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SpaceX delays Starhopper’s first flight a few days despite Raptor preburner test success

According to NASASpaceflight.com, SpaceX's Starhopper successfully completed a Raptor preburner taste on July 15th. A static fire ignition test should follow on July 16th.(NASASpaceflight - bocachicagal)

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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.

Starhopper (technically) came alive for the third time ever on July 15th, albeit only partially. SpaceX ignited the engine’s preburners as a precursor to a full static fire, now NET July 16th. (LabPadre – YouTube livestream)

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.

A Raptor engine is pictured here during a static fire test in McGregor, Texas. (SpaceX)

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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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 breaks his silence on the Starlink impact to Ukraine drones

Musk says the US military and president set Starshield limits, not SpaceX, amid Ukraine complaints.

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Elon Musk says the speed limit cutting out Ukraine’s military Starlink terminals is not SpaceX’s decision. In a post on X Wednesday, Musk wrote that “Starshield systems are owned and controlled by the US government. Any limits on speed or usage are decided by the US military and ultimately POTUS.” He added that Starlink is a commercial service limited to civilian or defensive activities and “cannot be used for offensive military action, as doing so would be inappropriate for a commercial company.”

He was replying to Mykhailo Fedorov, Ukraine’s former defense minister, who had thanked Musk for restoring connectivity at speeds up to 160 km/h and said removing the Starshield limit entirely is “now critical for Ukraine’s defense.”

The complaint started Tuesday night, when Ukrainian officials said military terminals began losing service above roughly 100 mph. Presidential adviser Serhiy Beskrestnov said the defense forces got no warning and several missions were disrupted, as Teslarati reported earlier Wednesday. The 7th Rapid Reaction Corps told Reuters connections dropped for 10 to 20 seconds at speeds well below the limit, which made drones harder to control. Poland’s foreign minister, Radoslaw Sikorski, asked Musk on X whether he is “playing politics with your products again.”

That is why the Starlink and Starshield distinction matters. SpaceX introduced Starshield in 2022 as the government version of Starlink, with an initial focus on Earth observation, communications and hosted payloads. It won a Space Force contract in 2023 with a $70 million ceiling. In December 2024, the Pentagon moved Ukraine’s terminals onto Starshield, covering about 3,000 units across two contracts. Ukraine’s military connections therefore run through a service that Musk now says sits under Washington’s control.

SpaceX pitches subscription model for Trump’s Golden Dome

While Musk’s post describes who holds authority, it does not infer that anyone ordered the limit, and neither SpaceX nor the US government has confirmed who set it. Ukrainian officials have pointed to the timing, which follows President Trump’s push for an energy ceasefire and Musk’s Saturday post that “Zelensky has gone too far.” The BBC noted Trump denied threatening to restrict intelligence sharing with Kyiv, and no evidence has been presented that Washington requested the cap.

The episode also revives a promise from 2025. After Poland accused him of threatening Ukraine’s access, Musk said Starlink “will never turn off its terminals” and would not be used as a bargaining chip. Poland has since supplied more than 29,000 terminals to Ukraine. Teslarati also covered Kyiv’s search for Starlink alternatives in 2025, and the latest dispute gives that search new urgency.

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Investor's Corner

Tesla opens the Q&A for its biggest earnings call yet

Tesla opens its Q3 earnings Q&A, and Cybercab, Robotaxi, Optimus and regulators loom over October 21.

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Tesla has opened its shareholder question portal for the Q3 2026 earnings call, with the Say Q&A page already listing questions. Investors have until 4:00 p.m. EDT on October 20 to submit and vote on what management should answer.

The call is set for Wednesday, October 21. Tesla will post results after the market closes, with a live webcast at 4:30 p.m. CT, or 5:30 p.m. ET, through its investor relations site.

Say ranks questions by the number of shares behind the votes, which gives institutional holders extra weight over the retail crowd.

Ahead of Q2, retail investors asked why Robotaxi growth had stalled, when Cybercab would start customer rides, and where the Optimus Gen 3 ramp stood, while an institutional holder asked how Tesla and SpaceX would split Terafab duties. Cybercab has since answered one of those. Tesla said last week it has 300 plus Cybercabs serving Austin, up eightfold in 30 days, with Dallas named as the next city. The questions now are likely to move from when to how fast.

There is also a regulatory question hanging over the call. NHTSA has demanded sworn answers on how the pedal free Cybercab was certified against federal safety standards, with responses due October 30, nine days after the call. Whether an analyst raises it live is unknown, but it is the kind of exposure that tends to find its way into a Q&A.

The numbers will not be the main draw. Tesla already reported 486,532 deliveries and 13.7 GWh of storage for the quarter. Consensus sits around 43 to 45 cents per share on roughly $27.8 billion in revenue, according to Zacks, after a Q2 report that missed on EPS. Goldman Sachs, which holds a Neutral rating and a $360 target, argues the outlook for Robotaxi, FSD and Optimus will matter more to the stock than the quarter itself.

The call also lands six days after the rescheduled Roadster event, which Tesla will stream on X on Thursday, October 15, at 7:55 p.m. CT. If the Roadster shows up with a production date or a SpaceX thruster package, expect it to climb the voting list before the deadline.

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Ukraine says Starlink is cutting out its military drones as Poland calls out Elon Musk

Ukrainian officials allege SpaceX limited military Starlink speeds, disrupting drone missions; SpaceX has not commented.

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Credit: Mykhailo Fedorov/Twitter

Ukrainian officials are accusing SpaceX of placing a speed limit on the military version of Starlink that their forces use to fly drones, but SpaceX has not confirmed that any change was made. Presidential adviser Serhiy Beskrestnov said in a Telegram post on Wednesday that Starshield terminals have begun losing service when they move faster than about 100 miles per hour, according to a Reuters report. “Our defense forces did not receive a warning about this limitation, and this led to the disruption of several missions,” he wrote.

Ukraine’s 7th Rapid Reaction Corps told Reuters that connections dropped for 10 to 20 seconds at just 68 to 75 mph, which made the drones harder to control. Volunteer Serhiy Sternenko, citing military reports, said the dropouts are now starting at 37 to 43 mph. These accounts come from Ukrainian officials and military sources and have not been independently verified. Regular civilian terminals were reportedly not affected, according to EUalive.


SpaceX has not publicly commented or explained what, if anything, changed. Beskrestnov and other Ukrainian officials believe the issue is intentional and point to the timing. Washington has been pressing Kyiv to stop long range strikes on Russian oil refineries after President Trump called for an “energy ceasefire,” and Musk posted on Saturday that “Zelensky has gone too far.” EUalive noted that neither Ukrainian nor Polish officials have presented evidence that the limit was ordered by Washington or by SpaceX, so the link to politics remains an allegation. Other explanations, such as a technical or policy change affecting fast moving terminals, have not been ruled out.

Poland’s foreign minister, Radosław Sikorski, responded on X by quote tweeting a Kyiv Independent report and writing: “Hey, @elonmusk, big man, are you playing politics with your products again? As your European customers, we are watching you.” Poland is the largest funder of Ukraine’s Starlink service, having supplied more than 29,000 terminals and covering operating costs Sikorski has put at roughly $50 million a year. The wording echoes their 2025 clash, when Musk told Sikorski to “be quiet, small man.” At the time of writing, neither Musk nor SpaceX had responded to the claims.

The dispute sits on top of a long history. Musk confirmed in February 2022 that Starlink was active in Ukraine after a request from a Ukrainian minister. That October, SpaceX asked the Pentagon to share the bill and Musk said the cost was approaching $20 million a month, before he reversed course and said SpaceX would keep paying. In December 2024 the Pentagon moved some of those terminals onto the Starshield service, the government version now at the center of the complaints.

SpaceX has also changed how its network treats certain terminals in Ukraine before, and that time it was with Kyiv’s cooperation. In February, Ukrainian officials confirmed that terminals believed to be used by Russian troops were disabled after coordination with SpaceX, a step that Ukrainian commanders later said hurt Russian assaults. Whether anything similar is behind the latest reports is unclear, which is why Kyiv is asking for answers.

Ukraine is already looking at backups. Defense tech company Stetman is developing its own satellite system, UASAT-NANO, and officials in Europe have discussed alternatives to Starlink since early 2025, though none match its scale yet.

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