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SpaceX Starship just aced another explosive tank test and Elon Musk has the results [video]
SpaceX has successfully repaired a leak in a Starship prototype, filled the giant tank with an ultra-cold liquid, and pressurized it until it (spectacularly) popped — and Elon Musk has the preliminary results.
Designed to determine the quality and capabilities of SpaceX’s current manufacturing and integration procedures, the company technically performed its first explosive Starship test back in November 2019, when it decided that the first full-scale prototype – Starship Mk1 – was not fit to fly. Instead of entering the final stages of assembly with a vehicle that SpaceX simply couldn’t be sure would survive the rigors of even a low-stress flight test, the massive vehicle’s tank section was installed at the company’s South Texas launch facilities and pressurized with liquid nitrogen until it burst.
Built almost entirely unprotected on the South Texas coast, Starship Mk1 simply wasn’t up to the standards needed for SpaceX to trust that the giant rocket would survive the stresses of flight. Much like Falcon 9, Starship and its Super Heavy booster will be structurally stable while their tanks are empty, but a great deal of additional (and absolutely critical) structural strength will be added by pressurizing those tanks with a combination of liquid and gaseous propellant. Achieving the required pressures, however, can be a major challenge and the purpose of test tanks like the one above is to prove that the company is up to the challenge. According to Elon Musk, after tonight’s test, SpaceX almost certainly is.
In all truthfulness, the real start of explosive Starship pressure testing actually happened all the way back in 2017 when SpaceX intentionally pressurized a vast 12m-diameter (40 ft) carbon composite tank until it popped. Back then, Starship was known as Big Falcon Rocket (BFR) and was designed to use carbon fiber composites for nearly all of its structure — propellant tanks included.
According to CEO Elon Musk, said carbon composite tank met SpaceX’s expectations (i.e. the necessary pressures for flight) and was pushed to 2.3 bar (33 psi) before it burst in a rather spectacular fashion, launching almost 100 m (300 ft) into the air. Around 2.5 years after that test, it’s believed that Starship Mk1 reached something like 3-5 bar before it popped, and Musk recently revealed that the new steel Starship and Super Heavy designs will require tanks pressures of at least 6 bar (90 psi) to survive the stresses of orbital flight.
Thankfully, although Starship Mk1 didn’t achieve those necessary pressures, the prototype was effectively a worst-case scenario for manufacturing and assembly, revealing the rather unsurprising reality that SpaceX needed to improve its uniquely sparse methods of production and assembly. Although the stainless steel SpaceX settled on for Starship is much more tolerant than aluminum or most other metals when it comes to welding, steel welds still suffer if exposed to more than a minor breeze, as wind will cause the welded metal to cool less than uniformly.


With the latest series of steel Starship tank prototypes, SpaceX has significantly improved its production infrastructure, finally offering at least a semblance of protection against the elements. Based on the first test tank’s explosive performance on January 10th, those improvements have paid dividends. According to Musk, test tank #1 made it all the way to 7.1 bar (105 psi) before it burst and test tank #2 reportedly did even better.
Meanwhile, SpaceX’s South Texas team has already finished and partially tested a second Starship test tank, ultimately reaching 7.5 bar with water before a small leak sprung on January 27th. Over the last 24 hours, technicians have worked to repair the apparently minor damage and began filling the Starship tank with ultra-cold liquid nitrogen (boiling point: -196°C / -320°F) around 5:30 pm CST (23:30 UTC) on January 28th. After filling with liquid nitrogen, SpaceX kept the steel tank topped off for several hours. The likely purpose behind that otherwise odd move: something called cryogenic hardening. By exposing certain types of steel to liquid nitrogen temperatures, the material can be dramatically strengthened in some regards.

Around four hours after Tuesday evening’s testing began, the Starship tank prototype appeared to develop a significant leak in its upper dome, hemorrhaging liquid nitrogen that immediately produced large clouds after coming into contact with the South Texas air. As it turns out, whatever was observed was almost certainly not a leak: 30 or so minutes later, the tank was pressurized to failure, releasing a spectacular tidal wave of liquid nitrogen that doused the surrounding area, temporarily killing nearby floodlights and creating a near-zero-visibility storm of fog.
We’ll have to wait for dawn tomorrow to see the extent of the damage, but it appears that Test Tank #2’s demise was dramatically more violent than its predecessor — a largely expected side effect of performing the pressure test with a cryogenic liquid. In fact, just minutes after it appeared to fail, Elon Musk revealed that the second test tank had burst around 8.5 bar (~125 psi), soundly trouncing all records set by earlier tests and suggesting SpaceX is unequivocally ready to begin building the first orbital Starships. Critically, Musk had previously indicated that if Starship’s tanks could survive up to 8.5 bar, SpaceX would have the minimum safety margins it needs to deem Starship safe enough for astronauts.
In other words, if Test Tank #2 really did reach 8.5 bar, SpaceX has effectively solved the biggest structural engineering challenge its Starship program faces, kicking the doors wide open for the more or less immediate mass-production of the first giant orbital-class spacecraft. As it turns out, what Musk has deemed as the first “orbital” Starship prototype – ‘SN01’ – is already under construction, and it’s safe to say that any lessons learned from January 28th’s cryogenic pressure test will be fed back into SN01 and all future prototypes.
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Elon Musk
Tesla Q1 Earnings: What Elon Musk and Co. will answer during the call
Tesla (NASDAQ: TSLA) is set to hold its Earnings Call for the first quarter of 2026 on Wednesday, and there are a lot of interesting things that are swirling around in terms of speculation from investors.
With the company’s executives, including CEO Elon Musk, answering a handful of questions that investors submit through the Say platform, fans want to know a lot of things about a lot of things.
These five questions come from Retail Investors, who are normal, everyday shareholders:
- When will we have the Optimus v3 reveal? When will Optimus production start, since we ended the Model S and Model X production earlier than mid-year? What’s the expected Optimus production rate exiting this year? What are the initial targeted skills?
- What milestones are you targeting for unsupervised FSD and Robotaxi expansion beyond Austin this year, and how will that drive recurring revenue?
- How will Hardware 3 cars reach Unsupervised Full Self-Driving?
- When do you expect Unsupervised Full Self-Driving to reach customer cars?
- When will Robotaxi expand past its current limited rollout?
Additionally, these are currently the three questions that are slated to be answered by Institutional Firms, which also answer a handful of questions during the call:
- Now that FSD has been approved in the Netherlands and is expected to launch across Europe this summer, can you discuss your Robotaxi strategy for the region?
- What enabled you to finish the AI5 tapeout early and were there any changes to the original vision? Last week, Elon said AI5 will go into Optimus and the Supercomputer, but one month ago said it would go into the Robotaxi. Has AI5 been dropped from the vehicle roadmap?
- Given the recent NHTSA incident filings, can you update us on the Robotaxi safety data? If safety validation remains the primary bottleneck, why not deploy thousands of vehicles to accelerate the removal of the safety driver?
The questions range through every current Tesla project, including FSD expansion and Optimus. However, many of the answers we will get will likely be repetitive answers we’ve heard in the past.
This is especially pertinent when the questions about when Unsupervised FSD will reach customer cars: we know Musk will say that it will happen this year. Is Tesla capable of that? Maybe. But a more transparent answer that is more revealing of a true timeline would be appreciated.
Hardware 3 owners are anxiously awaiting the arrival of FSD v14 Lite, which was promised to them last year for a release sometime this year.
The Earnings Call is set to take place on Wednesday at market close.
Elon Musk
Elon Musk reveals shocking Tesla Optimus patent detail
What looked promising on paper and in simulations failed to deliver the reliability required for a robot expected to handle delicate tasks like folding laundry, assembling electronics, or assisting in factories and homes.
Elon Musk revealed a shocking detail on the Tesla Optimus patent that was revealed last week. Despite it being made public for the first time, Musk said the company has already moved on from the design, an incredible truth about the development of new technology: things move fast.
Musk dropped a bombshell about the Tesla Optimus humanoid robot hand patent that was released last week. Musk, candidly replying to a post late at night on X, revealed that what is a new technology to many fans and insiders is actually old news to those developing the tech directly.
“We already changed the design,” Musk said. “This one didn’t actually work.”
We already changed the design. This one didnāt actually work.
ā Elon Musk (@elonmusk) April 19, 2026
Patents, after all, are often viewed as blueprints for future products. Yet Musk revealed that the rolling contact mechanismāintended to provide smooth, low-friction articulation in the fingersāhad already been scrapped after real-world testing exposed its shortcomings.
What looked promising on paper and in simulations failed to deliver the reliability required for a robot expected to handle delicate tasks like folding laundry, assembling electronics, or assisting in factories and homes.
The hand has been one of the biggest challenges for Tesla engineers since Optimus development started years ago. Musk has said that there is not enough recognition for how incredible and useful the human hand is, and designing one for a humanoid robot has been the biggest challenge of all.
Tesla is stumped on how to engineer this Optimus part, but they’re close
This moment underscores the persistent engineering hurdles in achieving reliable humanoid hand dexterity. Human fingers are marvels of evolution: 27 bones, intricate tendons, ligaments, and a network of sensors working in perfect harmony. Replicating that in metal and silicon is extraordinarily difficult.
Rolling contacts promised reduced wear and precise motion, but testing likely revealed issues with durability under repeated stress, grip stability on varied surfaces, or the micro-precision needed for fine motor skills.
These arenāt minor tweaks, but instead they represent fundamental challenges that have plagued robotics teams for decades. Even advanced competitors struggle hereāhands remain the Achillesā heel of most humanoids because the margin for error is razor-thin.
A fraction of a millimeter off, and a robot drops a glass or fails to button a shirt.
What makes Muskās reply remarkable is how it signals Teslaās direct communication style on prototype limitations. While many companies guard failures behind glossy marketing and vague timelines, Tesla openly shares setbacks.
Musk was forthcoming about the failure of this recent design. This transparency builds trust with investors, engineers, and fans. It shows Tesla treats Optimus development like true science: rapid iteration, rigorous testing, and zero tolerance for hype that doesnāt match reality.
The disclosure from Musk also highlights Tesla’s blistering pace of development. By the time the patents are published, which is often over a year after the initial filing, the technology has already evolved.
Optimus is far from a static product, and it’s a living project advancing weekly.
In the high-stakes race for general-purpose robots, Teslaās approach stands out. Admitting a finger-joint design ādidnāt actually workā isnāt a weaknessāitās confidence.
True innovation demands confronting failure head-on, and Musk just reminded the world that Optimus is being engineered that way. The next version of those hands is already in testing, and it will be better because Tesla isnāt afraid to say what didnāt work.
Elon Musk
Tesla is sending its humanoid Optimus robot to the Boston Marathon
Tesla’s Optimus robot is heading to the Boston Marathon finish line
Tesla’s Optimus humanoid robot will be stationed at the Tesla showroom at 888 Boylston Street in Boston, right along the final stretch of the Boston Marathon today, ready to cheer on runners and pose for photos with spectators.
According to a Tesla email shared by content creator Sawyer Merritt on X, Optimus will be at the Boston Boylston Street showroom on April 20, coinciding with Marathon Monday weekend. The Boston Marathon finishes on Boylston Street, and the surrounding area draws hundreds of thousands of spectators along with international broadcast coverage. Placing Optimus there puts it in front of a massive public audience at zero advertising cost.
Just got this email. @Teslaās Optimus robot is coming to Boston.
āJoin us from April 19 to 20, 2026, at Tesla Boston Boylston Street showroom to meet Optimus, our humanoid robot, for Marathon Monday. Optimus will be cheering with you on the sidelines and posing for photos.ā pic.twitter.com/chxoooO2xV
ā Sawyer Merritt (@SawyerMerritt) April 18, 2026
The Tesla showroom is at 888 Boylston Street, between Gloucester Street and Fairfield Street. The final mile of the marathon runs directly along Boylston Street, with runners passing the big stores before reaching the finish line at Copley Square.
Optimus was first announced at Tesla’s AI Day event on August 19, 2021, when Elon Musk presented a vision for a general-purpose robot designed to take on dangerous, repetitive, and unwanted tasks. In March 2026, Optimus appeared at the Appliance and Electronics World Expo in Shanghai, where on-site staff stated that mass production of the robot could begin by the end of 2026. Before that, it showed up at the Tesla Hollywood Diner opening in July 2025 and at a Miami showroom event in December 2025.
Tesla’s well-calculated display of Optimus gives the public a low-pressure first encounter with a robot that Tesla is preparing Ā to soon deploy at scale. The company has previously indicated plans to manufacture Optimus robots at its Fremont facility at up to 1 million units annually, with an Optimus production line at Gigafactory Texas targeting 10 million units per year.
Tesla showcases Optimus humanoid robot at AWE 2026 in Shanghai
Musk has said that Optimus “has the potential to be more significant than the vehicle business over time,” and separately that roughly 80 percent of Tesla’s future value will come from the robot program. Whether that holds depends on production execution. For now, Boston gets a preview of what that future looks like, standing at the finish line on Boylston Street while 32,000 runners pass by.