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Elon Musk’s SpaceX AMA: Living on Mars, Spaceship Info, Timeline
SpaceX CEO Elon Musk hosted a Reddit AMA (Ask Me Anything) earlier this afternoon and spent several hours drinking whiskey, trolling the audience, answering some great questions, and generally having a blast. He revealed a vast array of fascinating new details about SpaceX’s giant new rocket (BFR), its upper stage spaceship (BFS), and much more.
All of Musk’s answers from the AMA have been collated and organized by category below. You’ll want to shy away from the AMA page itself, currently clocking in at more 10,000 comments.
When useful, particularly dense and technical responses have been summarized in italics for a broader audience.
Living on Mars
Q: Obviously there will be an extreme amount of care put into what is sent on the first missions, and the obvious answer of “Solar Panels” and “Fuel Production Equipment” is included, but what else?
A (Elon): Our goal is get you there and ensure the basic infrastructure for propellant production and survival is in place. A rough analogy is that we are trying to build the equivalent of the transcontinental railway. A vast amount of industry will need to be built on Mars by many other companies and millions of people.
Q: Does your Mars city feature permanently anchored BFS spaceships?
A (Elon): Wouldn’t read too much into that illustration
The aforementioned Martian city. Spaceships can be seen near the center. (SpaceX)
Q: Have any candidate landing sites for the Mars base been identified?
A (Elon): Landing site needs to be low altitude to maximize aero braking, be close to ice for propellant production and not have giant boulders. Closer to the equator is better too for solar power production and not freezing your ass off.
Q: Who will design and build the ISRU system for the propellant depot, and how far along is it?
A (Elon): SpaceX. Design is pretty far along. It’s a key part of the whole system.
Without ISRU (In-Situ Resource Utilization), BFS is unlikely to ever be able to take humans to Mars affordably enough to enable large colonies. This news is thus of huge importance, and suggests that SpaceX will be able to focus on developing BFR and BFS near-term.
Another hypothetical SpaceX city on Mars. Bases will need to be located near water resources. (SpaceX)
SpaceX Big F** Spaceship (BFS)
Q: Will the BFS landing propellants have to be actively cooled on the long trip to Mars?
A (Elon): The main tanks will be vented to vacuum, the outside of the ship is well insulated (primarily for reentry heating) and the nose of the ship will be pointed mostly towards the sun, so very little heat is expected to reach the header tanks. That said, the propellant can be cooled either with a small amount of evaporation. Down the road, we might add a cryocooler.
A (Elon): exactly (while methane could be kept in its liquid form solely through high pressure storage, the pressures required are immense and would require tanks that would be far too heavy for a rocket’s second stage.
Cold liquid oxygen and methane will unavoidably warm up over time, eventually returning to their gaseous forms if allowed. SpaceX’s solution for BFS, which will spend several months between Earth and Mars, is to rely on the Ship’s already great insulation, as well as minimal evaporative cooling (similar to how swamp coolers work).
Q: Will the BFS heat shield be mounted on the skin, or embedded?
A (Elon): The heat shield plates will be mounted directly to the primary tank wall. That’s the most mass efficient way to go. Don’t want to build a box in box.
Dragon 2’s PICA-X heat shield can be seen on the right. BFS’s heat shield will be made of the same material, albeit on a much larger scale. (SpaceX)
Q: Can the BFS delta wings and heat shield be removed for deep space missions?
A (Elon): Wouldn’t call what BFS has a delta wing. It is quite small (and light) relative to the rest of the vehicle and is never actually used to generate lift in the way that an aircraft wing is used.
Its true purpose is to “balance out” the ship, ensuring that it doesn’t enter engines first from orbit (that would be really bad), and provide pitch and yaw control during reentry.
Q: Why is the 2017 BFS spaceship largely cylindrical?
A (Elon): Best mass ratio is achieved by not building a box in a box. The propellant tanks need to be cylindrical to be remotely mass efficient and they have to carry ascent load, so lowest mass solution is just to mount the heat shield plates directly to the tank wall.
For a rocket, mass ratio refers to its weight with a full load of propellant divided by its weight while completely empty. The lighter a rocket’s structure, the more mass it can lift into a given orbit.
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- SpaceX’s conceptual Interplanetary Transport System from 2016 was considerably larger and more structurally complex than 2017’s BFR. (SpaceX)
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- The relatively cylindrical BFS reduces complexity and lowers weight. (SpaceX)
Q: How does the BFS achieve vertical stabilization, without a tail?
A (Elon): Tails are lame
A (Elon): +1 (The space shuttle’s vertical stabilizer was completely useless for most of the reentry profile, as it was in complete aerodynamic shadow. I think it’s clear a craft doesn’t need one for reentry, only for subsonic gliding, which BFS doesn’t really do.)
BFS doesn’t need a tail because tails add weight, are of little use during orbital reentry, and BFS is not intended to glide.
Q: Why was the number of BFS landing legs increased from 3 to 4?
A (Elon): Because 4
A (Elon): Improves stability in rough terrain
Q: How is the radiation shielding in the ITS?
A (Elon): Ambient radiation damage is not significant for our transit times. Just need a solar storm shelter, which is a small part of the ship. Buzz Aldrin is 87.
While radiation fearmongers may balk at this statement, it is to some extent true. The risks from radiation (PDF) for a six month journey in deep space are approximately similar to several dozen CT scans, while two years spent on the surface of Mars with little to no shielding would result in about the same amount of exposure. Underground habitats could alleviate a considerable amount of the risk from living on Mars’ surface.
The issues and dangers posed by radiation ought not be trivialized but they can be dealt with, particularly if BFR can deliver massive payloads to the planet.
Q: Why was the location and shape of the BFS header/landing tanks changed?
A (Elon): The aspiration by the change was to avoid/minimize plumbing hell, but we don’t super love the current header tank/plumbing design. Further refinement is likely.
Header tanks refer to smaller tanks contained within the main propellant tanks that are used to ignite engines in microgravity. It’s easier to pressurize or simply fill the smaller tanks than it is to do so with the massive main tanks.
BFS’ header tanks circled in red. (SpaceX)
BFS Tanker
Q: Will the BFS tanker’s payload section be empty, or include extra propellant tanks?
A (Elon): At first, the tanker will just be a ship with no payload. Down the road, we will build a dedicated tanker that will have an extremely high full to empty mass ratio (warning: it will look kinda weird).
Using one version of the BFS as both a tanker and ship will streamline the initial development process for the rocket.
Two Spaceships docked for refuelling. (SpaceX)
Q: Will the BFS tanker ships (have to) do a hoverslam landing?
A (Elon): Landing will not be a hoverslam, depending on what you mean by the “slam” part. Thrust to weight of 1.3 will feel quite gentle. The tanker will only feel the 0.3 part, as gravity cancels out the 1. Launch is also around 1.3 T/W, so it will look pretty much like a launch in reverse….
BFS will land relatively gently, and BFR’s liftoff will also be gentle.
Development schedule
Q: With the first two cargo missions scheduled to land on Mars in 2022, what kind of development progress can we expect to see from SpaceX in the next 5 or so years leading up to the maiden flight?
Will we see BFS hops or smaller test vehicles similar to Grasshopper/F9R-Dev? Facilities being built? Propellant plant testing? etc. etc.
A (Elon): A lot. Yes, yes, and yes.
A (Elon): Will be starting with a full-scale Ship doing short hops of a few hundred kilometers altitude and lateral distance. Those are fairly easy on the vehicle, as no heat shield is needed, we can have a large amount of reserve propellant and don’t need the high area ratio, deep space Raptor engines.
Next step will be doing orbital velocity Ship flights, which will need all of the above. Worth noting that BFS is capable of reaching orbit by itself with low payload, but having the BF Booster increases payload by more than an order of magnitude. Earth is the wrong planet for single stage to orbit. No problemo on Mars.
The first real tests of the BFR will be done by hopping a full-scale BFS “several hundred kilometers”. BFS is capable of launching itself and a tiny payload into orbit, but the utility is limited on Earth. On Mars, BFS will be far more capable as a single stage to orbit (SSTO) launch vehicle.
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- F9R-dev, used to test vertical take off and landing for Falcon 9. BFR will go through a similar program with its spaceship upper stage prior to orbital missions. (Steve Jurvetson)
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- F9R sadly suffered a software bug and self-destructed in 2014, but SpaceX had already learned most of what it needed to begin Falcon 9 recoveries. (Steve Jurvetson)
Raptor and rocket propulsion
Q: Why was Raptor thrust reduced from ~300 tons-force to ~170 tons-force?
A (Elon): We chickened out. The engine thrust dropped roughly in proportion to the vehicle mass reduction from the first IAC talk. In order to be able to land the BF Ship with an engine failure at the worst possible moment, you have to have multiple engines. The difficulty of deep throttling an engine increases in a non-linear way, so 2:1 is fairly easy, but a deep 5:1 is very hard. Granularity is also a big factor. If you just have two engines that do everything, the engine complexity is much higher and, if one fails, you’ve lost half your power. Btw, we modified the BFS design since IAC to add a third medium area ratio Raptor engine partly for that reason (lose only 1/3 thrust in engine out) and allow landings with higher payload mass for the Earth to Earth transport function.
The Raptor engine’s maximum thrust has been decreased mainly because the size of the rocket decreased, from 12m to 9m in diameter. For redundancy’s sake, SpaceX has added a third central engine to the spaceship, versus the two engines mentioned at the 2017 IAC.
BFS’ delta “wings” from the rear of the ship. Also shown are the Raptors, with the two in the center now reportedly expanded to three engines. (SpaceX)
Q: Will the BFR autogenous pressurization system be heat exchanger based?
A (Elon): We plan to use the Incendio spell from Harry Potter
A (Elon): But, yes and probably
Autogenous pressurization refers to the method of propellant tank pressurization used. In microgravity conditions, tanks must be pressurized to keep fuel flowing to the engines and to improve the density of the fuel. While Falcon 9 currently uses high-pressure helium, ITS and now BFR have been designed to use the actual propellant in their tanks (methane and oxygen) for pressurization. This reduces the number of failure modes on BFR and improves the spaceship’s payload capabilities.
Q: Will the BFS methalox control thrusters be derived from Raptor or from SuperDraco engines?
A (Elon): The control thrusters will be closer in design to the Raptor main chamber than SuperDraco and will be pressure-fed to enable lowest possible impulse bit (no turbopump spin delay).
Like Falcon 9, BFR will need gas thrusters (RCS, reaction control system) to control its orientation (and refuel) while in microgravity conditions. While Falcon uses cold nitrogen gas thrusters, BFR will utilize the propellant it is already carrying for Raptor, methane and oxygen. Again, the goal of this is to reduce complexity.
Q: Could you update us on the status of scaling up the Raptor prototype to the final size?
A (Elon): Thrust scaling is the easy part. Very simple to scale the dev Raptor to 170 tons.
The flight engine design is much lighter and tighter, and is extremely focused on reliability. The objective is to meet or exceed passenger airline levels of safety. If our engine is even close to a jet engine in reliability, has a flak shield to protect against a rapid unscheduled disassembly and we have more engines than the typical two of most airliners, then exceeding airline safety should be possible.
That will be especially important for point to point journeys on Earth. The advantage of getting somewhere in 30 mins by rocket instead of 15 hours by plane will be negatively affected if “but also, you might die” is on the ticket.
SpaceX’s subscale Raptor, the one seen in videos and photos of it firing, is understood to be a bit more than half the size of the operational engine described at IAC 2017. Increasing the scale of the engine is not the difficult aspect of development. Rather, optimization, weight reduction, and extreme reusability are the main sources of difficulty needed before Raptor is flight-ready. This reusability is central to the goal of reliable and rapid reuse of orbital-class rockets.
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- SpaceX revealed this stunning photo of Raptor’s first (partial) hot-fire test the night before Musk’s talk at Guadalajara. (SpaceX)
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- SpaceX’s subscale Raptor engine has completed more than 1200 seconds of testing in less than two years. (SpaceX)
Q: Can BFS vacuum-Raptors be fired at sea level pressure?
A: The “vacuum” or high area ratio Raptors can operate at full thrust at sea level. Not recommended.
Put simply, vacuum nozzles do not like to operate in an atmosphere.
Mars communications
Q: Does SpaceX have any interest in putting more satellites in orbit around Mars (or even rockets) for internet/communications before we get feet on the ground? Or are the current 5-6 active ones we have there sufficient?
A (Elon): Yes
Q: Also will there be some form of an internet or communications link with Earth? Is SpaceX going to be in charge of putting this in or are you contracting some other companies?
A (Elon): If anyone wants to build a high bandwidth comm link to Mars, please do.
Taken side by side, this likely indicates that SpaceX will develop a high-bandwidth Mars-Earth communications link if nobody else does, but that they would logical prefer that someone else builds that infrastructure beforehand.
Q: The concept of an internet connection on Mars is kinda awesome. You could theoretically make an internet protocol that would mirror a subset of the internet near Mars. A user would need to queue up the parts of the internet they wanted available and the servers would sync the relevant data.
A (Elon): Nerd
A (Elon): But, yes, it would make sense to strip the headers out and do a UDP-style feed with extreme compression and a CRC check to confirm the packet is good, then do a batch resend of the CRC-failed packets. Something like that. Earth to Mars is over 22 light-minutes at max distance.
A (Elon): 3 light-minutes at closest distance. So you could Snapchat, I suppose. If that’s a thing in the future.
The communication delay between Earth and Mars (at least several minutes one-way) will prevent any Martian habitats from simply integrating with Earth’s Internet. The delay will require some sort of mediation. As an example, a user on Mars could select the websites they want to browse or videos they want to watch beforehand, and they would be available between several minutes and an hour later.
SpaceX’s Starlink satellite constellation efforts could provide the company with valuable experience that can be applied around Mars. (unofficial logo by Eric Ralph)
Boring!
Q: Boring question about Mars:
A (Elon): More boring!
Miscellaneous silliness
Q: This is one bizarre AMA so far…
A (Elon): Just wait…
Q: i feel like thats a threat. “just wait. it will get way more bizarre than that. let me finish my whiskey”
A (Elon): How did you know? I am actually drinking whiskey right now. Really.
…No comment…
All things considered, this was a wildly successful AMA. Elon clearly had a whole lot of fun, the audience got lightheartedly trolled, and SpaceX fans will undoubtedly be chewing over the technical details he elucidated for weeks to come. Special thanks are owed to the subreddit /r/SpaceX and user /u/_Rocket_, who together managed to flood the AMA with an array of intelligent, pointed, and reasonable questions, at least ten of which were answered by Musk.
Elon Musk
SpaceX is quietly becoming the U.S. Military’s only reliable rocket
Space Force drops ULA for SpaceX on GPS launch after Vulcan rocket anomaly investigation halts flights.
The U.S. Space Force announced today it is switching an upcoming GPS III satellite launch from United Launch Alliance’s Vulcan rocket to a SpaceX Falcon 9, a move that is as much a reflection of Vulcan’s mounting problems as it is a validation of SpaceX’s growing dominance in national security space launch. The GPS III Space Vehicle 09, originally contracted to fly on Vulcan this month, will now target a late April liftoff on Falcon 9, marking the fourth consecutive GPS III satellite the Space Force has moved to SpaceX after contracts were originally awarded to ULA.
The immediate trigger is a solid rocket motor anomaly that occurred on February 12 during Vulcan’s USSF-87 mission. Although the payloads reached orbit and ULA declared the mission successful, the company characterized the malfunction as a “significant performance anomaly” and has since paused all military launches on Vulcan pending a root cause investigation.
“With this change, we are answering the call for rapid delivery of advanced GPS capability while the Vulcan anomaly investigation continues,” said Systems Delta 81 Commander Col. Ryan Hiserote. “We are once again demonstrating our team’s flexibility and are fully committed to leverage all options available for responsive and reliable launch for the Nation.”
The broader reality is that SpaceX’s reliability record and launch cadence have made it the path of least resistance for the Pentagon, and bodes well with Elon Musk’s plans to IPO SpaceX sometime this year. Its Falcon 9 is the most flight-proven rocket in history, and the Space Force’s Rapid Response Trailblazer program was specifically designed to enable exactly this kind of provider swap for GPS missions, and effectively building SpaceX’s flexibility into the national security launch architecture by design.
For ULA, the stakes are existential. The company entered 2026 with aspirations of finally turning a corner after years of Vulcan delays, with interim CEO John Elbon pointing to a backlog of over 80 missions as reason for optimism. Meanwhile, SpaceX’s contracts with the Space Force have given it a formal pathway to take on even more national security launches going forward.
The significance of today’s announcement extends beyond one satellite swap. It reinforces that America’s most critical space infrastructure, including GPS, missile warning, and beyond, is increasingly dependent on a single commercial provider.
News
Tesla Full Self-Driving gets huge breakthrough on European expansion
All documentation for UN R-171 approval and Article 39 exemptions has been submitted, with RDW now conducting its internal review. Approval in the Netherlands is expected on April 10, shifted from the original March 20 target, following 18 months of rigorous collaboration.
Tesla Full Self-Driving has gotten a huge breakthrough as the company is still planning big things for its European expansion, hoping to bring the impressive platform into the continent after years of attempts.
Tesla Europe has announced a major breakthrough: the company has officially completed the final vehicle testing phase for Full Self-Driving (Supervised) in partnership with the Dutch vehicle authority RDW.
All documentation for UN R-171 approval and Article 39 exemptions has been submitted, with RDW now conducting its internal review. Approval in the Netherlands is expected on April 10, shifted from the original March 20 target, following 18 months of rigorous collaboration.
Together with RDW, we have officially completed the final vehicle testing phase for Full Self-Driving (Supervised) and have submitted all documentation required for the UN R-171 approval + Article 39 exemptions. The RDW team is now reviewing the documentation and test results…
— Tesla Europe, Middle East & Africa (@teslaeurope) March 20, 2026
The process has been exhaustive. Tesla said it has logged more than 1.6 million kilometers of FSD (Supervised) testing on European roads, conducted over 13,000 customer ride-alongs, executed 4,500+ track test scenarios, produced thousands of pages of documentation covering 400+ compliance requirements, and completed dozens of independent safety studies.
The company expressed pride in the partnership and anticipation of bringing the feature to “patient EU customers” soon after approval.
Europe’s regulatory landscape has presented steep challenges for Tesla’s advanced driver-assistance systems. The EU enforces some of the world’s strictest safety standards under the United Nations Economic Commission for Europe framework, particularly UN Regulation 171 on Driver Control Assistance Systems.
Unlike the more permissive U.S. environment, European rules historically limited system-initiated maneuvers, required constant driver supervision, and demanded country-by-country or bloc-wide exemptions. Tesla faced repeated delays, with initial February 2026 targets pushed back amid RDW’s insistence that safety, not public or corporate pressure, would govern timelines.
Tesla Europe builds momentum with expanding FSD demos and regional launches
A former Tesla executive warned in 2024 that certain regulatory elements could slip to 2028, highlighting bureaucratic hurdles, extensive audits, and the need for harmonized data privacy and liability frameworks across fragmented member states.
Yet progress is accelerating. Amendments to UN R-171 adopted in 2025 now permit hands-free highway lane changes and other automated features, clearing technical barriers. Once the Netherlands grants national approval, mutual recognition allows other EU countries to adopt it immediately, potentially leading to an EU-wide rollout by summer 2026.
This European breakthrough is part of Tesla’s broader push into foreign markets. Full Self-Driving (Supervised) is already live in the United States and expanding rapidly.
In China, where partial approvals exist, CEO Elon Musk has targeted full rollout around the same February–March 2026 window, despite lingering data-security reviews.
Additional markets, including the UAE, are slated for early 2026 launches. These expansions are critical as Tesla seeks to monetize software amid softening EV demand globally.
For European Tesla owners, the wait appears nearly over. Approval would unlock advanced autonomy features that have long been available elsewhere, marking a pivotal step in Tesla’s global autonomy ambitions and reinforcing its commitment to navigating complex international regulations.
Elon Musk
Tesla’s $2.9 billion bet: Why Elon Musk is turning to China to build America’s solar future
Tesla looks to bring solar manufacturing to the US, with latest $2.9 billion bet to acquire Chinese solar equipment.
Tesla is reportedly in talks to purchase $2.9 billion worth of solar manufacturing equipment from a group of Chinese suppliers, including Suzhou Maxwell Technologies, which is the world’s largest producer of screen-printing equipment used in solar cell production. According to Reuters sources, the equipment is expected to be delivered before autumn and shipped to Texas, where Tesla plans to anchor its next phase of domestic solar production.
The move is a direct extension of a vision Elon Musk has been building for months. At the World Economic Forum in Davos this past January, Musk announced that both Tesla and SpaceX were independently working to establish 100 gigawatts of annual solar manufacturing capacity inside the United States. Days later, on Tesla’s Q4 2025 earnings call, he made the ambition concrete: “We’re going to work toward getting 100 GW a year of solar cell production, integrating across the entire supply chain from raw materials all the way to finished solar panels.”
Job postings on Tesla’s website reflect that same target, with language explicitly calling for 100 GW of “solar manufacturing from raw materials on American soil before the end of 2028.”
Tesla job listing for Staff Manufacturing Development Engineer, Solar Manufacturing
The urgency behind the latest solar manufacturing target is rooted in a set of rapidly emerging pressures related to AI and Tesla’s own energy business. U.S. power consumption hit its second consecutive record high in 2025 and is projected to climb further through 2026 and 2027, driven largely by the explosion in AI data centers and the broader electrification of transportation. Tesla’s own energy division, which produces the Megapack utility-scale battery storage system, has been growing rapidly, and solar supply is a critical companion component for the business to scale. Musk has argued that solar is not just a clean energy option but the only one that makes economic sense at the scale AI infrastructure demands.
Tesla lands in Texas for latest Megapack production facility
Ironically, the path to domestic solar independence currently runs through China. Sort of.
Despite Tesla’s stated push to localize its supply chain, mirrored recently by the company’s plan for a $4.3 billion LFP battery manufacturing partnership with LG Energy Solution in Michigan, Tesla still relies on China-based suppliers to keep its cost structure intact.
The $2.9 billion equipment deal underscores a tension Musk himself acknowledged at Davos: “Unfortunately, in the U.S. the tariff barriers for solar are extremely high and that makes the economics of deploying solar artificially high, because China makes almost all the solar.” Building the factory in America requires buying the machinery from the country Tesla is trying to reduce its dependence on.
Tesla named by U.S. Gov. in $4.3B battery deal for American-made cells
The regulatory pathway adds another layer of complexity. Suzhou Maxwell has been seeking export approval from China’s commerce ministry, and it remains unclear how quickly that clearance will come. Still, the market has already reacted, with shares in the Chinese firms reportedly involved in the talks surged more than 7% following the Reuters report that broke the story.
Whether Tesla can hit its 2028 target of 100GW of solar manufacturing remains an open question. Though that scale may seem staggering, especially in such a short timeframe, we know that Musk has a documented history of “always pulling it off” in the face of ambitious deadlines that may slip. But, rest assured – it’ll get done.
SpaceX is quietly becoming the U.S. Military’s only reliable rocket
Tesla Full Self-Driving gets huge breakthrough on European expansion
