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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
Elon Musk breaks his silence on the Starlink impact to Ukraine drones
Musk says the US military and president set Starshield limits, not SpaceX, amid Ukraine complaints.
Elon Musk says the speed limit cutting out Ukraine’s military Starlink terminals is not SpaceX’s decision. In a post on X Wednesday, Musk wrote that “Starshield systems are owned and controlled by the US government. Any limits on speed or usage are decided by the US military and ultimately POTUS.” He added that Starlink is a commercial service limited to civilian or defensive activities and “cannot be used for offensive military action, as doing so would be inappropriate for a commercial company.”
He was replying to Mykhailo Fedorov, Ukraine’s former defense minister, who had thanked Musk for restoring connectivity at speeds up to 160 km/h and said removing the Starshield limit entirely is “now critical for Ukraine’s defense.”
Starshield systems are owned and controlled by the US government. Any limits on speed or usage are decided by the US military and ultimately POTUS.
Starlink is a commercial service owned and controlled by SpaceX. Usage of Starlink is limited to civilian or defensive activities and cannot be used for offensive military action, as doing so would be inappropriate for a commercial company.
— Elon Musk (@elonmusk) October 14, 2026
The complaint started Tuesday night, when Ukrainian officials said military terminals began losing service above roughly 100 mph. Presidential adviser Serhiy Beskrestnov said the defense forces got no warning and several missions were disrupted, as Teslarati reported earlier Wednesday. The 7th Rapid Reaction Corps told Reuters connections dropped for 10 to 20 seconds at speeds well below the limit, which made drones harder to control. Poland’s foreign minister, Radoslaw Sikorski, asked Musk on X whether he is “playing politics with your products again.”
That is why the Starlink and Starshield distinction matters. SpaceX introduced Starshield in 2022 as the government version of Starlink, with an initial focus on Earth observation, communications and hosted payloads. It won a Space Force contract in 2023 with a $70 million ceiling. In December 2024, the Pentagon moved Ukraine’s terminals onto Starshield, covering about 3,000 units across two contracts. Ukraine’s military connections therefore run through a service that Musk now says sits under Washington’s control.
While Musk’s post describes who holds authority, it does not infer that anyone ordered the limit, and neither SpaceX nor the US government has confirmed who set it. Ukrainian officials have pointed to the timing, which follows President Trump’s push for an energy ceasefire and Musk’s Saturday post that “Zelensky has gone too far.” The BBC noted Trump denied threatening to restrict intelligence sharing with Kyiv, and no evidence has been presented that Washington requested the cap.
The episode also revives a promise from 2025. After Poland accused him of threatening Ukraine’s access, Musk said Starlink “will never turn off its terminals” and would not be used as a bargaining chip. Poland has since supplied more than 29,000 terminals to Ukraine. Teslarati also covered Kyiv’s search for Starlink alternatives in 2025, and the latest dispute gives that search new urgency.
Investor's Corner
Tesla opens the Q&A for its biggest earnings call yet
Tesla opens its Q3 earnings Q&A, and Cybercab, Robotaxi, Optimus and regulators loom over October 21.
Tesla has opened its shareholder question portal for the Q3 2026 earnings call, with the Say Q&A page already listing questions. Investors have until 4:00 p.m. EDT on October 20 to submit and vote on what management should answer.
The call is set for Wednesday, October 21. Tesla will post results after the market closes, with a live webcast at 4:30 p.m. CT, or 5:30 p.m. ET, through its investor relations site.
Say ranks questions by the number of shares behind the votes, which gives institutional holders extra weight over the retail crowd.
Ahead of Q2, retail investors asked why Robotaxi growth had stalled, when Cybercab would start customer rides, and where the Optimus Gen 3 ramp stood, while an institutional holder asked how Tesla and SpaceX would split Terafab duties. Cybercab has since answered one of those. Tesla said last week it has 300 plus Cybercabs serving Austin, up eightfold in 30 days, with Dallas named as the next city. The questions now are likely to move from when to how fast.
There is also a regulatory question hanging over the call. NHTSA has demanded sworn answers on how the pedal free Cybercab was certified against federal safety standards, with responses due October 30, nine days after the call. Whether an analyst raises it live is unknown, but it is the kind of exposure that tends to find its way into a Q&A.
The numbers will not be the main draw. Tesla already reported 486,532 deliveries and 13.7 GWh of storage for the quarter. Consensus sits around 43 to 45 cents per share on roughly $27.8 billion in revenue, according to Zacks, after a Q2 report that missed on EPS. Goldman Sachs, which holds a Neutral rating and a $360 target, argues the outlook for Robotaxi, FSD and Optimus will matter more to the stock than the quarter itself.
The call also lands six days after the rescheduled Roadster event, which Tesla will stream on X on Thursday, October 15, at 7:55 p.m. CT. If the Roadster shows up with a production date or a SpaceX thruster package, expect it to climb the voting list before the deadline.
Elon Musk
Ukraine says Starlink is cutting out its military drones as Poland calls out Elon Musk
Ukrainian officials allege SpaceX limited military Starlink speeds, disrupting drone missions; SpaceX has not commented.
Ukrainian officials are accusing SpaceX of placing a speed limit on the military version of Starlink that their forces use to fly drones, but SpaceX has not confirmed that any change was made. Presidential adviser Serhiy Beskrestnov said in a Telegram post on Wednesday that Starshield terminals have begun losing service when they move faster than about 100 miles per hour, according to a Reuters report. “Our defense forces did not receive a warning about this limitation, and this led to the disruption of several missions,” he wrote.
Ukraine’s 7th Rapid Reaction Corps told Reuters that connections dropped for 10 to 20 seconds at just 68 to 75 mph, which made the drones harder to control. Volunteer Serhiy Sternenko, citing military reports, said the dropouts are now starting at 37 to 43 mph. These accounts come from Ukrainian officials and military sources and have not been independently verified. Regular civilian terminals were reportedly not affected, according to EUalive.
.@POTUS: We told Zelensky, ‘You can do whatever you want to Russia, but don’t hit the refineries because that’s a world problem.’ And what does he do? He goes and hits the diesel fuel. He better damn well stop. https://t.co/CdRlMcPlKr
— Rapid Response 47 (@RapidResponse47) October 10, 2026
SpaceX has not publicly commented or explained what, if anything, changed. Beskrestnov and other Ukrainian officials believe the issue is intentional and point to the timing. Washington has been pressing Kyiv to stop long range strikes on Russian oil refineries after President Trump called for an “energy ceasefire,” and Musk posted on Saturday that “Zelensky has gone too far.” EUalive noted that neither Ukrainian nor Polish officials have presented evidence that the limit was ordered by Washington or by SpaceX, so the link to politics remains an allegation. Other explanations, such as a technical or policy change affecting fast moving terminals, have not been ruled out.
Poland’s foreign minister, Radosław Sikorski, responded on X by quote tweeting a Kyiv Independent report and writing: “Hey, @elonmusk, big man, are you playing politics with your products again? As your European customers, we are watching you.” Poland is the largest funder of Ukraine’s Starlink service, having supplied more than 29,000 terminals and covering operating costs Sikorski has put at roughly $50 million a year. The wording echoes their 2025 clash, when Musk told Sikorski to “be quiet, small man.” At the time of writing, neither Musk nor SpaceX had responded to the claims.
Hey, @elonmusk, big man, are you playing politics with your products again?
As your European customers, we are watching you.— Radosław Sikorski 🇵🇱🇪🇺 (@sikorskiradek) October 14, 2026
The dispute sits on top of a long history. Musk confirmed in February 2022 that Starlink was active in Ukraine after a request from a Ukrainian minister. That October, SpaceX asked the Pentagon to share the bill and Musk said the cost was approaching $20 million a month, before he reversed course and said SpaceX would keep paying. In December 2024 the Pentagon moved some of those terminals onto the Starshield service, the government version now at the center of the complaints.
SpaceX has also changed how its network treats certain terminals in Ukraine before, and that time it was with Kyiv’s cooperation. In February, Ukrainian officials confirmed that terminals believed to be used by Russian troops were disabled after coordination with SpaceX, a step that Ukrainian commanders later said hurt Russian assaults. Whether anything similar is behind the latest reports is unclear, which is why Kyiv is asking for answers.
Ukraine is already looking at backups. Defense tech company Stetman is developing its own satellite system, UASAT-NANO, and officials in Europe have discussed alternatives to Starlink since early 2025, though none match its scale yet.
Elon Musk breaks his silence on the Starlink impact to Ukraine drones
Tesla opens the Q&A for its biggest earnings call yet
Ukraine says Starlink is cutting out its military drones as Poland calls out Elon Musk
The Pentagon taps Elon Musk to design the battlefield of the future
SpaceX reveals how its 1 Million AI satellite network will work and prevent space collisions
