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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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Elon Musk

How much of SpaceX will Elon Musk own after IPO will surprise you

SpaceX’s IPO filing confirms Musk will maintain his voting power to make key decisions for the company.

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Rendering of Elon Musk overlooking a Starship fleet (Credit: Grok)

Elon Musk will retain dominant voting control of SpaceX after it goes public, according to the company’s IPO prospectus that was filed with the SEC. The filing reveals a dual-class equity structure giving Class B shareholders 10 votes each, concentrating power with Musk and a handful of other insiders, while Class A shares sold to public investors carry one vote.

Musk holds approximately 42% of SpaceX’s equity and controls roughly 79% of its votes through super-voting shares. He will simultaneously serve as CEO, CTO, and chairman of the nine-member board after the listing. Beyond that, the filing includes provisions that may limit shareholders’ influence over board elections and legal actions, forcing disputes into arbitration and restricting where they can be brought.

The case for Musk holding this level of control is grounded in SpaceX’s actual history. The company’s most important bets, from reusable rockets to a global satellite internet constellation, were decisions that ran against conventional aerospace thinking and would likely have faced resistance from a board accountable to investor gains. Fully reusable rockets were considered economically irrational by established industry players for years. Starlink, which now generates over $4 billion in annual operating profit, was widely dismissed as financially unviable when it was proposed. The argument for concentrated founder control seems straightforward, and the decisions that built SpaceX into what it is today required someone willing to ignore consensus and absorb years of losses.

SpaceX files confidentially for IPO that will rewrite the record books

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For context, Musk’s position is significantly more dominant than Zuckerberg’s at Meta. The comparison with Tesla is also worth noting. When Tesla did its IPO in 2010, it did not issue dual-class shares. Musk has only recently pushed for enhanced voting protection, proposing at least 25% control at Tesla in 2024 after selling shares to fund his Twitter acquisition left him with around 13%.

SpaceX has clearly learned from that experience and structured the IPO differently by planning to allocate up to 30% of shares to retail investors, roughly three times the typical norm for a large offering. The roadshow is expected to begin the week of June 8, with a Nasdaq listing rumored to be a $1.75 trillion valuation and a $75 billion raise.

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Elon Musk

ARK’s SpaceX IPO Guide makes a compelling case on why $1.75T may not be the ceiling

ARK Invest breaks down six reasons SpaceX’s $1.75 trillion IPO valuation may be justified.

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ARK Invest, which holds SpaceX as its largest Venture Fund position at 17% of net assets, has published a detailed investor guide to why a SpaceX IPO may be grounded in a $1.75 trillion target valuation.

The financial case starts with Starlink, SpaceX’s satellite internet constellation, which has surpassed 10 million active subscribers globally as of early 2026, with 2026 revenue projected to exceed $20 billion. ARK’s research puts the total satellite connectivity market opportunity at roughly $160 billion annually at scale, and Starlink is adding customers faster than any telecom network in history. That growth alone would justify a substantial valuation.

Additionally,  ARK notes that SpaceX has reduced the cost per kilogram to orbit from roughly $15,600 in 2008 to under $1,000 today through reusable Falcon 9 hardware. A fully operational Starship targeting sub-$100 per kilogram would represent a significant cost decline and open markets that do not currently exist. SpaceX executed a staggering 165 missions in 2025 and now accounts for approximately 85% of all global orbital launches. That infrastructure position took decades to build and would be nearly impossible to replicate at comparable cost.

SpaceX officially acquires xAI, merging rockets with AI expertise

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The February 2026 merger with xAI added a layer to the valuation that straightforward financial models struggle to capture. ARK argues that at sub-$100 launch costs, orbital data centers could deliver compute roughly 25% cheaper than ground-based alternatives, without power grid delays, permitting friction, or land constraints. Musk has stated a goal of deploying 100 gigawatts of AI computing capacity per year from orbit.

The $1.75 trillion figure itself is not a conventional earnings multiple. At roughly 95x trailing revenue, it prices in Starlink’s adoption curve, Starship’s cost trajectory, and the orbital compute thesis together. The public S-1 prospectus, due at least 15 days before the June roadshow, will give investors their first complete look at the financials to test those assumptions. ARK’s position is that the track record earns the benefit of the doubt. Fully reusable rockets were considered unrealistic for years. Starlink was considered financially unviable. Both happened on timelines that surprised skeptics.

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Elon Musk

SpaceX wins its first MARS contract but it comes with a catch

NASA awarded SpaceX a $175 million Mars rover contract while the White House proposes cutting the mission.

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NASA just signed a $175.7 million contract with SpaceX to launch a Mars rover that the White House is simultaneously trying to defund. The contract, awarded on April 16, 2026, tasks SpaceX’s Falcon Heavy with launching the European Space Agency’s (ESA) Rosalind Franklin rover from Kennedy Space Center in Florida, no earlier than late 2028. It would mark the first time SpaceX has ever sent a payload to Mars.

Under NASA’s Rosalind Franklin Support and Augmentation project, known as ROSA, the agency is providing braking engines for the rover’s descent stage, radioisotope heater units that use decaying plutonium to keep the rover warm on the Martian surface, additional electronics, and a mass spectrometer instrument, as noted by SpaceNews.

Those nuclear heating units are the reason an American rocket was required at all. U.S. export controls on radioisotope technology mean any payload carrying them must launch on a domestic vehicle, which narrowed the field to SpaceX and United Launch Alliance. Falcon Heavy’s pricing made it the practical choice.

SpaceX is quietly becoming the U.S. Military’s only reliable rocket

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Falcon Heavy debuted in February 2018 and has 11 launches to its record. The rocket has not flown since October 2024, when it sent NASA’s Europa Clipper toward Jupiter. The three-core design, built from modified Falcon 9 first stages, gives it the lift capacity needed for deep space planetary missions that a single Falcon 9 cannot reach.

The Rosalind Franklin rover has been sitting in storage in Europe for years. It was originally due to launch in 2022 as a joint mission with Russia, but Russia’s invasion of Ukraine ended that partnership, leaving the rover built but stranded without a launch vehicle or landing hardware. NASA stepped back in through a 2024 agreement with ESA to rescue the mission. The rover is designed to drill up to two meters below the Martian surface in search of evidence of past life, a science objective no previous mission has attempted at that depth.

The contradiction at the center of this story is hard to ignore. The White House’s fiscal year 2027 budget proposal included no funding for ROSA and did not mention the mission at all in the detailed congressional justification document released April 3.

Musk has long argued that reaching Mars is not optional. “We don’t want to be one of those single planet species, we want to be a multi-planet species.” Whether this particular mission survives Washington’s budget fight, the Falcon Heavy contract means SpaceX is now formally on record as the rocket that could get humanity’s next Mars science mission off the ground.

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The timing of this contract carries extra weight given that SpaceX filed confidentially with the SEC in early April and is targeting an IPO roadshow in the week of June 8. It would be the largest public offering in history.

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