SpaceX
SpaceX’s Starship hopper spotted with trio of dual-bell Raptor engines
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.
Star ship hopper might be a bit bigger than we thought and with the crane placements over the nose end of the vehicle. This could suggest, @SpaceX are planning to move the segment elsewhere perhaps to the welding stand? We will have to wait and see. (Austin Barnard📸) #2019🚀 pic.twitter.com/kn8hhUPWCU
— Austin Barnard🚀 (@austinbarnard45) January 1, 2019
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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- SpaceX technicians and engineers are continuing to work at a breakneck pace on Starhopper. (NASASpaceflight – bocachicagal)
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- At this rate, the hopper will likely wind up around 40m (130 feet) tall. (NASASpaceflight – bocachicagal)
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- A close examination of these three engine-like protrusions suggests a level of fit and finish far exceeding a boilerplate stand-in. (NASASpaceflight – bocachicagal)
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.
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
Exactly
— Elon Musk (@elonmusk) December 27, 2018
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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- A gif of Raptor throttling over the course of a 90+ second static-fire test in McGregor, Texas. (SpaceX)
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- Note that Merlin 1D and prior Raptor prototypes both feature traditional single nozzles. (Pauline Acalin)
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- An overview of dual-bell and deflection nozzles. Raptor appears to have now graduated to the former style. (Johan Steelant, 2011)
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- Starhopper’s Raptors feature a very distinct seam and second curve, indicative of a dual-bell nozzle. (NASASpaceflight /u/bocachicagal)
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.
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Elon Musk
SpaceX’s Starship V3 is almost ready and it will change space travel forever
SpaceX is targeting April for the debut test launch of Starship V3 “Version 3”
SpaceX is closing in on one of the most anticipated rocket launches in history, as the company readies for a planned April test launch and debut of its next-gen Starship V3 “Version 3”.
The latest iteration of Starship V3 has a slightly taller Super Heavy booster and Starship upper stage than their predecessors, and produce stronger, more efficient thrust using SpaceX’s upgraded Raptor 3 engines. V3 also features increased propellant capacity, targeting a total payload capacity of over 100 tons to low Earth orbit, compared to around 35 tons for its predecessor. With Musk’s lifelong aspiration to colonize Mars one day, the increased payload capacity matters enormously, because Mars missions require moving massive amounts of cargo, fuel, and eventually, people. But the most critical upgrade may be orbital refueling. SpaceX’s entire deep space architecture depends on moving large amounts of propellant in space, and having orbital refueling capabilities turn Starship from just a rocket into a true transport system. Without it, neither the Moon nor Mars is reachable at scale.
Initial Super Heavy V3 and Starbase Pad 2 activation campaign complete, wrapping up several days of testing that loaded cryogenic fuel and oxidizer on a V3 vehicle for the first time. While the 10-engine static fire ended early due to a ground-side issue, we saw successful… pic.twitter.com/uHGji17srv
— SpaceX (@SpaceX) March 18, 2026
A fully reusable Starship and Super Heavy, SpaceX aims to drive marginal launch costs down and at a tenfold reduction compared to current market leaders. To put that in perspective, getting a kilogram of cargo to orbit today costs thousands of dollars. Bring that number down far enough and space stops being an exclusive domain. That price point unlocks mass deployment of satellite constellations, large-scale science payloads, and affordable human transport beyond Earth orbit. It also means the Moon stops being a destination we visit and starts being one we inhabit.
NASA expects Starship to take off for the Moon’s South Pole in 2028, with the ultimate goal of establishing a permanently crewed science station there. A successful V3 flight this spring keeps that timeline alive. As for Mars, Musk has shifted focus toward building a self-sustaining city on the Moon first, arguing that the Moon can be reached every 10 days versus Mars’s 26-month alignment window. Mars remains the horizon, but the Moon is the proving ground.
Elon Musk hasn’t been shy with hyping the upcoming Starship V3 launch. In a social media post on Wednesday, he confirmed the first V3 flight is getting closer to launch. SpaceX also announced its initial activation campaign for V3 and Starbase Pad 2 was complete, wrapping up several days of cryogenic fuel testing on a V3 vehicle for the first time. The countdown is on. April can’t come soon enough.
Elon Musk
FCC chair criticizes Amazon over opposition to SpaceX satellite plan
Carr made the remarks in a post on social media platform X.
U.S. Federal Communications Commission (FCC) Chairman Brendan Carr criticized Amazon after the company opposed SpaceX’s proposal to launch a large satellite constellation that could function as an orbital data center network.
Carr made the remarks in a post on social media platform X.
Amazon recently urged the FCC to reject SpaceX’s application to deploy a constellation of up to 1 million low Earth orbit satellites that could serve as artificial intelligence data centers in space.
The company described the proposal as a “lofty ambition rather than a real plan,” arguing that SpaceX had not provided sufficient details about how the system would operate.
Carr responded by pointing to Amazon’s own satellite deployment progress.
“Amazon should focus on the fact that it will fall roughly 1,000 satellites short of meeting its upcoming deployment milestone, rather than spending their time and resources filing petitions against companies that are putting thousands of satellites in orbit,” Carr wrote on X.
Amazon has declined to comment on the statement.
Amazon has been working to deploy its Project Kuiper satellite network, which is intended to compete with SpaceX’s Starlink service. The company has invested more than $10 billion in the program and has launched more than 200 satellites since April of last year.
Amazon has also asked the FCC for a 24-month extension, until July 2028, to meet a requirement to deploy roughly 1,600 satellites by July 2026, as noted in a CNBC report.
SpaceX’s Starlink network currently has nearly 10,000 satellites in orbit and serves roughly 10 million customers. The FCC has also authorized SpaceX to deploy 7,500 additional satellites as the company continues expanding its global satellite internet network.
Elon Musk
NASA watchdog says Starship development delays could affect Artemis timeline
The report noted that several technical milestones still need to be completed before Starship can serve as a crewed lunar lander.
A NASA watchdog report stated that continued development work on SpaceX’s Starship could affect the timeline for the agency’s planned Artemis moon missions. The report noted that several technical milestones still need to be completed before the spacecraft can serve as a crewed lunar lander.
The findings were detailed in a report from NASA’s Office of Inspector General, as noted in a report from Reuters.
NASA selected SpaceX’s Starship in 2021 to serve as the Human Landing System (HLS) for its Artemis lunar program. The vehicle is intended to transport astronauts from lunar orbit to the surface of the Moon and back as part of future Artemis missions.
According to the watchdog report, Starship’s development has experienced roughly two years of schedule delays compared to earlier expectations. Still, NASA is targeting 2028 for the first crewed lunar landing using the Starship lander.
One of the most significant technical milestones for Starship’s lunar missions is in-space refueling.
To support a crewed lunar landing, multiple Starship launches will be required to deliver propellant to orbit. Tanker versions of Starship will transfer fuel to a storage depot spacecraft, which will then refuel the lunar lander.
The report noted that this approach could require more than 10 Starship launches to fully refuel the spacecraft needed for a single lunar landing mission.
NASA officials indicated that demonstrating cryogenic propellant transfer in orbit remains one of the most important technical steps before Starship can be certified for lunar missions.
SpaceX has conducted 11 Starship test flights since 2023 as the company continues developing the fully reusable launch system. A 12th test flight, this time featuring Starship V3, is expected to be held in early April.
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