SpaceX’s South Texas Starship factory is churning out steel rocket hardware faster than ever before according to photos of yet another prototype already in the works.
At the same time as SpaceX works around the clock to test SN4 and prepare the ship for what will be the first flight of a full-scale Starship prototype, the company is building not one; not two; but three additional prototypes. A confirmation that a third Starship was being simultaneously manufactured in South Texas came on May 25th when local Boca Chica resident and observer Mary (bocachicagal) captured a photo of a pair of stacked steel rings rather conspicuously labeled “SN7”.
While it’s possible that “SN7” is just a coincidence, it’s far more likely that it refers to Starship serial number 7 (SN7), set to be the seventh full-scale prototype built by SpaceX. The apparent start of SN7’s steel ring assembly process some two weeks ago also suggests that no less than several other rings are likely being mated in one or more of SpaceX’s three main manufacturing tents or a much taller windbreak structure. In fact, SpaceX is building Starship prototypes so quickly that the company is actively assembling a second launch mount, suggesting that two Starships could soon be tested more or less simultaneously without stepping on each other’s steel toes.
The most impressive aspect of SN7’s appearance, however, is the fact that SpaceX is already in the late stages of stacking Starship SN5 and begun preparing to stack Starship SN6 directly beside it just a few days ago. Based on labels attached to the side of a new steel nosecone section rolled out of SpaceX’s tent factory a few days ago, Starship SN5 will likely become the first full-scale Starship to reach its full height in a permanent, functional fashion. Back in October 2019, SpaceX did technically stack Starship Mk1 to its full height for a few weeks, but the ship’s nose section was never permanently attached and really only served as a pathfinder and full-scale mockup.
Starship Mk1 ultimately failed prematurely during its first major cryogenic pressure test in November 2019, bursting well before it reached the tank pressures needed for low-velocity hop tests (let alone orbital flight). In the sixth months since, SpaceX refocused its resources and spent much of the time dramatically upgrading its South Texas Starship production facilities and methods. In a rapid-fire series of tests of custom-built Starship tanks, SpaceX quickly proved that those improved methods could produce steel tanks more than capable of surviving pressures of ~8.5 bar (~125 psi) and beyond.
More recently, Starship SN4 – a full-scale prototype with two propellant tanks and three tank domes – passed a ~7.5 bar (~110 psi) cryogenic pressure test with flying colors, just shy of fully validating the smaller tank tests that made it possible. According to CEO Elon Musk, ~8.5 bar is enough to perform orbital launches with the ~40% safety margin preferred for human spaceflight, while 7.5 bar meets the minimum needed for Starship to perform uncrewed orbital launches with a ~25% safety margin.
In other words, SpaceX isn’t simply churning out low-fidelity prototypes – the ships that are being mass-produced are of a high enough quality to be qualified for orbital-class launches. Of course, the physical structure of Starship is just one of many technologies that need to work in harmony for successful orbital flights, many of which need to pass their own challenging tests to be declared ready for launch, but it’s still undeniably impressive that SpaceX is already building complete Starship fuselages in a matter of weeks.
In fact, given that Starship SN4 could perform the first hop test and that SN5 could be assigned to the first high-altitude (3-20+ km) flight tests, there is definitely a chance, however minimal, that Starship SN6 or SN7 could eventually be upgraded for the system’s inaugural orbital launch attempt. Regardless, it’s safe to say that the next several weeks are going to be jam-packed with numerous Starship production and test milestones.