News
SpaceX Falcon 9 “Block 5” next-gen reusable rocket spied in Texas test site
SpaceX’s next and final generation of Falcon rockets is nearly ready to complete its biggest milestone yet, second only to operational launch. Known as Falcon 9 Block 5, the upgraded booster arrived at SpaceX’s McGregor, TX test facilities and went vertical on the static fire test stand.
Now vertical, that first integrated static fire is likely to occur within a handful of days at most. Once complete, assuming the data it produces do not betray any bugs or serious problems, the booster will be brought horizontal and transported to one of SpaceX’s three launch facilities for its first operational mission.
Why Block 5?
With nary a hint of hyperbole, it’s safe to say that Falcon 9 Block 5 will be the most significant piece of hardware ever developed and fielded by SpaceX. The reason lies in many of the changes and upgrades present in this newest iteration of the rocket. While Falcon 9 B5 and its similarly upgraded Merlin 1D engines include design changes intended to satisfy NASA requirements before SpaceX can be certified to launch humans, the brunt of the upgrades are laser-focused on ease and speed of reusability.
-
- SpaceX Block 5 Falcon9 at McGregor, Texas [Credit: Chris G – NSF via Twitter, Reprinted with permission from NASASpaceflight.com]
-
- SpaceX Block 5 Falcon9 at McGregor, Texas [Credit: Chris G – NSF via Twitter, Reprinted with permission from NASASpaceflight.com]
-
- SpaceX Block 5 Falcon9 at McGregor, Texas [Credit: Chris G – NSF via Twitter, Reprinted with permission from NASASpaceflight.com]
Photo courtesy of Chris G at nasaspaceflight.com via Twitter. Reprinted with permission.
The goal with those upgrades, as publicly stated by numerous SpaceX executives, is to enable as many as 10 flights with a bare minimum of refurbishment and 100 or more launches with intermittent maintenance. To achieve those titanic aspirations, SpaceX has gathered a flood of data and experience earned through the recovery of nearly 20 Falcon 9 and Heavy boosters, as well as the successful reflight and second recovery of several of those same boosters. With that data in hand, the company’s launch vehicle engineers optimized and upgraded the rocket’s design to combat the worst of the extreme forces each booster is subjected to while returning to land (or sea).
-
- Falcon Heavy side booster B1025 gives a sense of the sheer brutality of reentry conditions. (Tom Cross)
-
- Note the pieces of cork that have been torn off by the buffeting and heat on the lefthand side. (Tom Cross)
-
- An incredibly detail shot of the side of the octaweb. The large chunk of smooth metal in the center is actually one of the booster’s connection points to the Falcon Heavy center core. (Tom Cross/Teslarati)
-
- A beautiful capture of one of the booster’s nine Merlin engines, showing off the pipe used to cool the engine bell, as well as the ceramic blanket that protects its more sensitive plumbing. (Tom Cross/Teslarati)
As evidenced by photos taken by Gary Blair, one of NASASpaceflight.com‘s most renowned L2 forum contributors, many of the visible differences between Block 5 and previous versions of Falcon 9 are a result of drastically improved and expanded heat shielding of its most sensitive and crucial components. While Falcon 9 B5’s black sections by all appearances look like naked carbon fiber composite, they are likely to be coated with an incredibly heat-resistant material known a Pyron. Portions of the booster that suffer from incidental scorching and extreme heating (aside from the octaweb) appear to have been treated with this material, including a pathway down the side of the rocket known as a raceway. The raceway is a protective enclosure for a variety of cabling and piping, essentially the rocket’s nervous system as well as the home of several the cold gas thrusters it uses to orient itself outside of Earth’s atmosphere.
In the past, SpaceX has used high-quality cork as a quasi-ablative thermal protection system for those same components, including the payload fairing. A major downside of cork, however, is that it is very ablative and tends to come off rather haphazardly in large chunks, all of which must either be spot-fixed or replaced entirely before a booster reflight. By replacing that cork with Pyron or a similar internally-developed material, those sensitive Falcon components may be almost totally insulated from and resistant to temperatures as high as 2300 °F (1200 °C)
-
- Block 5 looks similar to this Falcon 9, but with a deep black interstage and a black enclosure instead of the white covering seen running down the left side of the booster. (SpaceX)
Titanium grid fins are another central feature of Block 5, acting as a near-indefinitely reusable replacement for the aluminum grid fins SpaceX has traditionally used. Put through a huge amount of heating during reentry; aluminum grid fins have famously appeared to partially melt during some of the hottest booster recovery attempts. Titanium, a metal with a much higher melting point, will have no such problems, does not need ablative white paint, and certainly appear all but untouched by reentry in the cases of both their June 2017 debut and second flight on Falcon Heavy’s side boosters.
Finally and perhaps most importantly, is the octaweb – the assembly at the base of Falcon 9 responsible for safely transmitting nearly two million pounds of thrust from its nine Merlin 1Ds to the rest of the rocket’s structure, while also taking the brunt of the heat of reentry. Before Block 5, the octaweb was protected from that heating with an ablative thermal protection system, likely around 80% cork and 20% PICA-X, the same material used on Cargo Dragon’s heat shield. Based on comments made privately by individuals familiar with SpaceX, that ablative shielding is to be replaced by a highly heat-resistant metal alloy known as inconel. By ridding Block 5 of ablative heat shielding, SpaceX will no longer have to carefully examine and replace those materials after each launch, removing one of the biggest refurbishment time-sinks.
Titanium grid fins complete the highly reusable changes to Block 5 of Falcon 9. (NASA)
Combined, these various upgrades are intended to enable Falcon 9’s first stage to be reused almost effortlessly compared to previous iterations. With this vehicle, including the reusable fairing debuted on the launch of PAZ, SpaceX may well be able to achieve Elon Musk’s famous goal of lowering the cost of launch by nearly an order of magnitude. While SpaceX will likely use that cost reduction to first recoup its considerable investments in reusability and Falcon Heavy, major price drops may reach customers soon after. This Falcon 9, in particular, is unlikely to launch for another month or so, but when it does, it is perhaps the biggest step SpaceX has yet taken on the path to routine, rapid, and affordable access to orbit.
Teslarati – Instagram – Twitter
Tom Cross – Twitter
Pauline Acalin – Twitter
Eric Ralph – Twitter
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 didn’t actually work.
— Elon Musk (@elonmusk) April 19, 2026
Patents, after all, are often viewed as blueprints for future products. Yet Musk revealed that the rolling contact mechanism—intended to provide smooth, low-friction articulation in the fingers—had 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 aren’t minor tweaks, but instead they represent fundamental challenges that have plagued robotics teams for decades. Even advanced competitors struggle here—hands remain the Achilles’ 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 Musk’s reply remarkable is how it signals Tesla’s 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 doesn’t 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, Tesla’s approach stands out. Admitting a finger-joint design “didn’t actually work” isn’t a weakness—it’s 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 isn’t afraid to say what didn’t 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. @Tesla’s Optimus robot is coming to Boston.
“Join 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.” pic.twitter.com/chxoooO2xV
— 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 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.
News
Tesla expands Unsupervised Robotaxi service to two new cities
This expansion builds directly on Tesla’s existing operations. Robotaxi has been ramping unsupervised rides in Austin for months and maintains activity in the San Francisco Bay Area.
Tesla has taken a major step forward in its autonomous ride-hailing ambitions.
On April 18, the company’s official Robotaxi account announced that Robotaxi service is now rolling out in Dallas and Houston, Texas. The update signals the rapid scaling of unsupervised autonomous operations in the Lone Star State.
The announcement includes a compelling 14-second video captured from inside a Model Y. Shot from the passenger perspective, the footage shows the vehicle navigating suburban roads in both cities with zero driver intervention, with no Safety Monitor to be seen.
Robotaxi now rolling out in Dallas & Houston 🤠 pic.twitter.com/G3KFQwqGxB
— Tesla Robotaxi (@robotaxi) April 18, 2026
Tesla also shared geofence maps highlighting the initial service areas: a compact zone in Houston covering parts of Willowbrook and Jersey Village, and a similarly defined area in Dallas near Highland Park and central neighborhoods.
🚨 Tesla has expanded Robotaxi to two new cities: Houston and Dallas, joining Austin and the SF Bay Area as active Robotaxi areas https://t.co/S3Ck4EaGpR pic.twitter.com/N0qu0bcTyd
— TESLARATI (@Teslarati) April 18, 2026
This expansion builds directly on Tesla’s existing operations. Robotaxi has been ramping unsupervised rides in Austin for months and maintains activity in the San Francisco Bay Area.
With Dallas and Houston now live, Texas hosts three active hubs—an impressive concentration that triples the company’s Lone Star footprint in just weeks. The move aligns with Tesla’s Q4 2025 earnings guidance, which outlined a broader H1 2026 rollout across seven U.S. cities, including Phoenix, Miami, Orlando, Tampa, and Las Vegas.
Texas offers favorable regulations, high ride-share demand, and relatively straightforward suburban-to-urban driving patterns ideal for early autonomous scaling. While initial geofences appear modest—roughly 25 square miles per city—Tesla has historically expanded these zones quickly as it gathers real-world data.
Tesla confirms Robotaxi expansion plans with new cities and aggressive timeline
Unsupervised operation marks a critical milestone: passengers can summon, ride, and exit without safety drivers, a leap beyond many competitors still requiring human oversight.
For Tesla, the implications are significant. Successful scaling in major metros could accelerate the transition to a fully driverless fleet, unlocking new revenue streams and validating years of Full Self-Driving investment.
Riders gain convenient, potentially lower-cost mobility, while the company edges closer to Elon Musk’s vision of Robotaxis transforming urban transport.
As Tesla pushes into more cities this year, today’s launch in Dallas and Houston underscores its momentum. Hopefully, Tesla will be able to expand unsupervised rides to another U.S. state soon, which will mark yet another chapter in this short-but-encouraging Robotaxi story.
Elon Musk reveals shocking Tesla Optimus patent detail
Tesla is sending its humanoid Optimus robot to the Boston Marathon
