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SpaceX rocket catch simulation raises more questions about concept

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CEO Elon Musk has published the first official visualization of what SpaceX’s plans to catch Super Heavy boosters might look like in real life. However, the simulation he shared raises just as many questions as it answers.

Since at least late 2020, SpaceX CEO Elon Musk has been floating the idea of catching Starships and Super Heavy boosters out of the sky as an alternative to having the several-dozen-ton steel rockets use basic legs to land on the ground. This would be a major departure from SpaceX’s highly successful Falcon family, which land on a relatively complex set of deployable legs that can be retracted after most landings. The flexible, lightweight structures have mostly been reliable and easily reusable but Falcon boosters occasionally have rough landings, which can use up disposable shock absorbers or even damage the legs and make boosters hard to safely recover and slower to reuse.

As a smaller rocket, Falcon boosters have to be extremely lightweight to ensure healthy payload margins and likely weigh about 25-30 tons empty and 450 tons fully fueled – an excellent mass ratio for a reusable rocket. While it’s still good to continue that practice of rigorous mass optimization with Starship, the vehicle is an entirely different story. Once plans to stretch the Starship upper stage’s tanks and add three more Raptors are realized, it’s quite possible that Starship will be capable of launching more than 200 tons (~440,000 lb) of payload to low Earth orbit (LEO) with ship and booster recovery.

One might think that SpaceX, with the most capable rocket ever built potentially on its hands, would want to take advantage of that unprecedented performance to make the rocket itself – also likely to be one of the most complex launch vehicles ever – simpler and more reliable early on in the development process. Generally speaking, that would involve sacrificing some of its payload capability and adding systems that are heavier but simpler and more robust. Once Starship is regularly flying to orbit and gathering extensive flight experience and data, SpaceX might then be able refine the rocket, gradually reducing its mass and improving payload to orbit by optimizing or fully replacing suboptimal systems and designs.

Instead, SpaceX appears to be trying to substantially optimize Starship before it’s attempted a single orbital launch. The biggest example is Elon Musk’s plan to catch Super Heavy boosters – and maybe Starships, too – for the sole purpose of, in his own words, “[saving] landing leg mass [and enabling] immediate reflight of [a giant, unwieldy rocket].” Musk, SpaceX executives, or both appear to be attempting to refine a rocket that has never flown. Further, based on a simulation of a Super Heavy “catch” Musk shared on January 20th, all that oddly timed effort may end up producing a solution that’s actually worse than what it’s trying to replace.

Based on the simulated telemetry shown in the visualization, Super Heavy’s descent to the landing zone appears to be considerably gentler than the ‘suicide burn’ SpaceX routinely uses on Falcon. By decelerating as quickly as possible and making landing burns as short as possible, Falcon saves a considerable amount of propellant during recovery – extra propellant that, if otherwise required, would effectively increase Falcon’s dry mass and decrease its payload to orbit. In the Super Heavy “catch” Musk shared, the booster actually appears to be landing – just on an incredibly small patch of steel on the tower’s ‘Mechazilla’ arms instead of a concrete pad on the ground.

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Aside from a tiny bit of lateral motion, the arms appear motionless during the ‘catch,’ making it more of a landing. Further, Super Heavy is shown decelerating rather slowly throughout the simulation and appears to hover for almost 10 seconds near the end. That slow, cautious descent and even slower touchdown may be necessary because of how incredibly accurate Super Heavy has to be to land on a pair of hardpoints with inches of lateral margin for error and maybe a few square feet of usable surface area. The challenge is a bit like if SpaceX, for some reason, made Falcon boosters land on two elevated ledges about as wide as car tires. Aside from demanding accurate rotational control, even the slightest lateral deviation would cause the booster to topple off the pillars and – in the case of Super Heavy – fall about a hundred feet onto concrete, where it would obviously explode.

What that slow descent and final hover mean is that the Super Heavy landing shown would likely cost significantly more delta V (propellant) than a Falcon-style suicide burn. Propellant has mass, so Super Heavy would likely need to burn at least 5-10 tons more to carefully land on arms that aren’t actively matching the booster’s position and velocity. Ironically, SpaceX could probably quite easily add rudimentary, fixed legs – removing most of the bad aspects of Falcon legs – to Super Heavy with a mass budget of 10 tons. But even if SpaceX were to make those legs as simple, dumb, and reliable as physically possible and they wound up weighing 20 tons total, the inherent physics of rocketry mean that adding 20 tons to Super Heavy’s likely 200-ton dry mass would only reduce the rocket’s payload to orbit by about 3-5 tons or 1-3%.

Further, per Musk’s argument that landing on the arms would enhance the speed of reuse, it’s difficult to see how landing Super Heavy or Starship in the exact same corridor – but on the ground instead of on the arms – would change anything. If Super Heavy is accurate enough to land on a few square meters of steel, it must inherently be accurate enough to land within the far larger breadth of those arms. The only process landing on the arms would clearly remove is reattaching the arms to a landed booster or ship, which it’s impossible to imagine would save more than a handful of minutes or maybe an hour of work. SpaceX’s Falcon booster turnaround record is currently 27 days, so it’s even harder to imagine why SpaceX would be worrying about cutting minutes or a few hours off of the turnaround and reuse of a rocket that has never even performed a full static fire test – let alone attempted an orbital-class launch, reentry, or landing.

Put simply, while Starbase’s launch tower arms will undoubtedly be useful for quickly lifting and stacking Super Heavy and Starship, it’s looking more and more likely that using those arms as a landing platform will, at best, be an inferior alternative to basic Falcon-style landings. More importantly, even if everything works perfectly, the arms actually cooperate with boosters to catch them, and it’s possible for Super Heavy to avoid hovering and use a more efficient suicide burn, the apparent best-case outcome of all that effort is marginally faster reuse and perhaps a 5% increase in payload to orbit. Only time will tell if such a radical change proves to be worth such marginal benefits.

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

SpaceX filed with the FCC for Starship Flight 14, its first true orbital launch attempt.

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SpaceX has asked the Federal Communications Commission for permission to fly Starlink terminals during Starship’s fourteenth flight test, and the filing lays out a genuine trip to orbit, something the program has never attempted.

Every Starship flight so far, including Flight 13’s successful splashdown in the Indian Ocean on July 24, has flown a suborbital arc that ends with the ship reentering the atmosphere within the same hour it launches. The FCC paperwork describes a mission profile built around an actual orbital insertion instead.

The payload is the other half of the story. Flight 13 carried 20 production Starlink V3 satellites, but because that mission never reached orbit, the satellites reentered along with the ship rather than joining the constellation, something Teslarati covered in detail after SpaceX released footage shot from one of those satellites as it drifted away from Starship in space. Flight 14 is designed to close that gap. If the orbital insertion holds, the roughly 20 V3 satellites onboard would separate into an operational orbit and could eventually go into service, each one rated for about 1 terabit per second of downlink capacity by SpaceX’s own account.

SpaceX announces new Starbase for ‘thousands of Starship launches annually’

Elon Musk first flagged the orbital attempt during SpaceX’s August 4 earnings call, the company’s first as a public entity following its June IPO under the ticker SPCX. He also floated catching the ship with the Starbase tower on the same flight, an idea he walked back on August 20, saying the catch attempt would more likely come “in a few months,” as Teslarati reported at the time. Flight 14 will instead target a splashdown for the ship in the Indian Ocean, the same recovery method used since Flight 12.

Hardware has been catching up to the ambition. Booster 21 completed a full 33-engine static fire on August 28, and Ship 41 finished its own six-engine test the week before. An airspace briefing circulated to pilots on August 20 listed September 15 as the target date, later than the end of August window Musk mentioned on the earnings call, though SpaceX has not confirmed a launch date publicly and Starship schedules routinely slip while hardware and FAA paperwork line up.

The FCC filing itself does not guarantee a launch date. It covers communications authority, and not flight readiness, considering SpaceX still needs Ship 41 fully stacked and cleared by the FAA before Flight 14 can fly. But the filing is a real marker of intent and it puts a specific regulatory process behind what had so far only been Musk’s word on the earnings call.

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Tesla Cybercab Event: what to expect from Austin

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Credit: Tesla

Tesla is set to launch Cybercab on Thursday at an event in Austin, Texas, which will officially bring the company’s first steering wheel-less and pedal-less vehicle to a limited number of consumers for the first time.

The event, which is invite-only, is still thin on details: we’ll be there, and it seems the event will be held at Gigafactory Texas, but the launch of this vehicle truly relies on it being operational outside of the factory and on public roads.

Nevertheless, there are some big things to expect, and other things to temper expectations on. For what it’s worth, we believe this event could be perhaps the biggest indication that Tesla is ready to truly enter a new phase and chapter in its historic story.

Tesla Cybercab’s First Foray into the Public with Real-World Riders

Cybercab will likely hit the streets of Austin and the surrounding areas, likely in the established geofence that Tesla has expanded on for the past 14 months. Just yesterday, Tesla expanded it once again by 9 percent.

Tesla will put, for the first time, a vehicle without any manual controls on public roads, likely without any help from teleoperators. This is a truly groundbreaking development if it comes through in this fashion: it would be groundbreaking for Tesla to roll out a truly driverless ride-hailing vehicle.

Cybercab Has Already Been Unveiled

This is not an unveiling event. Cybercab has been released for nearly two years, as Tesla first showed it to the public on October 10, 2024.

FIRST LOOK: Tesla ‘Cybercab’ Robotaxi makes its global debut

While there is some small speculation that Tesla could release the Roadster at the event as a surprise, it seems more likely the focus will be on the Cybercab and the huge accomplishment that will come with releasing a vehicle with no manual controls.

There Will Be a Lot of Hype

What’s important to remember about the Cybercab event is that Tesla will continue to prioritize safety and the rollout will likely be slow, just as it has been with Robotaxi.

One of the biggest complaints about Robotaxi is vehicle population, and the fact that the wait for a ride, at least in some instances, has been longer than most want to admit.

Tesla Cybercab fleet grows in Austin ahead of launch event

It will take time for this project to truly scale. It will take time for Tesla to roll this out in a large fashion. The important thing to note is that they are doing it, and they’re doing it with a vehicle that is completely engineered and built internally. That’s something no other ride-hailing service can say.

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SpaceX would not exist if this crucial early launch failed, Musk says

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Credit: SpaceX

Elon Musk recently restated a fact that still defines SpaceX’s origin story: if Falcon 1’s fourth launch had failed, the company would not exist. The comment answered a reminder that after three consecutive losses, SpaceX had money for only one more attempt.

On X, Peter Diamandis said that the present-day acknowledgement of SpaceX’s success does not discount the rough start the company had. “Almost nobody remembers that Elon’s first rocket failed three times, and there was money for exactly only one more attempt.”

Musk said, “If the 4th launch had failed, SpaceX would not exist.”

In late 2008, the firm was nearly out of cash. Another failure would have ended payroll, closed the Hawthorne factory, and left the Falcon 9 and Dragon programs as unfinished drawings.

The first flight lifted off from Omelek Island on 24 March 2006. Thirty-three seconds later, a corroded aluminum fitting on a fuel line leaked. Kerosene ignited around the Merlin engine, control was lost, and the vehicle came apart. The small DARPA payload, FalconSAT-2, survived the short flight only to land on a storage shed near the pad. Investigators later traced the fitting to a materials mix-up that should never have reached the rocket.

Flight 2, on 21 March 2007, looked far better at first. The first stage burned cleanly and handed off to the Kestrel-powered upper stage. The vehicle crossed 100 kilometers and reached a peak of about 289 kilometers. Then propellant slosh in the second-stage tank started a circular coning motion that grew until the engine shut down. Telemetry faded as the stage tumbled, and SpaceX had reached space but not orbit. Over the next year, the team redesigned everything from the ground up, including tanks, baffles, and the new regeneratively cooled Merlin 1C.

That engine flew on Flight 3 on 2 August 2008. The first stage performed almost perfectly and reached 217 kilometers. After main-engine cutoff, leftover fuel in the cooling channels produced a faint residual thrust, roughly 10 pounds per square inch of chamber pressure. On a Texas test stand, the effect was invisible beneath ambient air pressure. In vacuum it was enough to push the spent first stage back into the second stage after separation. The stages collided, the upper stage spun, and the mission was lost. Musk later said a slightly longer delay before staging would have saved the flight.

Six weeks later, the team assembled Flight 4 from remaining parts and flew it on 28 September 2008 at 23:15 UTC. The payload was Ratsat, a 165-kilogram aluminum mass simulator built in-house. Staging was delayed so residual thrust could decay. The Kestrel ignited, the fairing split away, and nine and a half minutes after liftoff the vehicle was in orbit. After a coast, the second stage restarted, settling into a 621-by-643-kilometer path at 9.35 degrees inclination. Falcon 1 became the first privately developed liquid-fueled rocket to reach Earth orbit. Musk called the insertion “middle of the bull’s-eye.”

SpaceX restores a Falcon 1 rocket for 10th anniversary of first launch success

That success unlocked NASA’s Commercial Resupply Services award later that year. Without it, there would have been no Falcon 9, no reusable first stages, and no Dragon cargo or crew flights to the International Space Station. Launch prices would have remained far higher. Starlink’s constellation would not exist; broadband from low Earth orbit would still be a paper concept.

Ride-share markets, high launch cadence, and the current pace of lunar and Mars hardware would be years behind. Communications, Earth observation, and the cost of putting anything into space would look more like the 2000s than the 2020s.

One extra second of residual thrust in August 2008 would have written a different decade.

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