Connect with us

News

SpaceX wiggles Starhopper’s Raptor engine, tests parts ahead of hover test debut

Repeating a test conducted in June with Raptor SN04, SpaceX tested Starhopper and Raptor SN06's thrust vectoring capabilities on July 12th. (NASASpaceflight - bocachicagal)

Published

on

On the evening of July 12th, SpaceX technicians put Starhopper’s freshly-installed Raptor – serial number 06 (SN06) – through a simple but decidedly entertaining test, effectively wiggling the engine in circles.

Designed to verify that Raptor’s thrust vectoring capabilities are in order and ensure that Starhopper and the engine are properly communicating, the wiggle test is a small but critical part of pre-flight acceptance and a good indicator that the low-fidelity Starship prototype is nearing its first hover test(s). Roughly 48 hours after a successful series of wiggles, Starhopper and Raptor proceeded into the next stage of pre-flight acceptance, likely the final more step before a tethered static fire.

Routine for all Falcon rockets, SpaceX’s exceptionally rigorous practice of static firing all hardware at least once (and often several times) before launch has unsurprisingly held firm as the company proceeds towards integrated Starhopper and Starship flight tests. Despite the fact that Raptor SN06 completed a static fire as recently July 10th, SpaceX will very likely put Starhopper and its newly-installed Raptor through yet another pre-flight static fire, perhaps its fourth or fifth test this month.

Although it would undoubtedly be easier, cheaper, and faster to skip that post-delivery static fire, it will simultaneously lower the risk of Raptor failing mid-flight and verify that Starhopper itself is healthy and ready for untethered hovering. Although SpaceX could likely live without Starhopper in the event that it’s lost during flight-testing, any failure capable of destroying the vehicle itself is at least as capable of severely damaging or completely destroying the spartan but still expansive test and launch facilities the company built over the course of several months.

SpaceX has been hard at work gradually building, expanding, and upgrading its South Texas launch facilities since December 2018. (NASASpaceflight – bocachicagal, 04/27/2019)

Would you like some testing with your testing?

Follow July 12th’s nighttime Raptor wiggle test, July 13th was mainly quiet and filled with inspections of Starhopper, Raptor, and other various work. The day after, however, SpaceX proceeded through several hours of propellant loading, ending with what looked like less energetic versions of the Raptor preburner ignition tests Starhopper previously performed with Raptor SN02.

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.

The first obvious test occurred around 7:30pm CT, July 14th. (LabPadre)
The second obvious test followed around 8:50 pm CT. (LabPadre)

Although the fireworks are so subtle that they are easily missed, the conditions inside the preburner – hidden away from view – are actually far more intense than the iconic blue, purple, and pink flame that exists Raptor’s nozzle. This is because the preburners have to nurture the conditions necessary for the pumps they power to fuel the main combustion chamber. 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 the main combustion chamber.

Thus, if the head 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 completely prevent Raptor from starting and running stably and can even trigger a “hard start” or shutdown that could damage or destroy the engine. As such, to preburners fundamentally have to operate at higher chamber pressures (and thus higher temperatures) than the main combustion chamber (the big firey bit at the end). According to Elon Musk, Raptor’s oxygen preburner has the worst of it, operating at pressures as high or higher than 800 bar (11,600 psi, 80 megapascals).

Coincidentally, this is roughly equivalent to the pressure at the bottom of the Pacific Ocean.

Starhopper and Raptor seen on the afternoon of July 14th, preparing for an evening of testing. (NASASpaceflight – bocachicagal)

In short, preburner testing is no less critical than full-on static fire testing with an engine like Raptor. July 14th’s test was also made doubly efficient due to the fact that preburner testing requires liquid propellant, which effectively makes the whole test a wet dress rehearsal (WDR) even before any engine ignition or partial ignition is involved. Per SpaceX moving from propellant loading to preburner/turbine testing, Starhopper is almost certainly healthy and operating as expected, an excellent sign that the ungainly vessel may be ready for a static fire of Raptor as early as 2pm CT, July 15th.

The memes, oh, the memes.

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

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

SpaceX’s next Starship launch is about to attempt its biggest leap yet

SpaceX targets September 22 for Starship Flight 14, its first attempt to reach real orbit.

Published

on

By

SpaceX has set September 22 as the target date for Starship’s 14th test flight, and this one carries a different goal than any of the 13 that came before it. Every previous Starship mission has intentionally flown a suborbital arc, reentering the atmosphere within the same hour it launched. Flight 14 is designed to send the craft into a genuine orbit around Earth for the first time.

The launch window opens at 7:15 a.m. Central time at Starbase in South Texas and runs for 75 minutes, pending regulatory approval, according to SpaceX’s mission description published Tuesday. If the flight goes as planned, Starship will circle the planet roughly six times at an altitude near 275 kilometers over about ten hours before a deorbit burn sends it toward a splashdown in the Pacific Ocean west of Chile, a departure from the Indian Ocean recoveries used on the last several flights.

The mission also marks the first attempt to put a working batch of Starlink V3 satellites into actual service. Flight 13 carried 20 of the new satellites in July, but because that mission never left a suborbital trajectory, the payload reentered along with the ship instead of separating into orbit.

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

Each V3 satellite is rated for roughly one terabit per second of downlink capacity, so a successful deployment on Flight 14 would be SpaceX’s largest single jump in network bandwidth since Starlink began flying on Falcon 9.

Flight 13 still did the heavier lifting on the technical side. That July mission flew a deliberately more stressful reentry profile to test Starship’s heat shield, and the ship survived its softest splashdown yet, intact enough for drone inspections shortly after landing. Elon Musk said the flight delivered “all the heat shield data we needed and then some,” a result Teslarati covered in detail when he later said SpaceX had solved the vehicle’s biggest reusability challenge. Flight 14 is where SpaceX starts spending that confidence on an actual orbital insertion rather than another controlled fall back to Earth.

One thing Flight 14 will not attempt is a tower catch of the ship. Musk floated the idea right after Flight 13, but walked the timeline back in August, saying a catch attempt was more likely “in a few months.” The Super Heavy booster will still aim for its own recovery, targeting an offshore landing point in the Gulf of America, the same approach used on recent flights.

September 22 is SpaceX’s own target, not a locked date. Starship’s schedule has slipped before over hardware readiness and FAA sign off, and the company has said as much in its own mission notes. But the plan itself represents the clearest marker yet that Starship is moving from a suborbital test program into something meant to carry paying payloads and, eventually, people.

Continue Reading

Elon Musk

Elon Musk gives his most telling Tesla-SpaceX merger conversation yet

Elon Musk hinted a Tesla-SpaceX merger could be coming, and Wall Street is taking notice.

Published

on

By

Elon Musk gave his clearest signal yet that Tesla and SpaceX could eventually combine, telling the All-In Summit in Los Angeles that the two companies’ deepening collaboration makes the question worth asking. Sawyer Merritt first surfaced the highlight on X Tuesday.

Asked directly why Tesla and SpaceX remain separate given how closely they already work together, Musk told hosts at the summit: “Great question there. With all this collaboration, on so many levels, who can imagine what action one might take when there’s so much close collaboration in so many areas.” SpaceX President Gwynne Shotwell, who joined Musk on stage, added that SpaceX personnel have already moved into xAI to fill leadership and engineering gaps, saying the businesses are integrating “faster than I thought,” though “not fully integrated yet,”

The comments landed on top of merger speculation that has been building on Wall Street for months. JPMorgan has called a tie-up “strategically coherent on paper,” pointing to overlapping ambitions in AI, robotics, energy, transportation and space. Jefferies went further, estimating Musk could retain roughly 55.3 percent voting control in a deal structured without a premium, a scenario that would still leave room for Tesla shareholders to come out ahead. On Kalshi, traders now put the odds of a merger before 2028 at 66 percent.

Tesla’s stake in SpaceX, still under one percent, traces back to its earlier investment in xAI, which converted to SpaceX equity after SpaceX absorbed the AI company. The two are also jointly building Terafab, a chip facility in Austin meant to serve both Tesla’s AI computing needs and SpaceX’s satellite ambitions. Wedbush analyst Dan Ives has stood by a 2027 merger timeline for months, and Cathie Wood’s ARK Invest recently floated a similar case, an idea Musk pushed back on directly at the time.

Another Tesla SpaceX merger prediction by ARK Invest has Elon Musk talking

The timing adds another layer. Tesla has scheduled an October 1 unveiling for its next generation Roadster at a venue near SpaceX’s McGregor, Texas test site, using the phrase “Go for launch” in its promotional material. Both stocks dipped roughly 2 percent Monday before recovering slightly in premarket trading Tuesday, with SpaceX shares up about 0.4 percent and Tesla essentially flat.

Musk stopped short of confirming anything is in motion. But unlike his past denials of a corporate restructuring, this response didn’t rule one out, and it came with Shotwell sitting next to him describing an integration that’s already underway.

Continue Reading

Elon Musk

Tesla Roadster unveiling is getting hyped up by Elon Musk

Published

on

tesla roadster
Credit: Petersen Auto Museum

The Tesla Roadster unveiling is getting hyped up by the company’s CEO Elon Musk, who has been a big reason the product has such high expectations due to delayed timelines and a constant need to make it even more insane than before.

Tesla announced on September 12 that it would officially unveil the Roadster in Waco, Texas, on October 1, ending years of patience for fans and reservation holders who have waited for the all-electric supercar to enter production since 2017.

Musk has said that this event will be well worth the wait on several occasions, and last year on the Joe Rogan Experience, he said that there should be a closing chapter to supercars- the end of cars that aren’t focused on safety.

He said:

“Whether it’s good or bad, it will be unforgettable. My friend Peter Thiel once reflected that the future was supposed to have flying cars, but we don’t have flying cars. I think if Peter wants a flying car, he should be able to buy one. I think it has a shot at being the most memorable product unveil ever. This is some crazy technology in this car. Let’s just put it this way: if you took all the James Bond cars and combined them, it’s crazier than that.”

Musk’s teases have continued, and now that the event is roughly two weeks away, it seems like Roadster is finally going to show up and blow some minds:

Tesla has definitely dragged out the development of the Roadster, but there is a good reason for it.

Tesla has been working on many other projects, most notably self-driving efforts to increase passenger safety, and those simply took priority over the Roadster, a low-volume, high-performance sports car that has a lightning-fast acceleration rate of 0-60 MPH in just 1.1 seconds, could potentially fly, and contributes very little to the company’s mission.

However, many people have the Roadster on pre-order through the referral program or with their own money, and it is time that Tesla delivers on that.

Continue Reading