Connect with us

News

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)

Published

on

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.

Check out Teslarati’s Marketplace! We offer Tesla accessories, including for the Tesla Cybertruck and Tesla Model 3.

Advertisement

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.

Advertisement
Comments

News

Tesla’s Supercharger Diner probably just secured more locations

Published

on

tesla diner
Credit: Tesla

Tesla’s Supercharger Diner in Los Angeles dominated the company’s global usage rankings after just one year, proving the concept is more than just a one-off novelty location that will fade away.

The performance could incite the company to build more locations, something that CEO Elon Musk has hinted at for some time.

Tesla’s Supercharger Diner delivered 21.2 GWh of energy in its first year of operation, the company’s head of Charging, Max de Zegher, revealed on X. Of the top 10 most utilized Supercharger locations in Tesla’s global infrastructure, the Diner in Los Angeles was the most used by drivers, and it wasn’t particularly close:

On its launch day one year ago, nobody was too sure what the Tesla Diner would be about. It seemed like an interesting concept, and considering it had been in the works for years, it was a highly anticipated launch that many were looking forward to.

Based on its success, we could see additional Diners with Superchargers built throughout the United States, and potentially beyond. Musk has said on several occasions that the company would be willing to bring the Diner idea to more markets.

Tesla makes major change at Supercharger Diner amid epic demand

Of the markets that Musk has mentioned, both Palo Alto and Austin have come to be perceived as ideal selections. However, there are no concrete plans as of now to build new Supercharger Diners anywhere; the location on Santa Monica Boulevard will remain the exclusive spot to pick up Tesla-inspired eats, at least for the time being.

Continue Reading

Investor's Corner

Tesla short sellers win big after shares fall after earnings

Published

on

A red Tesla Roadster driving around a turn
(Credit: Tesla)

Tesla short sellers won big following the company’s massive fall on Wall Street after it reported subpar Earnings on Wednesday.

Tesla short sellers collected about $4.12 billion in single-day profits on Thursday, according to BloombergShares fell as much as 15 percent during Thursday’s session. It closed as one of the worst days for Tesla on Wall Street in the past three years.

Investors sold off the stock after Tesla said it would aggressively direct its spending toward AI and its Optimus robot project. The company had record revenues, which were driven by one of the strongest quarters in terms of vehicle deliveries in company history.

However, it missed EPS estimates by reporting just $0.33, a far cry from the $0.53 analysts expected.

S3 Partners reported that about 3 percent of Tesla’s outstanding stock is sold short. Managing Director at S3, Ihor Dusaniwsky, provided the short seller’s potential profit, as well as another figure: shorts have likely had paper gains of $8.92 billion this year, as Tesla shares are down 30 percent in 2026.

Tesla (TSLA) Q2 2026 earnings results: miss on EPS, beat on revenue

Tesla has burned short sellers many times in the past, but the company’s latest Earnings Call was a chance for those skeptics to taste some payback. Although the company gave some very transparent information regarding future projects, the rollout of Robotaxi, Optimus, and Semi, many investors took their profits on Thursday.

Notable short sellers like Michael Burry have been transparent about their skepticism around Tesla shares. Burry just revealed three weeks ago that he had opened up a new short on the stock, stating he shorted Tesla shares at $416.22. “Happy it jumped back to this level,” he said in a blog post.

At the time of publication, Tesla shares were down about 3 percent and the stock was trading at $309.92.

Continue Reading

News

Tesla door handle saga gets its latest chapter and a big change is coming

Published

on

Credit: Tesla | Model 3 Owner's Manual

Tesla’s long-standing saga regarding its door handles and a manual release has entered its latest chapter, and as a result, a big change is coming.

On Friday, the National Highway Traffic Safety Administration (NHTSA) denied Tesla’s petition that was seeking a defect investigation into roughly 180,000 Model 3 vehicles for an issue involving the emergency mechanical door release.

NHTSA said that Tesla’s petition did not present evidence of a safety-related defect in the door handles or their emergency releases. Instead, the agency determined that it would rather solve the issue of the lack of labeling or location of emergency mechanical door releases and the federal safety rules that govern them.

Essentially, the NHTSA wants to create and enforce rules that would require automakers to make emergency door latch releases more clearly labeled in a car. Despite a Tesla having manual door releases on all four passenger doors, many people do not know they exist or how they work.

Tesla addresses door handle complaints with simple engineering fix

In recent times, Tesla has faced some criticism involving its door handles, specifically because some occupants have reported that they are unable to exit their vehicles after losing power. The door handles on a Tesla are electronically operated, but in the event that the 12V battery dies, there is a manual release that can be used.

The NHTSA only identified a single complaint involving the mechanical door releases: a 2022 Model 3 owner said the release was concealed and unlabeled after the vehicle lost power after a front-end collision. It has also already started to create a separate rulemaking process to make emergency door-egress systems more obvious.

It should be noted that all Teslas have mechanical emergency door releases, but they are placed in various locations as the vehicles have aged and been redesigned from year to year. Refer to the safety manual for your vehicle if you have any confusion about where the emergency releases are and how they work.

Continue Reading