Connect with us

News

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)

Published

on

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).

Check out Teslarati’s Marketplace! We offer Tesla accessories, including for the Tesla Cybertruck and Tesla Model 3.

Advertisement
-

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.

Advertisement
Comments

Elon Musk

Elon Musk says Tesla’s Roadster demo could be a bang, quite literally

Musk says tonight’s Roadster demo will be a banger, maybe literally. The clues add up.

Published

on

By

tesla roadster elon musk flying

Elon Musk spent Wednesday and Thursday stacking teases on top of Tesla’s Roadster event, and the wording is getting harder to read as routine hype. Tesla streams the unveil tonight at 7:55 p.m. Central on X. Musk has called it “a candidate for greatest product demo of all time,” then added that “this demo will be a BANGER, probably metaphorically, though some chance literally.”

The “some chance literally” part is the line to watch. The Roadster has been tied to a SpaceX option package since 2018, and as we reported when the date was announced, the system is reportedly codenamed A71 and uses cold gas thrusters fed by a composite overwrapped pressure vessel, the same tank design SpaceX uses on Falcon 9. Musk has said a thruster equipped car could reach 60 mph in about 1.1 seconds. Cold gas thrusters firing at full output are loud, and reports ahead of the event say the car will be unmanned with spectators kept several hundred yards back. A literal bang could simply mean a demonstration that sounds like one, though it is also an admission that something could go wrong on stage.

Then there is “Timing is everything,” which Musk posted a day earlier. Stocktwits noted that 7:55 p.m. is 19:55 on a 24 hour clock, which echoes 1955, the year Marty McFly travels to in Back to the Future. Musk has made that connection before. In 2019 he replied to an animation of a flying DeLorean by saying the new Roadster “will actually do something like this.” Nothing from Tesla confirms the movie reference, but the stream time was chosen by someone, and Tesla has not been shy about this kind of wink.

Also, Tesla said it moved the event because it “can only be held outdoors,” and Musk then wrote that the demo was postponed “due to high winds,” as Teslarati covered at the time. A car running a standing start in front of a crowd shrugs off wind. A car that leaves the ground does not. The venue near SpaceX’s McGregor test site and the FAA airspace closures reported around the original date point the same way, though we also noted the delay could be a plain safety precaution. Musk has also described the new Roadster as “beyond movies, beyond imagination, beyond human, yet still made by humans on Earth.”

The only official figures remain the 2017 ones: 620 miles of range, a top speed above 250 mph, a 1.9 second 0 to 60 time, and prices of $200,000 for the base car and $250,000 for the Founders Series. Production is expected at Giga Texas in 2027 or 2028. Tesla has said the event will cover pricing, specifications and production targets, and its livestream preview has the full rundown. Tesla reports third quarter earnings on October 21, so whatever lands tonight will be fresh going into that call. We will have live coverage as soon as the stream starts.

Continue Reading

Elon Musk

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.

Published

on

By

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.

Continue Reading

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.

Published

on

By

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.

Continue Reading