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SpaceX delays Starhopper’s first flight a few days despite Raptor preburner test success
SpaceX has (partially) ignited Starhopper’s freshly-installed Raptor engine, successfully verifying that the engine is ready for its next major test: a full ignition and static firing. Although successful, SpaceX still has some work to do before the vehicle is ready for its first untethered flight(s).
July 15th’s progress is just the latest in a several day-series of preflight tests designed to reduce the likelihood that Starhopper is destroyed over the coming days and (hopefully) weeks. If all goes planned during the awkward Starship prototype’s first foray into hover tests, SpaceX CEO Elon Musk has stated that he will provide an official presentation updating the public on the status of the company’s ever-changing next-generation rocket.
The past week or so of Starhopper preflight testing began with Raptor serial number 6 (SN06) completing the last of a series of acceptance test fires in McGregor, Texas on June 10th. Even on its own, this was a major milestone for the new SpaceX engine: Raptor SN06 was the first of the new, full-scale engines to pass the acceptance test program with flying colors. According to Musk, for the engine to complete those tests so successfully, SpaceX had to solve a challenging bug in which some sort of mechanical resonance (i.e. vibration) damaged or destroyed Raptors SN01-05.
Hours later, the engine began a short ~450 mi (720 km) journey south to Starhopper, located in Boca Chica, Texas. The engine arrived on July 11th and was fully installed on Starhopper by the following evening (July 12th), at which point SpaceX put Starhopper and Raptor through some mild but valuable thrust vector controller (TVC) tests, wiggling the car-sized engine to ensure it can accurately steer the prototype rocket.
Around two days after the above ‘wiggle’ test was successfully completed, SpaceX moved into the next stage, partially fueling Starhopper with liquid methane and oxygen propellant and helium pressurant in what is known in rocketry as a wet dress rehearsal (WDR). The (implicitly) successful WDR was capped off with a duo of what can now safely be concluded were some sort of Raptor test preceding even pre-ignition operations. Whatever the tests were, they appear to have been completed successfully.
That appears to be the case because less than 24 hours after their completion, on July 15th, SpaceX once again began loading Starhopper with propellant and pressurant for a second round of wet testing. This time around, SpaceX got right into more critical Raptor tests once enough propellant was loaded, igniting the engine’s interwoven oxygen and methane preburners.
Previously discussed 24 hours ago in a Teslarati article focused on Raptor wiggles and other miscellaneous tests, Raptor is an extremely advanced rocket engine based on a cycle (i.e. how propellant is turned into thrust) known as full-flow staged combustion.
“In a staged-combustion engine like Raptor, getting from the supercool liquid oxygen and methane propellant to 200+ tons of thrust is quite literally staged, meaning that the ignition doesn’t happen all at once. Rather, the preburners – essentially their own, unique combustion chambers – ignite an oxygen- or methane-rich mixture, the burning of which produces the gas and pressure that powers the turbines that bring fuel into the main combustion chamber. That fuel then ignites, producing thrust as they exit the engine’s bell-shaped nozzle.
Unintuitively, conditions inside the preburner – hidden away from view – are actually far more intense than the iconic blue, purple, and pink flame that visibly exists Raptor’s nozzle. Much like hot water will cool while traveling through pipes, the superheated gaseous propellant that Raptor ignites to produce thrust will also cool (and thus lose pressure) as it travels from Raptor’s preburner to its main combustion chamber. If the pressure produced in the preburners is too low, Raptor’s thrust will be (roughly speaking) proportionally limited at best. At worst, low pressure in the preburners can trigger a “hard start” or shutdown that could destroy the engine. According to Elon Musk, Raptor’s oxygen preburner thus has the worst of it, operating at pressures as high or higher than 800 bar (11,600 psi, 80 megapascals).”
In full-flow staged combustion (FFSC), even more complexity is added as all propellant that touches the engine must necessarily end up traveling through the main combustion chamber to eke every last ounce of thrust out of the finite propellant a rocket lifts off with. As such, FFSC engines can be about as efficient as the laws of physics allow any given chemical rocket engine to be, at the cost of exceptional complexity and brutally difficult development.
Additionally, FFSC physically requires two separate preburners and then makes things even harder by making each separate preburner (methane and oxygen) depend on each other’s operation for the engine to fully ignite. This means that no individual preburner can be used to kickstart Raptor – instead, SpaceX must somehow spin the turbopumps that feed propellant into each preburner with some separate system. This is all just to emphasize the fact that Raptor’s ignition sequence is a spectacularly complex orchestra of valves, spark plugs, sensors, and magic. This is why it’s valuable for Raptor to test its preburner system independently of an actual ignition test, at least as long as the engine is still in the development stages.
According to NASASpaceflight.com managing editor Chris Bergin, what this practically translates to is a minor Starhopper hover test delay of 1-2 days, while the static fire has also been pushed roughly 24 hours from July 15th to July 16th. If that full static fire produces lots of happy data, Starhopper could be cleared for a hover test debut attempt as early as Wednesday or Thursday (July 17/18).
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Investor's Corner
SpaceX and Nvidia team up on Musk’s orbital AI bet
SpaceX revealed a new Nvidia satellite partnership, then Musk pledged an exclusive Nvidia hardware commitment.
SpaceX and Nvidia are now working together on the hardware that will power Musk’s orbital data center ambitions. SpaceX announced on X on Tuesday that it is partnering with Nvidia to design the compute payload for Starmind AI1, the first satellite in a planned constellation built to run AI workloads directly in orbit. Each Starmind satellite will carry Nvidia’s Rubin GPUs and Vera CPUs, according to the post, which included renderings of the payload design.
The announcement landed hours before SpaceX’s first earnings call as a public company, where Musk went further, saying the company has committed to building its AI infrastructure exclusively on Nvidia hardware. “We think the Vera Rubin architecture is the best architecture. We think it’s the best AI computer, and we greatly value our close cooperation and partnership on many levels with Nvidia,” Musk told investors on the call,. “So we’re exclusive to Nvidia.”
Musk said SpaceX plans to deploy Nvidia’s Vera Rubin NVL72 rackscale system, codenamed Kyber, both on the ground and in space. He set a target of 2 gigawatts of compute capacity online by the end of this year, scaling to roughly 10 gigawatts by the end of 2027.
SpaceX’s newest Starmind will make earth data centers obsolete
Starmind has been in development since Musk confirmed the name in June, following an xAI trademark filing that tipped off the project before SpaceX made it official. The idea is massive in scope and instead of moving data down to ground based servers, satellites equipped with onboard processors and large solar arrays would compute AI workloads in orbit and beam results back to Earth. SpaceX has already filed with the FCC for a constellation of up to one million satellites to support the effort, citing constant solar power and the absence of zoning restrictions as advantages over terrestrial data centers.
The Nvidia exclusivity marks a shift in tone from just two weeks ago, when Musk was busy knocking down a report that SpaceX had ordered $52 billion worth of Nvidia GPUs through Foxconn, calling it fake news at the time. The dollar figure in that rumor may have been wrong, but the underlying direction seems correct. SpaceX’s AI division already leases Colossus compute capacity to Anthropic and Google, and Tuesday’s earnings report showed AI revenue climbing sharply as those deals ramp up.
Nvidia shares rose roughly 3% in Tuesday trading on the news, while SpaceX stock climbed nearly 9% during the day before giving back gains after hours as investors digested the earnings report’s capital spending figures.
SpaceX (NASDAQ: SPCX) reported a beat in revenues and EBITDA in its first earnings call report while also minimizing losses as its business continues to gain momentum.
After its IPO in July, SpaceX saw some tough losses on Wall Street due to a major selloff after a delay in its 13th Starship test flight. The ship launched later that week and completed what was arguably the most successful IFT operation in the Starship program’s history.
Nevertheless, the company is continuing on and reported some encouraging financials while also promoting what appears to be a robust outlook moving forward in its Space, AI, and Connectivity divisions.
SpaceX to report first-ever earnings today: here’s what to expect
Earnings Results
- Revenues: $7.8 billion reported vs. $6.7 billion expected
- Adjusted EBITDA: $3.5 billion vs. $2 billion expected
- Net loss of $541 million, an improvement of $467 million from net loss of $1.0 billion
Additionally, CFO Bret Johnsen had these comments:
“2026 has been a momentous year so far, and the second quarter demonstrated the true power of SpaceX. Revenue growth accelerated across all our business segments and we delivered strong operating leverage, with significant margin expansion led by our new AI compute agreements. Our unparalleled leadership in launch, Starlink subscriber growth, new enterprise and government partnerships, and best-in-class AI infrastructure underscore our ability to drive meaningful scale and deliver attractive returns. As a newly public company, we are delighted to welcome our broad base of shareholders and bondholders. We ended the second quarter with $100 billion of cash, cash equivalents, and marketable securities, and $47.5 billion in backlog. This financial strength gives us substantial capacity to invest in Starship, Starlink Broadband and Mobile satellites, and our AI platform, while maintaining a disciplined long-term capital allocation framework.”
Space Business Highlights
SpaceX shared some of its biggest Space Business Highlights for Q2:
- Space revenues grew 55% sequentially and 29% year-over-year to $962 million, driven by a higher number of large customer launches and a favorable customer shift compared to the prior year
- Total costs and expenses for the Space segment were up by $389 million year-over-year, as we continued to accelerate R&D investments in our Starship program, which we believe will reduce the cost to orbit by 99% or more relative to the historical average, and unlock significant revenue potential across all business segments
- Leading launch provider for the world with 78 launches and 1,041 metric tons of mass to orbit deployed over the six months ended June 30, 2026, primarily allocated to Connectivity for the deployment of our Starlink constellation
- Starship V3 development continued to advance towards full and rapid reusability:
- Completed Starship V3’s first suborbital mission in May, Flight 12, which achieved a successful lift off from our new Starbase pad, a precision landing of Starship’s upper stage, and deployment of modified V2 Starlink satellites
- Subsequent to the second quarter, completed Starship Flight 13 in July, which achieved all flight objectives including deploying 20 production V3 satellites, demonstrating in-space relight of a Raptor engine, and executing the softest ever splashdown of Starship, providing critical views of an intact heatshield
SpaceX will report its earnings today at 4:30 P.M. EDT.
Elon Musk issued a second pointed warning to SpaceX short sellers on Tuesday, just hours before the company was set to release its first quarterly earnings as a publicly traded firm. Responding to a report highlighting elevated short interest, Musk wrote on X: “I try to warn them, but they just double down …”
The comment came as data from S3 Partners showed roughly 95 percent of available SPCX shares to borrow were on loan, translating to about 34 percent short interest as a percentage of the float. The stock has traded under pressure since its record-breaking IPO in June 2026, declining significantly from early peaks.
I try to warn them, but they just double down … 🤷♂️
— Elon Musk (@elonmusk) August 4, 2026
This marks the second such message from Musk in under three weeks.
On July 17, amid post-IPO volatility, he stated: “The survival probability of firms who maintain a significant short position in SpaceX over time is very low.” At that time, SPCX had fallen roughly 30 percent from its peak above a $2.6 trillion valuation, with short sellers reportedly realizing gains of about $8.7 billion.
Musk’s warning aligned with optimistic analyses projecting that Starship-driven cost reductions could enable a multi-trillion-dollar space economy through applications such as orbital solar power, asteroid mining, data centers, and Mars-related projects, positioning SpaceX as critical infrastructure.
SpaceX is scheduled to report second-quarter results after the market close later today, followed by a webcast. Analysts anticipate revenue near $6.9 billion, reflecting growth in Starlink, launch services, and AI-related segments. The earnings release precedes a major lockup expiration on August 6 that could free hundreds of millions of insider shares.
Musk has a long track record of confronting short sellers, particularly regarding Tesla, where he has argued that persistent bearish positions underestimate transformative technologies. Critics view his optimism as overly ambitious given near-term stock fluctuations, while supporters see temporary dips as opportunities in a longer-term expansion of the space economy.
As SpaceX opens its books to public scrutiny for the first time, the high short interest and Musk’s repeated cautions set the stage for heightened market attention on the results and management’s commentary.
SpaceX and Nvidia team up on Musk’s orbital AI bet
SpaceX reports beat in first earnings while minimizing losses
