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SpaceX delays Starhopper’s first flight a few days despite Raptor preburner test success
SpaceX has (partially) ignited Starhopper’s freshly-installed Raptor engine, successfully verifying that the engine is ready for its next major test: a full ignition and static firing. Although successful, SpaceX still has some work to do before the vehicle is ready for its first untethered flight(s).
July 15th’s progress is just the latest in a several day-series of preflight tests designed to reduce the likelihood that Starhopper is destroyed over the coming days and (hopefully) weeks. If all goes planned during the awkward Starship prototype’s first foray into hover tests, SpaceX CEO Elon Musk has stated that he will provide an official presentation updating the public on the status of the company’s ever-changing next-generation rocket.
The past week or so of Starhopper preflight testing began with Raptor serial number 6 (SN06) completing the last of a series of acceptance test fires in McGregor, Texas on June 10th. Even on its own, this was a major milestone for the new SpaceX engine: Raptor SN06 was the first of the new, full-scale engines to pass the acceptance test program with flying colors. According to Musk, for the engine to complete those tests so successfully, SpaceX had to solve a challenging bug in which some sort of mechanical resonance (i.e. vibration) damaged or destroyed Raptors SN01-05.
Hours later, the engine began a short ~450 mi (720 km) journey south to Starhopper, located in Boca Chica, Texas. The engine arrived on July 11th and was fully installed on Starhopper by the following evening (July 12th), at which point SpaceX put Starhopper and Raptor through some mild but valuable thrust vector controller (TVC) tests, wiggling the car-sized engine to ensure it can accurately steer the prototype rocket.
Around two days after the above ‘wiggle’ test was successfully completed, SpaceX moved into the next stage, partially fueling Starhopper with liquid methane and oxygen propellant and helium pressurant in what is known in rocketry as a wet dress rehearsal (WDR). The (implicitly) successful WDR was capped off with a duo of what can now safely be concluded were some sort of Raptor test preceding even pre-ignition operations. Whatever the tests were, they appear to have been completed successfully.
That appears to be the case because less than 24 hours after their completion, on July 15th, SpaceX once again began loading Starhopper with propellant and pressurant for a second round of wet testing. This time around, SpaceX got right into more critical Raptor tests once enough propellant was loaded, igniting the engine’s interwoven oxygen and methane preburners.
Previously discussed 24 hours ago in a Teslarati article focused on Raptor wiggles and other miscellaneous tests, Raptor is an extremely advanced rocket engine based on a cycle (i.e. how propellant is turned into thrust) known as full-flow staged combustion.
“In a staged-combustion engine like Raptor, getting from the supercool liquid oxygen and methane propellant to 200+ tons of thrust is quite literally staged, meaning that the ignition doesn’t happen all at once. Rather, the preburners – essentially their own, unique combustion chambers – ignite an oxygen- or methane-rich mixture, the burning of which produces the gas and pressure that powers the turbines that bring fuel into the main combustion chamber. That fuel then ignites, producing thrust as they exit the engine’s bell-shaped nozzle.
Unintuitively, conditions inside the preburner – hidden away from view – are actually far more intense than the iconic blue, purple, and pink flame that visibly exists Raptor’s nozzle. Much like hot water will cool while traveling through pipes, the superheated gaseous propellant that Raptor ignites to produce thrust will also cool (and thus lose pressure) as it travels from Raptor’s preburner to its main combustion chamber. If the pressure produced in the preburners is too low, Raptor’s thrust will be (roughly speaking) proportionally limited at best. At worst, low pressure in the preburners can trigger a “hard start” or shutdown that could destroy the engine. According to Elon Musk, Raptor’s oxygen preburner thus has the worst of it, operating at pressures as high or higher than 800 bar (11,600 psi, 80 megapascals).”
In full-flow staged combustion (FFSC), even more complexity is added as all propellant that touches the engine must necessarily end up traveling through the main combustion chamber to eke every last ounce of thrust out of the finite propellant a rocket lifts off with. As such, FFSC engines can be about as efficient as the laws of physics allow any given chemical rocket engine to be, at the cost of exceptional complexity and brutally difficult development.
Additionally, FFSC physically requires two separate preburners and then makes things even harder by making each separate preburner (methane and oxygen) depend on each other’s operation for the engine to fully ignite. This means that no individual preburner can be used to kickstart Raptor – instead, SpaceX must somehow spin the turbopumps that feed propellant into each preburner with some separate system. This is all just to emphasize the fact that Raptor’s ignition sequence is a spectacularly complex orchestra of valves, spark plugs, sensors, and magic. This is why it’s valuable for Raptor to test its preburner system independently of an actual ignition test, at least as long as the engine is still in the development stages.
According to NASASpaceflight.com managing editor Chris Bergin, what this practically translates to is a minor Starhopper hover test delay of 1-2 days, while the static fire has also been pushed roughly 24 hours from July 15th to July 16th. If that full static fire produces lots of happy data, Starhopper could be cleared for a hover test debut attempt as early as Wednesday or Thursday (July 17/18).
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Tesla briefly offered one Robotaxi part in its Parts Catalog for your personal car, only to remove it just a short time after it was first noticed.
Tesla’s Robotaxi camera washer apparatus was briefly available for purchase on the company’s Online Parts Catalog. The camera washer was first noticed on Model Y Robotaxi vehicles about six months ago in Austin.
🚨 Tesla looks to have installed Camera Washers on the side repeater cameras on Robotaxis in Austin
pic.twitter.com/xemRtDtlRR— TESLARATI (@Teslarati) January 23, 2026
First noticed by Not a Tesla App, the Camera Washer entries appeared for the new “Juniper” Model Y under a category called “Halo,” which has also now disappeared. Interestingly, Halo probably is related to Tesla’s internal “Project Halo,” which was a project that aimed to retrofit customer-owned Model Ys into functional Robotaxis.
This hardware addition would likely be required for the vehicle to operate as a Robotaxi, as the Camera Washer seems to be a non-negotiable part of the vision-based system Tesla utilizes for self-driving efforts.
However, this part has since been removed and is no longer visible on the EPC.
Now the true question lingers: Why would Tesla add this Camera Washer to the Model Y parts catalog? Is it planning to make it available for owners to utilize on their own cars for personal use, or will it become a prerequisite for Robotaxi operation in customer-owned cars?
While discussing the upgrade options for Hardware 3 vehicles during the Q1 Earnings Call, Tesla CEO Elon Musk had said that the company could establish small, satellite shops that would upgrade cameras and self-driving computers. Perhaps this same strategy could be utilized for vehicles that want to be included in Robotaxi but do not have the correct hardware.
AI4 is currently represented as capable of unsupervised self-driving, and the same was said about HW3 at one point, only for Tesla to admit last quarter that it would, unfortunately, not be possible. Perhaps AI4 vehicles might need this camera washer as a prerequisite, just as HW3 cars will need that camera and computer upgrade.
This could be the first hint of that’s where we are headed.
Tesla has started rolling out a broader change to the ride experience for its Robotaxi fleet by silencing turn signals, but the change is certainly polarizing.
Tesla has generally made it clear that its purpose-built ride-hailing platform, Robotaxi, will cater to the rider in nearly every way possible. This includes having climate preferences, music, and other personal settings loaded up in the car as the rider enters.
But Tesla is taking it a step further by muting turn signal chimes altogether, a change that appears to be a way to make the ride more peaceful:
Tesla has finally turned off the blinker/turn signal noises in their Model Y Robotaxis.
This is a small update, but will definitely be noticeable for riders. It didn’t really make much sense to leave the turn signal sound on when it’s Unsupervised. pic.twitter.com/ITwx60PAMO
— Sawyer Merritt (@SawyerMerritt) July 27, 2026
However, there are a handful of people who are not thrilled about this change. Turn signals are a conditioned part of the human mind for those who ride in a car regularly.
Taking a turn without one feels strange and odd, and not hearing it click while activated could set off some alarms for riders, who might use the noise as confirmation that other drivers know of their intention to turn.
I kind of like it being on, threw me off when riding with Zoox who has had it disabled
— Dan Burkland (@DBurkland) July 27, 2026
Turn signal noises are still audible in customer cars, so if you use FSD in your personal vehicle, you will still hear the turn signal.
The move is certainly one that is unique, but not one that separates it from other ride-sharing services. In a normal car, the clicking sound confirms to the driver that the blinker is active. In a fully driverless Robotaxi, that feedback serves no purpose for passengers, other than peace of mind.
Tesla released Full Self-Driving version 14.3.6 last week, and after what was potentially one of the best FSD releases in v14.3.5, there has been a bit of a regression. While there are some bright spots, the changes made to v14.3.6 seem to have backtracked some behaviors.
Overall, it is hard to really complain about FSD in any sense; it has revolutionized how I travel literally anywhere. According to my self-driving app, the last time I went a day without using it was 59 days ago.
However, I think it’s also important to recognize when things are just plain bad with FSD. There are times it does truly mind-boggling things, and I’ll dive into those here. Additionally, I only had these issues on local roads, not on highways. Highway operation, generally, is always incredible other than the occasional complaint about speed or left lane camping.
With those things being said, my personal experience may not represent others’ experiences. A handful of people have said they have had a similar experience on v14.3.6, while others have said it is more than normal.
Turning Hesitancy, Inaccuracy
I’ve noticed more inaccuracy turning into multi-lane stretches of road than in any version I can remember. I’ve had at least three instances of FSD turning into a stretch of roadway that has two or more lanes, and not selecting a lane confidently as it has in past versions.
I think Tesla FSD v14.3.6 is a regression from previous .3 branches
This version in particular has been incredibly hesitant, jerky, and indecisive at times. There’s actually been two drives that I have decided to not used FSD for the remainder of the trip. These were local trips… pic.twitter.com/YobHDOKRS6
— TESLARATI (@Teslarati) July 26, 2026
Instead, the car will drive over one of the dashed road lines, and the steering wheel will jerk back and forth before picking the lane. It should be said that it has always picked the correct lane when choosing based on the navigation, but it is still very indecisive. The steering wheel jerking is reminiscent of some of the later versions of v13.
I admit I really hate to see the steering wheel jerking come back. However, I think when Tesla releases v14.3.7, it won’t be present. When there are occurrences of it in FSD versions, it is usually resolved by the following release.
FSD Disregards Manual Turn Signals
This is my biggest bone to pick with FSD other than Navigation issues, but this one seems like it would be such an easy fix.
If Tesla is going to put the word “Supervised” on the end of “Full Self-Driving,” then when I tell the car to do something, it should do it. If I input an increase in speed by pressing the accelerator, the car will immediately respond. It does not disregard my input because it feels it is traveling at the right speed.
FSD should never disobey and turn off turn signals that the driver inputs. Trying to direct the car into the correct lane, I had initiated the left turn signal not once, not twice, but three times, with the car turning it off all three times and continuing in a lane that would end in just one block. The only solution at this point would be to zipper merge.
This goes back to the fact that self-driving’s biggest bottleneck might be rider preference. A zipper merge might have been more than reasonable, might have saved me time that I spent sitting through an additional light cycle, and might be something many drivers would do. I was in no hurry, I traditionally do not try to zipper merge because it feels inconsiderate, and lastly, the car should have just followed my input.
This caused me to disengage and drive manually the rest of the way home. Sometimes I just do not need FSD to try to pass every car it can at intersections.
Bird Braking is a Thing of the Past
The big complaint with recent versions of Full Self-Driving has been what we’ve coined as “bird braking,” which is when the car will brake suddenly as a bird flies past.
There have been zero issues with this so far in v14.3.6, which is an excellent improvement.
FSD Might Already Be Taking Note of Driver Preferences
Another thing I have noticed over the past few days is that v14.3.6 seems to already be taking my preferences with navigation into account.
This is something that is supposed to be rolling out with the Summer Update, but I have a hunch it’s already present and might have been included in this v14.3.6 build. On Friday, FSD pulled into an entrance to a local convenience store that it had never attempted to go into before.
Typically, I manually pull into this entrance because it avoids heavy cross traffic at the main entrance. FSD has always chosen that congested main entrance.
I don’t want to get anyone excited but my Tesla running FSD v14.3.6 just:
✅ Pulled into an entrance at my local Sheetz that I routinely pull into manually but FSD never has entered
✅ Pulled into my assigned parking space at home despite many other spots being vacant https://t.co/ZUShvknTWO pic.twitter.com/83O5a2S0eh
— TESLARATI (@Teslarati) July 24, 2026
Additionally, FSD has pulled into my assigned parking spot at my townhouse community on multiple occasions with this release. This is something that used to happen ocassionally, but not consistently.
It also navigated back to the same convenience store last night, drove through crazy cars scrambling to gas pumps, navigated out of the parking lot correctly, drove me home, and, once again, parked in my assigned spot.
As previously stated, this release just seems to have a few things that need to be brought to Tesla’s attention, and also to make others who use FSD aware of some things that I’ve experienced. I look forward to the next release that will remedy these issues, just as Tesla has always done in the past.
Tesla briefly offered this Robotaxi part for your personal car
Tesla Robotaxi gets sweeping but polarizing change
