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SpaceX CEO Elon Musk explains how Starships will return from orbit

SpaceX's Starship spacecraft will eventually have to survive orbital-velocity reentries, a spectacularly difficult feat for large spacecraft. (NASASpaceflight - bocachicagal)

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In the near future, SpaceX wants to begin putting its first two full-scale Starship prototypes through a series of increasingly challenging test flights, eventually culminating in their first Super Heavy-supported orbital launch attempts.

SpaceX CEO Elon Musk took to Twitter over the last 48 or so hours to answer a number of questions about how exactly Starship is meant to make it through orbital reentries – by far the most strenuous period for the ship and without a doubt the single most challenging engineering problem SpaceX must tackle.

Starship glows from heating as it reenters Earth’s atmosphere in this official render. (SpaceX)

Discussed yesterday on Teslarati, SpaceX technicians began the process of attaching numerous Tesla Model S/X battery packs to a subcomponent that will eventually be installed inside Starship Mk1’s nose, offering a storage capacity of up to 400 kWh. The need for all that power (Crew Dragon relies on a few-kWh battery) is directly related to Starship Mk1’s methods of reentry and recovery, recently described in detail by Elon Musk.

As noted above, ~400 kWh of batteries are needed to power the electric motors that will actuate Starship’s massive control surfaces – two large aft wings and two forward canards/fins. According to Musk, Starship’s “stability is controlled by (very) rapid movement of rear & fwd fins during entry & landing”, meaning that the spacecraft will need to constantly tweak its control surfaces to remain in stable flight.

This official graphic covers Starship’s exotic method of flight and landing. (SpaceX)

By far the biggest challenge SpaceX faces is ensuring that Starship can survive numerous orbital-velocity reentries with little to no wear and tear, a necessity for Starship to be cost-effective. In Low Earth Orbit (LEO), Starship will be traveling no less than 7.8 km/s (Mach 23, 17,500 mph) at the start of atmospheric reentry. In simple terms, the process of slowing from orbital velocity to landing on Earth involves turning the vast majority of that kinetic energy into heat. As Musk noted yesterday, this reality is just shy of unavoidable but there is some flexibility in terms of how quickly one wants to convert that energy into heat.

The fastest route to Earth would involve diving straight into the atmosphere, dramatically increasing peak heating on a spacecraft’s surface to the point that extremely exotic heat shields and thermal protections systems become an absolute necessity. SpaceX wants to find a middle ground with Starship in which the spacecraft uses its aerodynamic control surfaces and body to generate lift, slowly and carefully lowering itself into Earth’s atmosphere over a period of 15+ minutes. Musk notes that this dramatically lessens peak heating at the cost of increasing the overall amount of energy Starship has to dissipate, a bit like cooking something in the oven at 300 degrees for 30 minutes instead of 600 degrees for 10 minutes.

To an extent, Starship’s reentry profile is actually quite similar to NASA’s now-retired Space Shuttle, which took approximately 30 minutes to go from its reentry burn to touchdown. Per the above infographic, it looks like Starship will take approximately 20 minutes from orbit to touchdown, owing to a dramatically different approach once it reaches slower speeds. Originally described by Musk in September 2018 and again in recent weeks, Starship will essentially stall itself until its forward velocity is nearly zero, after which the giant spacecraft will fall belly-down towards the Earth, using its wings and fins to maneuver like a skydiver. The Space Shuttle landed on a runway like a (cement-encased) glider.

This unusual approach allows SpaceX to sidestep the need for huge wings, preventing Starship from wasting far more mass on aerodynamic surfaces it will rarely need. The Space Shuttle is famous for its massive, tile-covered delta wing and the leading-edge shielding that partially contributed to the Columbia disaster. However, it’s a little-known fact that the wing’s size and shape were almost entirely attributable to US Air Force demands for cross-range performance, meaning that the military wanted Shuttles to be able to travel 1000+ miles during reentry and flight. This dramatically constrained the Shuttle’s design and was never once used for its intended purpose.

Space Shuttle Endeavor shows off its main heat shield during an on-orbit inspection in August 2007. (NASA)

SpaceX thankfully doesn’t have its own “US Air Force” stand-in making highly consequential demands (aside from Elon Musk ?). Instead, Starship will continue the SpaceX tradition of vertical landing, falling straight down – a bit like a skydiver (or a brick) – on its belly and flipping itself over with fins and thrusters for a propulsive vertical landing. In this way, Starship doesn’t have to be a brick forced to fly, like the Shuttle was – it just needs to be able to stably fall and quickly flip itself from a horizontal to vertical orientation.

Additionally, Starship is built almost entirely out of steel, whereas the Shuttle relied on an aluminum alloy and needed thermal protection over every square inch of its hull. Steel melts at nearly twice the temperature of the Shuttle’s alloy, meaning that Starship will (hopefully) be able to get away with nothing more than ceramic tiles on its windward half, saving mass, money, and time. Once Starship completes its first 20 km (12.5 mi) flight test(s), currently scheduled no earlier than mid-October, SpaceX will likely turn its focus on verifying Starship’s performance at hypersonic speeds, ultimately culminating in its first orbital-velocity reentries.

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Eric Ralph is Teslarati's senior spaceflight reporter and has been covering the industry in some capacity for almost half a decade, largely spurred in 2016 by a trip to Mexico to watch Elon Musk reveal SpaceX's plans for Mars in person. Aside from spreading interest and excitement about spaceflight far and wide, his primary goal is to cover humanity's ongoing efforts to expand beyond Earth to the Moon, Mars, and elsewhere.

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Tesla Cybercab spotted with interesting charging solution, stimulating discussion

The port is located in the rear of the vehicle and features a manual door and latch for plug-in, and the video shows an employee connecting to a Tesla Supercharger.

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Credit: What's Inside | X

Tesla Cybercab units are being tested publicly on roads throughout various areas of the United States, and a recent sighting of the vehicle’s charging port has certainly stimulated some discussions throughout the community.

The Cybercab is geared toward being a fully-autonomous vehicle, void of a steering wheel or pedals, only operating with the use of the Full Self-Driving suite. Everything from the driving itself to the charging to the cleaning is intended to be operated autonomously.

But a recent sighting of the vehicle has incited some speculation as to whether the vehicle might have some manual features, which would make sense, but let’s take a look:

The port is located in the rear of the vehicle and features a manual door and latch for plug-in, and the video shows an employee connecting to a Tesla Supercharger.

Now, it is important to remember these are prototype vehicles, and not the final product. Additionally, Tesla has said it plans to introduce wireless induction charging in the future, but it is not currently available, so these units need to have some ability to charge.

However, there are some arguments for a charging system like this, especially as the operation of the Cybercab begins after production starts, which is scheduled for April.

Wireless for Operation, Wired for Downtime

It seems ideal to use induction charging when the Cybercab is in operation. As it is for most Tesla owners taking roadtrips, Supercharging stops are only a few minutes long for the most part.

The Cybercab would benefit from more frequent Supercharging stops in between rides while it is operating a ride-sharing program.

Tesla wireless charging patent revealed ahead of Robotaxi unveiling event

However, when the vehicle rolls back to its hub for cleaning and maintenance, standard charging, where it is plugged into a charger of some kind, seems more ideal.

In the 45-minutes that the car is being cleaned and is having maintenance, it could be fully charged and ready for another full shift of rides, grabbing a few miles of range with induction charging when it’s out and about.

Induction Charging Challenges

Induction charging is still something that presents many challenges for companies that use it for anything, including things as trivial as charging cell phones.

While it is convenient, a lot of the charge is lost during heat transfer, which is something that is common with wireless charging solutions. Even in Teslas, the wireless charging mat present in its vehicles has been a common complaint among owners, so much so that the company recently included a feature to turn them off.

Production Timing and Potential Challenges

With Tesla planning to begin Cybercab production in April, the real challenge with the induction charging is whether the company can develop an effective wireless apparatus in that short time frame.

It has been in development for several years, but solving the issue with heat and energy loss is something that is not an easy task.

In the short-term, Tesla could utilize this port for normal Supercharging operation on the Cybercab. Eventually, it could be phased out as induction charging proves to be a more effective and convenient option.

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Tesla confirms that it finally solved its 4680 battery’s dry cathode process

The suggests the company has finally resolved one of the most challenging aspects of its next-generation battery cells.

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tesla 4680
Image used with permission for Teslarati. (Credit: Tom Cross)

Tesla has confirmed that it is now producing both the anode and cathode of its 4680 battery cells using a dry-electrode process, marking a key breakthrough in a technology the company has been working to industrialize for years. 

The update, disclosed in Tesla’s Q4 and FY 2025 update letter, suggests the company has finally resolved one of the most challenging aspects of its next-generation battery cells.

Dry cathode 4680 cells

In its Q4 and FY 2025 update letter, Tesla stated that it is now producing 4680 cells whose anode and cathode were produced during the dry electrode process. The confirmation addresses long-standing questions around whether Tesla could bring its dry cathode process into sustained production.

The disclosure was highlighted on X by Bonne Eggleston, Tesla’s Vice President of 4680 batteries, who wrote that “both electrodes use our dry process.”

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Tesla first introduced the dry-electrode concept during its Battery Day presentation in 2020, pitching it as a way to simplify production, reduce factory footprint, lower costs, and improve energy density. While Tesla has been producing 4680 cells for some time, the company had previously relied on more conventional approaches for parts of the process, leading to questions about whether a full dry-electrode process could even be achieved.

4680 packs for Model Y

Tesla also revealed in its Q4 and FY 2025 Update Letter that it has begun producing battery packs for certain Model Y vehicles using its in-house 4680 cells. As per Tesla: 

“We have begun to produce battery packs for certain Model Ys with our 4680 cells, unlocking an additional vector of supply to help navigate increasingly complex supply chain challenges caused by trade barriers and tariff risks.”

The timing is notable. With Tesla preparing to wind down Model S and Model X production, the Model Y and Model 3 are expected to account for an even larger share of the company’s vehicle output. Ensuring that the Model Y can be equipped with domestically produced 4680 battery packs gives Tesla greater flexibility to maintain production volumes in the United States, even as global battery supply chains face increasing complexity.

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Tesla Giga Texas to feature massive Optimus V4 production line

This suggests that while the first Optimus line will be set up in the Fremont Factory, the real ramp of Optimus’ production will happen in Giga Texas.

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Credit: Tesla/YouTube

Tesla will build Optimus 4 in Giga Texas, and its production line will be massive. This was, at least, as per recent comments by CEO Elon Musk on social media platform X.  

Optimus 4 production

In response to a post on X which expressed surprise that Optimus will be produced in California, Musk stated that “Optimus 4 will be built in Texas at much higher volume.” This suggests that while the first Optimus line will be set up in the Fremont Factory, and while the line itself will be capable of producing 1 million humanoid robots per year, the real ramp of Optimus’ production will happen in Giga Texas. 

This was not the first time that Elon Musk shared his plans for Optimus’ production at Gigafactory Texas. During the 2025 Annual Shareholder Meeting, he stated that Giga Texas’ Optimus line will produce 10 million units of the humanoid robot per year. He did not, however, state at the time that Giga Texas would produce Optimus V4. 

“So we’re going to launch on the fastest production ramp of any product of any large complex manufactured product ever, starting with building a one-million-unit production line in Fremont. And that’s Line one. And then a ten million unit per year production line here,” Musk stated. 

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How big Optimus could become

During Tesla’s Q4 and FY 2025 earnings call, Musk offered additional context on the potential of Optimus. While he stated that the ramp of Optimus’ production will be deliberate at first, the humanoid robot itself will have the potential to change the world. 

“Optimus really will be a general-purpose robot that can learn by observing human behavior. You can demonstrate a task or verbally describe a task or show it a task. Even show it a video, it will be able to do that task. It’s going to be a very capable robot. I think long-term Optimus will have a very significant impact on the US GDP. 

“It will actually move the needle on US GDP significantly. In conclusion, there are still many who doubt our ambitions for creating amazing abundance. We are confident it can be done, and we are making the right moves technologically to ensure that it does. Tesla, Inc. has never been a company to shy away from solving the hardest problems,” Musk stated. 

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