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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 gives its biggest signal yet that Cybercab launch is imminent

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Credit: Joe Tegtmeyer | X

Tesla just gave what is perhaps its biggest signal yet that the launch of the Cybercab, its autonomous ride-hailing-geared car, is imminent.

The Cybercab has been spotted outside of Gigafactory Texas in massive numbers over the past few days, with hundreds of units being stored on property just days after the vehicle received a Certificate of Conformity from the EPA.

Today, things were a bit different.

Cybercabs spotted on Giga Texas property today had an addition: a Cybercab decal on the side, reminiscent of the “Robotaxi” ones that were placed on Model Ys just as the company launched its ride-sharing platform about a year ago.

Giga Texas drone operator Joe Tegtmeyer noticed the change today:

Tesla could be signaling that the Cybercab is preparing to enter the Robotaxi fleet in the coming weeks or months with this move. It seems more symbolic than anything; Tesla is ready to throw Cybercabs in the ride-hailing platform just as it did with Model Ys last year.

The addition of the Certificate of Conformity awarded to the Cybercab is another major factor working to Tesla’s advantage. The company now has permission from the EPA to allow the vehicle to operate on public roads and enter the chain of commerce. It’s officially street legal.

Tesla Cybercab specs revealed: range, curb weight, range ratings, and more

The big question that remains is whether Tesla will be able to operate the car without a safety monitor, especially considering it plans to put the car out there without a steering wheel or pedals. With the Cybercab only having a seating capacity of two, it is hard to believe Tesla will even consider putting a Safety Monitor in the car.

It did recently self-certify as Level 4 and has the ability to operate driverless vehicles in the State of Texas under a law that took effect on May 28. You can read more about that here:

Tesla’s Robotaxi dreams just took a massive step toward reality

We’d imagine Cybercabs will be on the roads as soon as July, but August will likely be a better estimate of when the car will be entered into the Cybercab fleet. It all depends at where Tesla is, as they’ve truly prioritized safety with the rollout of the Robotaxi platform.

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Elon Musk challenges Tesla credit rating from Moody’s after SpaceX gets a higher one

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Justin Pacheco, Public domain, via Wikimedia Commons

Elon Musk has publicly questioned Moody’s credit assessments following the rating agency’s decision to assign SpaceX a Baa1 investment-grade rating, two notches above Tesla’s Baa3. The comments came amid discussions comparing the two companies’ financial profiles.

SpaceX earned its first-time Baa1 rating with a stable outlook from Moody’s. The agency highlighted the company’s leadership in orbital launches, the growing recurring revenue from its Starlink satellite network, strong vertical integration, U.S. government contracts, and emerging opportunities in AI infrastructure.

These factors were cited as supporting robust cash flows, margin expansion, and financial flexibility.

Musk responded directly: “Tesla’s credit rating is ridiculously low tbh,” and added, “Yeah, makes no sense. Tesla has over $40B in cash, no debt, and is consistently profitable!” His remarks underscored Tesla’s balance sheet strength and profitability at a time when many traditional automakers continue to report losses in the shift to electric vehicles.

Tesla maintains a leading position in the global EV market, with diversification into energy and storage, battery technology, and robotics through projects like Optimus. Recent financial updates show the company generated positive free cash flow of $1.4 billion in Q1 2026, supported by operating cash flow of $3.9 billion. Cash and short-term investments stood at approximately $44.7 billion.

Moody’s has affirmed Tesla’s Baa3 issuer rating with a stable outlook in periodic reviews, acknowledging the company’s EV leadership, technology strengths, including AI for autonomous vehicles, solid profitability, and strong liquidity.

Tesla (TSLA) scores Baa3 Moody’s rating for ‘stable’ outlook

However, the agency has also noted challenges in the automotive segment and expectations for margin pressures.

Musk’s critique highlights a common debate about how traditional rating methodologies apply to high-growth, capital-intensive technology companies. SpaceX benefits from long-term government-backed contracts and diversified, recurring revenue streams, while Tesla’s valuation reflects heavy investment in future technologies such as autonomy and robotics.

Both ratings remain investment-grade, yet the one-notch difference has fueled online discussion about potential inconsistencies in evaluating innovative firms.

The exchange comes as SpaceX explores financing options following its recent valuation milestones, while Tesla continues executing on its multi-year roadmap. Musk’s pointed response serves as a reminder that credit ratings, though influential for borrowing costs, represent one lens through which markets assess corporate strength—and that company leaders often view their financial positions through the lens of long-term innovation and cash generation rather than short-term risk metrics alone.

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Tesla faces Full Self-Driving pushback in EU over ‘speeding’

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Credit: Tesla

A new report from Reuters claims that a transport authority in Sweden is pushing back against the approval of Tesla’s Full Self-Driving suite because it will travel over speed limits.

The report says the Swedish Transport Administration (TRV) recommends the European Union votes against FSD’s approval. TRV believes it should not be approved until Tesla disables FSD’s ability to speed.

TRV sent a letter to the European Union’s Technical Committee on Motor Vehicles (TCMV), which is set to meet on June 30 to discuss the potential approval of the Tesla FSD suite in the country. Tesla, which has received various approvals in Europe over the past two months, has not provided a comment.

Tesla Full Self-Driving gets first-ever European approval

Teslas operating on FSD do travel over the speed limit, depending on the Speed Profile that is chosen. Drivers have the ability to disengage FSD at any point; Tesla specifically states that those supervising the suite are responsible for its actions.

Let’s cut to the chase: humans operating any vehicle speed almost daily in the United States. Realistically, speed limits in the U.S. are more frequently treated as speed minimums. However, other countries are different, and driving behaviors are less aggressive.

TRV believes that “allowing automated systems to systematically exceed legal speed limits…risks undermining both the legal framework and the expected safety benefits of ​vehicle automation,” the report stated. It’s surprising that Tesla has not received this claim from other countries previously.

This could be a good argument to bring Max Speed back, the setting that previously allowed the driver to choose the absolute fastest the car would travel.

This would still put the responsibility of supervision in the hands of the driver. It would allow the driver to choose whether the car would travel over the speed limit or not, acknowledging that they set the speed, and if they get pulled over, there would be no ability to argue it.

However, it does not seem as if this is something Tesla will do, especially considering many U.S. drivers have requested the feature in an effort to eliminate speeding or at least tone it down. The company has not shown any interest in bringing it back.

Tesla has approvals for FSD in Europe in Estonia, Lithuania, Denmark, the Netherlands, and Belgium.

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