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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 AI lead Ashok Elluswamy said this week that 24-hour Robotaxi service is close. Replying on X to a rider who wanted Cybercab trips all night, he wrote that the capability would arrive “next month or so” once “the next tech to merge on the v15 plan” is ready.
The comment landed on September 4, one day after Tesla opened public Cybercab rides in Austin. It is the clearest near-term timeline yet for overnight unsupervised operation. Tesla’s paid Robotaxi network currently runs from 6 a.m. to 10 p.m. seven days a week across Austin, Dallas, Houston, Miami, Orlando, and Tampa.
next month or so. the next tech to merge on the v15 plan will enable it.
— Ashok Elluswamy (@aelluswamy) September 4, 2026
That 16-hour window is shorter than the 6 a.m. to 2 a.m. schedule the company used for much of the prior year.
Elluswamy did not name the specific feature or say whether the change would apply first to purpose-built Cybercabs, the existing Model Y fleet, or both. He also offered no city-by-city rollout list. The link to Full Self-Driving v15 is nevertheless significant.
Tesla has described v15 as a step-change architecture with seven parallel improvement tracks and roughly ten times more parameters than earlier builds. Early versions of that software already operate on the Robotaxi fleet and contain about 40 percent of the planned gains.
By July 2026, the unsupervised fleet had logged more than 380,000 miles across six cities in two states with what the company called an impeccable safety record and no notable incidents caused by the vehicles themselves. Tesla has repeatedly argued that camera-based end-to-end neural networks, rather than extra sensors, are the core of the solution.
Overnight service would test that claim in lower-light conditions and would also raise vehicle utilization, a key variable for Robotaxi unit economics. The company has already begun using public Superchargers at night and is building dedicated Robotaxi charging sites.
Riders have asked why software must change if the cars already drive in the dark. The practical answer appears to be reliability and scale: Tesla has held back mass expansion until more of the v15 stack is merged, citing the need for higher confidence before putting thousands of unoccupied vehicles on streets around the clock.
If the next module arrives on the timetable Elluswamy sketched, 24-hour service could begin in October 2026 in at least some markets.
That would mark a shift from a daytime-bounded pilot to a service that can run whenever demand exists, including the late-night hours that have so far remained out of reach.
Tesla is beginning to roll out Full Self-Driving Supervised v14.3.9 with a new active safety layer that can take control even when the driver is operating the car manually.
Tesla AI said the software can activate FSD on the driver’s behalf when an imminent collision is detected and Automatic Emergency Braking may not be enough. It may also engage if the system detects heavy distraction or an accidental FSD disengagement.
FSD Supervised v14.3.9 starting to roll out shortly
This release includes a new active safety feature set: FSD Supervised can now activate on your behalf when an imminent collision is detected and Automatic Emergency Braking (AEB) may not be enough.
It may also engage if we…
— Tesla AI (@Tesla_AI) September 4, 2026
The capability is essentially Automatic Collision Evasion. However, unlike conventional AEB, which mainly applies the brakes in a straight line, this feature can use steering, braking, and acceleration together if the car calculates that stopping alone will not prevent impact and a safer path exists. The system may change lanes or move toward a shoulder when conditions allow, then continue driving after the immediate threat is handled rather than simply coming to a stop.
The intervention is meant as a last-resort safety net, not a replacement for attentive driving.
Tesla Full Self-Driving v14.3.7 early review: FSD saved me from an accident
Tesla’s own description still frames FSD as supervised assistance. Secondary reports on internal release notes say the feature can fire while the car is being driven manually if cabin-camera monitoring suggests the driver is not sufficiently attentive, such as reaching toward the back seat, or if FSD appears to have been turned off unintentionally.
After the emergency maneuver, the car is expected to alert the driver and request a return to manual control.
The safety case is straightforward. Many collisions happen in the last second because a driver is looking away, fumbles a control, or faces an obstacle that braking cannot fully solve. A system that can both recognize that AEB is insufficient and execute a coordinated evasive path can reduce those remaining high-severity events.
Re-engaging after accidental disengagement also addresses a practical failure mode: a small steering nudge that drops FSD at the worst moment. The advantage is a background safety net that uses the same vision stack already running in v14, instead of leaving the car solely to emergency braking once the driver is no longer in command.
The feature still depends on FSD being enabled and, according to reports, an active FSD purchase or subscription. It does not make the vehicle unsupervised. Drivers remain responsible, and Tesla has not published how often the system is expected to intervene or how it will handle false positives.
If the rollout is conservative and the false-alarm rate stays low, the update is a meaningful step: FSD is no longer only a feature the driver turns on. In the rare moments when disaster is already forming, it can step in.
Tesla launched the all-electric, steering wheel-less, and pedal-less Cybercab last night at a quiet and small event in downtown Austin, Texas.
The launch, which marked the beginning of unsupervised ride-hailing for Tesla’s Robotaxi platform with Cybercab, has already caught the attention of the National Highway Traffic Safety Administration (NHTSA) who has more questions.
NHTSA opened an Audit Query (AQ) into the Cybercab’s Federal Motor Vehicle Safety Standards (FMVSS) certification that Tesla gave the vehicle. Manufacturers self-certify vehicles much of the time to avoid excessive regulatory delays.
Tesla Cybercab interior, note the lack of steering wheel and pedals. (Credit: @niccruzpatane/X< /a>)
However, the agency needs more information; it said in a summary:
“On September 3, 2026, Tesla began commercial deployment with a small number of its Cybercab vehicles in Austin, Texas. Tesla notified the Agency that it certified those Cybercab vehicles as compliant with all applicable Federal Motor Vehicle Safety Standards (FMVSS). Tesla also notified the Agency that it plans to gradually expand commercial deployment of the Cybercab to include additional vehicles and locations.”
It also went on to state that the Cybercab lacks traditional automotive controls, which is a groundbreaking move. The process is entirely new to the NHTSA, which gives the agency some leverage to put Tesla’s launch under a microscope:
“The vehicles lack permanently attached, conventional manual controls, such as a brake pedal, gas pedal, steering wheel, and mirrors. NHTSA is opening this AQ to examine the process and technical data on which Tesla relied when certifying the Cybercab and related issues. Among other things, NHTSA will consider the extent to which Tesla’s certification depended on determinations that certain FMVSS are inapplicable to the Cybercab.”
Tesla has added 45 Cybercab units to its fleet of Robotaxi-enabled cars in Austin, according to public documents the company submitted to the State of Texas over the past week. Enabling this level of self-driving is something Tesla has worked toward for many years, and now that it is finally here, it seems more than reasonable that regulatory agencies will have some questions.
Many outlets might try to frame this as a negative, but it is truly an agency looking to gain more information about groundbreaking tech that Tesla has been developing for years.
In an effort to keep riders, pedestrians, and property safe, any and all data accumulated from these first days, weeks, and months of rides will likely be shared with the NHTSA to enable broader rollout strategies across the United States and more in the future.
Tesla Robotaxi will be a 24/7 service: here’s when
Tesla Full Self-Driving will now overtake manual driving to avoid disaster
