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SpaceX's new Starship test stand to make life a little easier for Raptor engine engineers

According to SpaceX CEO Elon Musk, one seemingly small tweak to Starship engine testing could make life much easier for Raptor engineers. (SpaceX)

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SpaceX recently debuted a new rocket engine test stand at its Central Texas development facilities and one specific aspect of the so-called ‘tripod stand’ could make life a lot easier for Starship’s Raptor engine engineers.

The success of SpaceX’s extremely ambitious Starship spacecraft and Super Heavy boosters hinges heavily on the prior success of a next-generation rocket engine the company is developing itself. Known as Raptor, the engine is likely one of the most complex ever developed, owing to its use of a combustion cycle that’s as challenging and unforgiving as it is efficient. That efficiency is the draw.

The decision to base the Starship launch system around methane and oxygen propellant – relatively dense, safe to handle, and easy to generate on Mars – means that it can never be as efficient as a rocket based on hydrogen and oxygen, the pinnacle of chemical combustion-based propulsion. For a methalox rocket as nominally reusable as Starship, going to extremes to eke even a smidge of extra efficiency out of its Raptor engines is a reasonable – if not necessary – decision. However, that pursuit of efficiency carries many hurdles with it, some of which can even be exacerbated by the equipment used to test those engines on the ground.

SpaceX mocked up Starship Mk1 with three Raptor engines in late-September, but all three departed Boca Chica shortly after Musk’s presentation. (SpaceX)

Raptor is less than unique in this particular case but SpaceX’s engine development and testing has matured to the point that the stands it’s relied on for static fires have become a detriment to the engine’s progress. Specifically, aside from Starhopper, all previous Raptor static fires have been performed with engines installed horizontally in test bays located at SpaceX’s McGregor, Texas development facilities. While in flight, Raptor engines will theoretically never experience wear and tear similar to the unique conditions imposed by horizontal testing – engine burns will almost invariably exert forces along a vertical (up and down) axis.

To almost anyone else, even other engine development companies, this might seem like an insignificant difference. Built around the full-flow staged combustion (FFSC) cycle and meant to be unprecedentedly reusable and reliable, the Raptor engine is not quite as forgiving. Since the engine’s inaugural full-scale static fire test just one year ago, SpaceX CEO Elon Musk has noted several times that Raptor could benefit from new vertical test stands.

Speaking in October 2019, Musk stated that a new vertical test stand would “hopefully allow simplification of Raptor design, as pump shaft wear & drainage is better in vertical config.” More generally, testing Raptor engines vertically would also be “more representative of flight [conditions]”, allowing SpaceX to live up to its proven “test as you fly” philosophy.

Pictured here in April 2018, SpaceX’s McGregor, Texas ‘tripod stand’ is visible to the right of the more functional flat-ground stand that replaced it. Also present is the first Falcon 9 Block 5 booster, B1046. (Aero Photo)

Indeed, aside from Starhopper’s two successful test flights and a handful of static fires, Raptor has performed barely any vertical testing despite more than 3200 seconds of static fires completed with 18 full-scale engine prototypes in the last 12 months alone. Including subscale engines tested from 2016 through 2018, SpaceX’s Raptor engine has likely completed some 5000 seconds (>80 minutes) of test fires over the course of three and a half years of development.

Aside from allowing SpaceX engineers to potentially simplify the Raptor engine design and test the Starship engines in conditions much closer to what they will experience in flight, the addition of a new dedicated test stand – on top of two existing horizontal bays – should allow even more testing to be done in a given time-frame. The more testing that can be done, the more engines SpaceX can quickly qualify for flight, and given that every Starship/Super Heavy pair could require up to 43 new Raptor engines, SpaceX will need all the testing capacity it can get.

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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 briefly offered this Robotaxi part for your personal car

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Credit: @tpgoebel | X

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.

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.

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Tesla Robotaxi gets sweeping but polarizing change

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Credit: Tesla

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:

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.

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.

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Tesla Full Self-Driving v14.3.6 review: a rare regression, but some bright spots

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Credit: Tesla

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.

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.

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.

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