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Relativity’s first 3D-printed rocket aims to debut a new rocket fuel
Relativity can almost taste the vacuum of space. A substantial amount of work remains, but the startup continues to defy expectations with its relentless and methodical push towards the first orbital launch of a 3D-printed rocket.
Founded in 2015, the Los Angeles-based aerospace company has taken its few years of obligatory delays in stride while pursuing a 2020 debut for its (relatively) small Terran 1 rocket. In a world with dozens of serious rocket startups, missing one’s initial launch target is practically a rite of passage – the path to orbit is never as straight and bump-free as the highway on-ramps that are often promised in pitch decks. Relativity Space, however, is no average rocket startup.
Save for SpaceX, which operates in a league of its own, no other private rocket startup has come close to matching the $1.3 billion Relativity has raised to develop Terran 1 and the much larger Terran R. More importantly, in a recent interview with Aviation Week, CEO Tim Ellis (a former Blue Origin engineer) revealed that the company could be “weeks away” from the first launch of Terran 1, a rocket that is 85% 3D-printed by mass and could simultaneously debut a new kind of rocket fuel.
Once fully assembled, Terran 1 – weighing around 9.3 tons (~20,500 lb) empty and measuring 33.5 meters (110 ft) tall – will be the largest metal 3D-printed object in the history of the technology. From that perspective, it’s hardly surprising that Relativity Space is a few years behind schedule. In fact, it’s odd that the startup isn’t more delayed, and it’s even more impressive that Terran 1’s first launch campaign has gone as smoothly as it has.
Slow, Smooth and Fast
Terran 1 Flight 1’s booster stage and upper stage both arrived at the company’s leased Cape Canaveral Space Force Station LC-16 pad sometime in May 2022. Terran 1’s first stage came directly from the California factory. The second stage (S2), however, first shipped to a Mississippi test stand a few months prior and, on its first try, completed a full-duration multi-minute static fire test known as a mission duty cycle (MDC) – about as close as it’s possible to get to replicating orbital upper stage operations on the ground. The flawless MDC was preceded by a number of simpler precursor tests, of course, but the rocket performed more or less as expected throughout the entire qualification program. If Terran’s second stage ignites again, it’ll be at the edge of space.
Since June, the critical path for Terran 1’s launch debut has thus been qualifying the first finished Terran booster. Rather than modify its Mississippi test facilities, Relativity decided to temporarily modify its heavily upgraded LC-16 pad to support booster qualification testing. Thanks to the heroic work of a shockingly small team of five people, the pad was ready to kick off testing as soon as the Terran 1 booster arrived in Florida. Even more surprisingly, senior manager Lorenzo Locante says that LC-16 – practically a new pad after Relativity’s extensive modifications – has “performed perfectly” during every booster qualification test attempted thus far.
That testing has included pneumatic proofing (an ambient-temperature gas pressure test), possible cryogenic proof tests, multiple rounds of propellant loading, preignition testing of its nine Aeon engines, and multiple spin-start tests (the last step before static fire testing) with the same engines. Given that LC-16 and Terran 1 must handle cryogenic oxidizer (liquid oxygen) and cryogenic fuel (liquid methane), which can easily create a flammable and bomb-like mixture of gases from even the smallest of leaks, it’s difficult to emphasize just how difficult it is to ensure that a complex launch pad and rocket perform nominally during their first joint testing.
According to engineers onsite during a private Teslarati tour of Relativity’s Florida launch facilities, Terran 1 S1’s next goal is to fully ignite its Aeon engines. After one or more successful static fires, the booster will be integrated with the upper stage and nosecone for a final full-duration static fire test that will also double as a full wet dress rehearsal (WDR). Testing the fully-integrated Terran 1 rocket will only be possible once LC-16’s full strongback and launch mount (also known as a transporter/erector) is completed, but that final piece of the puzzle should be ready any day now.
De Terra Ad Astra
The coming weeks will likely be some of the company’s riskiest and most difficult yet. If the rocket and LC-16 continue to operate as smoothly as they have been, however, there’s a nonzero chance that Terran 1 could beat the likes of SpaceX (Starship), Blue Origin (New Glenn), and the United Launch Alliance (Vulcan Centaur) to the punch to become the first methane and oxygen-fueled rocket in history to attempt an orbital launch.*
*While SpaceX’s Starship is technically the first large-scale suborbital methalox rocket to attempt (and complete) a launch, there has never been an orbital methalox launch attempt.
Capable of carrying up to 1.25 tons (~2750 lb) to low Earth orbit for as little as $12 million, Terran 1 also has a shot at becoming the first new privately-developed 1-ton-class rocket of any kind to successfully reach orbit. On that front, though, Relativity is in a neck-and-neck race with Firefly Aerospace and ABL Space, both of which intend to launch similarly-sized rockets at some point in the next few months. It’s never been less clear who will cross the finish line first but one would be hard-pressed to count Relativity out.
Tesla Cybertruck Lead Engineer Wes Morrill revealed the company has made several changes to the all-electric pickup, which he calls a “living thing, constantly evolving and improving.”
Cybertruck is manufactured at Tesla’s Gigafactory Texas just outside of Austin, and over the past few years, Tesla has continued to make small changes to the pickup to improve everything from cost, reliability, serviceablility, and manufacturability.
“The finish line isn’t getting to production. A product is a living thing, constantly evolving and improving,” Morrill added.
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Some of those changes are yet to be revealed, but perhaps the most notable one was the change Tesla made to the aero shield that sits underneath the truck. In the past, it was aluminum, but now the Cybertruck is using a self-reinforcing polypropylene.
Morrill said that the polypropylene is “stretched into fibers and then laminated into the form,” and is much more durable, much lighter, and significantly cheaper than aluminum when it is manufactured this way.
It also enabled some improvements in the geometry of the Cybertruck, improving the manufacturing around the bolts and edges, in addition to minor form changes. These all benefitted the Cybertruck in more ways than one: specifically with durability and improved drag.
I was surprised by how interested people were to find out we made a relatively benign change to the Cybertruck aero shield, a part of the car most people never even see. So I’ll share some more details.
Here are two photos, the left is one of the latest trucks off the… pic.twitter.com/F5cZo2CZKf
— Wes (@wmorrill3) September 7, 2026
Typically, Teslas are not necessarily identified by model year because these changes are fluid and occur when the company sees fit to implement them. It is not like other automotive companies, which usually make sweeping manufacturing changes when building a new model year.
Instead, Teslas are recognized by their “generation” or “era.” For example, those with a newer Model Y might refer to their car as a “Juniper.” This is the same with Model 3, as many refer to the new body style as the “Highland.”
Tesla’s manufacturing changes are proof of the company’s constant need to improve its products and move things forward with its vehicles. There is no need to drag one’s feet and wait until next year if the product can be made better right now, and that’s precisely what Tesla did with the Cybertruck.
Elon Musk
Tesla Cybercabs narrowly miss deadly Amazon cargo plane crash
An Amazon cargo plane crash near Miami’s airport stopped feet from dozens of Tesla Cybercabs.
An Amazon Prime Air Boeing 767 cargo jet overran the runway at Miami International Airport on Sunday afternoon, killing five people and injuring five more. The jet, operated by North Carolina based carrier 21 Air as Flight 7598, touched down around 2 p.m. after arriving from San Juan, Puerto Rico, then crossed the airport perimeter, plowed across NW 67th Avenue and struck multiple vehicles before catching fire, according to the Associated Press.
Photos and video from the scene show the aircraft’s nose stopped within meters of a fenced staging lot holding dozens of gold painted Tesla Cybercabs, the steering wheel free robotaxi Tesla began putting on public roads in Austin last week. Miami-Dade Fire Rescue has confirmed the plane struck “multiple vehicles” but has not said whether any Cybercabs were among them, and neither Tesla nor airport officials have addressed the fleet directly.
The Cybercabs had not yet entered commercial service in Miami. Tesla’s existing Robotaxi operation there runs on modified Model Y vehicles and has been unsupervised since Ashok Elluswamy confirmed the detail on X in July.
Footage of the plane crash from earlier today | #ONLYinDADE pic.twitter.com/iGoOtnd6cD
— ONLY in DADE (@ONLYinDADE) September 6, 2026
Elon Musk offered the briefest of reactions. Replying to a Zero Hedge post about the Cybercabs sitting so close to the wreckage, he wrote a single word: “Weird.” He has not commented further, and Tesla has not issued a statement.
The timing puts Tesla’s newest vehicle near an unrelated but highly visible tragedy just days after its Austin debut, a launch that had already drawn scrutiny from federal regulators. The National Highway Traffic Safety Administration opened an audit how Tesla certified the Cybercab as compliant with federal vehicle safety standards, a process Teslarati covered after the vehicle’s September 3 launch event. That inquiry concerns the car’s lack of a steering wheel and pedals, not the Miami crash.
Investigators from the FAA and NTSB are focused on the plane, not the parking lot beside it. Flight data reviewed by outlets including Simple Flying show the 767 touched down around 170 knots, well above the 135 to 140 knot range typical for the aircraft, though investigators have not determined a cause. Amazon said it is working with authorities and that its priority is the safety of everyone affected.
Whether any Cybercabs were damaged, and what Tesla plans for the fleet parked near one of the country’s busiest airports, remain open questions.
Tesla has reached a notable benchmark in its autonomous driving program after its Robotaxi fleet surpassed one million miles of unsupervised operation. The company made the announcement during its Cybercab event in Austin on September 3.
Tesla Vice President of AI Ashok Elluswamy told attendees he was happy to report the fleet had achieved one million miles of unsupervised Robotaxi operation as a testament to safety.
The new total marked a sharp increase from the 380,000 unsupervised miles Tesla disclosed during its second-quarter 2026 earnings update in late July.
In roughly six weeks, the company added about 620,000 miles. That acceleration followed Tesla’s decision to remove in-vehicle safety monitors from most of its operations outside the San Francisco Bay Area.
Credit: Tesla
Tesla first launched Robotaxi service in Austin in June 2025 with safety drivers present. It later began fully unsupervised rides and expanded into Dallas, Houston, Miami, Orlando, and Tampa. The San Francisco Bay Area remains the exception, where a safety monitor still rides in the vehicle under California permitting rules.
The company has not released a city-by-city breakdown of the one million unsupervised miles.
The milestone arrived as Tesla began offering public Cybercab rides in Austin. The purpose-built vehicle has no steering wheel or pedals and is designed only for autonomous ride-hailing. Production versions joined the existing fleet of modified Tesla vehicles already operating in the service.
Tesla’s unsupervised mileage is growing at a double-digit weekly rate according to earlier company comments, yet its fleet size remains modest compared with established competitors. Waymo has accumulated more than 200 million fully autonomous rider-only miles. Tesla has described its own unsupervised operations as having recorded zero notable incidents in the period leading up to the July update.
The one-million-mile figure reflects Tesla’s shift from supervised testing to broader driverless service in multiple states. It also highlights the company’s strategy of using both existing Model Y vehicles and the new Cybercab to scale its network.
Credit: Tesla
Whether the rapid recent growth continues will depend on further city expansions, regulatory approvals, and the performance of the purpose-built Cybercab in everyday paid rides. Tesla has not specified how many of the latest miles involved the new vehicle versus the rest of the fleet.
The announcement underscores Tesla’s progress toward a larger robotaxi network while illustrating the remaining gap in total autonomous experience relative to longer-operating rivals.
Tesla Cybertruck engineer reveals new changes in ‘constantly evolving’ pickup
Tesla Cybercabs narrowly miss deadly Amazon cargo plane crash
