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SpaceX scrubs Starhopper’s final Raptor-powered flight as Elon Musk talks “finicky” igniters
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.
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.
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.
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.
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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After launching in Austin, Texas, last week, Tesla is looking to expand the Cybercab to new parts of the United States in an effort that will see the driverless, steering wheel-less, and pedal-less vehicle chauffeur people around as part of the Robotaxi ride-hailing service.
However, the expansion will go far beyond the United States, and CEO Elon Musk revealed he hopes Europe will be the next market where Cybercab will be operational.
Musk has publicly expressed hope that Tesla’s Cybercab robotaxi will reach Europe in the near future.
On September 8, Tesla’s Chief Executive quoted a German rider who had just completed a trip in Austin, Texas, and wrote that he hoped the vehicle would not take years to arrive in Germany. Musk replied with a short but notable message: “Hopefully soon in Europe too.”
Hopefully soon in Europe too https://t.co/vqQ69bLJuN
— Elon Musk (@elonmusk) September 8, 2026
The comment arrived only days after Tesla opened Cybercab ride-hailing to the public in Austin. The two-seat vehicle has no steering wheel or pedals and relies entirely on Tesla’s Full Self-Driving software. Early passengers have described the rides as quiet, smooth, and more stylish than competing robotaxis such as Waymo.
Austin is currently the only city where members of the public can hail a Cybercab through Tesla’s Robotaxi app. The initial fleet is small; Texas registration records show only a few dozen of the purpose-built vehicles on the road.
Tesla set to open Cybercab rides to the public, with no steering wheel or pedals
Tesla has also been operating a larger number of conventional Model Y robotaxis in the same area, but the Cybercab itself represents the company’s first dedicated, controls-free taxi design.
Europe presents a different regulatory picture. The European Union does not permit manufacturers to self-certify vehicles the way Tesla did in the United States.
Type-approval rules and a small-series limit of 1,500 automated vehicles per type per year apply across the bloc.
Supervised Full Self-Driving has gained provisional approval in several member states through national recognition of Dutch certification, yet unsupervised robotaxi operation remains a separate and more distant step. Tesla has not announced a European launch city, date, or approval pathway for the Cybercab.
Musk himself has previously cautioned that the company does not control European regulators. In an earnings call earlier in 2026, he noted that even supervised FSD took an “immense amount of time” to clear and that unsupervised service would be “somewhat at the mercy of the governments in Europe and the EU.”
The latest social-media remark therefore functions more as an expression of intent than a timetable.
If the Cybercab eventually reaches European streets, it would mark a significant expansion of Tesla’s robotaxi ambitions beyond the United States. For now, the vehicle remains an Austin-only experience, and the gap between Musk’s hope and actual deployment will be decided by regulators rather than by engineering alone.
Tesla Cybercab might have just rolled out to the public as it entered the company’s Robotaxi suite in Austin this past week. However, the vehicle might already be on its way to becoming even better, as the company is asking riders to describe what they’d like to see improved with the Cybercab.
Tesla sent a rider experience survey to Cybercab passengers only days after paid rides began in Austin. The questionnaire asks how satisfied riders were with the overall trip. Then it requests star ratings for availability and wait time, door functionality, vehicle touchscreen, mobile app experience, seat comfort, interior space, ride comfort, cleanliness, and cargo space.
A later section asks which features riders would most like to have and allows selection of up to three items from a list that includes heated seats, ventilated seats, fully reclining seats, a tray table, a wireless phone charger, a better sound system, and more storage. Respondents may also choose none of these or write in another idea. The survey closes with a recommendation score from zero to ten.
Tesla just sent out a Cybercab rider experience survey so you can give feedback to the team. pic.twitter.com/YsU5OYdAjW
— Sawyer Merritt (@SawyerMerritt) September 8, 2026
This rapid request for input illustrates Tesla’s habit of treating early users as collaborators rather than mere customers. The company has long refined vehicles through software updates and hardware changes informed by real-world use across its passenger cars.
Collecting structured opinions so soon after commercial service started shows the same mindset applied to a purpose-built autonomous taxi. The questions themselves reveal an openness to cabin changes even after the first vehicles reached public streets, which is no surprise.
Tesla has always hoped to cater a great experience to anyone in its vehicles, which is why so many fan-requested features have made it into its vehicles.
Replies already circulating online favor reclining seats, tray tables, wireless charging, improved audio, and extra room when seats fold back.
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Those preferences point toward comfort upgrades that Tesla can implement in later production batches or through cabin revisions. Because the Cybercab is designed around software first principles, many requested amenities can arrive faster than in traditional automakers.
Tesla’s willingness to survey riders immediately after launch therefore makes near-term cabin and experience improvements likely as the team reviews responses and iterates toward a more refined robotaxi people will choose daily.
Tesla Cybertruck Lead Engineer Wes Morrill revealed the company has made several changes to the all-electric pickup, which he calls a “living thing, constantly evolving and improving.”
Cybertruck is manufactured at Tesla’s Gigafactory Texas just outside of Austin, and over the past few years, Tesla has continued to make small changes to the pickup to improve everything from cost, reliability, serviceablility, and manufacturability.
“The finish line isn’t getting to production. A product is a living thing, constantly evolving and improving,” Morrill added.
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Some of those changes are yet to be revealed, but perhaps the most notable one was the change Tesla made to the aero shield that sits underneath the truck. In the past, it was aluminum, but now the Cybertruck is using a self-reinforcing polypropylene.
Morrill said that the polypropylene is “stretched into fibers and then laminated into the form,” and is much more durable, much lighter, and significantly cheaper than aluminum when it is manufactured this way.
It also enabled some improvements in the geometry of the Cybertruck, improving the manufacturing around the bolts and edges, in addition to minor form changes. These all benefitted the Cybertruck in more ways than one: specifically with durability and improved drag.
I was surprised by how interested people were to find out we made a relatively benign change to the Cybertruck aero shield, a part of the car most people never even see. So I’ll share some more details.
Here are two photos, the left is one of the latest trucks off the… pic.twitter.com/F5cZo2CZKf
— Wes (@wmorrill3) September 7, 2026
Typically, Teslas are not necessarily identified by model year because these changes are fluid and occur when the company sees fit to implement them. It is not like other automotive companies, which usually make sweeping manufacturing changes when building a new model year.
Instead, Teslas are recognized by their “generation” or “era.” For example, those with a newer Model Y might refer to their car as a “Juniper.” This is the same with Model 3, as many refer to the new body style as the “Highland.”
Tesla’s manufacturing changes are proof of the company’s constant need to improve its products and move things forward with its vehicles. There is no need to drag one’s feet and wait until next year if the product can be made better right now, and that’s precisely what Tesla did with the Cybertruck.
Elon Musk hints at Tesla Cybercab’s next market
Tesla Cybercab improvements are already on the minds of company engineers
