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SpaceX’s Starship hopper spotted with trio of dual-bell Raptor engines

Starship revealed a trio of what appear to be new Raptor engines when SpaceX technicians moved the assembly from stand to ground. (NSF - bocachicagal)

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Following a brief ‘hop’ (via crane) off of a concrete build stand, the aft section of SpaceX’s first full-scale Starship hopper (Starhopper?) revealed that SpaceX technicians have already installed what appear to be three real Raptor engines, presumably the first time the propulsion system has ever been mounted to something that might eventually fly.

For a number of reasons, there is a strong chance that these Raptors are actually just boilerplate placeholders standing in as structural guides for the real deal some months down the line. On the other hand, there are also a number of reasons to assume that these apparent engines are indeed real Raptors.

Despite an already shocking series of rapid-fire developments in the South Texas Starhopper saga, the abrupt appearance of what appears to be three Raptor engines – mirroring CEO Elon Musk’s recent statement that the test vehicle would sport three Raptors – is by far the most unexpected moment yet for the prototype Starship. Purportedly a full-scale prototype of BFR’s upper stage/spaceship (now known as Starship), Musk indicated over the last two weeks that the hopper has been designed to perform a number of hop tests in which the craft’s three Raptors would power it to a range of (relatively low) altitudes above Boca Chica, Texas.

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According to a recent FCC filing related to this test program, SpaceX is currently seeking a license for Starship hop tests that will not exceed 5 km (3.1 mi) in altitude and/or 6 minutes in duration. There is admittedly nothing mentioned about the maximum allowed velocity during those tests, but – much like Blue Origin performs supersonic tests of New Shepard in Cape Horn, Texas – SpaceX will likely seek and be granted permission to break the sound barrier during those hypothetical tests. Nevertheless, a 5km ceiling is a fairly significant cap on the range of performance Starhopper will be able to test – accelerating vertically at 2Gs, Starhopper could travel from sea level to 5km in less than 30 seconds while reaching speeds no higher than Mach 1-1.5.

 

Combined with the apparent fact that this Starhopper’s fins seem unlikely to ever actuate (i.e. no aerodynamic control surfaces), it’s probable that this ad hoc prototype is only meant to perform a very limited range of hop tests, perhaps as basic as ironing out the kinks of operating a trio of gimballed Raptors and ensuring that they can safely and reliably launch, hover, and land a very large Starship-shaped mass simulator. Falcon 9’s Grasshopper and F9R reusability testbeds performed a very similar task some five years ago, offering SpaceX engineers the opportunity to optimize software and hardware needed to reliably recover real orbital-class rockets after launch. Although Falcon 9 has nine gimballed Merlin 1D engines, SpaceX has long sided with the sole center Merlin as the dedicated landing engine and has only briefly experimented with triple-Merlin landing burns.

Dual-expansion whaaaaat?

According to Musk, Raptor –  an advanced liquid methane and oxygen engine with a uniquely efficient propulsion cycle – was expected to produce an impressive ~2000 kN (200 ton, 450K lbf) of thrust in its finished form as of September 2018. However, Musk also mentioned in a late-2017 Reddit AMA that SpaceX engineers were modifying the ship’s design to ensure engine-out reliability during all regimes of flight, landing in particular. To accomplish this feat with an engine as powerful as Raptor, two or three Raptors – capable of producing as much as 600 tons of thrust total – would need to reliably throttle as low as 25%, assuming a landing mass of around 150t. To allow a nearly empty ship (~100t) to still reliably land with three Raptors ignited, the engines would need to be able to throttle to 20% or less.

A trio of Raptors (or Raptor stand-ins) were spotted on Starhopper on Dec 31 by NASASpaceflight user bocachicagal.

Known as deep throttling in rocketry, ensuring stable combustion and thrust at 20% (let alone 40%) throttle is an extraordinarily challenging feat, often subjecting engines to forces that can literally tear non-optimized hardware apart. To achieve such a deep throttle capability without excessively disrupting the engine’s design, SpaceX appears to have potentially sided with less efficient but extremely simple alternative, known as a dual-bell (or dual-expansion) rocket nozzle. A 1999 Rocketdyne paper concisely explained the primary draws of such a nozzle:

“The [altitude-compensating] dual-bell nozzle offers a unique combination of performance, simplicity, low weight, and ease of cooling” – Horn & Fisher, 1999

Given that SpaceX has decided to delay the introduction and certification of a vacuum-optimized Raptor engine, choosing to instead use the same Raptor on both BFR stages, something like a dual-bell nozzle would be one of the best possible ways for the company to retain some of the efficiency benefits of a vacuum engine while also drastically improving design simplicity, ease of manufacturing, and cutting development time. Aside from offering efficiency gains by way of altitude compensation, a dual-bell nozzle also happens to enable a given engine to operate a much wider throttle range by mitigating problems with flow separation and instability.

 

For Starhopper and Starship, both aspects are an undeniable net-gain and it’s entirely possible that these dual-bell nozzles – if successfully demonstrated – could find their way onto Falcon 9 and Falcon Heavy to further boost their booster performance and efficiency.


For prompt updates, on-the-ground perspectives, and unique glimpses of SpaceX’s rocket recovery fleet check out our brand new LaunchPad and LandingZone newsletters!

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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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SpaceX is partnering with chipmakers to enable Starlink satellite-to-cell service

President Gwynne Shotwell outlined the effort during a space industry conference in Paris.

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Credit: SpaceX/X

SpaceX is working with microchip manufacturers to integrate satellite-connectivity hardware into smartphones, advancing its plan for direct-to-device services through Starlink. 

The move follows the company’s $17 billion acquisition of wireless spectrum from EchoStar Corp., a deal that positions SpaceX to operate more independently of traditional telecom carriers. 

President Gwynne Shotwell outlined the effort during a space industry conference in Paris this week, as noted in a Bloomberg News report.

Starlink direct-to-device

Starlink currently serves millions of customers in over 100 countries, primarily through ground-based dishes. The company, however, is now expanding into satellite-to-cell service, which should enable unmodified phones to connect directly with orbiting satellites. While SpaceX has a partnership with T-Mobile US, the EchoStar spectrum purchase gives it more control to negotiate with global carriers on its own terms.

“We’re working with chip manufacturers to get the proper chips in phones,” the SpaceX President stated. “We will now be initiating discussions with telcos in a different way now. Now it’s our spectrum, but we want to work with them, almost providing capacity and wholesaling capacity to their customers.”

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The company plans to launch satellites capable of supporting its direct-to-device business within two years, with early mobile phone testing expected by late 2026.

Starship program continues test flights

Shotwell also addressed SpaceX’s Starship program, which recently completed its 10th test flight in August. She said the mission met all objectives, providing a critical morale boost to teams after a challenging development year. 

“My Starship team needed that win,” Shotwell noted. “Development programs always are kind of a 24/7 operation, and I was really pleased for them.”

SpaceX is planning to fly one more iteration of the current Starship prototype, known as V2, before transitioning to the next-generation V3 vehicle. That version, expected to debut late this year or early 2026, is designed to be more capable and support eventual crewed missions to the Moon and Mars. 

“The V3, which we want to fly hopefully late this year, but maybe early next year, is really the vehicle that could take humans to the moon and Mars,” Shotwell stated.

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U.S. Judge dismisses lawsuit against SpaceX Starship Boca Chica launch site

The ruling found that the FAA had met its obligations in reviewing the potential environmental effects of Starship launches.

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(Credit: SpaceX)

A U.S. district court judge has dismissed a lawsuit brought by conservation groups challenging the Federal Aviation Administration’s approval of SpaceX’s expanded rocket launch operations in Boca Chica, Texas. 

The ruling, issued Monday, found that the FAA had met its obligations in reviewing the potential environmental effects of Starship launches.

FAA review withstands legal challenge

The lawsuit centered on whether the FAA properly assessed the impact of SpaceX’s operations on endangered wildlife, including ocelots, jaguarundis, and Kemp’s Ridley sea turtles, as noted in a report from The Guardian. The plaintiffs argued that noise, light pollution, and construction activity degraded the surrounding habitat, which also serves as nesting grounds for threatened shorebirds.

The lawsuit cited SpaceX’s April 2023 Starship test, which destroyed its launchpad and scattered debris across a large area. The blast reportedly ignited a grassfire and damaged wildlife habitats, including a bobwhite quail nest.

Judge Carl Nichols, for his part, ruled that the FAA had satisfied its obligation“to take a hard look at the effects of light on nearby wildlife.” The decision effectively cleared a regulatory hurdle for SpaceX, which has been working to expand Starship launch activity at its Boca Chica facility.

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A continued ramp

SpaceX continues to scale its operations nationwide. Beyond Starship, the company is also seeking approval to nearly double Falcon rocket launches from Vandenberg Space Force Base in California, from 50 annually to 95. 

Former President Trump has also shared his intention to increase U.S. launch capacity, setting a target for substantial growth by 2030. Considering that SpaceX is by far the world’s dominant launch provider, Trump’s support for more launches will likely benefit the private space company.

For now, at least, the ruling should allow continued expansion at a time when Starship remains central to long-term goals such as Mars missions and NASA’s Artemis program.

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Elon Musk

SpaceX to expand Central Texas facility with $8M Bastrop project

Bastrop is already the site of several Elon Musk-led ventures.

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Credit: SpaceX

SpaceX is set to expand its presence in Central Texas with an $8 million project to enlarge its Bastrop facility, as per state filings. 

The 80,000-square-foot addition, which is scheduled to begin construction on September 24 and wrap in early January 2026, was registered with the Texas Department of Licensing and Regulation and initially reported by My San Antonio

New investment

Bastrop is already the site of several Elon Musk-led ventures. The upcoming expansion will extend SpaceX’s office at 858 FM 1209, near Starlink’s operations and The Boring Company’s facilities. Just down the road, X is housed in the Hyperloop Plaza at 865 FM 1209.

SpaceX’s expansion reflects a steady buildup of resources in Bastrop since the private space firm established its presence in the area. The addition was praised by Tesla Governor Greg Abbott, who wrote on X that the expansion will “bring more jobs, innovations and will strengthen Starlink’s impact worldwide.” 

State support

In March, Gov. Greg Abbott announced a $17.3 million state grant to SpaceX for an “expansion of their semiconductor research and development (R&D) and advanced packaging facility in Bastrop.” The project is expected to create more than 400 new jobs and generate over $280 million in capital investment.

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Following the grant award, the Texas Governor also noted that SpaceX’s facility would be growing by 1 million square feet across three years to boost its Starlink program. SpaceX’s Starlink division is among the company’s fastest-growing segments, with the satellite internet system connecting over 6 million users and counting worldwide. 

Recent reports have also indicated that Starlink has struck a deal with EchoStar to acquire 50 MHz of exclusive S-band spectrum in the United States and global Mobile Satellite Service (MSS) licenses. This should pave the way for Starlink to provide 5G coverage worldwide, even in remote areas. 

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