News
SpaceX Starship passed “cryo proof” test for the first time and here’s what’s next
Elon Musk says a SpaceX Starship prototype has passed a critical “cryo proof” test for the first time, opening the door for the rocket to move on to even bigger tests.
Late on April 26th, SpaceX’s South Texas team (and possibly a console team in California) readied the fourth full-scale Starship prototype (SN4) for its second major test. Known as a cryogenic proof test, it began less than 24 hours after the rocket completed a room-temperature gas pressure test to check for leaks and verify that the pressure vessel was sound. Musk quickly confirmed that Starship SN4 passed through that “ambient proof test” without issue.
For the cryo proof test, room-temperature nitrogen gas was replaced with ultra-cold liquid nitrogen, serving as a chemically neutral (i.e. non-explosive) simulant for Starship’s liquid oxygen and methane propellant. After a few hours of partial loading and offloading cycles meant to ensure that Starship’s valves and propellant supply hardware was working as intended, SpaceX controllers fully filled the rocket with some ~1000 metric tons (2.2 million lb) of liquid nitrogen. Once full, a hydraulic ram setup was activated to exert forces akin to Raptor engines operating at full thrust. After several prior failures, Starship SN4 thus became the first to survive the ordeal and graduate into the next stage of testing.
According to CEO Elon Musk, that next step will be a static fire test with a lone Raptor engine installed. Able to produce at least 200 metric tons of thrust (~450,000 lbf) at full throttle, Raptor is an exceptionally efficient methalox (methane/oxygen) rocket engine designed by SpaceX to power Starship and its Super Heavy booster. Methane and oxygen was chosen in large part because of the relative potential ease of its extraction and refinement on Mars.
Per Musk, that static fire could occur within the next six or so days, meaning that SpaceX will likely install a functional Raptor engine on a full-scale Starship for the first time ever within the next day or two. Before a static fire can be performed, though, another significant test or two will have to be completed.
Known as a wet dress rehearsal (WDR), the first of those tests will be similar to April 26th’s cryo proof but with the neutral liquid nitrogen placed by real liquid oxygen and methane propellant. This is much riskier than the cryo proof in the sense that if a tank failure were to occur or a fire to accidentally start, 1000+ tons of highly-pressurized propellant could easily create a massive explosion and fireball, destroying or damaging much of the surrounding pad equipment. The WDR could potentially be rolled into another Raptor engine test that would verify its preburner performance.


To operate, Raptors first take liquid oxygen and liquid methane into separate parts of the engine and rapidly heat them to turn them into high temperature gas. Those preburners then send that hot gas to separate turbopumps that spin up and allow the engines to keep supplying themselves with large quantities of propellant, followed by the process of actually igniting the engine itself with a complex series of blowtorches.
If the preburner and turbopump spin-up test is successful, SpaceX can then move on to the actual static fire. Featuring a single Raptor engine, Starship SN4 will hopefully become the first full-scale rocket to safely operate a flight-grade engine since SpaceX began full-scale tests in November 2019. If successful, that static fire could pave the way for Starship SN4 to perform a Starhopper-style 150m (500 ft) hop test as early as May 2020 – a hop that would be powered by a single Raptor engine according to Musk.
Starship SN5 will reportedly be the first ship to both have a nosecone installed and three Raptor engines installed if SN4 has a very successful few weeks and that new ship is perhaps just 5-10 days from being fully assembled. In short, things are about to get very busy and very exciting at SpaceX’s South Texas Starship factory and launch pad.
News
Tesla Cybercab display highlights interior wizardry in the small two-seater
Photos and videos of the production Cybercab were shared in posts on social media platform X.
The Tesla Cybercab is currently on display at the U.S. Department of Transportation in Washington, D.C., and observations of the production vehicle are highlighting some of its notable design details.
Photos and videos of the production Cybercab were shared in posts on social media platform X.
Observers of the Cybercab display unit noted that the two-seat Robotaxi provides unusually generous legroom for a vehicle of its size. Based on the vehicle’s video, the compact two-seater appears to offer more legroom than Tesla’s larger vehicles such as the Model Y, Model X, and Cybertruck.
The Cybercab’s layout allows Tesla to dedicate nearly the entire cabin to passengers. The vehicle is designed without a steering wheel or pedals, which helps maximize interior space.
Footage from the display also highlights the Cybercab’s large center screen, which is positioned prominently in front of the passenger bench. The display appears intended to provide entertainment and ride information while the vehicle operates autonomously.
Images of the vehicle also show an additional camera integrated into the Cybercab’s C-pillar. The extra camera appears to expand the vehicle’s field of view, which would be useful as Tesla works toward fully unsupervised Full Self-Driving.
Tesla engineers have previously explained that the Cybercab was designed to be highly efficient both in manufacturing and in operation. Cybercab Lead Engineer Eric E. stated in 2024 that the Robotaxi would be built with roughly half the number of parts used in a Model 3 sedan.
“Two seats unlocks a lot of opportunity aerodynamically. It also means we cut the part count of Cybercab down by a substantial margin. We’re gonna be delivering a car that has roughly half the parts of Model 3 today,” the Tesla engineer said.
The Tesla engineer also noted that the Cybercab’s cargo area can accommodate multiple golf bags, two carry-on suitcases, and two full-size checked bags. The trunk can also fit certain bicycles and a foldable wheelchair depending on size, which is quite impressive for a small car like the Cybercab.
Elon Musk
Elon Musk’s xAI wins permit for power plant supporting AI data centers
The development was reported by CNBC, citing confirmation from the Mississippi Department of Environmental Quality (MDEQ).
Mississippi regulators have approved a permit allowing Elon Musk’s artificial intelligence company xAI to construct a natural gas power plant in Southaven. The facility is expected to support the company’s expanding AI infrastructure tied to its Colossus data center operations near Memphis.
The development was reported by CNBC, citing confirmation from the Mississippi Department of Environmental Quality (MDEQ).
According to the report, regulators “voted to approve the permit” of xAI subsidiary MZX Tech LLC to construct a power plant featuring 41 natural gas-burning turbines “after careful consideration of all public comments and community concerns.”
The Mississippi Department of Environmental Quality stated that the permit followed a regulatory review process that included public comments and community input. Jaricus Whitlock, air division chief for the MDEQ, stated that the project met all applicable environmental standards.
“The proposed PSD permit in front of the board today not only meets all state and federal permitting regulations, but goes above and beyond what is required by law. MDEQ and the EPA agree that not a single person around our facilities will be exposed to unhealthy levels of air pollution,” Whitlock stated.
The planned facility will help provide electricity for xAI’s AI computing infrastructure in the Memphis region.
The Southaven project forms part of xAI’s efforts to scale computing capacity for its artificial intelligence systems.
The company currently operates two major data centers in Memphis, known as Colossus 1 and Colossus 2, which provide computing power for xAI’s Grok AI models. xAI is also planning to build another large data center in Southaven called Macrohardrr, which would be located in a warehouse previously used by GXO Logistics.
Large-scale AI training requires substantial computing power and electricity, prompting technology companies to develop dedicated energy infrastructure for their data centers.
SpaceX President Gwynne Shotwell previously stated that xAI plans to develop 1.2 gigawatts of power capacity for its Memphis-area AI supercomputer site as part of the federal government’s Ratepayer Protection Pledge. The commitment was announced during an event with United States President Donald Trump.
“As part of today’s commitment, we will take extensive additional steps to continue to reduce the costs of electricity for our neighbors. xAI will therefore commit to develop 1.2 GW of power as our supercomputer’s primary power source. That will be for every additional data center as well. We will expand what is already the largest global Megapack power installation in the world,” Shotwell said.
“The installation will provide enough backup power to power the city of Memphis, and more than sufficient energy to power the town of Southaven, Mississippi where the data center resides. We will build new substations and invest in electrical infrastructure to provide stability to the area’s grid.”
Elon Musk
Tesla China teases Optimus robot’s human-looking next-gen hands
The image was shared by Tesla AI’s account on Weibo and later reposted by Tesla community members on X.
A new teaser shared by Tesla’s China team appears to show a pair of unusually human-like hands for Optimus.
The image was shared by Tesla AI’s account on Weibo and later reposted by Tesla community members on X.
As could be seen in the teaser image, the new version of Optimus’ hands features proportions and finger structures that look strikingly similar to those of a human hand. Their appearance suggests that they might have dexterity approaching that of a human hand.
If the image reflects a new generation of Optimus’ hands, it could indicate Tesla is continuing to refine one of the most critical components of its humanoid robot.
Hands are widely viewed as one of the most difficult engineering challenges in robotics. For Optimus to perform complex real-world work, from manufacturing tasks to household activities, its hands would need to be the best in the industry.
Elon Musk has repeatedly described Optimus as Tesla’s most important long-term product. In posts on social media platform X, Musk has stated that Optimus could eventually become the first real-world Von Neumann machine.
In theory, a Von Neumann machine is a self-replicating system capable of building copies of itself using available materials. The concept was originally proposed by mathematician John von Neumann in the mid-20th century.
“Optimus will be the first Von Neumann machine, capable of building civilization by itself on any viable planet,” Musk wrote in a post on X.
If Optimus is expected to carry out complex work autonomously in the future, high levels of dexterity will likely be essential. This makes the development of advanced robotic hands a key step towards Musk’s long-term expectations for the product.