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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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8 years ago

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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.

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.

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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.

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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

SpaceX turned a heralding moment for Starship into its greatest

Starship reached orbit despite losing an engine, deployed 26 Starlink V3 satellites on Flight 14.

Published

16 hours ago

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September 28, 2026

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SpaceX’s Starship reached orbit for the first time on Monday, and for a few nail-biting minutes it looked like it wouldn’t. During ascent on Flight 14, one of Ship 41’s six Raptor engines shut down early, and SpaceX’s livestream host Dan Huot told viewers the team had decided not to commit to orbit. Minutes later, after what Huot described as a lot of conversation in the control room, the final poll came back in favor, and a roughly 19 second burn of a single Raptor pushed the ship into orbit about 170 miles up.

The reversal matters because SpaceX had written the exit ramp into the mission plan. The company said it would only fire the orbital insertion burn if flight controllers confirmed enough backup hardware remained for the deorbit burn, a condition Teslarati laid out ahead of the flight. Losing an engine was exactly the scenario that rule was built for.

Pressing forward fits Elon Musk’s history. Falcon 1 failed three straight times before its fourth launch reached orbit in 2008, with SpaceX nearly out of money, and Starship was developed by flying prototypes until they broke. What changed this year SpaceX going public, and with $SPCX sliding below its IPO price in July when Flight 13 slipped, the short interest climbed significantly, as Teslarati reported at the time. A Starship potentially lost today with revenue generating next-gen Starlink satellites aboard would have landed directly on shareholders.

That pressure showed up after orbit. SpaceX cut a flight planned to last nearly 10 hours to about three, moving splashdown from west of Chile to the North Pacific near Hawaii. SpaceX gave no reason, though Musk said this month the company was being extremely cautious about debris risk. The single Raptor for deorbit worked, and Ship 41 completed its flip and landing burn before breaking apart in the water, an outcome SpaceX expected. Musk has structured SpaceX’s governance to shield long term bets from market pressure.

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The payload is the bigger business story. Musk posted that all 26 Starlink V3 satellites deployed and are “operating nominally.” Each V3 is rated for about 1 Tbps of downlink and 160 Gbps of uplink, so this single launch adds roughly 26 Tbps, about 10 times what a Falcon 9 load of V2 Mini satellites adds. The V3 is too large for Falcon 9, making Starship the only vehicle that can build out the planned 100,000 satellite constellation, at up to 60 per flight once it reaches routine service. Unlike the 20 V3 units on Flight 13, which reentered on a suborbital path, these will raise their orbits and could begin serving customers within weeks and bring in hundreds of millions of additional dollars in projected Starlink revenue.

SpaceX has already begun winding down Falcon 9 Starlink launches from Florida in favor of Starship. Reported targets put Flight 15 as early as October 19, leaving about three weeks to diagnose Monday’s engine shutdown before the next orbital attempt.

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Elon Musk

SpaceX just got the green light Starship has waited years for

The FAA has cleared Starship Flight 14, setting up SpaceX’s first orbital attempt on Monday.

Published

2 days ago

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September 27, 2026

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SpaceX has cleared the last regulatory hurdle standing between Starship and its first trip to orbit. The Federal Aviation Administration issued the launch license for Starship Flight 14 late Saturday, keeping the mission on track for liftoff Monday, September 28, from Pad 2 at Starbase, Texas.

The 75 minute launch window opens at 7:15 a.m. Central, and Boca Chica Beach closures are also scheduled for September 29 and 30 as backup dates. This will be Starship’s first revenue generating mission.

The license was the missing piece after SpaceX completed a full wet dress rehearsal with Booster 21 and Ship 41 on September 24. At the time, the company said the flight remained on track pending regulatory approval. Because Flight 14 flies an orbital profile, the FAA had to sign off on a modified license that met its safety, payload and financial responsibility requirements.

Observers combing through the new FAA paperwork also noticed that lightning no longer appears among Starship’s listed launch hazards. If that holds, it matters more for where Starship is headed than for Monday’s attempt. Florida and Louisiana, home to LC-39A and the planned Starbase Louisiana site, see some of the most frequent lightning in the United States.

SpaceX tells the FCC that Starship Flight 14 is going to orbit

Flight 14 is the mission SpaceX has been building toward for months. Ship 41 will carry 26 Starlink V3 satellites, the first operational V3 units to be deployed, and attempt roughly six orbits at about 275 kilometers over a flight lasting just under 10 hours. SpaceX says the ship will only perform its orbital insertion burn after flight controllers confirm enough hardware redundancy remains for the deorbit burn at the end of the mission. Ship 41 is targeting a splashdown in the Pacific west of Chile, while Super Heavy will return to the Gulf of Mexico.

The date carries some symbolism as well. A Monday launch would come 10 years and one day after Elon Musk first presented the Interplanetary Transport System, the design that became Starship, at the International Astronautical Congress in Guadalajara, Mexico.

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SpaceX has not announced what comes next, but air traffic planning slides reported this week, list Flight 15 no earlier than October 19 and a first Starship launch from LC-39A in Florida no earlier than October 30. Both dates depend on how Monday goes.

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News

SpaceX completes another secret Pentagon launch, adding to suspected Starshield buildout

SpaceX launched the classified USSF-385 mission from Vandenberg, landing its booster on a tenth flight.

Published

3 days ago

on

September 26, 2026

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US Golden Dome space defense system (Concept render by Grok)

SpaceX launched another classified mission for the U.S. Space Force from California early Saturday morning, and the Falcon 9 booster that carried it landed on a drone ship in the Pacific for the tenth time. The USSF-385 mission lifted off from Space Launch Complex 4E at Vandenberg Space Force Base at 7:00 a.m. PT.

Booster B1100 touched down on Of Course I Still Love You roughly eight and a half minutes after liftoff. It was the booster’s tenth flight and tenth successful landing, following the NROL-95 national security mission and eight Starlink launches. Its previous flight, a Starlink Group 15 mission on August 22, came just 35 days earlier. SpaceX ended its livestream shortly after the landing, which is standard for classified payloads, and neither the company nor the Space Force has said what the rocket carried.

USSF-385 is the fourth Space Force launch from the same Vandenberg pad in roughly six weeks, following USSF-366 on August 15, USSF-153 on September 10, and USSF-259 on September 17. When SpaceX flew USSF-366 in August, independent trackers noted that the rocket’s stage drop zones matched SpaceX’s Starlink Group 15 missions, pointing to Starshield, the government version of the Starlink satellite bus. The Space Force later cataloged 23 satellites after both USSF-366 and USSF-153, while USSF-259 placed 17 satellites into a different orbital plane, per KeepTrack. Launch databases describe USSF-385 the same way, though the payload remains officially unidentified.

Starlink’s Starshield wins contract with US Space Force

The cadence lines up with the contracts, because in July, the Space Force awarded SpaceX $1.6 billion in task orders for 18 Falcon 9 missions from Vandenberg through the end of 2027. SpaceX also holds contracts to build pieces of that same network, which pushed its Pentagon contract total for 2026 past $8 billion.

Saturday’s flight was also the sixth and final Falcon 9 launch from Vandenberg in September, according to Spaceflight Now, while only one Falcon 9 flew from the East Coast this month as SpaceX shifts its Florida infrastructure toward Starship. Launch trackers list it as SpaceX’s 112th mission of 2026 and the 108th Falcon 9 flight of the year, with SLC-4E turned around about six and a half days after its previous launch.

The West Coast pad will not stay quiet for long, considering SpaceX has another Starlink mission scheduled from SLC-4E on September 30. Meanwhile, in Texas, the company is two days away from Starship Flight 14, which is targeting Monday at 7:15 a.m. CT for the vehicle’s first attempt to reach orbit.

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