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SpaceX wiggles Starhopper’s Raptor engine, tests parts ahead of hover test debut

Repeating a test conducted in June with Raptor SN04, SpaceX tested Starhopper and Raptor SN06's thrust vectoring capabilities on July 12th. (NASASpaceflight - bocachicagal)

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On the evening of July 12th, SpaceX technicians put Starhopper’s freshly-installed Raptor – serial number 06 (SN06) – through a simple but decidedly entertaining test, effectively wiggling the engine in circles.

Designed to verify that Raptor’s thrust vectoring capabilities are in order and ensure that Starhopper and the engine are properly communicating, the wiggle test is a small but critical part of pre-flight acceptance and a good indicator that the low-fidelity Starship prototype is nearing its first hover test(s). Roughly 48 hours after a successful series of wiggles, Starhopper and Raptor proceeded into the next stage of pre-flight acceptance, likely the final more step before a tethered static fire.

Routine for all Falcon rockets, SpaceX’s exceptionally rigorous practice of static firing all hardware at least once (and often several times) before launch has unsurprisingly held firm as the company proceeds towards integrated Starhopper and Starship flight tests. Despite the fact that Raptor SN06 completed a static fire as recently July 10th, SpaceX will very likely put Starhopper and its newly-installed Raptor through yet another pre-flight static fire, perhaps its fourth or fifth test this month.

Although it would undoubtedly be easier, cheaper, and faster to skip that post-delivery static fire, it will simultaneously lower the risk of Raptor failing mid-flight and verify that Starhopper itself is healthy and ready for untethered hovering. Although SpaceX could likely live without Starhopper in the event that it’s lost during flight-testing, any failure capable of destroying the vehicle itself is at least as capable of severely damaging or completely destroying the spartan but still expansive test and launch facilities the company built over the course of several months.

SpaceX has been hard at work gradually building, expanding, and upgrading its South Texas launch facilities since December 2018. (NASASpaceflight – bocachicagal, 04/27/2019)

Would you like some testing with your testing?

Follow July 12th’s nighttime Raptor wiggle test, July 13th was mainly quiet and filled with inspections of Starhopper, Raptor, and other various work. The day after, however, SpaceX proceeded through several hours of propellant loading, ending with what looked like less energetic versions of the Raptor preburner ignition tests Starhopper previously performed with Raptor SN02.

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.

The first obvious test occurred around 7:30pm CT, July 14th. (LabPadre)
The second obvious test followed around 8:50 pm CT. (LabPadre)

Although the fireworks are so subtle that they are easily missed, the conditions inside the preburner – hidden away from view – are actually far more intense than the iconic blue, purple, and pink flame that exists Raptor’s nozzle. This is because the preburners have to nurture the conditions necessary for the pumps they power to fuel the main combustion chamber. 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 the main combustion chamber.

Thus, if the head 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 completely prevent Raptor from starting and running stably and can even trigger a “hard start” or shutdown that could damage or destroy the engine. As such, to preburners fundamentally have to operate at higher chamber pressures (and thus higher temperatures) than the main combustion chamber (the big firey bit at the end). According to Elon Musk, Raptor’s oxygen preburner has the worst of it, operating at pressures as high or higher than 800 bar (11,600 psi, 80 megapascals).

Coincidentally, this is roughly equivalent to the pressure at the bottom of the Pacific Ocean.

Starhopper and Raptor seen on the afternoon of July 14th, preparing for an evening of testing. (NASASpaceflight – bocachicagal)

In short, preburner testing is no less critical than full-on static fire testing with an engine like Raptor. July 14th’s test was also made doubly efficient due to the fact that preburner testing requires liquid propellant, which effectively makes the whole test a wet dress rehearsal (WDR) even before any engine ignition or partial ignition is involved. Per SpaceX moving from propellant loading to preburner/turbine testing, Starhopper is almost certainly healthy and operating as expected, an excellent sign that the ungainly vessel may be ready for a static fire of Raptor as early as 2pm CT, July 15th.

The memes, oh, the memes.

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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 improvements are already on the minds of company engineers

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Credit: Tesla Europe & Middle East | X

Tesla Cybercab might have just rolled out to the public as it entered the company’s Robotaxi suite in Austin this past week. However, the vehicle might already be on its way to becoming even better, as the company is asking riders to describe what they’d like to see improved with the Cybercab.

Tesla sent a rider experience survey to Cybercab passengers only days after paid rides began in Austin. The questionnaire asks how satisfied riders were with the overall trip. Then it requests star ratings for availability and wait time, door functionality, vehicle touchscreen, mobile app experience, seat comfort, interior space, ride comfort, cleanliness, and cargo space.

A later section asks which features riders would most like to have and allows selection of up to three items from a list that includes heated seats, ventilated seats, fully reclining seats, a tray table, a wireless phone charger, a better sound system, and more storage. Respondents may also choose none of these or write in another idea. The survey closes with a recommendation score from zero to ten.

This rapid request for input illustrates Tesla’s habit of treating early users as collaborators rather than mere customers. The company has long refined vehicles through software updates and hardware changes informed by real-world use across its passenger cars.

Collecting structured opinions so soon after commercial service started shows the same mindset applied to a purpose-built autonomous taxi. The questions themselves reveal an openness to cabin changes even after the first vehicles reached public streets, which is no surprise.

Tesla has always hoped to cater a great experience to anyone in its vehicles, which is why so many fan-requested features have made it into its vehicles.

Replies already circulating online favor reclining seats, tray tables, wireless charging, improved audio, and extra room when seats fold back.

Tesla Cybercabs narrowly miss deadly Amazon cargo plane crash

Those preferences point toward comfort upgrades that Tesla can implement in later production batches or through cabin revisions. Because the Cybercab is designed around software first principles, many requested amenities can arrive faster than in traditional automakers.

Tesla’s willingness to survey riders immediately after launch therefore makes near-term cabin and experience improvements likely as the team reviews responses and iterates toward a more refined robotaxi people will choose daily.

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Tesla Cybertruck engineer reveals new changes in ‘constantly evolving’ pickup

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Credit: Joe Tegtmeyer | YouTube

Tesla Cybertruck Lead Engineer Wes Morrill revealed the company has made several changes to the all-electric pickup, which he calls a “living thing, constantly evolving and improving.”

Cybertruck is manufactured at Tesla’s Gigafactory Texas just outside of Austin, and over the past few years, Tesla has continued to make small changes to the pickup to improve everything from cost, reliability, serviceablility, and manufacturability.

“The finish line isn’t getting to production. A product is a living thing, constantly evolving and improving,” Morrill added.

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Some of those changes are yet to be revealed, but perhaps the most notable one was the change Tesla made to the aero shield that sits underneath the truck. In the past, it was aluminum, but now the Cybertruck is using a self-reinforcing polypropylene.

Morrill said that the polypropylene is “stretched into fibers and then laminated into the form,” and is much more durable, much lighter, and significantly cheaper than aluminum when it is manufactured this way.

It also enabled some improvements in the geometry of the Cybertruck, improving the manufacturing around the bolts and edges, in addition to minor form changes. These all benefitted the Cybertruck in more ways than one: specifically with durability and improved drag.

Typically, Teslas are not necessarily identified by model year because these changes are fluid and occur when the company sees fit to implement them. It is not like other automotive companies, which usually make sweeping manufacturing changes when building a new model year.

Instead, Teslas are recognized by their “generation” or “era.” For example, those with a newer Model Y might refer to their car as a “Juniper.” This is the same with Model 3, as many refer to the new body style as the “Highland.”

Tesla’s manufacturing changes are proof of the company’s constant need to improve its products and move things forward with its vehicles. There is no need to drag one’s feet and wait until next year if the product can be made better right now, and that’s precisely what Tesla did with the Cybertruck.

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Tesla Cybercabs narrowly miss deadly Amazon cargo plane crash

An Amazon cargo plane crash near Miami’s airport stopped feet from dozens of Tesla Cybercabs.

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Photorealistic depiction of the Amazon Prime plane crash in Miami on Sep 3, 2026 near a fleet of Tesla Cybercab
Photorealistic depiction of the Amazon Prime plane crash in Miami on Sep 3, 2026 near a fleet of Tesla Cybercab

An Amazon Prime Air Boeing 767 cargo jet overran the runway at Miami International Airport on Sunday afternoon, killing five people and injuring five more. The jet, operated by North Carolina based carrier 21 Air as Flight 7598, touched down around 2 p.m. after arriving from San Juan, Puerto Rico, then crossed the airport perimeter, plowed across NW 67th Avenue and struck multiple vehicles before catching fire, according to the Associated Press.

Photos and video from the scene show the aircraft’s nose stopped within meters of a fenced staging lot holding dozens of gold painted Tesla Cybercabs, the steering wheel free robotaxi Tesla began putting on public roads in Austin last week. Miami-Dade Fire Rescue has confirmed the plane struck “multiple vehicles” but has not said whether any Cybercabs were among them, and neither Tesla nor airport officials have addressed the fleet directly.

The Cybercabs had not yet entered commercial service in Miami. Tesla’s existing Robotaxi operation there runs on modified Model Y vehicles and has been unsupervised since Ashok Elluswamy confirmed the detail on X in July.


Elon Musk offered the briefest of reactions. Replying to a Zero Hedge post about the Cybercabs sitting so close to the wreckage, he wrote a single word: “Weird.” He has not commented further, and Tesla has not issued a statement.

The timing puts Tesla’s newest vehicle near an unrelated but highly visible tragedy just days after its Austin debut, a launch that had already drawn scrutiny from federal regulators. The National Highway Traffic Safety Administration opened an audit how Tesla certified the Cybercab as compliant with federal vehicle safety standards, a process Teslarati covered after the vehicle’s September 3 launch event. That inquiry concerns the car’s lack of a steering wheel and pedals, not the Miami crash.

Investigators from the FAA and NTSB are focused on the plane, not the parking lot beside it. Flight data reviewed by outlets including Simple Flying show the 767 touched down around 170 knots, well above the 135 to 140 knot range typical for the aircraft, though investigators have not determined a cause. Amazon said it is working with authorities and that its priority is the safety of everyone affected.

Whether any Cybercabs were damaged, and what Tesla plans for the fleet parked near one of the country’s busiest airports, remain open questions.

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