News
SpaceX wiggles Starhopper’s Raptor engine, tests parts ahead of hover test debut
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.
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.
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.
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.
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Elon Musk
Tesla investors will be shocked by Jim Cramer’s latest assessment
Jim Cramer is now speaking positively about Tesla, especially in terms of its Robotaxi performance and its perception as a company.
Tesla investors will be shocked by analyst Jim Cramer’s latest assessment of the company.
When it comes to Tesla analysts, many of them are consistent. The bulls usually stay the bulls, and the bears usually stay the bears. The notable analysts on each side are Dan Ives and Adam Jonas for the bulls, and Gordon Johnson for the bears.
Jim Cramer is one analyst who does not necessarily fit this mold. Cramer, who hosts CNBC’s Mad Money, has switched his opinion on Tesla stock (NASDAQ: TSLA) many times.
He has been bullish, like he was when he said the stock was a “sleeping giant” two years ago, and he has been bearish, like he was when he said there was “nothing magnificent” about the company just a few months ago.
Now, he is back to being a bull.
Cramer’s comments were related to two key points: how NVIDIA CEO Jensen Huang describes Tesla after working closely with the Company through their transactions, and how it is not a car company, as well as the recent launch of the Robotaxi fleet.
Jensen Huang’s Tesla Narrative
Cramer says that the narrative on quarterly and annual deliveries is overblown, and those who continue to worry about Tesla’s performance on that metric are misled.
“It’s not a car company,” he said.
He went on to say that people like Huang speak highly of Tesla, and that should be enough to deter any true skepticism:
“I believe what Musk says cause Musk is working with Jensen and Jensen’s telling me what’s happening on the other side is pretty amazing.”
Tesla self-driving development gets huge compliment from NVIDIA CEO
Robotaxi Launch
Many media outlets are being extremely negative regarding the early rollout of Tesla’s Robotaxi platform in Austin, Texas.
There have been a handful of small issues, but nothing significant. Cramer says that humans make mistakes in vehicles too, yet, when Tesla’s test phase of the Robotaxi does it, it’s front page news and needs to be magnified.
He said:
“Look, I mean, drivers make mistakes all the time. Why should we hold Tesla to a standard where there can be no mistakes?”
It’s refreshing to hear Cramer speak logically about the Robotaxi fleet, as Tesla has taken every measure to ensure there are no mishaps. There are safety monitors in the passenger seat, and the area of travel is limited, confined to a small number of people.
Tesla is still improving and hopes to remove teleoperators and safety monitors slowly, as CEO Elon Musk said more freedom could be granted within one or two months.
News
Tesla launches ultra-fast V4 Superchargers in China for the first time
Tesla has V4 Superchargers rolling out in China for the first time.
Tesla already has nearly 12,000 Supercharger piles across mainland China. However, the company just initiated the rollout of the ultra-fast V4 Superchargers in China for the first time, bringing its quick-charging piles to the country for the first time since their launch last year.
The first batch of V4 Superchargers is now officially up and running in China, the company announced in a post on Chinese social media outlet Weibo today.
The company said in the post:
“The first batch of Tesla V4 Superchargers are online. Covering more service areas, high-speed charging is more convenient, and six-layer powerful protection such as rain and waterproof makes charging very safe. Simultaneously open to non-Tesla vehicles, and other brands of vehicles can also be charged. There are more than 70,000 Tesla Superchargers worldwide. The charging network layout covers 100% of the provincial capitals and municipalities in mainland China. More V4 Superchargers will be put into use across the country. Optimize the charging experience and improve energy replenishment efficiency. Tesla will accompany you to the mountains, rivers, lakes, and seas with pure electricity!”
The first V4 Superchargers Tesla installed in China are available in four cities across the country: Shanghai, Zhejiang, Gansu, and Chongqing.
Credit: Tesla China
Tesla has over 70,000 Superchargers worldwide. It is the most expansive and robust EV charging network in the world. It’s the main reason why so many companies have chosen to adopt Tesla’s charging connector in North America and Europe.
In China, some EVs can use Tesla Superchargers as well.
The V4 Supercharger is capable of charging vehicles at speeds of up to 325kW for vehicles in North America. This equates to over 1,000 miles per hour of charging.
Elon Musk
Elon Musk hints at when Tesla could reduce Safety Monitors from Robotaxi
Tesla could be reducing Safety Monitors from Robotaxi within ‘a month or two,’ CEO Elon Musk says.
Elon Musk hinted at when Tesla could begin reducing Safety Monitors from its Robotaxis. Safety Monitors are Tesla employees who sit in the front passenger seat during the driverless rides, and are there to ensure safety for occupants during the earliest rides.
Tesla launched its Robotaxi fleet in Austin last Sunday, and after eight days, videos and reviews from those who have ridden in the driverless vehicles have shown that the suite is safe, accurate, and well coordinated. However, there have been a few hiccups, but nothing that has put anyone’s safety in danger.
A vast majority — close to all of the rides — at least according to those who have ridden in the Robotaxi, have been performed without any real need for human intervention. We reported on what was the first intervention last week, as a Safety Monitor had to step in and stop the vehicle in a strange interaction with a UPS truck.
Watch the first true Tesla Robotaxi intervention by safety monitor
The Tesla and UPS delivery truck were going for the same street parking space, and the Tesla began to turn into it. The UPS driver parallel parked into the spot, which was much smaller than his truck. It seemed to be more of an instance of human error instead of the Robotaxi making the wrong move. This is something that the driverless cars will have to deal with because humans are aggressive and sometimes make moves they should not.
The Safety Monitors have not been too active in the vehicles. After all, we’ve only seen that single instance of an intervention. There was also an issue with the sun, when the Tesla braked abnormally due to the glare, but this was an instance where the car handled the scenario and proceeded normally.
With the Robotaxi fleet operating impressively, some are wondering when Tesla will begin scaling back both the Safety Monitors and Teleoperators that it is using to ensure safety with these early rides.
CEO Elon Musk answered the inquiry by stating, “As soon as we feel it is safe to do so. Probably within a month or two.”
As soon as we feel it is safe to do so.
Probably within a month or two. We continue to improve the Tesla AI with each mile driven.
— Elon Musk (@elonmusk) June 30, 2025
Musk’s response seems to confirm that there will be fewer Teleoperators and Safety Monitors in the coming months, but there will still be some within the fleet to ensure safety. Eventually, that number will get to zero.
Reaching a point where Tesla’s Robotaxi is driverless will be another significant milestone for the company and its path to fully autonomous ride-sharing.
Eventually, Tesla will roll out these capabilities to consumer-owned vehicles, offering them a path to generate revenue as their car operates autonomously and completes rides.
For now, Tesla is focusing on perfecting the area of Austin where it is currently offering driverless rides for just $4.20 to a small group of people.
Tesla investors will be shocked by Jim Cramer’s latest assessment
Tesla launches ultra-fast V4 Superchargers in China for the first time
Elon Musk hints at when Tesla could reduce Safety Monitors from Robotaxi
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