News
SpaceX to replace Falcon 9’s titanium grid fins with steel on Starship’s Super Heavy booster
Following a question on Twitter about how SpaceX intends to manufacture the truly massive grid fins shown in renders of Starship’s Super Heavy booster, CEO Elon Musk revealed that SpaceX will build them out of welded steel.
For the first several years of Falcon 9 and Falcon Heavy booster recovery operations, SpaceX built grid fins – used for maneuvering the rockets at high speeds – out of aluminum. With Falcon 9 Block 5, aluminum grid fins were phased out entirely in favor of larger titanium fins, necessitated by exceptionally high-speed reentries that nearly melted through the aluminum fins on several occasions. Now, SpaceX wants to move from titanium to steel fins for its next-generation Starship launch vehicle.
Welded steel— Elon Musk (@elonmusk) October 3, 2019
In response to the Twitter user’s question, Musk simply stated that Super Heavy’s grid fins would be manufactured out of “welded steel”, certainly keeping with the CEO’s now well-known love for the material. In October 2018, Musk finally managed to convince most of the senior engineers reporting to him that – despite years of work and full-scale testing – SpaceX needed to radically redesign Starship.
Prior to this radical change, SpaceX had spent at least 2-3 years on a Starship design (formerly Big F_____ Spaceship; BFS) made almost entirely out of carbon fiber composites, an extremely lightweight material that can be optimized for high strength. However, as Musk ultimately concluded in late 2018, although carbon composites are undeniably light and strong (optimal for spaceflight), they have extremely low heat tolerance and can react violently with supercooled liquid oxygen. Built almost entirely out of aluminum alloys with similarly low melting points, Falcon 9 has also struggled with the challenges posed by material choices, made far more difficult by the need to recover and reuse orbital-class rocket stages.
Musk ultimately decided that redesigning Starship with steel (alloys with particularly high melting points and good strength) was the right way to go. According to Musk, the high-quality carbon fiber composites SpaceX was originally pursuing cost something like $130,000 per metric ton, translating to a truly gobsmacking cost – accounting for unavoidable wastage – of $400M-$500M or more just to buy the materials needed to build a single Starship and Super Heavy booster. Steel, on the other hand, is quite literally 50 times cheaper, costing SpaceX around $2500 per ton, or as little as $10M in structural materials for each ship/booster pair.
Man of Stainless Steel
Speaking at a September 28th presentation on the 2019 status of Starship’s design, CEO Elon Musk couldn’t praise his decision to move to stainless steel enough, describing it as likely being the single best design decision he has ever made. It remains to be seen if the eccentric self-taught engineer’s decision was the correct one, but the progress SpaceX has made in just 10-11 months is undeniable. SpaceX has gone from a nearly blank slate to Starhopper’s 150m (500ft) test flight in ~6 months and gone from nothing to Starship Mk1 in another 6 or so months.
According to Musk, the properties of stainless steel – mainly a high melting point/working temperature and a tendency to strengthen at cryogenic temperatures – mean that the relatively heavy material is able to produce a launch vehicle that could eventually be far lighter and higher-performance than one made with carbon composites (BFR) or aluminum alloys (Falcon 9). Thanks to those properties, Starship/Super Heavy will become much stronger when filled with cold propellant and will also require little to no external heat shielding on its leeward half, whereas a reusable Al/composite rocket would require major thermal protection on nearly all exposed surfaces.
As part of the move to remove any ultra-expensive nonessential materials from the designs of Starship and Super Heavy, Musk has apparently also turned his gaze on the booster’s grid fins. As described at the top of this article, SpaceX replaced Falcon 9’s aluminum grid fins with titanium fins, requiring the company to create the largest single-piece titanium casting in the world. Musk has repeatedly indicated that each grid fin is extremely expensive.
In light of their expense, Musk (or SpaceX) has seemingly decided that future (larger?) SpaceX rockets will try to avoid large, titanium castings. Super Heavy nevertheless still needs massive grid fins: official renders published by SpaceX last month revealed a new diamond shape for the booster’s fins, and Musk later took to Twitter to reveal that they would be made out of welded steel instead of titanium.
Based on SpaceX’s official 2019 Super Heavy renders, the booster’s grid fins measure approximately 7m by 3m (23 ft by 10 ft), dwarfing Falcon 9’s titanium fins (perhaps 2m by 1.2m) with something like 8-10 times the surface area. Although 301-series stainless steel has a melting point and heat capacity roughly 15% lower than Grade 5 titanium, its strength characteristics are otherwise similar, while also remaining mechanically functional at almost three times the working temperature of titanium (840C vs. 330C).
Most importantly, not only is 301 steel roughly 15-20 times cheaper than titanium, but the process of fabricating large steel components – particularly with welding instead of casting – is dramatically faster, easier, and cheaper than working with and forming titanium. With their reasonably similar properties and the increased size of Super Heavy, it’s likely that steel grid fins would exhibit little to no ablation during even the hottest atmospheric reentries, and it would nevertheless be extremely easy and cheap to either repair or replace fins in the unlikely event of damage.
Given just how quickly and relatively easily SpaceX has built full-scale flight hardware out of steel and assuming there are no technical showstoppers caused by changing scales, it wouldn’t be surprising in the slightest to see SpaceX fabricate and test welded steel grid fins on Falcon 9 boosters in the near future.
Check out Teslarati’s Marketplace! We offer Tesla accessories, including for the Tesla Cybertruck and Tesla Model 3.
News
Tesla Giga Texas continues to pile up with Cybercab castings
Tesla sure is gathering a lot of Cybercab components around the Giga Texas complex.
Tesla may be extremely tight-lipped about the new affordable models that it was expected to start producing in the first half of the year, but the company sure is gathering a lot of Cybercab castings around the Giga Texas complex. This is, at least, as per recent images taken of the facility.
Cybercab castings galore
As per longtime drone operator Joe Tegtmeyer, who has been chronicling the developments around the Giga Texas complex for several years now, the electric vehicle maker seems to be gathering hundreds of Cybercab castings around the factory.
Based on observations from industry watchers, the drone operator appears to have captured images of about 180 front and 180 rear Cybercab castings in his recent photos.
Considering the number of castings that were spotted around Giga Texas, it would appear that Tesla may indeed be preparing for the vehicle’s start of trial production sometime later this year. Interestingly enough, large numbers of Cybercab castings have been spotted around the Giga Texas complex in the past few months.
Cybercab production
The Cybercab is expected to be Tesla’s first vehicle that will adopt the company’s “unboxed” process. As per Tesla’s previous update letters, volume production of the Cybercab should start in 2026. So far, prototypes of the Cybercab have been spotted testing around Giga Texas, and expectations are high that the vehicle’s initial trial production should start this year.
With the start of Tesla’s dedicated Robotaxi service around Austin, it might only be a matter of time before the Cybercab starts being tested on public roads as well. When this happens, it would be very difficult to deny the fact that Tesla really does have a safe, working autonomous driving system, and it has the perfect vehicle for it, too.
Investor's Corner
Two Tesla bulls share differing insights on Elon Musk, the Board, and politics
Two noted Tesla bulls have shared differing views on the recent activities of CEO Elon Musk and the company’s leadership.
Two noted Tesla (NASDAQ:TSLA) bulls have shared differing views on the recent activities of CEO Elon Musk and the company’s leadership.
While Wedbush analyst Dan Ives called on Tesla’s board to take concrete steps to ensure Musk remains focused on the EV maker, longtime Tesla supporter Cathie Wood of Ark Invest reaffirmed her confidence in the CEO and the company’s leadership.
Ives warns of distraction risk amid crucial growth phase
In a recent note, Ives stated that Tesla is at a critical point in its history, as the company is transitioning from an EV maker towards an entity that is more focused on autonomous driving and robotics. He then noted that the Board of Directors should “act now” and establish formal boundaries around Musk’s political activities, which could be a headwind on TSLA stock.
Ives laid out a three-point plan that he believes could ensure that the electric vehicle maker is led with proper leadership until the end of the decade. First off, the analyst noted that a new “incentive-driven pay package for Musk as CEO that increases his ownership of Tesla up to ~25% voting power” is necessary. He also stated that the Board should establish clear guidelines for how much time Musk must devote to Tesla operations in order to receive his compensation, and a dedicated oversight committee must be formed to monitor the CEO’s political activities.
Ives, however, highlighted that Tesla should move forward with Musk at its helm. “We urge the Board to act now and move the Tesla story forward with Musk as CEO,” he wrote, reiterating its Outperform rating on Tesla stock and $500 per share price target.
Tesla CEO Elon Musk has responded to Ives’ suggestions with a brief comment on X. “Shut up, Dan,” Musk wrote.
Cathie Wood reiterates trust in Musk and Tesla board
Meanwhile, Ark Investment Management founder Cathie Wood expressed little concern over Musk’s latest controversies. In an interview with Bloomberg Television, Wood said, “We do trust the board and the board’s instincts here and we stay out of politics.” She also noted that Ark has navigated Musk-related headlines since it first invested in Tesla.
Wood also pointed to Musk’s recent move to oversee Tesla’s sales operations in the U.S. and Europe as evidence of his renewed focus in the electric vehicle maker. “When he puts his mind on something, he usually gets the job done,” she said. “So I think he’s much less distracted now than he was, let’s say, in the White House 24/7,” she said.
TSLA stock is down roughly 25% year-to-date but has gained about 19% over the past 12 months, as noted in a StocksTwits report.
News
Tesla China achieves this year’s second highest domestic sales in June
The figure represents Tesla’s second-best performance in 2025 so far.
Domestic sales for Tesla China reached 61,484 units in June, marking a sharp recovery from recent months and positioning the company for a stronger finish to the second quarter. The figure represents Tesla’s second-best performance in 2025 so far, trailing only March, when the company delivered 74,127 vehicles domestically.
A strong comeback for Tesla China
According to data from the China Passenger Car Association (CPCA), Tesla sold a total of 71,599 cars wholesale in June 2025. This means that Tesla’s domestic sales last month rose 59.3% compared to May’s 38,588 units and increased 3.75% year-over-year from 59,261 units in June 2024, as noted in a CNEV Post report.
The rebound ends a two-month streak of year-over-year declines and helped lift Tesla’s Q2 retail total in China to 128,803 units, though that still marks an 11.7% drop from the same period last year. For context, Tesla China sold 263,410 vehicles domestically, down 5.36% year-over-year, in the first six months of 2025.
Tesla’s stronger domestic showing in June came as the company scaled back its export output from Giga Shanghai. The factory exported 10,115 vehicles last month, down 56.2% from May and 13.9% from a year earlier. For the first half of 2025, Tesla China’s total exports reached 101,064 units, down 31.85% compared to the same period in 2024.
Tesla China’s 2025 performance
June saw continued growth across China’s broader new energy vehicle (NEV) market, with retail sales reaching 1.11 million units, up 29.7% year-over-year. Battery electric vehicles (BEVs) accounted for 661,000 of those sales. Tesla’s NEV market share for June was then 5.53%, down from 6.92% a year earlier but an improvement over May’s 3.78%.
The Model Y continues to be Tesla China’s primary driver of sales, with the vehicle’s wholesale figures reaching 51,253 units in June, up 16.6% from a year ago and nearly 30% from May. Wholesale numbers for the Model Y totaled 214,034 units in the first six months of the year. The Model 3, in comparison, saw wholesale volumes reach 150,440 units in the first six months of the year.
Tesla Giga Texas continues to pile up with Cybercab castings
Two Tesla bulls share differing insights on Elon Musk, the Board, and politics
Tesla China achieves this year’s second highest domestic sales in June
-
Elon Musk1 week agoTesla investors will be shocked by Jim Cramer’s latest assessment
-
News2 weeks agoTesla Robotaxi’s biggest challenge seems to be this one thing
-
Elon Musk16 hours agoElon Musk confirms Grok 4 launch on July 9 with livestream event
-
News2 weeks agoWatch the first true Tesla Robotaxi intervention by safety monitor
-
News5 days agoTesla Model 3 ranks as the safest new car in Europe for 2025, per Euro NCAP tests
-
Elon Musk2 weeks agoA Tesla just delivered itself to a customer autonomously, Elon Musk confirms
-
Elon Musk2 weeks agoElon Musk confirms Tesla Optimus V3 already uses Grok voice AI
-
Elon Musk2 weeks agoxAI welcomes Memphis pollution results, environmental groups push back