While a separate team closes in on the completion of a new and improved Starship nosecone, SpaceX also appears to have begun assembling upgraded ‘tank domes’ that feature a similar underlying design change.
On the nose front, SpaceX has been working on a new and improved version of Starship’s nosecone for at least a year and assembling pathfinders and prototypes of varying fidelity since mid-2020 – around the same time when Starship SN15 became the first (and only) prototype to successfully launch and land. Further down the rocket, hints of Starship dome upgrades are a much more recent development.
Excluding Starship Mk1, which never had its far flimsier nose fully installed, the Starship nose design has been extremely consistent ever since SpaceX began building the first prototypes in mid-2020. Early prototypes were inevitably scrapped as SpaceX quickly iterated on the nose design and assembly process, culminating in Starship SN8, which became the first prototype to have its basic structure (tank section, nose, and flaps) fully assembled.
Though improvements and changes have almost certainly been made in the last ~18 months, the early unflown prototypes and the noses of Starships SN8, SN9, SN10, SN11, SN15, SN16, S20, and S22 have all been constructed in roughly the same way. SpaceX would first produce a series of thin, stamped sheets (gores) of steel. Once aligned on custom-built jigs, each of those gores would be welded together to form a slightly conical ring. Five total ‘rings’ would be assembled, each narrower and more conical than the last. The five sections would then be stacked one by one and welded together along their circumferences.
Altogether, something like 120 complex vertical welds would be needed just to assemble the most basic structure of a nose, followed by four or five no less complex circumferential welds to turn those sections into one cone. SpaceX’s upgraded design seeks to simplify that process mainly by increasing the size of the gores. Aside from modestly reducing the number of longitudinal sections needed to form the cone, SpaceX has also reduced the number of stacked sections from five to two, slashing the total number of gores needed by at least a factor of two or three. While not quite as substantial, the same simplification also reduces the length of vertical and circumferential welds needed to assemble a nosecone.
The spirit behind SpaceX’s new dome design appears to be very similar. Presumably doubling down on the stretch-forming production method developed for nosecone gores, SpaceX appears to have also decided to increase the size of dome gores and reduce the number of stacked sections required for dome assembly – albeit from three to two instead of five to two.
Collectively, this behavior is mostly predictable. With increasing confidence in the current design of Starship and Super Heavy, SpaceX now appears to be looking for ways to streamline and simplify manufacturing while simultaneously optimizing Starship’s design. Regardless of whether one is dealing with a highly advanced rocket factory or a smartphone assembly line, part count reduction is a very common and desirable way to reduce both cost and complexity. Additionally, drastically reducing the number of individual welds – and, to a slightly lesser degree, the total length of welds – required should also reduce the number of possible points of failure and the time needed for weld inspection and repair.
Having already scrapped a number of new nose pathfinders, it appears that Starship S24 will be the first to feature the new design. The process of stacking the ship has already begun. For domes, SpaceX appears to have only just begun assembling the first prototypes. If past dome changes are indicative of future behavior, one or several new ‘test tanks’ will likely be built to ensure that the new dome design performs as well as present-day hardware. It’s also unclear if SpaceX aims to replace all domes with a more spherical design or if, say, current Starship and Super Heavy thrust domes will remain the same for the time being.