SpaceX
SpaceX CEO Elon Musk says that BFR could cost less to build than Falcon 9
SpaceX CEO Elon Musk believes that there may be a path for the company to ultimately build the massive Starship spacecraft and Super Heavy booster (formerly BFR) for less than Falcon 9/Falcon Heavy, a rocket 3-9 times smaller than BFR.
While it certainly ranks high on the list of wild and wacky things the CEO has said over the years, there may be a few ways – albeit with healthy qualifications – that Starship/Super Heavy production costs could ultimately compare favorably with SpaceX’s Falcon family of launch vehicles. Nevertheless, there are at least as many ways in which the next-gen rocket can (or should) never be able to beat the production cost of what is effectively a far simpler rocket.
This will sound implausible, but I think there’s a path to build Starship / Super Heavy for less than Falcon 9
— Elon Musk (@elonmusk) February 11, 2019
Dirty boosters done dirt cheap
On the one hand, Musk might not necessarily be wrong, especially if one throws the CEO several bones in the interpretation of his brief tweet. BFR at its simplest is going to require a full 38 main rocket engines to achieve its nominal performance goals, 7 on Starship and 31 on Super Heavy. As a dramatically more advanced, larger, and far more complex engine, Raptor will (with very little doubt) cost far more per engine than the relatively simple Merlin 1D. BFR avionics (flight computers, electronics, wiring, harnesses) are likely to be more of a known quantity, meaning that costs will probably be comparable or even lower than Falcon 9’s when measured as a proportion of overall vehicle cost. Assuming that BFR can use the exact same cold gas thruster assemblies currently flying on Falcon 9, that cost should only grow proportionally with vehicle size. Finally, Starship will not require a deployable payload fairing (~10% of Falcon 9’s production cost).
All of those things mean that Starship/Super Heavy will probably be starting off with far better cost efficiency than Falcon 9 was able to, thanks to almost a decade of interim experience both building, flying, and refurbishing the rocket since its 2010 debut. Still, BFR will have to account for entirely new structures like six large tripod fins/wings and their actuators, wholly new thrust structures (akin to Falcon 9’s octaweb) for both stages, and more. Considering Starship on its own, the production of a human-rated spacecraft capable of safely housing dozens of people in space for weeks or months will almost without a doubt rival the cost of airliner production, where a 737 – with almost half a century of production and flight heritage – still holds a price tag of $100-130+ million.
-
- BFR shown to scale with Falcon 1, 9, and Heavy. (SpaceX)
-
- A September 2018 render of Starship (then BFS) shows one of the vehicle’s two hinged wings/fins/legs. (SpaceX)
-
- BFR’s booster, now known as Super Heavy. (SpaceX)
-
- Sadly, this is a not a sight that will greet Falcon 9 booster B1046’s fourth launch – Crew Dragon’s critical In-Flight Abort test. (SpaceX)
Adding one more assumption, the most lenient interpretation of Musk’s tweet assumes that he is really only subjecting the overall structure (sans engines and any crew-relevant hardware) of BFR relative to Falcon 9. In other words, could a ~300-ton stainless steel rocket structure (BFR) cost the same amount or less to fabricate than a ~30-ton aluminum-lithium alloy rocket structure (Falcon 9/Heavy)? From the very roughest of numerical comparisons, Musk estimated the cost of the stainless steel alloys (300-series) to be used for BFR at around $3 per pound ($6.60/kg), while aluminum-lithium alloys used in aerospace (and on Falcon 9) are sold for around $20/lb ($44/kg)*. As such, simply buying the materials to build the basic structures of BFR and Falcon 9 would cost around and $7.5M and $5M, respectively.
Assuming that the process of assembling, welding, and integrating Starship and Super Heavy structures is somehow 5-10 times cheaper, easier, and less labor-intensive, it’s actually not inconceivable that the cost of building BFR’s structure could ultimately compete with Falcon 9 after production has stabilized after the new rocket’s prototyping phase is over and manufacturing processes are mature.
*Very rough estimate, difficult to find a public cost per unit mass from modern Al-Li suppliers
Costs vs. benefits
On the opposite hand, stainless steel rockets do not have a history of being uniquely cost-effective relative to vehicles using alternative materials. The only orbital-class launch vehicles to use stainless steel (and balloon) tanks are the Atlas booster and the Centaur upper stage, with Atlas dating back to the late 1950s and Centaur beginning launches in the early ’60s. Stainless steel Atlas launches ended in 2005 with the final Atlas III mission, while multiple forms of Centaur continue to fly regularly on ULA’s Atlas V and Delta IV.
Based on a 1966 contract between NASA and General Dynamics placed shortly after Centaur’s tortured development had largely been completed, Centaur upper stages were priced around $25M apiece (2018 USD). In 1980, the hardware for a dedicated Atlas-Centaur launch of a ~1500 kg Comstar I satellite to GTO cost the US the 2018 equivalent of a bit less than $40M ($71M including miscellaneous administrative costs) – $22.4M for Centaur and $17.6M for Atlas. For Atlas, the rocket’s airframe (tanks and general structure) was purchased for around $8.5M. That version of Atlas-Centaur (Atlas-SLV3D Centaur-D1A) was capable of lifting around 5100 kg (11,250 lb) into Low Earth Orbit (LEO) and 1800 kg (~4000 lb) to geostationary transfer orbit (GTO), while it stood around 40m (130 ft) tall, had a tank diameter of 3.05m (10 ft), and weighed ~150t (330,000 lb) fully fueled.
-
- Atlas shows off its shiny steel balloon tanks. (SDASM)
-
- The original space-faring Atlas, known as SM-65, seen here with a Mercury space capsule. (NASA)
-
- A Centaur upper stage is pictured here in 1964. (NASA)
-
- Atlas SLV3D is pictured here launching a Comstar I satellite.
-
- A Falcon 9 booster is seen here near the end of its tank welding, just prior to painting. (SpaceX)
-
- An overview of SpaceX’s Hawthorne factory floor in early 2018. (SpaceX)
In a very loose sense, that particular stainless steel Atlas variant was about half as large and half as capable as the first flight-worthy version of Falcon 9 at roughly the same price at launch ($60-70M). What does this jaunt through the history books tell us about the prospects of a stainless steel Starship and Super Heavy? Well, not much. The problem with trying to understand and pick apart official claims about SpaceX’s next-generation launch architecture is quite simple: only one family of rockets in the history of the industry (Atlas) regularly flew with stainless steel propellant tanks, a half-century lineage that completed its final launch in 2005.
Generally speaking, an industrial sample size of more or less one makes it far from easy to come to any particular conclusions about a given technology or practice, and SpaceX – according to CEO Elon Musk – fully intends to push past the state of the art of stainless steel rocket tankage with BFR. Ultimately, American Marietta/Martin Marietta/Lockheed Martin was never able to produce launch vehicle variants of the stainless steel Atlas family at a cost more than marginally competitive with Falcon 9, despite the latter rocket’s use of a far more expensive metal alloy throughout its primary tanks and structure.
At least 10X cheaper
— Elon Musk (@elonmusk) February 11, 2019
At some point, it’s even worth asking whether the per-unit cost of Starship and Super Heavy should be relevant at all to their design and construction, at least within reason. If the goal of BFR is to drastically lower the cost of launch by radically improving the ease of reuse, it would be truly bizarre (and utterly unintuitive) if those goals could somehow be achieved without dramatically raising the cost of initial hardware procurement. Perhaps the best close comparison to BFR’s goals, modern airliners are eyewateringly expensive ($100-500M apiece) as a consequence of the extraordinary reliability, performance, efficiency, and longevity customers and regulatory agencies demand from them, although those costs are admittedly not the absolute lowest they could be in a perfect manufacturing scenario.
At the end of the day, it appears that Musk is increasingly of the opinion that the pivot to stainless steel could ultimately make BFR simultaneously “better, faster, [&] cheaper”. However improbable that may be, if it does turn out to be the case, Starship and Super Heavy could be an unfathomable leap ahead for reliable and affordable access to space. It could also be another case of Musk’s excitement and optimism getting the better of him and hyping a given product well beyond what it ultimately is able to achieve. Time will tell!
Check out Teslarati’s newsletters for prompt updates, on-the-ground perspectives, and unique glimpses of SpaceX’s rocket launch and recovery processes!
News
SpaceX’s Starfall just went from secret to storefront
SpaceX now pitches Starfall missions with 1,000 kg payloads, weeks of microgravity, and Starlink connectivity.
SpaceX has put up a dedicated commercial page for Starfall, its disk shaped reentry capsule, laying out for the first time what customers actually get when they book a flight. The page, live at spacex.com/starfall, pitches “affordable, routine access to microgravity” and invites companies to get in touch about flying manufacturing, research or testing payloads.
The specs are short and specific. Each Starfall mission carries up to 1,000 kg of payload, supplies 1 kW of power and connects through an Ethernet interface. Mission length is tailored to the customer, and the payload stays online the entire time through Starlink, which means researchers can pull data from an experiment while it is still in orbit instead of waiting for splashdown.
SpaceX is launching a secret spacecraft that could change how things are made in space
SpaceX is aiming the service at three markets. Biomedical customers are told they can grow stem cell organoids, replacement tissue and layered biomaterials. Pharmaceutical companies are pitched on protein and small molecule drug crystals, which form smaller and more uniform shapes without gravity driven convection. Materials science rounds out the list, with semiconductors and other next generation materials grown in vacuum and microgravity.
The page also makes clear which rocket SpaceX is counting on. “By launching on Starship, Starfall brings a reliable and scalable cadence previously unavailable to the market,” the company wrote, contrasting weeks of continuous microgravity with the seconds offered by drop towers and parabolic flights. No price or first operational flight date is listed.
The commercial push is a sharp turn from how Starfall started. SpaceX said almost nothing about the capsule ahead of its first flight in June, and nearly everything known came from FAA and FCC filings describing a disk about 10.2 feet wide and 2.5 feet tall that can return 2,200 pounds of cargo. By its second flight on the Bandwagon-5 rideshare in October, Starfall was listed by name on the mission page, though SpaceX still did not say what it carried.
Customers appear to be lining up. SpaceX said in its third quarter results that it signed three commercial Starfall missions during the quarter. On the earnings call, President Gwynne Shotwell described the capsule as providing “routine relatively low cost access to microgravity environments for scientific research, including improving our understanding of diseases like cancer and diabetes,” and said the three new missions would fly on Starship.
The branding effort extends past the website. SpaceX added a Starfall T-shirt to its online store on Monday as part of a batch of new merchandise, giving the program a place next to Starship, Starlink and Starshield in the company’s lineup.
The move also puts SpaceX in more direct competition with companies it launches. Varda Space Industries, which has built much of the in-space manufacturing market so far, flew its W-Series 7 capsule on the same Bandwagon-5 mission as Starfall in October. Varda’s capsules are roughly three times smaller than Starfall, and SpaceX controls the ride to orbit for both.
Starfall’s near term cadence depends on Starship. SpaceX is preparing for Flight 15 after completing static fires of Ship 42 and its Super Heavy booster in late October, and is aiming to catch both stages with the launch tower on that flight.
Elon Musk said weeks ago during SpaceX’s third-quarter earnings call that the company’s Grok Bot, its autonomous AI Agent platform, was showing “the fastest growth of a product” that he’d ever seen in his life.
Now, SpaceXSI is scaling back Grok Bot users’ weekly limits, much to the surprise of those who have relied on it to take away monotonous tasks in their lives.
Elon Musk’s terse November 1 reply on X captured a sharp tension in the early days of agentic AI. Responding to a user who asked for a Grok Bot usage reset after hitting 100 percent with four days still left on the weekly cycle, Musk wrote: “The cost of serving Grok Bot was unsustainably high relative to revenue.”
@DogecoinNorway The cost of serving Grok Bot was unsustainably high relative to revenue
— Elon Musk (@elonmusk) November 1, 2026
The post arrived amid a wave of similar complaints from paying subscribers whose meters had jumped unexpectedly toward or to the limit, sometimes overnight and with little corresponding activity. It also stood in clear contrast to statements Musk had made only days and weeks earlier.
On the SpaceX third-quarter earnings call in mid-to-late October, Musk had described Grok Bot in almost the opposite terms. He called it “the fastest growth of a product that I’ve ever seen in my life” and said he had “never seen anything grow this fast.”
Company figures put paid weekly users at roughly 800,000 earlier in the month, more than doubling over the prior period. Daily active users had climbed from under 100,000 in early September to over 600,000 by late October.
Musk emphasized that the product has no free tier and that users appear to be getting real value beyond what they pay. In other remarks, he noted that usage per user was rising rather than declining, the opposite of the usual decay pattern for new software.
Grok Bot, launched around August, functions as an always-available agent with its own persistent cloud computer; it can schedule, research, shop, browse, and execute multi-step workflows even after the user steps away. Access is bundled into X subscription tiers (roughly $30, $100, and $200 per month) and certain Cursor plans, drawing from shared weekly usage pools whose exact sizes have not been publicly detailed.
The economics of that model are what Musk’s November 1 post put in the spotlight. Agentic systems burn far more compute than ordinary chatbot exchanges. Each task can trigger repeated model calls, tool use, web actions, and sustained background work.
When growth is as rapid as Musk celebrated, the absolute compute bill scales quickly even if average revenue per user stays fixed under flat monthly subscriptions. Industry observers noted the opportunity cost as well: the same GPUs can be rented to other AI labs at higher rates.
A simple back-of-the-envelope comparison circulating after the post illustrated the gap: if every reported daily user paid the top tier, annualized subscription revenue would still be modest relative to the scale of compute infrastructure SpaceX is building and leasing to companies like Anthropic.
Some users also reported possible dashboard anomalies around the same period, though Musk’s framing treated the underlying cost-revenue imbalance as the core issue rather than a pure metering glitch.
The juxtaposition is the core of this exchange. Within roughly two weeks of publicly framing Grok Bot as an unprecedented success with strong unit economics and no free tier, Musk acknowledged that serving the same product had become unsustainable relative to the revenue it generates.
For the broader industry, the episode underscores a structural challenge of the agent era: demand is real and growing faster than many expected, yet the cost of fulfilling that demand through always-on, multi-step agents can outrun subscription pricing before companies can adjust limits, introduce metered billing, or raise prices.
Musk’s reply did not promise an immediate reset or higher allowances; it simply stated the constraint. In doing so, it supplied a rare, explicit public data point on the unit economics of a high-profile AI agent just as adoption numbers were still being celebrated as the fastest in Musk’s experience.
The tension between rapid, paid growth and the compute required to deliver it is now on the record.
Elon Musk
Elon Musk calls Earth’s data centers “peanuts” next to what SpaceX is planning in orbit
Elon Musk says SpaceX capex efficiency is underestimated as orbital data centers loom by 2028.
Elon Musk is pushing back on one of the biggest worries hanging over SpaceX stock. In a reply on X on Sunday, Musk said the company’s capital expenditure efficiency is severely underestimated. He was responding to a Milk Road Stocks post citing analyst Kyle Reidhead, who estimates SpaceX will need to spend roughly $470 billion over the next five quarters.
Reidhead built that figure around the target SpaceX set on its third quarter earnings call: 13 gigawatts or more of compute by the end of 2027. In his breakdown, Nvidia captures 83 to 89 percent of the spending. SpaceX ended the quarter with 1.7 GW of nameplate compute and guided to $35 billion to $40 billion in fourth quarter capex, as Teslarati reported.
Musk did not attach a number to his claim, but the earnings call shows the argument. CFO Bret Johnsen said new compute currently pays for itself in under a year at today’s pricing, and Musk said that window could shrink to six months next year. Using that pace, Reidhead argues about $230 billion of the $470 billion could come from operating cash flow and about $60 billion from SpaceX’s roughly $90 billion cash pile, leaving around $180 billion to borrow. Musk confirmed last week that SpaceX had already closed a new $40 billion debt raise to buy GPUs.
The ground buildout is not the end goal. It is what is meant to pay for the move to orbit. Replying on Friday to charts built from Sequoia partner Shaun Maguire’s SpaceX model, Musk wrote that “Terrestrial compute will be peanuts compared to orbital compute,” adding that orbital compute deployed per month “probably exceeds terrestrial around the end of 2028 and then far exceeds it in 2029.”
Maguire’s model shows how steep that path is. It has capex climbing from $88 billion this year to $290 billion in 2027 and $369 billion in 2028, with SpaceX burning $77.8 billion in cash this year and $122.6 billion next year before turning $114.9 billion cash positive in 2028. Musk’s response to the model was, “I think we can do better.”
The orbital half runs through Starmind. SpaceX plans to operate up to 1 million AI satellites flying in clusters of about 10, linked by roughly 10 terabits of bandwidth, with deployment of thousands of units starting as soon as late 2027 out of its Gigasat factory in Bastrop, Texas, according to SpaceX’s space safety page. Musk has said each Starmind spacecraft will carry more than 250 kW of solar power.
Getting there depends on launch volume. Maguire’s model assumes 250 Starship flights in 2028, up from two this year and 38 next year. The nearer test is financial: SpaceX guided to $33 billion to $37 billion in first quarter 2027 revenue, more than double the $14.58 billion it booked in Q3, and Musk reposted that guidance again on Sunday morning.
SpaceX’s Starfall just went from secret to storefront
Grok Bot users hit with weekly limits early, Elon Musk explains what happened
