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SpaceX's Elon Musk works through holidays on Starship's "most difficult part"
SpaceX CEO Elon Musk says he has been working through the holidays at the company’s Boca Chica facilities to get Starship’s “most difficult part” ready for the next-generation spacecraft’s next prototype and flight tests.
Known as tank domes or bulkheads, Musk says that the hardware is the most difficult part of building and assembly Starship’s primary structure, referring to the steel engine section, tanks, and pointed nose that comprise most of the spaceship’s body. Starship’s primary structure must stand up to the rigors of all aspects of flight, including highly-pressurized propellant tanks, extreme G-forces during launches, orbital reentry, and more.
It was never officially determined whether the failure was intentional or not but during the first Starship prototype’s (Mk1) last test campaign, the vehicle experience an overpressure event while being filled with liquid oxygen or nitrogen. Localized to the weld connecting the upper tank dome to Starship’s cylindrical tank section, the dome essentially sheared off at the weld and launched hundreds of feet into the air, sending a shockwave through the vehicle that crumpled many of its steel structures as if they were aluminum foil.
It’s likely that Starship Mk1’s failure was an intentional overpressure event, meaning that SpaceX may have purposely pressed the vehicle’s tanks beyond their design limits to determine how structurally sound they were. What is less clear is whether the rocket burst before or after reaching its theoretical design limit.
For reference, SpaceX’s Falcon 9 rocket operates with its fuel and oxygen tanks pressurized to about 50 psi (3.5 atm) with localized pressures likely doubling or tripling near the bottom of both tanks during the first minute or two of launch. Some amateur back-of-the-envelope calculations from videos of Starship Mk1’s burst event suggest that it was pressurized to at least 60-75 psi (4-5 atm) at its upper tank dome, meaning that the pressure on its two lower domes and tank walls would have been even higher. If correct, those unofficial figures mean that Mk1 actually performed quite well considering the ramshackle facilities and unprecedentedly spartan methods used to fabricate and assemble it.
As such, Musk likely considers Starship’s tank domes the “most difficult part of [its] primary structure” in large part because of how difficult it is to make giant propellant tank domes simultaneously light and strong. Musk has previously implied that Starship Mk1 was more 200 tons (450,000 lb) empty while the ultimate goal for the spacecraft’s empty weight is closer to 120 tons, and a large portion of that weight savings will likely have to come from making its tank domes as light as possible.
In line with that educated speculation, the last month or so of SpaceX’s Starship work in Boca Chica, Texas has been marked by a distinct focus on building tank domes. In fact, Musk himself tweeted that he had worked all night with SpaceX engineers in Boca Chica in a bid to get dome production ready for Starship’s Mk3 prototype, the first Super Heavy hardware, and many more rockets to come.
Prior to Musk’s tweet, a Starship tank dome was actually shipped all the way from Florida to Texas and arrived earlier this month. Meanwhile, technicians have been briskly building up an additional dome using what appears to be a different method of integration involving new parts. SpaceX is currently attempting to weld Starship’s tank domes together from several dozen pre-formed sheets of stainless steel.
The sheets of steel assembled into the dome Musk showed on December 27th likely arrived in Boca Chica on December 13th, implying that SpaceX has managed to complete the majority of the first dome prototype – using a new process – in barely two weeks.




After SpaceX lifted the partially-completed dome off one of its custom assembly jigs, workers almost instantly began staging new sections of steel, beginning the process of integrating yet another tank dome – now likely the fourth on-site in Boca Chica. Meanwhile, at a nearby section of SpaceX’s Boca Chica production facilities, yet another dome was visible on the 28th. In short, SpaceX should soon have more than enough tank domes to complete the next Starship prototype – said to be a significantly improved and refined design compared to Mk1.
Known as Starship Mk3 (or Starship SN01), Musk says that the rocket – currently just a miscellaneous collection of separate parts – could (“hopefully”) be ready for its first flight as soon as February or March 2020.
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Elon Musk
Tesla shows what Roadster drivers will see on screen before thruster activation
Tesla’s Roadster video reveals a fighter jet inspired cockpit with a 5,500 PSI thruster gauge.
Tesla has given future owners their clearest look yet at the cockpit of its next generation Roadster. In a 34 second video posted to X on Friday afternoon, the company walked through the car’s touchscreen with a caption: “Inspired by fighter jet cockpits, Roadster’s interface was designed around the pilot.”
The clip opens on a black screen with red graphics and a 3D wireframe of the car, which sits beside the Roadster’s squared off yoke. Tapping parts of the model brings up controls for the rear wing, including low drag and high downforce positions, along with a charging page with a charge limit bar and a small music player. A row of tabs along the bottom reads Home, Vehicle, Listen, Climate and Navigate.
Most of the video is spent in Track Mode. The dashboard shows a live circuit map, a list of session lap times, brake and motor temperatures, and pressure and temperature readouts for each tire. A setup page lets the driver pick Auto, Low Drag, High Downforce or Custom aero modes, adjust aero balance and brake balance, and switch stability and traction control off. Along the bottom, a status bar reads “Thruster · 5,500 PSI” next to a “Boost Ready” indicator.
That gauge ties the software to the hardware Tesla showed off near Waco, Texas on October 15. The Thrust and Rocket versions use cold gas thrusters fed by carbon overwrapped pressure vessels, and Tesla lists 0 to 60 mph times of under 0.9 seconds and under 0.59 seconds for them, as Teslarati detailed in its breakdown of the three Roadster configurations. The base Performance car relies on a fan and ground sealing system for grip, and the aero settings on screen match the active wings and suction setup covered in our look at how the Roadster generates downforce.
The Roadster layout is a departure from the rest of Tesla’s lineup. Instead of a map centered screen, the Roadster puts the car itself at the center of the home page, and Tesla’s Roadster page lists two smaller forward displays alongside the main touchscreen. Tesla has not said whether any of the Track Mode telemetry will make its way to the Model 3 Performance or other vehicles.
The interface could still change before deliveries. Elon Musk said at the event that Roadster production will begin in 2028, and Tesla says the flagship Rocket version is not approved for public road use. Reservations are open with a $50,000 payment, while Thrust is listed as a limited release and Rocket is invite only.
Those who want to see the car in person will get their first chance this weekend. The Roadster goes on display in the lobby of the Petersen Automotive Museum in Los Angeles from October 24 to 27, according to Sawyer Merritt, the first time the public will be able to view it up close.
Elon Musk
Tesla reveals Optimus Academy, where robots teach themselves
Tesla has begun building production quality Optimus robots in Fremont and revealed its training plan.
Tesla has started building Optimus on the high volume line it set up inside its Fremont factory, and the company says the robots coming off it are the first that meet the bar for a real product. “The bots coming off this line are the first production-quality bots that we have manufactured,” Tesla wrote in its third quarter shareholder letter, adding that it has “proven that the current manufacturing process for Optimus is suitable for a commercial product.”
The line sits in space that built the Model S and Model X until this spring. Tesla cleared the old vehicle line in 46 days, as Teslarati reported in July, to make room for robot production sized for one million units a year. On Wednesday’s earnings call, Elon Musk said most of the equipment for that capacity is already in Fremont, with output set to climb toward roughly 20,000 robots a week as the line ramps.
Musk described the ramp as a classic S curve. “The growth of Optimus is an S curve, but the initial curve is a shallow slope,” he said. The team is now refining the robot’s AI, electromechanical design, reliability and service life, and Musk expects that work to be finished by the end of next year, when Tesla plans to start delivering Optimus to outside companies for dangerous, repetitive and around the clock jobs.
The most interesting part of the call was how Tesla plans to teach the robots. Its cars send real driving data back to the AI team from millions of vehicles, but Optimus has no fleet like that yet. “A big difference with Optimus versus the cars is we don’t have this vast fleet of cars from which we can gather training data,” Musk said. Tesla’s answer is an Optimus Academy, where 10,000 to 20,000 robots will practice a wide range of tasks and feed what they learn into the next version of the model. Every unit off the Fremont line becomes a source of that training data.
Smarter hardware is on the way too. Tesla plans to put its AI5 chip into Optimus next year, and Musk said a new Optimus video should arrive within one or two months showing the robot completing tasks driven by AI rather than preprogrammed motions. He took aim at rival humanoid demos that only run scripted routines, saying those would not hold up in the real world.
The supply chain is lining up behind the program. In September, Tesla certified Tuopu, Joyson and Sanhua as mass production partners for Optimus components. A far larger Optimus factory is also rising at Giga Texas, where drone footage from Joe Tegtmeyer showed the steel frame nearing completion, and Musk has pegged that plant’s long term target at 10 million robots a year.
Tesla executives also said Optimus production costs are trending toward the expected manufacturing cost of Cybercab, a sign the robot is being engineered for volume from the start. The hands remain the toughest piece of the design, a point Musk also made at the X Takeover event earlier this month, as Teslarati covered at the time, and that is where much of the current engineering effort is focused.
Elon Musk
The Starship moon landing number NASA and Elon Musk can’t agree on
Musk disputes NASA estimate of 22 Starship launches for Moon landing, predicting 6 to 8.
Elon Musk is disputing a new NASA safety panel estimate of how many Starship launches it will take to put astronauts on the Moon, saying the real number will be less than half the panel’s figure.
On Thursday, NASA’s Aerospace Safety Advisory Panel held its quarterly public meeting. Panel member Charlie Precourt, a former NASA astronaut, flagged the fueling process for SpaceX’s lunar lander as a major risk for Artemis IV, the mission planned to land a crew on the Moon in 2028. “We need to keep our eyes on numerous required fuelings for the lander,” Precourt said, according to Ars Technica. “I think the last estimate is around 22 flights.”
Ars Technica’s Eric Berger posted the comment on X, and Musk replied. “That’s way too high,” Musk wrote. “Actual number will be more like 6 to 8.”
The disagreement comes down to a basic problem with sending a ship as large as Starship to the Moon. Starship burns nearly all of its propellant just reaching Earth orbit, so it cannot continue on to the Moon without stopping for a refill. SpaceX’s answer is a gas station in space. First, a Starship that works as a storage tank, called a depot, is launched into orbit. Then a series of tanker Starships launch one at a time, dock with the depot and pump their leftover propellant into it. Once the depot is full, the lunar lander version of Starship launches, docks, fills up and heads for the Moon.
Every tanker trip is its own full rocket launch, which is why the count matters. More launches mean more time, more cost and more chances for something to go wrong before astronauts ever leave Earth. Berger estimated that even if SpaceX reaches twice weekly Starship launches by the end of 2027, filling a depot at the panel’s number would still take roughly three months.
How many tankers are needed depends mostly on how much propellant each one can carry to orbit and how much is lost along the way. Starship’s fuel and oxygen are stored at extremely cold temperatures, and some of it slowly boils off while waiting in orbit. More is lost in each transfer. NASA appears to be working from what Starship can lift today, while Musk’s range assumes a more capable rocket.
Musk has pushed back on higher counts before. In 2021, after a government document suggested 16 launches, he called that “extremely unlikely” and said eight tankers would be the most required.
Much of the answer depends on hardware SpaceX has not finished flying. As Teslarati noted earlier this year, the company plans to carry out the refueling process with its upgraded V3 Starship, and Precourt described Artemis IV as carrying “a large number of firsts.” He also praised NASA Administrator Jared Isaacman’s team for working to clear obstacles for both SpaceX and Blue Origin, whose Blue Moon lander does not rely on orbital refueling for its first mission.