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SpaceX Starship fires up three Raptor engines in prelude to high-altitude flight

Starship SN8 appears to have successfully fired up three Raptor engines simultaneously in a huge milestone for both the rocket and engine. (NASASpaceflight - bocachicagal)

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Update: At 1:21am CDT (6:21 UTC) on October 20th, Starship SN8 ignited all three of its Raptors’ preburners, producing a spectacular fireball noticeably larger than the one produced during the rocket’s first October 19th preburner test. A mere two hours later, with no break in between, the steel rocket prototype fully ignited all three Raptor engines for the first time ever, likely producing thrust equivalent to ~90% of a nine engine Falcon 9 booster for a brief moment.

Crucially, aside from physically demonstrating Raptor’s multi-engine capabilities, Starship SN8 – already a first-of-a-kind prototype – completed and survived a static fire seemingly unscathed on its first attempt. If the data SpaceX gathers from the milestone is as good as the test appeared to be, the company could be just a few days away from installing Starship SN8’s recently-stacked nosecone, followed by a second triple-Raptor static fire test. If that second static fire goes well, SN8’s next task will be the first high-altitude Starship flight test.

Minutes after an adjacent highway was scheduled to reopen, SpaceX’s first high-altitude Starship prototype – serial number 8 – attempted what was likely the first multi-engine Raptor test ever.

At 6:01 am, October 19th, Starship SN8’s trio of Raptor engines were barely unleashed, producing a large fireball indicative of a ‘preburner’ ignition test. One of the most complex rocket engines ever developed, Raptor relies on a maximally efficient but temperamental “full-flow staged combustion” cycle (FFSC), a concise name for the many, many steps required to turn liquid propellant into thrust.

Adding additional difficulty, Raptor’s full-flow staged combustion necessitates ignition of gaseous oxygen and methane in the combustion chamber. Given that the Raptor-powered Starship spacecraft and Super Heavy booster exclusively use cryogenic liquid methane and oxygen, a major challenge posed by FFSC is the need to efficiently turn that ultra-cold propellant into hot gas almost instantaneously. This is where gas generators (or preburners) come in.

In a full-flow staged combustion engine, both oxidizer and fuel require their own separate turbopumps, which then require their own preburners to create the pressures needed to power those turbopumps and the gas the combustion chamber ignites to produce thrust. A step further, to enable high combustion chamber pressure like Raptor’s 300+ bar (~4400+ psi), those preburners need to produce gas at far higher pressures to account for energy losses as those gases wind their way through the engine’s plumbing.

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As a result, preburners are possibly the single most stressed system in an engine like Raptor. Unsurprisingly, this has often lead SpaceX to separately test each engine’s preburners as a sort of partial static fire before the actual engine ignition test. This is the test Starship SN8 attempted in the early morning on October 19th, representing Raptor’s very first multi-engine ignition event.

Curiously, moments before preburner ignition, one of the three Raptor engines appeared to command an aggressive jet-like vent of liquid oxygen identical to a vent seen just a few hours prior during the first aborted preburner test. There’s thus a chance that only two of SN8’s three Raptor engines successfully started their preburners

Raptor is the first FFSC engine in the world to fly and – as far as the duration of lifetime testing and volume production goes – is almost certainly the most advanced of the three FFSC programs to graduate to static fire tests. In other words, given that SN8’s test campaign is the first time SpaceX has ever attempted to operate multiple adjacent Raptor engines at the same time, it’s not a huge surprise that progress towards the first three-engine static fire has been cautious and halting. Mirroring its Sunday/Monday testing, SpaceX will put Starship SN8 through another preburner and/or static fire attempt between 9pm and 6am CDT (UTC-5) on October 19/20. Even more 9-6 test windows are scheduled on October 21st and 22nd.

Nose section stacking beginneth. (NASASpaceflight – bocachicagal)

Meanwhile, not long after Starship SN8’s first preburner test was completed, SpaceX teams rolled a section of five steel rings inside a small windbreak and stacked the first truly functional nosecone – already outfitted with forward flaps – atop it. If Starship SN8 survives its first full triple-Raptor preburner and static fire tests, that new nosecone will likely be rolled to the launch pad for in-situ installation, topping off the rocket ahead of a spectacular 15 km (~50,000 ft) flight test.

A visual comparison of Starship Mk1’s (left) and Starship SN8’s nose sections make clear some of the refinements SpaceX has made in ~12 months. (NASASpaceflight – Nomadd)

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 hints toward Premium Robotaxi offering with Model S testing

Why Tesla has chosen to use a couple of Model S units must have a reason; the company is calculated in its engineering and data collection efforts, so this is definitely more than “we just felt like giving our drivers a change of scenery.”

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Credit: Sawyer Merritt | X

Tesla Model S vehicles were spotted performing validation testing with LiDAR rigs in California today, a pretty big switch-up compared to what we are used to seeing on the roads.

Tesla utilizes the Model Y crossover for its Robotaxi fleet. It is adequately sized, the most popular vehicle in its lineup, and is suitable for a wide variety of applications. It provides enough luxury for a single rider, but enough room for several passengers, if needed.

However, the testing has seemingly expanded to one of Tesla’s premium flagship offerings, as the Model S was spotted with the validation equipment that is seen entirely with Model Y vehicles. We have written several articles on Robotaxi testing mules being spotted across the United States, but this is a first:

Why Tesla has chosen to use a couple of Model S units must have a reason; the company is calculated in its engineering and data collection efforts, so this is definitely more than “we just felt like giving our drivers a change of scenery.”

It seems to hint that Tesla could add a premium, more luxury offering to its Robotaxi platform eventually. Think about it: Uber has Uber Black, Lyft has Lyft Black. These vehicles and services are associated with a more premium cost as they combine luxury models with more catered transportation options.

Tesla could be testing the waters here, and it could be thinking of adding the Model S to its fleet of ride-hailing vehicles.

Reluctant to remove the Model S from its production plans completely despite its low volume contributions to the overall mission of transitioning the world to sustainable energy, the flagship sedan has always meant something. CEO Elon Musk referred to it, along with its sibling Model X, as continuing on production lines due to “sentimental reasons.”

However, its purpose might have been expanded to justify keeping it around, and why not? It is a cozy, premium offering, and it would be great for those who want a little more luxury and are willing to pay a few extra dollars.

Of course, none of this is even close to confirmed. However, it is reasonable to speculate that the Model S could be a potential addition to the Robotaxi fleet. It’s capable of all the same things the Model Y is, but with more luxuriousness, and it could be the perfect addition to the futuristic fleet.

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Rivian unveils self-driving chip and autonomy plans to compete with Tesla

Rivian, a mainstay in the world of electric vehicle startups, said it plans to roll out an Autonomy+ subscription and one-time purchase program, priced at $49.99 per month and $2,500 up front, respectively, for access to its self-driving suite.

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Credit: Rivian

Rivian unveiled its self-driving chip and autonomy plans to compete with Tesla and others at its AI and Autonomy Day on Thursday in Palo Alto, California.

Rivian, a mainstay in the world of electric vehicle startups, said it plans to roll out an Autonomy+ subscription and one-time purchase program, priced at $49.99 per month and $2,500 up front, respectively, for access to its self-driving suite.

CEO RJ Scaringe said it will learn and become more confident and robust as more miles are driven and it gathers more data. This is what Tesla uses through a neural network, as it uses deep learning to improve with every mile traveled.

He said:

“I couldn’t be more excited for the work our teams are driving in autonomy and AI. Our updated hardware platform, which includes our in-house 1600 sparse TOPS inference chip, will enable us to achieve dramatic progress in self-driving to ultimately deliver on our goal of delivering L4. This represents an inflection point for the ownership experience – ultimately being able to give customers their time back when in the car.”

At first, Rivian plans to offer the service to personally-owned vehicles, and not operate as a ride-hailing service. However, ride-sharing is in the plans for the future, he said:

“While our initial focus will be on personally owned vehicles, which today represent a vast majority of the miles to the United States, this also enables us to pursue opportunities in the rideshare space.”

The Hardware

Rivian is not using a vision-only approach as Tesla does, and instead will rely on 11 cameras, five radar sensors, and a single LiDAR that will face forward.

It is also developing a chip in-house, which will be manufactured by TSMC, a supplier of Tesla’s as well. The chip will be known as RAP1 and will be about 50 times as powerful as the chip that is currently in Rivian vehicles. It will also do more than 800 trillion calculations every second.

RAP1 powers the Autonomy Compute Module 3, known as ACM3, which is Rivian’s third-generation autonomy computer.

ACM3 specs include:

  • 1600 sparse INT8 TOPS (Trillion Operations Per Second).
  • The processing power of 5 billion pixels per second.
  • RAP1 features RivLink, a low-latency interconnect technology allowing chips to be connected to multiply processing power, making it inherently extensible.
  • RAP1 is enabled by an in-house developed AI compiler and platform software

As far as LiDAR, Rivian plans to use it in forthcoming R2 cars to enable SAE Level 4 automated driving, which would allow people to sit in the back and, according to the agency’s ratings, “will not require you to take over driving.”

More Details

Rivian said it will also roll out advancements to the second-generation R1 vehicles in the near term with the addition of UHF, or Universal Hands-Free, which will be available on over 3.5 million miles of roadway in the U.S. and Canada.

Rivian will now join the competitive ranks with Tesla, Waymo, Zoox, and others, who are all in the race for autonomy.

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Tesla partners with Lemonade for new insurance program

Tesla recently was offered “almost free” coverage for Full Self-Driving by Lemonade’s Shai Wininger, President and Co-founder, who said it would be “happy to explore insuring Tesla FSD miles for (almost) free.”

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Credit: Tesla

Tesla owners in California, Oregon, and Arizona can now use Lemonade Insurance, the firm that recently said it could cover Full Self-Driving miles for “almost free.”

Lemonade, which offered the new service through its app, has three distinct advantages, it says:

  • Direct Connection for no telematics device needed
  • Better customer service
  • Smarter pricing

The company is known for offering unique, fee-based insurance rates through AI, and instead of keeping unclaimed premiums, it offers coverage through a flat free upfront. The leftover funds are donated to charities by its policyholders.

On Thursday, it announced that cars in three states would be able to be connected directly to the car through its smartphone app, enabling easier access to insurance factors through telematics:

Tesla recently was offered “almost free” coverage for Full Self-Driving by Lemonade’s Shai Wininger, President and Co-founder, who said it would be “happy to explore insuring Tesla FSD miles for (almost) free.”

The strategy would be one of the most unique, as it would provide Tesla drivers with stable, accurate, and consistent insurance rates, while also incentivizing owners to utilize Full Self-Driving for their travel miles.

Tesla Full Self-Driving gets an offer to be insured for ‘almost free’

This would make FSD more cost-effective for owners and contribute to the company’s data collection efforts.

Data also backs Tesla Full Self-Driving’s advantages as a safety net for drivers. Recent figures indicate it was nine times less likely to be in an accident compared to the national average, registering an accident every 6.36 million miles. The NHTSA says a crash occurs approximately every 702,000 miles.

Tesla also offers its own in-house insurance program, which is currently offered in twelve states so far. The company is attempting to enter more areas of the U.S., with recent filings indicating the company wants to enter Florida and offer insurance to drivers in that state.

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