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SpaceX Starship test tank survives first two nights of stress testing

SpaceX's newest Starship test tank has survived the first round of stress testing. SN2 - very similar to SN7.1 - is pictured here in March 2020. (NASASpaceflight - bocachicagal)

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SpaceX’s newest Starship test tank has survived the first two nights of stress testing, pushing the steel tank one step closer to a destructive finale.

Known as Starship SN7.1, the new tank – aside from one critical difference – is similar to Starship SN2 (pictured above), a full-scale prototype SpaceX repurposed into a test tank in March 2020. SN2 served to test improvements made to the design of Starship’s “thrust puck,” a dense steel cone that must transmit the thrust of three Raptor engines through the rest of the rocket. Much like SN2, SN7.1 is a test tank with a focus on the behavior of Starship’s engine section under extreme loads at cryogenic temperatures.

Unlike SN2, however, SN7.1 is built almost entirely out of a new steel alloy – closer to 304L than the 301 stainless used on all previous prototypes.

SN2, July 2020. (NASASpaceflight – bocachicagal)
Design-wise, SN7.1 is almost identical to SN2. (NASASpaceflight – bocachicagal)

SpaceX rolled the tank to the launch site and pressurized it with cryogenic liquid nitrogen on September 10th as part of a routine “cryo proof” acceptance test. SN7.1 appeared to complete that proof without issue, exhibiting no leaks or unusual behavior, and likely reached pressures of 7.5-8 bar (~110-120 psi) before detanking.

Over the next three days, SpaceX inspected the test tank, relocated it to a more capable (and expensive) test stand, and connected hydraulic rams (used to mechanically simulate engine thrust) to its thrust puck.

While SpaceX never confirmed results, Starship test tank SN7 is believed to have broken pressure records before it burst, a strong sign that the new steel alloy is the superior choice for future prototypes. (NASASpaceflight – bocachicagal

Around midnight on September 15th, SpaceX kicked off the first round of SN7.1 stress testing, repeatedly loading and unloading the tank with liquid nitrogen. While it’s impossible to visually confirm the use of the stand’s hydraulic rams, it’s safe to assume that SpaceX used them to stress SN7.1’s thrust puck while chilled to cryogenic temperatures. The new steel alloy SpaceX is using on SN7.x and prototypes SN8 and beyond is designed to be less brittle at cryogenic temperatures, nominally ensuring that flawed or aged Starship tanks leak before they burst or explode.

Aside from the obvious triple-Raptor thrust simulation, SpaceX likely also simulated thrust from one or two Raptors to verify the new design’s ability to survive asymmetric thrust in engine-out scenarios. Ultimately, SN7.1 made it through the night without obvious issues and there have been no signs of leak-fixing today, suggesting that the tank performed well. SpaceX has a second SN7.1 test period scheduled to begin on September 17th, as well as backups on the 15th, 16th, 20th, and 21st. More likely than not, SN7.1’s next test will end when the tank is intentionally pressurized to failure.

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Update: SpaceX has kicked off another night of SN7.1 stress testing, beginning almost as soon as the nine-hour window opened (9pm CDT (UTC-5) on September 15th). As of midnight, the company has already put the test tank through one cycle, rapidly filling and pressurizing it with liquid nitrogen before detanking. It remains to be seen if the company will continue testing this window, which closes at 6am on Wednesday. There is also a chance that SpaceX will intentionally pressurize SN7.1 to failure tonight, although it’s much more likely that the tank will be returned to a cheaper, simpler transport stand rather than risking damage to a new launch mount.

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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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GM takes latest step to avoid disaster as EV efforts get derailed

There was an even larger step taken this morning, as the Detroit Free Press reported that GM was idling its Factory Zero plant in Michigan until late November, placing about 1,200 workers on indefinite layoff status.

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Credit: GM

General Motors has taken its latest step to avoid financial disaster as its electric vehicle efforts have been widely derailed.

GM’s electric vehicle manufacturing efforts started off hot, and CEO Mary Barra seemed to have a real hold on how the industry and consumers were starting to evolve toward sustainable powertrains. Even former President Joe Biden commended her as being a major force in the global transition to EVs.

However, the company’s plans have not gone as they’ve drawn them up. GM has reported some underwhelming delivery figures in recent quarters, and with the loss of the $7,500 tax credit, the company is planning for what is likely a substantial setback in its entire EV division.

Earlier this month, the company reported it would include a $1.6 billion charge in its quarterly earnings results from EV investments. It was the first true sign that things with GM’s EV projects were going to slow down.

There was an even larger step taken this morning, as the Detroit Free Press reported that GM was idling its Factory Zero plant in Michigan until late November, placing about 1,200 workers on indefinite layoff status.

This is in addition to the 280 employees it has already laid off after production cuts that happened earlier this year at the Detroit-Hamtramck plant.

After November 24, GM will bring back 3,200 people to work until January 5 to operate both shifts. On January 5, GM is expected to keep 1,200 workers on indefinite layoff.

GM is not the only legacy automaker to make a move like this, as Ford has also started to make a move that reflects a cautious tone regarding how far and how committed it can be to its EV efforts.

After the tax credit was lost, it seemed to be a game of who would be able to float their efforts longest without the government’s help. Tesla CEO Elon Musk long said that the loss of these subsidies would help the company and hurt its competitors, and so far, that is what we are seeing.

Elon Musk was right all along about Tesla’s rivals and EV subsidies

However, Tesla still has some things to figure out, including how its delivery numbers will be without the tax credit. Its best quarter came in Q3 as the credit was expiring, but Tesla did roll out some more affordable models after the turn of the quarter.

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Tesla expands Robotaxi geofence, but not the garage

This has broadened its geofence to nearly three times the size of Waymo’s current service area, which is great from a comparative standpoint. However, there seems to be something that also needs to be expanded as the geofence gets larger: the size of the Robotaxi fleet.

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Credit: Joe Tegtmeyer | X

Tesla has expanded its Robotaxi geofence four times, once as recently as this week.

However, the company has seemingly kept its fleet size relatively small compared to the size of the service area, making some people — even pro-Tesla influencers — ask for more transparency and an expansion of the number of vehicles it has operating.

Over the past four months, Tesla has done an excellent job of maintaining growth with its service area in Austin as it continues to roll out the early stages of what is the Robotaxi platform.

The most recent expansion brought its size from 170 square miles (440.298 sq. km) to 243 square miles (629.367 sq. km).

Tesla sends clear message to Waymo with latest Austin Robotaxi move

This has broadened its geofence to nearly three times the size of Waymo’s current service area, which is great from a comparative standpoint. However, there seems to be something that also needs to be expanded as the geofence gets larger: the size of the Robotaxi fleet.

Tesla has never revealed exactly how many Model Y vehicles it is using in Austin for its partially driverless ride-hailing service (We say partial because the Safety Monitor moves to the driver’s seat for freeway routes).

When it first launched Robotaxi, Tesla said it would be a small fleet size, between 10 and 20 vehicles. In late August, after its second expansion of the service area, it then said it “also increased the number of cars available by 50 percent.”

Tesla reveals it has expanded its Robotaxi fleet in Austin

The problem is, nobody knows how many cars were in the fleet to begin with, so there’s no real concrete figure on how many Robotaxis were available.

This has caused some frustration for users, who have talked about the inability to get rides smoothly. As the geofence has gotten larger, there has only been one mentioned increase in the fleet.

Tesla did not reveal any new figures or expansion plans in terms of fleet size in the recent Q3 Earnings Call, but there is still a true frustration among many because the company will not reveal an exact figure.

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Tesla recalls 6,197 Cybertrucks for light bar adhesive issue

On October 20, Tesla issued a voluntary recall of the impacted vehicles and has identified 619 warranty claims and just a single field report that is related to the issue. 

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Credit: Francisco Garcia (via Greggertruck on X)

Tesla has recalled 6,197 Cybertrucks for a light bar adhesive issue that was utilized by Service to install the aftermarket part.

According to the National Highway Traffic Safety Administration (NHTSA), impacted vehicles may have had the light bar “inadvertently attached to the windshield using the incorrect surface primer.”

Tesla identified an issue with the light bar’s adhesion to glass back in February and worked for months to find a solution. In October, the company performed chemical testing as a part of an engineering study and determined the root cause as the BetaPrime primer it utilized, figuring out that it was not the right surface priming material to use for this specific application.

On October 20, Tesla issued a voluntary recall of the impacted vehicles and has identified 619 warranty claims and just a single field report that is related to the issue.

The component is manufactured by a Romanian company called Hella Romania S.R.L., but the issue is not the primer’s quality. Instead, it is simply the fact that it is not the correct adhesive for this specific type of application.

Tesla says there are no reports of injuries or deaths due to this issue, and it will be resolved. In the 473 report that the NHTSA released this morning, Tesla said:

“At no charge to customers, Tesla will inspect the service-installed optional off-road light bar accessory for delamination or damage and if either is present, replace the light bar with a new light bar adhered with tape and a positive mechanical attachment. If no delamination or damage is present, Tesla will retrofit the service-installed optional off-road light bar accessory with a positive mechanical attachment.”

This is the third recall applied to Cybertrucks this year, as one on March 18 highlighted the potential for exterior trim panels to detach while driving, and another earlier this month when the NHTSA said its front parking lights were too bright.

Tesla resolved the first with a free assembly replacement, while the headlight issue was fixed with an Over-the-Air software update earlier this week. Owners said there was a noticeable difference in the brightness of the lights now compared to previously.

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