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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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SpaceX weighs Nasdaq listing as company explores early index entry: report

The company is reportedly seeking early inclusion in the Nasdaq-100 index.

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Credit: SpaceX/X

Elon Musk’s SpaceX is reportedly leaning toward listing its shares on the Nasdaq for a potential initial public offering (IPO) that could become the largest in history. 

As per a recent report, the company is reportedly seeking early inclusion in the Nasdaq-100 index. The update was reported by Reuters, citing people familiar with the matter.

According to the publication, SpaceX is considering Nasdaq as the venue for its eventual IPO, though the New York Stock Exchange is also competing for the listing. Neither exchange has reportedly been informed of a final decision.

Reuters has previously reported that SpaceX could pursue an IPO as early as June, though the company’s plans could still change.

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One of the publication’s sources also suggested that SpaceX is targeting a valuation of about $1.75 trillion for its IPO. At that level, the company would rank among the largest publicly traded firms in the United States by market capitalization.

Nasdaq has proposed a rule change that could accelerate the inclusion of newly listed megacap companies into the Nasdaq-100 index.

Under the proposed “Fast Entry” rule, a newly listed company could qualify for the index in less than a month if its market capitalization ranks among the top 40 companies already included in the Nasdaq-100.

If SpaceX is successful in achieving its target valuation of $1.75 trillion, it would become the sixth-largest company by market value in the United States, at least based on recent share prices. 

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Newly listed companies typically have to wait up to a year before becoming eligible for major indexes such as the Nasdaq-100 or S&P 500.

Inclusion in a major index can significantly broaden a company’s shareholder base because many institutional investors purchase shares through index-tracking funds.

According to Reuters, Nasdaq’s proposed fast-track rule is partly intended to attract highly valued private companies such as SpaceX, OpenAI, and Anthropic to list on the exchange.

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The Boring Company’s Prufrock-2 emerges after completing new Vegas Loop tunnel

The new tunnel measures 2.28 miles, making it the company’s longest single Vegas Loop tunnel to date.

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Credit: The Boring Company/X

The Boring Company announced that its Prufrock-2 tunnel boring machine (TBM) has completed another Vegas Loop tunnel in Las Vegas. The company shared the update in a post on social media platform X.

According to The Boring Company’s post, the new tunnel measures 2.28 miles, making it the company’s longest single Vegas Loop tunnel to date.

The new tunnel marks the fourth tunnel constructed near Westgate Las Vegas as the Vegas Loop network continues expanding across the city.

The Boring Company also noted that the new tunnel surpassed its previous internal record of 2.26 miles for a single Vegas Loop segment.

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Construction of the tunnel involved moving roughly 68,000 cubic yards of dirt. The excavation process also used about 4.8 miles of continuous conveyor belt, powered by six motors totaling 825 horsepower.

The Boring Company’s Prufrock-series all-electric tunnel boring machines are designed to support the rapid expansion of company’s underground transportation projects, including the growing Vegas Loop network. Prufrock machines are designed for reusability, thanks in no small part to their capability to be deployed and retrieved easily through their “porposing” feature.

The Vegas Loop, specifically the Las Vegas Convention Center (LVCC) Loop segment, has already been used during major events. Most recently, the LVCC Loop supported the 2026 CONEXPO-CON/AGG construction trade show, which was held from March 3-7, 2026. 

As per The Boring Company, the LVCC Loop transported roughly 82,000 passengers across the convention center campus during the event’s duration. 

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CONEXPO-CON/AGG is one of the largest construction trade shows in North America, drawing more than 140,000 construction professionals from 128 countries this year.

The LVCC Loop forms the initial segment of the broader Vegas Loop network, which remains under active development as The Boring Company continues building new tunnels throughout the city.

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Tesla gathers Cybercab fleet in Gigafactory Texas

Images and video of the Cybercab fleet were shared by longtime Giga Texas observer Joe Tegtmeyer in posts on social media platform X.

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Credit: Credit: @JoeTegtmeyer/X

Tesla appears to be assembling a growing number of Cybercabs at Gigafactory Texas as preparations continue for the vehicle’s mass production. Recent footage shared online has shown over 30 Cybercabs being transported by trucks or staged near testing areas at the facility.

The images and video were shared by longtime Giga Texas observer and drone operator Joe Tegtmeyer in posts on social media platform X.

Interestingly enough, Tegtmeyer noted that many of the Cybercabs being loaded onto transport trucks were still equipped with steering wheels. This suggests that the vehicles are likely testing units rather than the final driverless configuration expected for the company’s Robotaxi service.

The vehicles could potentially be headed to testing sites across the United States as Tesla prepares to expand its Robotaxi fleet.

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Additional footage captured at Gigafactory Texas also showed the Cybercab’s side and rear camera washer system operating as vehicles were being loaded onto transport trucks.

The growing number of Cybercabs at Giga Texas comes amidst the company’s announcement that the first production Cybercab has been produced at the facility. Full Cybercab production is expected to begin in April.

The vehicle is expected to play a central role in Tesla’s Robotaxi ambitions as the company looks to expand autonomous ride-hailing operations beyond its early deployments using Model Y vehicles.

Tesla has also linked Cybercab production to its proposed Unboxed manufacturing process, which assembles large vehicle modules separately before integrating them. The approach is intended to reduce production costs and accelerate output.

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Musk has also noted that the Cybercab’s ramp will likely begin slowly due to the number of new components and manufacturing steps involved. However, he stated that once the process matures, Cybercab production could scale quickly.

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