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SpaceX scrubs Starhopper’s final Raptor-powered flight as Elon Musk talks “finicky” igniters

SpaceX scrubbed Starhopper's second flight test on August 26th. Another attempt will follow on the 27th. (SpaceX)

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For unknown reasons, SpaceX’s Starhopper prototype suffered a hold just 0.8 seconds prior to its second planned flight test, a hold that was eventually followed by a decision to scrub the August 26th attempt and try again tomorrow, August 27th.

Starhopper is a full-scale, partial-height testbed for SpaceX’s next-generation Starship launch vehicle, serving more as a semi-mobile test stand for steel rockets and Raptor engines than an actual Starship prototype. The unusual vehicle took flight for the first time ever on July 25th, reaching an altitude of roughly 20m (65 ft) under the power of a single Raptor engine, capable of producing up to 200 tons (450,000 lbf) of thrust. That test also suffered a minor scrub on the 24th, followed by a successful flight one day later, a chapter that Starhopper may now mirror on its second attempted flight, a 150m (500 ft) hop.

Notably, SpaceX CEO Elon Musk took to Twitter just seconds after the rocket’s scheduled liftoff suffered a last-second hold to indicate that Raptor’s torch igniters were proving somewhat finicky relative to the chemical alternative used by SpaceX’s proven Merlin engines.

The CEO later confirmed that that comment was directly related to the 26th’s scrub, indicating that Raptor serial number 06 (SN06) needed to have its igniters inspected prior to a second hop test attempt, now scheduled to occur no earlier than 6pm EDT (22:00 UTC) on August 27th. The gist of the difficulties with Raptor’s igniter starts with the reason that SpaceX is attempting to integrate an entirely new form of ignition into the engine, replacing the methods successfully used over tens or even hundreds of thousands of seconds of firing with the company’s Merlin 1 and Merlin Vacuum engines.

Merlin 1D and MVacD both rely on a relatively simple, reliable, cheap, and easy method of chemical ignition, using a duo of pyrophoric materials known as triethylaluminum-triethylborane (TEA-TEB). When mixed, these materials immediately combust, generating an iconic green flash visible during Falcon 9 and Heavy launches, and thus producing the ‘spark’ needed to start Merlin engines.

Falcon 9 and Heavy use chemical means – TEA-TEB – to ignite all of their main and upper stage Merlin engines. (SpaceX)

Generally speaking, TEA-TEB is an excellent method of igniting rockets, even if it is more of a brute-force, inelegant solution than alternatives. It does, however, bring limitations: every single ignition requires a new ‘cartridge’ be expended, fundamentally limiting the number of times Merlin 1D (and Merlin Vacuum) engines can be ignited before and after liftoff.

This doesn’t even consider the fact that TEA-TEB are extremely complex chemical products that would be next to impossible to produce off of Earth, at least for the indefinite future.

To combat these downsides, SpaceX has designed Raptor with an entirely different method of ignition, known as torch ignition. Technically speaking, Raptor’s power, design, and methalox propellant combine to demand more than a relatively common solution, in which spark plugs are used to ignite an engine. Instead, Raptor uses those spark plugs to ignite its ignition sources, what CEO Elon Musk has described as full-up blow torches. Once ignited, those blow torches – likely miniature rocket engines using the same methane and oxygen fuel as Raptor – then ignite the engine’s methane and oxygen preburners before finally igniting those mixed, high-pressure gases in the combustion chamber.

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In simple terms, the fact that Raptor is a full-flow staged-combustion (FFSC) engine means that the pressures it must operate under are extreme, verging on unprecedented in large-scale rocketry. Extremely high-pressure gases (on the order of 3,000-10,000+ psi or 200-700+ bar) are just as difficult to reliably ignite, especially if hypergolic solutions (i.e. TEA-TEB) are off the table.

To get an even ignition – critical to avoid burn-through, minor explosions, and even catastrophic engine failures – Raptor’s torch ignition may actually involve a 360-degree ring of spark plug-lit torches around the point of ignition, an undeniably complex solution.

The first finalized Raptor engine (SN01) completed a successful static fire debut on the evening of February 3rd. (SpaceX)

However, as Musk notes, these significant, “finicky” challenges brought on by Raptor’s exotic ignition method are motivated by the potential benefits such a solution might bring. Relative to Merlin 1D’s TEA-TEB ignition, torch ignition – once optimized and matured into a reliable solution – will permit an almost unlimited number of Raptor ignitions before, during, and after flight.

Avoiding TEA-TEB and other complex chemical igniters also means that Starship will technically be able to launch to Mars or the Moon, perform injection and landing burns, maybe even hop around the surface, and still be able to return to Earth – all without resupply. Such a return voyage would still be predicated on the ability to generate the methane and oxygen propellant needed to fuel Starships, but – assuming that challenge can be solved – torch-lit Raptors would be ready for such a mission. In the event that, say, something like August 26th’s scrub happens to a Starship on Mars, the crew would also be able to get out, inspect Starship’s Raptors, and even replace faulty spark plugs if necessary.

For Starship to remain readily reusable in either of these situations, Raptor’s use of torch ignition will be absolutely critical. (SpaceX)

Technically, one could bring lots of spare TEA-TEB cartridges and install those in space or after landing, but those cartridges are quite literally firebombs waiting to ignite, whereas spare spark plugs are entirely inert.

For now, we’ll have to wait for SpaceX technicians to get their eyes and hands-on Starhopper’s lone Raptor engine to verify that its ignition hardware is in good health. If all goes well, Starhopper will attempt its final flight test as early as August 27th.

Update (August 27th): Starhopper is reportedly set for a second attempted 150m (500 ft) flight test today, scheduled to occur no earlier than 5pm EDT (21:00 UTC) on August 27th. Stay tuned for SpaceX’s official Livestream!

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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 Full Self-Driving set to get an awesome new feature, Elon Musk says

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Credit: Teslarati

Tesla Full Self-Driving is set to get an awesome new feature in the near future, CEO Elon Musk confirmed on X.

Full Self-Driving is the company’s semi-autonomous driving program, which is among the best available to the general public. It still relies on the driver to ultimately remain in control and pay attention, but it truly does make traveling less stressful and easier.

However, Tesla still continuously refines the software through Over-the-Air updates, which are meant to resolve shortcomings in the performance of the FSD suite. Generally, Tesla does a great job of this, but some updates are definitely regressions, at least with some of the features.

Tesla Cybertruck owner credits FSD for saving life after freeway medical emergency

Tesla and Musk are always trying to improve the suite’s performance by fixing features that are presently available, but they also try to add new things that would be beneficial to owners. One of those things, which is coming soon, is giving the driver the ability to prompt FSD with voice demands.

For example, asking the car to park close to the front door of your destination, or further away in an empty portion of the parking lot, would be an extremely beneficial feature. Adjusting navigation is possible through Grok integration, but it is not always effective.

Musk confirmed that voice prompts for FSD would be possible:

Tesla Full Self-Driving is a really great thing, but it definitely has its shortcomings. Navigation is among the biggest complaints that owners have, and it is easily my biggest frustration with using it. Some of the routes it chooses to take are truly mind-boggling.

Another thing it has had issues with is being situated in the correct lane at confusing intersections or even managing to properly navigate through local traffic signs. For example, in Pennsylvania, there are a lot of stop signs with “Except Right Turn” signs directly under.

This gives those turning right at a stop sign the opportunity to travel through it. FSD has had issues with this on several occasions.

Parking preferences would be highly beneficial and something that could be resolved with this voice prompt program. Grocery stores are full of carts not taken back by customers, and many people choose to park far away. Advising FSD of this preference would be a great advantage to owners.

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Cybertruck

Elon Musk clarifies Tesla Cybertruck ’10 day’ comment, fans respond

Some are arguing that the decision to confirm a price hike in ten days is sort of counterproductive, especially considering it is based on demand. Giving consumers a timeline of just ten days to make a big purchase like a pickup truck for $60,000, and basically stating the price will go up, will only push people to make a reservation.

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Credit: Tesla

Elon Musk has clarified what he meant by his comment on X yesterday that seemed to indicate that Tesla would either do away with the new All-Wheel-Drive configuration of the Cybertruck or adjust the price.

The response was cryptic as nobody truly knew what Musk’s plans were for the newest Tesla Cybertruck trim level. We now have that answer, and fans of the company are responding in a polarizing fashion.

On Thursday night, Tesla launched the Cybertruck All-Wheel-Drive, priced competitively at $59,990. It was a vast improvement from the Rear-Wheel-Drive configuration Tesla launched last year at a similar price point, which was eventually cancelled just a few months later due to low demand.

Tesla launches new Cybertruck trim with more features than ever for a low price

However, Musk said early on Friday, “just for 10 days,” the truck would either be available or priced at $59,990. We can now confirm Tesla will adjust the price based on more recent comments from the CEO.

Musk said the price will fluctuate, but it “depends on how much demand we see at this price level.”

Some are defending the decision, stating that it is simply logical to see how the Cybertruck sells at this price and adjust accordingly.

Others, not so much.

Some are arguing that the decision to confirm a price hike in ten days is sort of counterproductive, especially considering it is based on demand. Giving consumers a timeline of just ten days to make a big purchase like a pickup truck for $60,000, and basically stating the price will go up, will only push people to make a reservation.

Demand will look strong because people want to lock in this price. The price will inevitably go up, and demand for the trim will likely fall a bit because of the increased cost.

Many are arguing Musk should have kept this detail internal, but transparency is a good policy to have. It is a polarizing move to confirm a price increase in just a week-and-a-half, but the community is obviously split on how to feel.

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Cybertruck

Tesla Cybertruck’s newest trim will undergo massive change in ten days, Musk says

It appears as if the new All-Wheel-Drive trim of Cybertruck won’t be around for too long, however. Elon Musk revealed this morning that it will be around “only for the next 10 days.”

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(Credit: Tesla)

Tesla’s new Cybertruck trim has already gotten the axe from CEO Elon Musk, who said the All-Wheel-Drive configuration of the all-electric pickup will only be available “for the next ten days.”

Musk could mean the price, which is $59,990, or the availability of the trim altogether.

Last night, Tesla launched the All-Wheel-Drive configuration of the Cybertruck, a pickup that comes in at less than $60,000 and features a competitive range and features that are not far off from the offerings of the premium trim.

Tesla launches new Cybertruck trim with more features than ever for a low price

It was a nice surprise from Tesla, considering that last year, it offered a Rear-Wheel-Drive trim of the Cybertruck that only lasted a few months. It had extremely underwhelming demand because it was only $10,000 cheaper than the next trim level up, and it was missing a significant number of premium features.

Simply put, it was not worth the money. Tesla killed the RWD Cybertruck just a few months after offering it.

With the news that Tesla was offering this All-Wheel-Drive configuration of the Cybertruck, many fans and consumers were encouraged. The Cybertruck has been an underwhelming seller, and this seemed to be a lot of truck for the price when looking at its features:

  • Dual Motor AWD w/ est. 325 mi of range
  • Powered tonneau cover
  • Bed outlets (2x 120V + 1x 240V) & Powershare capability
  • Coil springs w/ adaptive damping
  • Heated first-row seats w/ textile material that is easy to clean
  • Steer-by-wire & Four Wheel Steering
  • 6’ x 4’ composite bed
  • Towing capacity of up to 7,500 lbs
  • Powered frunk

It appears as if this trim of Cybertruck won’t be around for too long, however. Musk revealed this morning that it will be around “only for the next 10 days.”

Musk could mean the price of the truck and not necessarily the ability to order it. However, most are taking it as a cancellation.

If it is, in fact, a short-term availability decision, it is baffling, especially as Tesla fans and analysts claim that metrics like quarterly deliveries are no longer important. This seems like a way to boost sales short-term, and if so many people are encouraged about this offering, why would it be kept around for such a short period of time?

Some are even considering the potential that Tesla axes the Cybertruck program as a whole. Although Musk said during the recent Q4 Earnings Call that Cybertruck would still be produced, the end of the Model S and Model X programs indicates Tesla might be prepared to do away with any low-volume vehicles that do not contribute to the company’s future visions of autonomy.

The decision to axe the car just ten days after making it available seems like a true head-scratcher.

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