Connect with us

News

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)

Published

on

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.

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!

Check out Teslarati’s Marketplace! We offer Tesla accessories, including for the Tesla Cybertruck and Tesla Model 3.

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.

Advertisement
Comments

Elon Musk

SpaceX reportedly discussing merger with xAI ahead of blockbuster IPO

Published

on

Credit: SpaceX/X

In a groundbreaking new report from Reuters, SpaceX is reportedly discussing merger possibilities with xAI ahead of the space exploration company’s plans to IPO later this year, in what would be a blockbuster move.

The outlet said it would combine rockets and Starlink satellites, as well as the X social media platform and AI project Grok under one roof. The report cites “a person briefed on the matter and two recent company filings seen by Reuters.”

Musk, nor SpaceX or xAI, have commented on the report, so, as of now, it is unconfirmed.

With that being said, the proposed merger would bring shares of xAI in exchange for shares of SpaceX. Both companies were registered in Nevada to expedite the transaction, according to the report.

Tesla announces massive investment into xAI

On January 21, both entities were registered in Nevada. The report continues:

“One of them, a limited liability company, lists SpaceX ​and Bret Johnsen, the company’s chief financial officer, as managing members, while the other lists Johnsen as the company’s only officer, the filings show.”

The source also stated that some xAI executives could be given the option to receive cash in lieu of SpaceX stock. No agreement has been reached, nothing has been signed, and the timing and structure, as well as other important details, have not been finalized.

SpaceX is valued at $800 billion and is the most valuable privately held company, while xAI is valued at $230 billion as of November. SpaceX could be going public later this year, as Musk has said as recently as December that the company would offer its stock publicly.

SpaceX IPO is coming, CEO Elon Musk confirms

The plans could help move along plans for large-scale data centers in space, something Musk has discussed on several occasions over the past few months.

At the World Economic Forum last week, Musk said:

“It’s a no-brainer for building solar-powered AI data centers in space, because as I mentioned, it’s also very cold in space. The net effect is that the lowest cost place to put AI will be space and that will be true within two to three years, three at the latest.”

He also said on X that “the most important thing in the next 3-4 years is data centers in space.”

If the report is true and the two companies end up coming together, it would not be the first time Musk’s companies have ended up coming together. He used Tesla stock to purchase SolarCity back in 2016. Last year, X became part of xAI in a share swap.

Continue Reading

Elon Musk

Tesla hits major milestone with Full Self-Driving subscriptions

Published

on

Credit: Ashok Elluswamy/X

Tesla has announced it has hit a major milestone with Full Self-Driving subscriptions, shortly after it said it would exclusively offer the suite without the option to purchase it outright.

Tesla announced on Wednesday during its Q4 Earnings Call for 2025 that it had officially eclipsed the one million subscription mark for its Full Self-Driving suite. This represented a 38 percent increase year-over-year.

This is up from the roughly 800,000 active subscriptions it reported last year. The company has seen significant increases in FSD adoption over the past few years, as in 2021, it reported just 400,000. In 2022, it was up to 500,000 and, one year later, it had eclipsed 600,000.

In mid-January, CEO Elon Musk announced that the company would transition away from giving the option to purchase the Full Self-Driving suite outright, opting for the subscription program exclusively.

Musk said on X:

“Tesla will stop selling FSD after Feb 14. FSD will only be available as a monthly subscription thereafter.”

The move intends to streamline the Full Self-Driving purchase option, and gives Tesla more control over its revenue, and closes off the ability to buy it outright for a bargain when Musk has said its value could be close to $100,000 when it reaches full autonomy.

It also caters to Musk’s newest compensation package. One tranche requires Tesla to achieve 10 million active FSD subscriptions, and now that it has reached one million, it is already seeing some growth.

The strategy that Tesla will use to achieve this lofty goal is still under wraps. The most ideal solution would be to offer a less expensive version of the suite, which is not likely considering the company is increasing its capabilities, and it is becoming more robust.

Tesla is shifting FSD to a subscription-only model, confirms Elon Musk

Currently, Tesla’s FSD subscription price is $99 per month, but Musk said this price will increase, which seems counterintuitive to its goal of increasing the take rate. With that being said, it will be interesting to see what Tesla does to navigate growth while offering a robust FSD suite.

Continue Reading

News

Tesla confirms Robotaxi expansion plans with new cities and aggressive timeline

Tesla plans to launch in Dallas, Houston, Phoenix, Miami, Orlando, Tampa, and Las Vegas. It lists the Bay Area as “Safety Driver,” and Austin as “Ramping Unsupervised.”

Published

on

Credit: Tesla

Tesla confirmed its intentions to expand the Robotaxi program in the United States with an aggressive timeline that aims to send the ride-hailing service to several large cities very soon.

The Robotaxi program is currently active in Austin, Texas, and the California Bay Area, but Tesla has received some approvals for testing in other areas of the U.S., although it has not launched in those areas quite yet.

However, the time is coming.

During Tesla’s Q4 Earnings Call last night, the company confirmed that it plans to expand the Robotaxi program aggressively, hoping to launch in seven new cities in the first half of the year.

Tesla plans to launch in Dallas, Houston, Phoenix, Miami, Orlando, Tampa, and Las Vegas. It lists the Bay Area as “Safety Driver,” and Austin as “Ramping Unsupervised.”

These details were released in the Earnings Shareholder Deck, which is published shortly before the Earnings Call:

Late last year, Tesla revealed it had planned to launch Robotaxi in Las Vegas, Phoenix, Dallas, and Houston, but Tampa and Orlando were just added to the plans, signaling an even more aggressive expansion than originally planned.

Tesla feels extremely confident in its Robotaxi program, and that has been reiterated many times.

Although skeptics still remain hesitant to believe the prowess Tesla has seemingly proven in its development of an autonomous driving suite, the company has been operating a successful program in Austin and the Bay Area for months.

In fact, it announced it achieved nearly 700,000 paid Robotaxi miles since launching Robotaxi last June.

With the expansion, Tesla will be able to penetrate more of the ride-sharing market, disrupting the human-operated platforms like Uber and Lyft, which are usually more expensive and are dependent on availability.

Tesla launched driverless rides in Austin last week, but they’ve been few and far between, as the company is certainly easing into the program with a very cautiously optimistic attitude, aiming to prioritize safety.

Continue Reading