News
SpaceX is installing Tesla battery packs on its Starship MK1 rocket prototype
First noticed by NASASpaceflight.com forum member “exilon”, SpaceX appears to have selected off-the-shelf Tesla battery packs as the power storage method of choice for its Starship Mk1 prototype, currently in the midst of a busy period of integration
Potentially taken directly from Tesla Model S/X powertrains otherwise headed for recycling, SpaceX technicians have spent the last 24 or so hours attaching numerous battery packs to part of a Starship subsystem known as header tanks. This is the latest addition to SpaceX and Tesla’s relatively close relationship – the two have begun to work together to solve challenges with materials science, batteries, and more within the last 12-24 months.
While initially surprising, the appearance of battery packs quite literally taken from Tesla Model S/X vehicles or their Gigafactory assembly line actually makes a lot of sense. By using prepackaged, off-the-shelf battery systems with industry-leading power management capabilities, SpaceX is probably saving a huge amount of time, money, and effort. If the battery packs were already nearing the end of their useful automotive lives, the net cost could very well approach zero, aside from what looks like a minimal mounting brace. It’s possible that SpaceX has even pursued modifying and certifying large Tesla-derived battery packs for use on orbital Starship missions.
These battery packs were spotted by an eagle-eyed forum user who was first to recognize the hardware for what it likely was. Per the above photo, SpaceX appears to have joined two self-contained Tesla battery packs into single units that were then installed on a header tank. Knowing that the highest capacity Tesla offers is ~100 kWh, the 2×2 packs could store up to 400 kWh and offer instantaneous power output (ignoring thermal limitations) well into the megawatt (MW) range. It’s unclear if the first header tank also had batteries attached but SpaceX technicians began installing that tank inside Starship’s nose cone on the evening September 22nd. Tank #2 will likely follow in the next 24 hours per Musk’s indication that Starship Mk1 would be stacked to its full height on Wednesday.
For unknown reasons, SpaceX is choosing to mount the ~1000 kg (2200 lb) battery pack pairs directly onto the outside of one of Starship Mk1’s two header tanks. These tanks compliment the rocket prototype’s main propellant tanks and are meant to serve as small reserves of fuel (methane) and oxidizer (oxygen) that can be pressurized independently. During dramatic in-space and in-atmosphere maneuvers, the g-forces exerted on Starship could easily find the vehicle’s propellant pushed away from the ‘bottom’ of its main tanks, creating bubbles or voids that can damage and destroy rocket engines if ingested.
Pressurizing the entirety of the main tanks (a cylinder measuring 9m by ~40m or 30×130 ft) is extremely impractical – hence the need for much smaller header tanks. Falcon 9 boosters are able to sidestep this issue because they are small and light enough (relatively speaking) that cold gas thrusters can efficiently generate the positive Gs needed to safely ignite its engines for recovery and landing maneuvers. Empty, Starship alone will likely weigh no less than 4-6 times as much as a Falcon 9 booster (~25 tons, 55,000 lb).
According to CEO Elon Musk, SpaceX has decided to install those header tanks in the very tip of Starship Mk1’s conical nose to help balance out the vehicle’s center of mass. As a side-effect, SpaceX will have to install feed lines that run the entire length of the spacecraft and protect them with steel aero-covers. It’s unclear if this design choice is necessitated by Starship’s early, prototypical form or if – once outfitted with crew quarters or a functional cargo bay – it’s possible that that added mass will serve as enough of a counterbalance to preclude the need for ballast in the nose.
Musk posted a view inside an adjacent SpaceX fabrication facility in Boca Chica on September 23rd, showing a large row of staged steel sheets that will eventually be formed into aerodynamic shrouds for Starship Mk1’s raceways, fins, and wings.
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Tesla CEO Elon Musk posted a photo of himself standing with the Optimus production team inside Tesla’s Fremont factory, arms crossed amid workers in hard hats and safety vests. The image captures a pivotal industrial shift: the same facility space once dedicated to building Tesla’s flagship Model S sedan and Model X SUV is now home to the company’s humanoid robot manufacturing line.
Walking the Optimus production line in Fremont pic.twitter.com/ABS0tuRibW
— Elon Musk (@elonmusk) July 1, 2026
Tesla’s Fremont Factory, acquired in 2010 from the former NUMMI joint venture between Toyota and GM, has been the company’s original U.S. manufacturing hub since Model S production began in 2012.
The Model X followed soon thereafter. These premium vehicles offered lower annual volumes, recently around 30,000 combined, compared to the high-volume Model 3 and Model Y lines that continue around the site. Over their combined run, the S and X accounted for roughly 610,000 units.
In late January 2026, during Tesla’s Q4 2025 earnings call, Elon Musk announced the end of Model S and Model X production in Q2 2026. The final vehicles rolled off the line in early May. Rather than retooling for another vehicle, Tesla chose to convert the dedicated S/X assembly area into a dedicated Optimus Gen 3 production line.
Model 3 and Y manufacturing remains unaffected. Tesla’s official Fremont Factory page now lists Optimus alongside the 3 and Y as core products.
The conversion was executed with remarkable speed. After production stopped, crews dismantled the existing vehicle line and installed entirely new modular equipment—including lines sourced from Germany and dozens of sub-lines for actuators, batteries, and other components—in roughly four months.
Musk described the timeline as “insanely fast,” noting it would be unprecedented for any other manufacturer. Initial Optimus output is expected to ramp slowly due to the robot’s roughly 10,000 unique parts and the brand-new production processes involved. The Fremont line targets an eventual capacity of 1 million Optimus units per year.
Tesla isn’t joking about building Optimus at an industrial scale: Here we go
Optimus Development Timeline
- August 19, 2021: Optimus (then called Tesla Bot) formally announced at Tesla’s first AI Day. A concept video showed a person in a suit demonstrating the vision for a general-purpose humanoid capable of dangerous, repetitive, or boring tasks using the same AI architecture as Full Self-Driving.
- 2022: Early prototypes displayed. At the second AI Day in September, semi-functional units demonstrated walking across a stage and basic arm movements
- 2023: September videos showed improved capabilities, including sorting colored blocks, precise limb awareness, and holding a Yoda pose.
- 2024-early 2025: Factory integration videos showed Optimus navigating workspaces and handling objects like battery cells.
- January 2026: Gen 3 mass-production activities began at Fremont, with reports of over 1,000 Gen 3 units already operating inside the factory for real-world learning and AI training
- April 2026: Musk confirms Optimus production on converted Fremont line would begin in late July or August 2026. The Gen 3 reveal, originally eyed for Q1, was pushed closer to production start. A second, much larger Optimus factory at Giga Texas is under construction, with volume production targeted for Summer 2027 and long-term capacity of 10 million units annually
- July 1, 2026: Musk’s on-site visit and team photo confirm the Optimus line is operational and the transition is actively progressing
Tesla positions Optimus as potentially its largest project ever, leveraging vertical integration, AI expertise, and car-like manufacturing know-how to scale humanoid robots first for its own factories and later for broader industrial and consumer use.
The Fremont conversion serves as a critical proving ground for this ambitious new chapter in Tesla’s already-rich history.
Investor's Corner
Tesla gets its latest short from Michael Burry: ‘Happy it jumped back to this level’
Tesla short seller Michael Burry, the subject of the film “The Big Short,” where he was portrayed by Steve Carell, has revealed he has opened a new bet against the stock.
In a new update to his Substack newsletter in a post titled “Trading Post June 30, 2026,” Burry revealed a new set of bets against Tesla, Caterpillar, NVIDIA, Applied Materials Inc., and the iShares Semiconductor ETF.
In regard to Tesla, Burry wrote:
“And finally I shorted Tesla at 416.22. Happy it jumped back to this level.”
This means Burry likely opened his new short position after the company’s recent rally on Wall Street, which saw Tesla shares sink in mid-May, only to recover to well over the $400 mark. Currently, shares trade at around $427.
The company saw a big Tuesday as shares climbed considerably, over 10 percent. The size of the Tesla short was not provided, nor did Burry give any information on the position’s structure, the number of shares, dollar value, or whether options were used in the short.
The Tesla and SpaceX merger everyone is talking about is quietly building
Over the years, Burry has been one of the more vocal critics of Tesla, calling its share price “media inflated,” and saying it was “ridiculously overvalued” as recently as December.
The company has largely transitioned away from being known as an automotive company and instead is much more widely regarded as an AI play, mostly due to its Full Self-Driving efforts, Optimus robot development, and data collection related to both.
This has not pulled those skeptics away from being vocal about their distaste for how Tesla is valued, but there’s no denying that the company is a global force in many things, including sustainable energy, automotive, and AI.
Wedbush Securities is initiating stock coverage on SpaceX (NASDAQ: SPCX), marking the first comments on the company since it went public several weeks ago. Wedbush and its analyst handling coverage, Dan Ives, are widely bullish on fellow Musk company Tesla (NASDAQ: TSLA).
Ives wrote his first note initiating coverage of SpaceX shares on Wednesday with a $190 price target and an ‘Outperform’ rating. The firm believes the company is well positioned off of its IPO because of its wide array of projects, including AI compute power and infrastructure, connectivity projects, and launches.
“We view SpaceX as one of the most differentiated assets within the tech market with a strong footprint across its three core markets, with Starlink driving success with connectivity,” Ives wrote, “Starship launches leading to a demand flywheel and increasing deal flow for its Colossus clusters.”
Elon Musk called it Epic: The full story of SpaceX’s Starship Flight 12
Wedbush leans heavily on Starlink, which they say is the “profitability driver given the strength of its recurring revenue base of ~12 million subscribers as of June 5th.” Ives believes Starlink is still in the “early innings” of penetrating the global telecommunications and broadband market, as it only holds less than a 1 percent share. However, this number is sure to increase over time.
It also highlights the importance of Starship, which it says is an “essential layer” of SpaceX’s overall success. SpaceX developing and displaying the ability to reuse rockets is a major cost and reliability advantage “as it reduces the necessary hardware launch costs while generating a feedback loop for future flights to improve their launch flight rate without accelerating capex spend.”
Finally, SpaceX’s recent AI/Compute projects are also very elementary, Ives writes. It is worth mentioning Wedbush said its $190 price target is derived from a valuation forecast that sees the company yielding roughly $2.48 trillion of implied enterprise value.
There are also some factors that Wedbush did not take into account with its initial coverage. The firm wrote in the note:
“We note that there is optional value coming from Starship’s accelerating scale towards sub-$200/kg unit economics, orbital data centers, and enterprise AI monetization as these factors could drive meaningful upside but these face major hurdles, so we do not take that into account with our valuation.”
SpaceX shares are down just over 2 percent today, trading at around $167 at the time of publication.
Tesla Optimus project fires up as Musk sees production line progress
Tesla gets its latest short from Michael Burry: ‘Happy it jumped back to this level’
