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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.

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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.

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.

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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.

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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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Musk bankers looking to trim xAI debt after SpaceX merger: report

xAI has built up $18 billion in debt over the past few years, with some of this being attributed to the purchase of social media platform Twitter (now X) and the creation of the AI development company. A new financing deal would help trim some of the financial burden that is currently present ahead of the plan to take SpaceX public sometime this year.

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Credit: SpaceX

Elon Musk’s bankers are looking to trim the debt that xAI has taken on over the past few years, following the company’s merger with SpaceX, a new report from Bloomberg says.

xAI has built up $18 billion in debt over the past few years, with some of this being attributed to the purchase of social media platform Twitter (now X) and the creation of the AI development company. Bankers are trying to create some kind of financing plan that would trim “some of the heavy interest costs” that come with the debt.

The financing deal would help trim some of the financial burden that is currently present ahead of the plan to take SpaceX public sometime this year. Musk has essentially confirmed that SpaceX would be heading toward an IPO last month.

SpaceX IPO is coming, CEO Elon Musk confirms

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The report indicates that Morgan Stanley is expected to take the leading role in any financing plan, citing people familiar with the matter. Morgan Stanley, along with Goldman Sachs, Bank of America, and JPMorgan Chase & Co., are all expected to be in the lineup of banks leading SpaceX’s potential IPO.

Since Musk acquired X, he has also had what Bloomberg says is a “mixed track record with debt markets.” Since purchasing X a few years ago with a $12.5 billion financing package, X pays “tens of millions in interest payments every month.”

That debt is held by Bank of America, Barclays, Mitsubishi, UFJ Financial, BNP Paribas SA, Mizuho, and Société Générale SA.

X merged with xAI last March, which brought the valuation to $45 billion, including the debt.

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SpaceX announced the merger with xAI earlier this month, a major move in Musk’s plan to alleviate Earth of necessary data centers and replace them with orbital options that will be lower cost:

“In the long term, space-based AI is obviously the only way to scale. To harness even a millionth of our Sun’s energy would require over a million times more energy than our civilization currently uses! The only logical solution, therefore, is to transport these resource-intensive efforts to a location with vast power and space. I mean, space is called “space” for a reason.”

The merger has many advantages, but one of the most crucial is that it positions the now-merged companies to fund broader goals, fueled by revenue from the Starlink expansion, potential IPO, and AI-driven applications that could accelerate the development of lunar bases.

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SpaceX launches Crew-12 on Falcon 9, lands first booster at new LZ-40 pad

Beyond the crew launch, the mission also delivered a first for SpaceX’s Florida recovery operations.

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Credit: SpaceX/X

SpaceX opened February 13 with a dual milestone at Cape Canaveral, featuring a successful Crew-12 astronaut launch to the International Space Station (ISS) and the first Falcon 9 booster landing at the company’s newly designated Landing Zone 40 (LZ-40). 

A SpaceX Falcon 9 lifted off at 5:15 a.m. Eastern from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station, placing the Crew Dragon Freedom into orbit on the Crew-12 mission. 

The spacecraft is carrying NASA astronauts Jessica Meir and Jack Hathaway, ESA astronaut Sophie Adenot, and Roscosmos cosmonaut Andrey Fedyaev, as noted in a report from Space News.

The flight marked NASA’s continued shift of Dragon crew operations to SLC-40. Historically, astronaut missions launched from Launch Complex 39A at Kennedy Space Center. NASA is moving Falcon 9 crew and cargo launches at SLC-40 to reserve 39A for Falcon Heavy missions and future Starship flights.

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Crew-12 is scheduled to dock with the ISS on Feb. 14 and will remain in orbit for approximately eight months.

Beyond the crew launch, the mission also delivered a first for SpaceX’s Florida recovery operations. The Falcon 9 first stage returned to Earth and touched down at Landing Zone 40, a new pad built adjacent to SLC-40.

The site replaces Landing Zone 1, located several kilometers away, which has been reassigned by the U.S. Space Force to other launch providers. By bringing the landing area next to the launch complex, SpaceX is expected to reduce transport time and simplify processing between flights.

Bill Gerstenmaier, SpaceX’s vice president of build and flight reliability, stated that landing close to the pad keeps “launch and landing in the same general area,” improving efficiency. The company operates a similar side-by-side launch and landing configuration at Vandenberg Space Force Base in California.

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Starlink terminals smuggled into Iran amid protest crackdown: report

Roughly 6,000 units were delivered following January’s unrest.

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Credit: Starlink/X

The United States quietly moved thousands of Starlink terminals into Iran after authorities imposed internet shutdowns as part of its crackdown on protests, as per information shared by U.S. officials to The Wall Street Journal

Roughly 6,000 units were delivered following January’s unrest, marking the first known instance of Washington directly supplying the satellite systems inside the country.

Iran’s government significantly restricted online access as demonstrations spread across the country earlier this year. In response, the U.S. purchased nearly 7,000 Starlink terminals in recent months, with most acquisitions occurring in January. Officials stated that funding was reallocated from other internet access initiatives to support the satellite deployment.

President Donald Trump was aware of the effort, though it remains unclear whether he personally authorized it. The White House has not issued a comment about the matter publicly.

Possession of a Starlink terminal is illegal under Iranian law and can result in significant prison time. Despite this, the WSJ estimated that tens of thousands of residents still rely on the satellite service to bypass state controls. Authorities have reportedly conducted inspections of private homes and rooftops to locate unauthorized equipment.

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Earlier this year, Trump and Elon Musk discussed maintaining Starlink access for Iranians during the unrest. Tehran has repeatedly accused Washington of encouraging dissent, though U.S. officials have mostly denied the allegations.

The decision to prioritize Starlink sparked internal debate within U.S. agencies. Some officials argued that shifting resources away from Virtual Private Networks (VPNs) could weaken broader internet access efforts. VPNs had previously played a major role in keeping Iranians connected during earlier protest waves, though VPNs are not effective when the actual internet gets cut.

According to State Department figures, about 30 million Iranians used U.S.-funded VPN services during demonstrations in 2022. During a near-total blackout in June 2025, roughly one-fifth of users were still able to access limited connectivity through VPN tools.

Critics have argued that satellite access without VPN protection may expose users to geolocation risks. After funds were redirected to acquire Starlink equipment, support reportedly lapsed for two of five VPN providers operating in Iran.

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A State Department official has stated that the U.S. continues to back multiple technologies,  including VPNs alongside Starlink, to sustain people’s internet access amidst the government’s shutdowns.

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