish buttoning up the rest of Booster 7. In an adjacent assembly bay, SpaceX appears to have nearly finished assembling a similarly upgraded Starship – Ship 24 – that’s first in line to ride Booster 7 into space. The company has also tentatively requested road closures for three 12-hour test windows on May 23rd, 24th, and 25th that either vehicle could use.
News
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.