SpaceX
SpaceX CEO Elon Musk: Starship prototype to have 3 Raptors and “mirror finish”
Taking to Twitter once more to reveal additional information about SpaceX’s radically changing BFR/Starship prototype program, CEO Elon Musk has made an unexpected visit to the company’s South Texas BFR testing facilities to oversee rapid progress with a low-fidelity hop test prototype of the orbital Starship spacecraft.
Included in a handful of replies that followed the tweeted image, Musk described some of the key advantages of a stainless steel Starship – including mirror-like thermal reflectivity for hot reentries and a “usable” strength-to-mass ratio superior to carbon fiber – as well as features of prototype cousin.
Stainless Steel Starship pic.twitter.com/rRoiEKKrYc
— Elon Musk (@elonmusk) December 24, 2018
While the CEO did imply on Saturday that the Mars-focused Raptor engine had been what he described as “radically redesigned”, Musk’s statement that the Starship hopper will feature three Raptor engines does at least set a lower bound for the ship’s maximum gross takeoff weight when the time comes for it to take flight.
Yes. Radically redesigned Raptor ready to fire next month.
— Elon Musk (@elonmusk) December 22, 2018
While the suggestion that Raptor’s turbopumps (basically fuel pumps) would need at least 100,000 HP per engine seems to indicate that the flight design’s thrust has been appreciably uprated, a past figure of ~2000 kN (450,000 lbf) per engine suggests that Starship V0.1 could weigh as much as an entire Falcon 9 Block 5 rocket (~1.2 million pounds, 550,000 kg) and still having a solid 80-100% of Falcon 9’s liftoff thrust. Put simply, the rocket that appears to be coming together in the boonies of South Texas could rival almost any other liquid fuel rocket booster in service, while still being the testbed for BFR’s upper stage alone.
While it’s ambiguous if several additional comments applied to the Starship prototype, the final product, or both, Musk also indicated that some of the biggest benefits of a shift away from carbon composites to stainless steel would be relative ease with which the material handles extreme heating. Thanks to the fact that stainless steel can ultimately be polished to mirror-like levels of reflectivity and that mirrors are some of the most efficient reflectors of thermal energy (heat), shiny and unpainted steel would ultimately perform far better than carbon composites and could end up requiring “much less” heat shielding for the same performance.
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- ¯\_(ツ)_/¯ (bocachicagal – NASASpaceflight)
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- A conspicuous nosecone appears to have arisen inside SpaceX’s new Boca Chica tent, adjacent to what looks like a water tower with tube legs. (bocachicagal – NASASpaceflight)
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- Boca Chica, 12/23/18. (NASASpaceflight /u/bocachicagal)
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- It remains to be seen if BFR can be made as reusable and reliable as it will need to be to sustainably support interplanetary humans. (SpaceX)
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- Starship – in its 2018 design iteration – seen landing on Mars atop pillars of Raptor flame. (SpaceX)
Perhaps most unintuitive is the fact that steel can apparently beat carbon composites when it comes to usable strength-to-weight ratios at supercool temperatures. According to Musk, steel also performs “vastly better” at high temperatures and appreciably better at room temperatures. A comment made on Saturday may lend additional credence to what seems at face value to contradict basic material intuition – at least some of the stainless steel SpaceX is examing would be a special (presumably SpaceX-engineered) alloy that has undergone what is known as cryogenic treatment, in which metals are subjected to extremely cold conditions to create some seriously unintuitive properties. Ultimately, cold-formed/worked or cryo-treated steel can be dramatically lighter and more wear-resistant than traditional hot-rolled steel.
Usable strength/weight of full hard stainless at cryo is slightly better than carbon fiber, room temp is worse, high temp is vastly better
— Elon Musk (@elonmusk) December 24, 2018
Combined with advanced new alloys and a uniquely strong handle on working with supercool propellant (likely transferable to cold-forming steel), SpaceX and CEO Elon Musk could have a true breakthrough on their hands, especially if it turns out that a great deal of deep thought, analysis, and refinement fed into these “radical” design changes. With Starship Alpha’s hop tests potentially beginning as early as March 2019, we won’t have long to wait to find out.
For prompt updates, on-the-ground perspectives, and unique glimpses of SpaceX’s rocket recovery fleet check out our brand new LaunchPad and LandingZone newsletters!
Elon Musk
Elon Musk’s Biggest Revelations on AI, Robots, and the Future of Work from the Moonshots Podcast
Elon Musk’s appearance on the Moonshots with Peter Diamandis podcast was packed with bold predictions, candid admissions, and surprising tech insights. The nearly three-hour conversation covered everything from artificial intelligence to humanoid robots, geopolitics, and the future of work. Here are the top 10 most intriguing takeaways:
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Aggressive AGI Timeline Predictions
Musk offered a detailed view on when artificial general intelligence (AGI) could emerge, suggesting it may arrive sooner than many expect, emphasizing both transformative potential and risks.
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U.S. vs. China in the AI Race
He discussed the strategic competition between the United States and China over AI development, noting that geopolitical dynamics will shape how and who leads in the next decades.
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Future of Job Markets
Musk touched on how AI and automation could reshape employment, predicting massive boosts in productivity alongside potential disruptions in traditional work structures.
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Clean Energy Transition
A recurring theme was the role of clean energy in future economies, with Musk reiterating the importance of scaling sustainable power generation and storage.
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Humanoid Robots Are Coming
On the podcast, Musk elaborated on Tesla’s work on humanoid robots, hinting at timelines and applications that go beyond factories to general-purpose assistance.
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Tesla Roadster “Last Human-Driven Car”
Outside the core discussion topics, Musk teased features of the upcoming Tesla Roadster — calling it “the best of the last of the human-driven cars” and suggesting safety won’t be its main selling point.
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The Role of AI in Clean Energy and Robotics
Linking AI to both energy optimization and robotics, Musk explained how smarter systems could accelerate decarbonization and task automation across industries.
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U.S. Innovation Leadership
Musk argued that maintaining American leadership in key tech sectors like AI, space, and robotics should be a national priority, with thoughtful policy and investment.
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Job Creation vs. Job Elimination
While acknowledging automation’s disruptive effects, he also outlined scenarios where new industries and opportunities could emerge, particularly in AI, space, and advanced manufacturing.
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Long-Term Vision for Humanity
Throughout the conversation, Musk revisited his long-term philosophical views — including a belief in humanity’s responsibility to become a multi-planetary and technologically empowered species.
Whether you agree with Musk’s optimism or not, the podcast offers a window into the thinking of one of the most influential figures in tech today, in and why his visions continue to spark debate and inspiration.
Elon Musk
Starlink achieves major milestones in 2025 progress report
Starlink wrapped up 2025 with impressive growth, adding more than 4.6 million new active customers and expanding service to 35 additional countries, territories, and markets.
Starlink wrapped up 2025 with impressive growth, adding more than 4.6 million new active customers and expanding service to 35 additional countries, territories, and markets. The company also completed deployment of its first-generation Direct to Cell constellation, launching over 650 satellites in just 18 months to enable cellular connectivity.
SpaceX highlighted Starlink’s impressive 2025 progress in an extensive report.
Key achievements from Starlink’s 2025 Progress
Starlink connected over 4.6 million new customers with high-speed internet while bringing service to 35 more regions worldwide in 2025. Starlink is now connecting 9.2 million people worldwide. The service achieved this just weeks after hitting its 8 million customer milestone.
Starlink is now available in 155 markets, including areas that are unreachable by traditional ISPs. As per SpaceX, Starlink has also provided over 21 million airline passengers and 20 million cruise passengers with reliable high-speed internet connectivity during their travels.
Starlink Direct to Cell
Starlink’s Direct to Cell constellation, more than 650 satellites strong, has already connected over 12 million people at least once, marking a breakthrough in global mobile coverage.
Starlink Direct to Cell is currently rolled out to 22 countries and 6 continents, with over 6 million monthly customers. Starlink Direct to Cell also has 27 MNO partners to date.
“This year, SpaceX completed deployment of the first generation of the Starlink Direct to Cell constellation, with more than 650 satellites launched to low-Earth orbit in just 18 months. Starlink Direct to Cell has connected more than 12 million people, and counting, at least once, providing life-saving connectivity when people need it most,” SpaceX wrote.
Elon Musk
Starlink passes 9 million active customers just weeks after hitting 8 million
The milestone highlights the accelerating growth of Starlink, which has now been adding over 20,000 new users per day.
SpaceX’s Starlink satellite internet service has continued its rapid global expansion, surpassing 9 million active customers just weeks after crossing the 8 million mark.
The milestone highlights the accelerating growth of Starlink, which has now been adding over 20,000 new users per day.
9 million customers
In a post on X, SpaceX stated that Starlink now serves over 9 million active users across 155 countries, territories, and markets. The company reached 8 million customers in early November, meaning it added roughly 1 million subscribers in under seven weeks, or about 21,275 new users on average per day.
“Starlink is connecting more than 9M active customers with high-speed internet across 155 countries, territories, and many other markets,” Starlink wrote in a post on its official X account. SpaceX President Gwynne Shotwell also celebrated the milestone on X. “A huge thank you to all of our customers and congrats to the Starlink team for such an incredible product,” she wrote.
That growth rate reflects both rising demand for broadband in underserved regions and Starlink’s expanding satellite constellation, which now includes more than 9,000 low-Earth-orbit satellites designed to deliver high-speed, low-latency internet worldwide.
Starlink’s momentum
Starlink’s momentum has been building up. SpaceX reported 4.6 million Starlink customers in December 2024, followed by 7 million by August 2025, and 8 million customers in November. Independent data also suggests Starlink usage is rising sharply, with Cloudflare reporting that global web traffic from Starlink users more than doubled in 2025, as noted in an Insider report.
Starlink’s momentum is increasingly tied to SpaceX’s broader financial outlook. Elon Musk has said the satellite network is “by far” the company’s largest revenue driver, and reports suggest SpaceX may be positioning itself for an initial public offering as soon as next year, with valuations estimated as high as $1.5 trillion. Musk has also suggested in the past that Starlink could have its own IPO in the future.
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