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SpaceX sends “radically redesigned” Starship engine to Texas for hot-fire tests

As of September 2017, subscale Raptor engines had been cumulatively fired for more than 1200 seconds in just 12 months of testing. (SpaceX)

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7 years ago

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SpaceX has shipped one of the first of a group of Starship engines known as Raptor, described last month by CEO Elon Musk as “radically redesigned”. A culmination of more than 24 months of prototype testing, the first flight-worthy Raptor could be ignited for the first time as early as February.

According to Musk, three of these redesigned Raptors will power the first full-scale BFR prototype, a Starship (upper stage) test article meant to conduct relatively low-altitude, low-velocity hop tests over the southern tip of Texas. Those tests could also begin next month, although a debut sometime in March or April is increasingly likely.

Effectively designed on a blank slate, Raptor began full-scale component-level tests in 2014 at NASA’s Mississippi-based Stennis Space Center, evolving from main injector development to oxygen preburner hot-fires in 2015. Soon after Raptor’s prototype preburner design was validated at Stennis, SpaceX moved testing to its privately-owned and operated facilities in McGregor, Texas, where Raptor static fire testing has remained since.

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Just days before CEO Elon Musk was scheduled to reveal SpaceX’s next-generation rocket (BFR, formerly known as the Interplanetary Transport System or ITS) in September 2016, he announced in a tweet that propulsion engineers and technicians had successful hot-fired an integrated Raptor prototype – albeit subscale – for the first time ever. Just 12 months later, Musk once again took to the stage to announce an update to BFR’s design, while also revealing that prototype Raptor engines had already completed more than 1200 seconds (20 minutes) of cumulative hot-fire tests, an extremely aggressive and encouraging rate of progress for such a new engine.

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Although Raptor undoubtedly borrows heavily from much of the same expertise that designed Merlin 1 and operated and improved it for years, that is roughly where the similarities between Raptor and M1D end. M1D, powered by refined kerosene (RP-1) and liquid oxygen, uses a combustion cycle (gas-generator) that is relatively simple and reliable at the cost of engine efficiency, although SpaceX propulsion expertise still managed to give M1D the highest thrust-to-weight ratio of any liquid rocket engine ever flown. Still, measured by ISP (instantaneous specific impulse), M1D’s inefficient kerolox gas-generator cycle ultimately means that the engine simply can’t compete with the performance of engines with more efficient propellants and combustion cycles.

While SpaceX’s Falcon 9 and Heavy rockets – powered by Merlin 1D and Merlin Vacuum – are more than adequate in and around Earth orbit, a far more efficient engine was needed for the company to enable the sort of interplanetary colonization Musk had in mind when he created SpaceX. Raptor was the answer. Ultimately settling on liquid methane and oxygen (methalox) as the propellant and a full-flow staged-combustion (FFSC) cycle, Raptor was designed to be extraordinarily reliable and efficient in order to safely power a spacecraft (BFS/Starship) meant to ferry dozens or hundreds of people to and from Mars.

An excellent NASASpaceflight article explores the engine’s journey from a blank sheet to integrated static-fire tests and offers a deeper explanation of the technical details.

Raptor enters a new era

For all the extensive and invaluable testing SpaceX has done with a series of prototype Raptor engines, the engines tested were subscale versions with around 30% the thrust of the c. 2016 Raptor and around 40-50% of the updated c. 2017 iteration, producing almost the same amount of thrust as Merlin 1D (914 kN to Raptor’s ~1000 kN). In September 2018, Musk described Raptor as an “approximately…200-ton (~2000 kN) thrust engine” that would eventually operate with a chamber pressure as high as 300 bar (an extraordinary ~4400 psi), requiring at least one of the FFSC engine’s two preburners (used to power separate turbopumps) to operate at a truly terrifying ~810 bar (nearly 12,000 psi).

Conveniently stood beside a Merlin 1D engine also ready for hot-fire acceptance testing, the Raptor engine spotted departing SpaceX’s Hawthorne, CA factory last week was reportedly immense in person, towering over an M1D engine. Raptor also featured a mass of spaghetti-like plumbing (complexity necessary for its advanced combustion cycle), with a significant fraction of the metallic pipes and tubes displaying mirror-like finishes. Most notable was an obvious secondary preburner/turbopump stack and the lack of any exhaust port, whereas M1D relies on a single turbopump and exhausts the gases used to power it. Raptor’s full-flow staged-combustion cycle uses separate oxygen and methane preburners to power separate turbopumps, significantly improving mass flow rate and smoothing out combustion mixing.

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Unlike all previous hot-fired Raptors, those shipping now to McGregor, Texas are expected to be the first completed engines with a finalized design, arrived at only after a period of extensive testing and iterative improvement. They also appear to be full-scale, meaning that the test bays dedicated to Raptor will likely need to be upgraded (if they haven’t been already) to support a two- or threefold increase in maximum thrust.

SpaceX’s Starship hopper will need three finalized engines, meaning that the Raptor now in McGregor, Texas may not have been the first to arrive. Nevertheless, the shipment of full-scale hardware is always an extremely encouraging milestone for any advanced technology development program, while also foreshadowing the first imminent static-fires of the “radcally redesigned” rocket engine. With hardware now at the test site before January is out, a February test debut – one month behind a January debut teased by Elon Musk last December – is not out of the question.

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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 refines Full Self-Driving, latest update impresses where it last came up short

We were able to go out and test it pretty extensively on Saturday, and the changes Tesla made from the previous version were incredibly impressive, especially considering it seemed to excel where it last came up short.

Published

9 minutes ago

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December 14, 2025

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Credit: TESLARATI

Tesla released Full Self-Driving v14.2.1.25 on Friday night to Early Access Program (EAP) members. It came as a surprise, as it was paired with the release of the Holiday Update.

We were able to go out and test it pretty extensively on Saturday, and the changes Tesla made from the previous version were incredibly impressive, especially considering it seemed to excel where it last came up short.

Tesla supplements Holiday Update by sneaking in new Full Self-Driving version

With Tesla Full Self-Driving v14.2.1, there were some serious regressions. Speed Profiles were overtinkered with, causing some modes to behave in a strange manner. Hurry Mode was the most evident, as it refused to go more than 10 MPH over the speed limit on freeways.

It would routinely hold up traffic at this speed, and flipping it into Mad Max mode was sort of over the top. Hurry is what I use most frequently, and it had become somewhat unusable with v14.2.1.

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It seemed as if Speed Profiles should be more associated with both passing and lane-changing frequency. Capping speeds does not help as it can impede the flow of traffic. When FSD travels at the speed of other traffic, it is much more effective and less disruptive.

With v14.2.1.25, there were three noticeable changes that improved its performance significantly: Speed Profile refinements, lane change confidence, and Speed Limit recognition.

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Speed Profile Refinement

Speed Profiles have been significantly improved. Hurry Mode is no longer capped at 10 MPH over the speed limit and now travels with the flow of traffic. This is much more comfortable during highway operation, and I was not required to intervene at any point.

With v14.2.1, I was sometimes assisting it with lane changes, and felt it was in the wrong place at the wrong time more frequently than ever before.

However, this was one of the best-performing FSD versions in recent memory, and I really did not have any complaints on the highway. Speed, maneuvering, lane switching, routing, and aggressiveness were all perfect.

Lane Changes

v14.2.1 had a tendency to be a little more timid when changing lanes, which was sort of frustrating at times. When the car decides to change lanes and turn on its signal, it needs to pull the trigger and change lanes.

It also changed lanes at extremely unnecessary times, which was a real frustration.

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There were no issues today on v14.2.1.25; lane changes were super confident, executed at the correct time, and in the correct fashion. It made good decisions on when to get into the right lane when proceeding toward its exit.

It was one of the first times in a while that I did not feel as if I needed to nudge it to change lanes. I was very impressed.

Speed Limit Recognition

So, this is a complex issue. With v14.2.1, there were many times when it would see a Speed Limit sign that was not meant for the car (one catered for tractor trailers, for example) or even a route sign, and it would incorrectly adjust the speed. It did this on the highway several times, mistaking a Route 30 sign for a 30 MPH sign, then beginning to decelerate from 55 MPH to 30 MPH on the highway.

This required an intervention. I also had an issue leaving a drive-thru Christmas lights display, where the owners of the private property had a 15 MPH sign posted nearly every 200 yards for about a mile and a half.

The car identified it as a 55 MPH sign and sped up significantly. This caused an intervention, and I had to drive manually.

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It seems like FSD v14.2.1.25 is now less reliant on the signage (maybe because it was incorrectly labeling it) and more reliant on map data or the behavior of nearby traffic.

A good example was on the highway today: despite the car reading that Route 30 sign and the Speed Limit sign on the center screen reading 30 MPH, the car did not decelerate. It continued at the same speed, but I’m not sure if that’s because of traffic or map data:

A Lone Complaint

Tesla has said future updates will include parking improvements, and I’m really anxious for them, because parking is not great. I’ve had some real issues with it over the past couple of months.

Today was no different:

Full Self-Driving v14.2.1.25 is really a massive improvement over past versions, and it seems apparent that Tesla took its time with fixing the bugs, especially with highway operation on v14.2.1.

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Tesla hints at Starlink integration with recent patent

“By employing polymer blends, some examples enable RF transmission from all the modules to satellites and other communication devices both inside and outside the vehicle.”

Published

18 hours ago

on

December 13, 2025

By

Credit: Grok

Tesla hinted at a potential Starlink internet terminal integration within its vehicles in a recent patent, which describes a vehicle roof assembly with integrated radio frequency (RF) transparency.

The patent, which is Pub. No U.S. 2025/0368267 describes a new vehicle roof that is made of RF-transparent polymer materials, allowing and “facilitating clear communication with external devices and satellites.”

Tesla believes that a new vehicle roof design, comprised of different materials than the standard metallic or glass elements used in cars today, would allow the company to integrate modern vehicular technologies, “particularly those requiring radio frequency transmission and reception.

Instead of glass or metallic materials, Tesla says vehicles may benefit from high-strength polymer blends, such as Polycarbonate, Acrylonitrile Butadiene Styrene, or Acrylonitrile Styrene Acrylate.

These materials still provide ideal strength metrics for crashworthiness, stiffness for noise, vibration, and harshness control, and are compliant with head impact regulations.

They would also enable better performance with modern technologies, like internet terminals, which need an uninterrupted signal to satellites for maximum reception. Tesla writes in the patent:

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“By employing polymer blends, some examples enable RF transmission from all the modules to satellites and other communication devices both inside and outside the vehicle.”

One of the challenges Tesla seems to be aware of with this type of roof design is the fact that it will still have to enable safety and keep that at the forefront of the design. As you can see in the illustration above, Tesla plans to use four layers to increase safety and rigidity, while also combating noise and vibration.

It notes in the patent that disclosed examples still meet the safety requirements outlined in the Federal Motor Vehicle Safety Standards (FMVSS).

Starlink integrated directly into Tesla vehicles would be a considerable advantage for owners. It would come with a handful of distinct advantages.

Initially, the inclusion of Starlink would completely eliminate cellular dead zones, something that is an issue, especially in rural areas. Starlink would provide connectivity in these remote regions and would ensure uninterrupted service during road trips and off-grid adventures.

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It could also be a critical addition for Robotaxi, as it is crucial to have solid and reliable connectivity for remote monitoring and fleet management.

Starlink’s growing constellation, thanks to SpaceX’s routine and frequent launch schedule, will provide secure, stable, and reliable internet connectivity for Tesla vehicles.

SpaceX reaches incredible milestone with Starlink program

Although many owners have already mounted Starlink Mini dishes under their glass roofs for a similar experience, it may be integrated directly into Teslas in the coming years, either as an upgrade or a standard feature.

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Tesla supplements Holiday Update by sneaking in new Full Self-Driving version

It seems Tesla was waiting for the Hardware 4 rollout, as it wanted to also deploy a new Full Self-Driving version to those owners, as it appeared in the release notes for the Holiday Update last night.

Published

19 hours ago

on

December 13, 2025

By

Credit: Tesla

Tesla has surprised some owners by sneaking in a new Full Self-Driving version with the wide release of the Holiday Update, which started rolling out to Hardware 4 owners on Friday night.

Tesla has issued a controlled and very slow release pattern with the Holiday Update, which rolls out with Software Version 2025.44.25.5.

For the past two weeks, as it has rolled out to Hardware 3 and older Tesla owners, the company has kept its deployment of the new Software Version relatively controlled.

It seems Tesla was waiting for the Hardware 4 rollout, as it wanted to also deploy a new Full Self-Driving version to those owners, as it appeared in the release notes for the Holiday Update last night.

Tesla Full Self-Driving v14.2.1.25 made its first appearance last night to Hardware 4 owners who are members of the Early Access Program (EAP). It appears to be a slight refinement from FSD v14.2.1, which has been out for a couple of weeks.

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Many owners welcome the new FSD version, us included, because we’ve been less than impressed with v14.2.1. We have experienced some minor regressions with v14.2.1, especially with Speed Limit recognition, Speed Profile tinkering, and parking performance.

As it stands, Full Self-Driving is still particularly impressive, but Tesla is evidently having an issue with some of the adjustments, as it is still refining some of the performance aspects of the suite. This is expected and normal with some updates, as not all of them are an improvement in all areas; we routinely see some things backtrack every once in a while.

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This new FSD version is likely to take care of those things, but it also includes all of the awesome Holiday Update features, which include:

  • Grok with Navigation Commands (Beta) – Grok will now add and edit destinations.
  • Tesla Photobooth – Take pictures inside your car using the cabin-facing camera
  • Dog Mode Live Activity – Check on your four-legged friend on your phone through periodic snapshots taken of the cabin
  • Dashcam Viewer Update – Includes new metrics, like steering wheel angle, speed, and more
  • Santa Mode – New graphics, trees, and a lock chime
  • Light Show Update – Addition of Jingle Rush light show
  • Custom Wraps and License Plates – Colorizer now allows you to customize your vehicle even further, with custom patterns, license plates, and tint
  • Navigation Improvements – Easier layout and setup
  • Supercharger Site Map – Starting at 18 pilot locations, a 3D view of the Supercharger you’re visiting will be available
  • Automatic Carpool Lane Routing – Navigation will utilize carpool lanes if enabled
  • Phone Left Behind Chime – Your car will now tell you if you left a phone inside
  • Charge Limit Per Location – Set a charge limit for each location
  • ISS Docking Simulator –  New game
  • Additional Improvements – Turn off wireless charging pad, Spotify improvements, Rainbow Rave Cave, Lock Sound TRON addition

Tesla also added two other things that were undocumented, like Charging Passport and information on USB drive storage to help with Dashcam.

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