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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.
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Elon Musk shared an incredible detail about Tesla Cybercab’s potential efficiency, as the company has hinted in the past that it could be one of the most affordable vehicles to operate from a per-mile basis.
ARK Invest released a report recently that shed some light on the potential incremental cost per mile of various Robotaxis that will be available on the market in the coming years.
The Cybercab, which is detailed for the year 2030, has an exceptionally low cost of operation, which is something Tesla revealed when it unveiled the vehicle a year and a half ago at the “We, Robot” event in Los Angeles.
Musk said on numerous occasions that Tesla plans to hit the $0.20 cents per mile mark with the Cybercab, describing a “clear path” to achieving that figure and emphasizing it is the “full considered” cost, which would include energy, maintenance, cleaning, depreciation, and insurance.
Probably true
— Elon Musk (@elonmusk) January 22, 2026
ARK’s report showed that the Cybercab would be roughly half the cost of the Waymo 6th Gen Robotaxi in 2030, as that would come in at around $0.40 per mile all in. Cybercab, at scale, would be at $0.20.
Credit: ARK Invest
This would be a dramatic decrease in the cost of operation for Tesla, and the savings would then be passed on to customers who choose to utilize the ride-sharing service for their own transportation needs.
The U.S. average cost of new vehicle ownership is about $0.77 per mile, according to AAA. Meanwhile, Uber and Lyft rideshares often cost between $1 and $4 per mile, while Waymo can cost between $0.60 and $1 or more per mile, according to some estimates.
Tesla’s engineering has been the true driver of these cost efficiencies, and its focus on creating a vehicle that is as cost-effective to operate as possible is truly going to pay off as the vehicle begins to scale. Tesla wants to get the Cybercab to about 5.5-6 miles per kWh, which has been discussed with prototypes.
Additionally, fewer parts due to the umboxed manufacturing process, a lower initial cost, and eliminating the need to pay humans for their labor would also contribute to a cheaper operational cost overall. While aspirational, all of the ingredients for this to be a real goal are there.
It may take some time as Tesla needs to hammer the manufacturing processes, and Musk has said there will be growing pains early. This week, he said regarding the early production efforts:
“…initial production is always very slow and follows an S-curve. The speed of production ramp is inversely proportionate to how many new parts and steps there are. For Cybercab and Optimus, almost everything is new, so the early production rate will be agonizingly slow, but eventually end up being insanely fast.”
Elon Musk
Elon Musk to attend 2026 World Economic Forum at Davos
The Tesla CEO was confirmed as a last-minute speaker for a session with BlackRock CEO Larry Fink.
Elon Musk is poised to attend the 2026 World Economic Forum in Davos. The Tesla CEO was confirmed as a last-minute speaker for a session with BlackRock CEO Larry Fink, signaling a thaw in Musk’s long-strained relationship with the event.
A late addition
Organizers of the World Economic Forum confirmed that Elon Musk was added shortly before the event to a Thursday afternoon session, where he was scheduled to speak with Fink, as noted in a Bloomberg News report. Musk’s upcoming appearance marks Musk’s first participation in the forum, which annually draws political leaders, business executives, and global media to Davos, Switzerland.
Musk’s attendance represents a departure from his past stance toward the event. He had been invited in prior years but declined to attend, including in 2024. His upcoming appearance followed remarks from his political ally, Donald Trump, who addressed the forum earlier in the week with a wide-ranging speech.
A previously strained relationship
Musk had frequently criticized the World Economic Forum in the past, describing it as elitist and questioning its influence. In earlier posts, he characterized the gathering as “boring” and accused it of functioning like an unelected global authority. Those remarks contributed to a long-running distance between Musk and WEF organizers.
The forum previously said Musk had not been invited since 2015, though that position has since shifted. Organizers indicated last year that Musk was welcome amid heightened interest in his political and business activities, including his involvement in the Trump administration’s Department of Government Efficiency (DOGE). Musk later stepped away from that role.
Despite his friction with the World Economic Forum, Musk has remained central to several global events, from SpaceX’s provision of satellite internet services in geopolitically sensitive regions through Starlink to the growing use of xAI’s Grok in U.S. government applications.
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Tesla states Giga Berlin workforce is stable, rejects media report
As per the electric vehicle maker, production and employment levels at the facility remain stable.
Tesla Germany has denied recent reports alleging that it has significantly reduced staffing at Gigafactory Berlin. As per the electric vehicle maker, production and employment levels at the facility remain stable.
Tesla denies Giga Berlin job cuts report
On Wednesday, German publication Handelsblatt reported that Tesla’s workforce in Gigafactory Berlin had been reduced by about 1,700 since 2024, a 14% drop. The publication cited internal documents as its source for its report.
In a statement to Reuters, Tesla Germany stated that there has been no significant reduction in permanent staff at its Gigafactory in Grünheide compared with 2024, and that there are no plans to curb production or cut jobs at the facility.
“Compared to 2024, there has been no significant reduction in the number of permanent staff. Nor are there any such plans. Compared to 2024, there has been no significant reduction in the number of permanent staff. Nor are there any such plans,” Tesla noted in an emailed statement.
Tesla Germany also noted that it’s “completely normal” for a facility like Giga Berlin to see fluctuations in its headcount.
A likely explanation
There might be a pretty good reason why Giga Berlin reduced its headcount in 2024. As highlighted by industry watcher Alex Voigt, in April of that year, Elon Musk reduced Tesla’s global workforce by more than 10% as part of an effort to lower costs and improve productivity. At the time, several notable executives departed the company, and the Supercharger team was culled.
As with Tesla’s other factories worldwide, Giga Berlin adjusted staffing during that period as well. This could suggest that a substantial number of the 1,700 employees reported by Handelsblatt were likely part of the workers who were let go by Elon Musk during Tesla’s last major workforce reduction.
In contrast to claims of contraction, Tesla has repeatedly signaled plans to expand production capacity in Germany. Giga Berlin factory manager André Thierig has stated on several occasions that the site is expected to increase output in 2026, reinforcing the idea that the facility’s long-term trajectory remains growth-oriented.
Elon Musk shares incredible detail about Tesla Cybercab efficiency
Elon Musk to attend 2026 World Economic Forum at Davos
