Connect with us

News

SpaceX’s Starhopper readies for more ambitious Raptor-powered flight tests

On June 1st, SpaceX technicians began installing a new Raptor - this time SN04 - on Starhopper. (NASASpaceflight - bocachicagal)

Published

7 years ago

on

For the second time in two months, SpaceX technicians have begun to install a Raptor engine on Starhopper, a full-scale Starship testbed theoretically capable of low-velocity, moderate-altitude ‘hops’.

Back in late March, Raptor and Starhopper were joined for the first time, enabling a lengthy series of attempted tests that were followed by two engine ignitions and tethered hops before Raptor was removed for inspection. In the two months since that first round of integrated testing, SpaceX has significantly upgraded Starhopper and its spartan launch facilities, all focused on transforming the odd vehicle from a largely fixed test stand into a giant, mobile Grasshopper.

All the way back in 2012, SpaceX began testing Falcon 9 recovery and reusability concepts with a low-fidelity prototype known as Grasshopper – essentially a minimalist Falcon 9 first stage with ad hoc legs and a single Merlin engine. It supported a series of 8 major test flights – all successful and a source of valuable data – before the vehicle’s 2013 retirement. An upgraded Grasshopper – known instead as Falcon 9 Reusable Development Vehicle (F9R Dev1) – began testing around the same time and continued even higher altitude vertical takeoff/vertical landing (VTVL) tests until its untimely demise in August 2014.

Starhopper is quite similar, although it is also serving as a testbed for a far more varied range of technologies due to the fact that it has been developed before the inaugural launch of its namesake (Starship/Super Heavy). By the time SpaceX started Grasshopper/F9R tests, Falcon 9 had already completed several successful launches. With Starhopper, SpaceX is building and testing its first 9m-diameter ‘flight’ hardware, its first propellant tanks built out of steel, its first flight-capable rocket fueled by methane and oxygen, and its first mobile Raptor testbed, among numerous other things. The challenges are inherently much greater, but SpaceX has the luxury of taking the opposite approach it took towards Falcon 9 and building a launch vehicle entirely around its intended reusability, rather than trying to squeeze a method of reusability around an already-flying rocket.

Saurid Oddities

As noted by NASASpaceflight.com in a June 2nd article, SpaceX seems to be juggling its growing selection of newly-produced and tested Raptor engines in pursuit of Starhopper’s return to flight. According to the publication’s reliable sources,

“Up until recently, [SpaceX] was planning to utilize Raptor SN4 for [Starhopper’s first] untethered hops. However, the company has now decided to utilize this engine only for fit checks, and will instead perform the hops with SN5 – the latest Raptor to come out of SpaceX’s factory in Hawthorne, California.” – NASASpaceflight.com, June 2nd, 2019

This indicates that the Raptor engine delivered to Boca Chica on June 1st and currently in the process of being installed on Starhopper is actually more of a stand-in* for a future Raptor, SN05. The reasons behind this Raptor shuffle elude detection, but it’s possible that the simplest explanation – also posed by NASASpaceflight – is the correct one. By shipping a Raptor that may not be ready for flight tests, SpaceX could likely save anywhere from a few days up to a few weeks by doing everything short of lifting off under the powered of Raptor SN04.

*By all appearances, SN04 is a flight-grade Raptor that has completed assembly and likely been test-fired in McGregor, Texas. Why it may currently be resigned to a “stand-in” role is unknown.

Very curiously, upon Raptor SN04’s South Texas arrival, it appears that SpaceX technicians have indeed rapidly installed the engine on Starhopper, but in a position that is decidedly off-center. Pictured above, the photo could have simply caught the engine while technicians were moving it to its actual installation spot, but it could also indicate that SpaceX is speeding towards Starhopper’s first triple-Raptor test flights.

Advertisement
-

Starhopper delays?

In line with the last-second switch from Raptor SN04 to Raptor SN05 as the engine-to-be for untethered hops, SpaceX has pushed the start of that test series from approximately May 31st to June 11th. More likely than not, the ~11-day delay is meant to allow time for Raptor SN05’s McGregor, Texas acceptance testing, given that – per CEO Elon Musk – the engine wasn’t even finished as of May 22nd.

On the other hand, with Raptor SN05 now scheduled to support Starhopper hop tests as early as mid-June, it begs the question of whether SpaceX is instead working towards expedited triple-Raptor testing. For unknown reasons, neither Raptor SN03 or SN04 are apparently ready to support flight operations, although both have been thoroughly hot-fired in McGregor. Perhaps each engine is a distinct prototype with a different level of experimental readiness, or perhaps SpaceX is just testing certain engines (like SN03) more extensively than others (SN05).

Regardless, SpaceX now seems to have 3-4 intact, functional Raptor engines (excluding SN01; destroyed during stress testing), 2-3 of which are actively testing or being worked on a day’s drive north of Boca Chica. SN02 – having successfully supported a brief duo of ignition tests with Starhopper – could still be intact and test-ready. SN03 is an unknown quantity, but SN04 is clearly in excellent shape and is probably close to flight-readiness if it isn’t already. This is to say that SpaceX likely already has three Raptors on hand that are capable of supporting multi-engine Starhopper testing, whether or not such a test regime would actually be valuable.

Musk has noted that both orbit-capable Starship prototypes will be far closer to finished products and will thus fly with “at least 3 engines” (3 sea level engines, as it would turn out) or even “all 6” (3 sea level, 3 vacuum-optimized). In the meantime, Starhopper stands with an off-centered Raptor, awaiting the arrival of a different Raptor to kick off a second hop test program. If nothing else, SpaceX’s Starship/Super Heavy development program is operating in a spectacularly hardware-rich fashion, lending itself to the breakneck-pace of iteration and improvement SpaceX is famous for.

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

Related Topics:

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

Investor's Corner

Tesla Optimus Gen 3 shows off a cleaner, factory-ready design in new app discovery

Renders hidden inside Tesla’s Android app show Optimus Gen 3’s design before any official reveal.

Published

7 hours ago

on

September 23, 2026

By

Tesla Optimus Gen 3 [Credit: Tesla]

Tesla may have accidentally given a first look at its newest Optimus Gen 3 humanoid robot when photos were found in the Tesla smartphone app.

Design files tucked inside a recent Android version of the Tesla app appear to show the third generation humanoid robot next to the older Gen 2.5 prototype. The assets were extracted from the app package by Tesla community member @wholemars, who posted the renders on X late Tuesday night before deleting them. The Tesla Newswire reshared the side by side comparison on Wednesday, and the images have circulated widely since.

Tesla Optimus Gen 2.5 vs Gen 3 comparison via @WholeMars on X

Tesla Optimus Gen 2.5 vs Gen 3 comparison via @WholeMars on X

The files are labeled “gen3” and were built as models for Tesla app’s own interface, as validated directly by Grok to be official.

The comparison shows a robot that looks built for a factory line rather than a lab bench. Gen 2.5’s exposed mechanical linkages and gold plating on the knees and shins are gone. In their place, Gen 3 uses matte black fairings on the lower legs, paired with a more contoured champagne gold body. Flexible covers now seal the joint where the torso meets the upper thighs, keeping bearings and moving parts sealed from debris and unnecessary contact.

The body panels fit more tightly, and the hands, which Tesla has said carry 22 degrees of freedom, look far more refined than those on earlier units.

This most recent leak fills a gap Tesla has left open for most of the year. Elon Musk said on March 31 that Optimus 3 was walking around but needed “some finishing touches” before it could be shown, a delay Teslarati covered when Tesla missed its first quarter reveal target. Musk later said Tesla would hold the design back until closer to production, partly to keep competitors from copying it. No reveal date has been announced.

The app itself has been preparing for Optimus for months. In July, code in the Tesla app pointed to a dedicated robot phone key, a consent screen for collecting video and spatial data while Optimus works inside a home, and an alert system for low battery and mechanical faults. Finished 3D models of Gen 3 suggest the interface owners will eventually use is moving past placeholder code toward something Tesla intends to ship.

Manufacturing is moving in parallel. Tesla tore out the original Model S and Model X lines at Fremont this summer to make room for Optimus production, with a planned capacity of one million robots a year. At Giga Texas, the steel frame of a dedicated Optimus factory is nearing completion ahead of a targeted 2027 start, with Musk pointing to an eventual output of 10 million units annually.

Continue Reading

News

Tesla Semi lands the biggest electric truck deal in U.S. history

Tesla leads a record 2,500 truck order, but not every truck will be a Semi.

Published

1 day ago

on

September 22, 2026

By

Tesla has landed the largest electric truck order in U.S. history. ZET SCALE, a new alliance of shippers and carriers, named Tesla its primary manufacturer on Tuesday for an initial order of 2,500 electric Class 8 trucks. The deal alone would nearly double the number of electric heavy trucks operating in the country.

According to the press release from Catalyst Mobility, the nonprofit formerly known as CALSTART, Kenworth, RIDE and Volvo were also selected as secondary manufacturers that carriers can pick if their operations call for it. No split between the four brands has been published, so the exact number of Semis in the order is not yet known.

Tesla won the top slot through a competitive request for proposals. The alliance, which Catalyst Mobility runs with the Smart Freight Centre, scored bidders on price, range, charging capability and production capacity. Pooling freight demand from founding shippers, including Microsoft and PepsiCo, let every truck maker bid lower than it would for a single fleet. “The Tesla Semi is designed for lower cost per mile operations than diesel,” said Dan Priestley, director of the Tesla Semi program, as noted in the press release.

The financing is built to pull in carriers who have avoided electric trucks. ZET Financial is issuing the purchase order for all 2,500 units and will place them with fleets through a fair market value lease. The trucks will be deployed over the next few years across 10 freight hubs in Los Angeles, Stockton, Bakersfield, Seattle and Tacoma, Houston, Dallas, San Antonio, Chicago, Atlanta, and the Newark and New York area. ZET SCALE says the first order is only the opening round, with a longer term goal of 10,000 trucks or more.

Even if Tesla ends up with only a majority share, it would still be the biggest Semi deal to date. Einride’s 500 unit order in August was the previous record, and WattEV’s 370 truck order in May was the largest California deal at the time. Einride’s CEO has since said he expects all 500 trucks delivered by the end of 2027.

The announcement lands two days before Tesla formally inaugurates its Semi factory in Nevada on September 24. The 1.7 million square foot plant sits next to Gigafactory Nevada’s 4680 cell lines and is designed for 50,000 trucks a year.

Continue Reading

News

Tesla integrates Grok Bot into its vehicles for the ultimate personal assistant

Published

1 day ago

on

September 22, 2026

By

Credit: Grok

Tesla has expanded Grok from an in-car chatbot into a hands-free work assistant. On September 22, Tesla officially launched Grok Bot capability, confirming that drivers can now manage email, calendars, files, chats, and tasks by voice and then hand more ambitious errands to the AI-fueled productivity cheat code.

Grok itself is built by xAI. The new car features split into two layers: Connectors link Grok to outside accounts. Grok Bot, currently limited to SuperGrok Heavy subscribers, can complete multi-step tasks such as placing a usual coffee order, booking a reservation, or scheduling an appointment. It truly puts the driver in a nearly complete hands-free driving and productivity setting, with ironically the only task truly requiring your hands being to touch the “Start Self-Driving” button.

We were granted access to Grok Bot’s Tesla integration a few weeks back, and we’ve been able to do a handful of things with it. On a handful of occasions, we’ve used it to order food and have it ready for pickup slightly later into the evening; we’ve managed to pick up groceries after a day of errands with Grok Bot, and outside of the car, it’s helped with budgeting and even my fantasy football draft.

Tesla shows another way to utilize it: in their demo, a driver says “Hey Grok,” asks the assistant to check an inbox, and hears that a message concerns a weekend reservation. Grok then scans the calendar, reports no conflicts, and confirms the Tahoe trip is clear. It can also add check-in details to a road-trip itinerary. The point is not novelty chat. It is keeping eyes on the road, or on Full Self-Driving, while the car handles the paperwork of a trip:

This Grok rollout is not a gadget add-on as much as it is Tesla’s thesis in software form: the car should stop being a machine you operate and start being a room you occupy.

Connectors and Grok Bot treat the cabin as an office that happens to move, and that has truly been Tesla’s intention for years now. The car has slowly become an extension of a home more than a vehicle. Inbox, calendar, groceries, takeout, and reservations become voice work, not dashboard chores that you need to do before you get in your car.

Responsibility shifts from the driver to the stack, and as many Tesla owners rely on FSD for travel, Grok Bot now handles the monotony of dinner reservations or appointments.

Continue Reading