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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 Sentry Mode helps lock up drive-by shooting suspect in Seattle

“A nearby Tesla actually captured the video that showed a man crouched behind a vehicle firing gunshots. A lot of vehicles record, and officers know that Teslas, especially, record, so we use that video all the time in these instances.”

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tesla side repeater camera
(Credit: Tesla)

Police in Seattle, Washington, are crediting Tesla’s well-known Sentry Mode for helping find a suspect in a drive-by shooting case.

A 21-year-old was arrested for an alleged drive-by shooting in the Pioneer Square neighborhood of Seattle this past Sunday, and the leads on the case seemed to be slim.

However, a Tesla parked nearby was able to record the shooting, as well as the car that the suspect hopped in after the crime occurred. It helped police identify the person they were looking for.

Seattle Police Department Detective Brian Pritchard said to MyNorthwest that the Tesla was a critical part of finding the suspect and placing him under arrest:

“A nearby Tesla actually captured the video that showed a man crouched behind a vehicle firing gunshots. A lot of vehicles record, and officers know that Teslas, especially, record, so we use that video all the time in these instances.”

The Tesla footage helped the Police put the suspect into handcuffs about an hour after the crime was committed. They are currently charged with drive-by shooting and unlawful possession of a firearm.

Tesla Sentry Mode is a security feature the vehicle utilizes to help solve crimes like vandalism, but it is also a cool feature that has caught things like accidents and other incidents on camera.

Many people still do not know about it, including the many vandals who keyed or broke the windows of Teslas earlier this year, as people damaged others’ cars in an act of retaliation against CEO Elon Musk when he became involved in politics.

This is far from the first time Sentry Mode has helped Police Departments solve crimes. Last September, we reported on Oakland’s Police Department in California using Teslas near crime scenes to help solve cases.

Tesla Sentry Mode is Oakland PD’s secret weapon against rising crime

Sergeant Ben Therriault, president of the Richmond Police Officers Association, said, “We have all these mobile video devices floating around,” in reference to the Teslas that sit and capture nearly everything that surrounds them.

Sentry Mode has helped officers arrest a variety of suspects, including several people who were allegedly involved in the murder of a 27-year-old woman in Northern California.

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Tesla investors are ditching Charles Schwab after its vote against Musk comp plan

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Tesla CEO Elon Musk unveils futuristic Cybertruck in Los Angeles, Nov. 21, 2019 (Photo: Teslarati)

Tesla investors are ditching Charles Schwab as their brokerage after the firm said earlier this week that it would vote against CEO Elon Musk’s new compensation package.

Several high-profile Tesla influencers are speaking out against Charles Schwab, saying its decision to vote against the plan that would retain Musk as CEO and give him potentially more voting power if he can achieve the tranches set by the company’s Board of Directors.

The Tesla community recognized that Schwab is one firm that tends to vote against Musk’s compensation plans, as they also voted against the CEO’s 2018 pay package, which was passed by shareholders but then denied by a Delaware Chancery Court.

Schwab’s move was recognized by investors within the Tesla community and now they are speaking out about it:

At least six of Charles Schwab’s ETFs have voted against Tesla’s Board recommendation to support the compensation plan for Musk. The six ETFs represent around 7 million Tesla $TSLA shares.

Jason DeBolt, an all-in Tesla shareholder, summarized the firm’s decision really well:

As a custodian of ETF shares, your fiduciary duty is to vote in shareholders’ best interests. For a board that has delivered extraordinary returns, voting against their recommendations doesn’t align with retail investors, Tesla employees, or the leadership we invested to support. If Schwab’s proxy voting policies don’t reflect shareholder interests, my followers and I will move our collective tens of millions in $TSLA shares (or possibly hundreds of millions) to a broker that does, via account transfer as soon as this week.”

Tesla shareholders will vote on Musk’s pay package on Thursday at the Annual Shareholders Meeting in Austin, Texas.

It seems more likely than not that it will pass, but investors have made it clear they want a decisive victory, as it could clear the path for any issues with shareholder lawsuits in the future, as it did with Musk’s past pay package.

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Tesla Cybertruck explosion probe ends with federal involvement and new questions

The 78-page document detailed a planned attack by former Green Beret Matthew Livelsberger, who died by suicide before the blast that injured six people.

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Credit: IAA Auctions

The Las Vegas Metropolitan Police Department (LVMPD) has released its final investigative report into the New Year’s Day Cybertruck explosion outside the Trump International Hotel. But instead of bringing clarity, the findings have only raised more questions. 

The 78-page document detailed a planned attack by former Green Beret Matthew Livelsberger, who died by suicide before the blast that injured six people.

The perpetrator’s manifesto

According to a Fox News report, Livelsberger rented the all-electric pickup through Turo while on leave from his Special Forces unit. He filled the rented Cybertruck with fireworks, gas cans, and camping fuel before driving it to the hotel shortly after 8:40 a.m. on January 1. Surveillance footage showed him pouring accelerant into the truck bed moments before detonation, confirming premeditation.

Livelsberger left a manifesto on his phone, which was later deemed classified by the Department of War. This case was then handed over to federal authorities. Still, the LVMPD and federal investigators noted in their report that the incident was a “vehicle-borne improvised explosive device” (VBIED) attack “with the potential to cause mass casualties and extensive structural damage.” Officials, however, stopped short of labeling it terrorism.

In digital notes, Livelsberger wrote that his act was not terror-related but intended as “a wake-up call,” criticizing what he called America’s “feckless leadership.” He wrote, “Americans only pay attention to spectacles and violence. What better way to get my point across than a stunt with fireworks and explosives.”

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The incident ironically showcased the Cybertruck’s durability

Tesla CEO Elon Musk was among the first to respond publicly after the blast, confirming through X that the company’s senior team was investigating the incident. He later stated that vehicle telemetry showed no malfunction and that the explosion was caused by “very large fireworks and/or a bomb” placed in the Cybertruck’s bed.

Ironically, footage of the incident in the Cybertruck’s bed showed that the vehicle’s durable construction actually helped contain the explosion by directing the blast upwards. The bed remained largely intact after the explosion as well. Even more surprisingly, the Cybertruck’s battery did not catch fire despite the blast.

Months later, the same Cybertruck appeared on the online auction platform IAA, marked as “not ready for sale.” The listing has stirred debate among Tesla fans about why the historic vehicle wasn’t reclaimed by the company. The vehicle, after all, could serve as a symbol of the Cybertruck’s resilience, even in extreme circumstances.

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