SpaceX CEO Elon Musk has confirmed that Starship’s Super Heavy rocket booster will get its own tower-like vehicle assembly building (VAB) – and work on the structure may have already begun.
While the only visible work SpaceX has thus far completed on its next-generation Starship launch vehicle is related to the more complex and unproven upper stage of the rocket, its Super Heavy first stage (booster) is just as critical. For SpaceX, Starship was the perfect starting point, itself following on the footsteps of a largely successful multi-year Raptor engine development program. Substantially smaller than Super Heavy and requiring 5-10 times fewer engines, Starship serves as a testbed for an almost entirely new suite of technologies and strategies SpaceX is employing to build massive rockets out of commodity steel.
In recent months, particularly following the first successful pressure test of a full-scale Starship tank section in April, SpaceX has effectively proven that those uncharacteristically cheap and simple materials and methods can, in fact, build rocket structures that should stand up to orbital spaceflight. In theory, aside from the booster’s 31-engine thrust structure, the same methods and materials used to build Starships can be applied unchanged to manufacture Super Heavy. The booster’s almost unfathomable size, however, will necessitate its own dedicated assembly facilities.
While Starship itself is not exactly small at ~50m (165 ft) tall and 9m (30ft) wide, the Super Heavy booster tasked with launching the ship on its way to orbit will easily be the largest individual rocket stage ever built. Currently expected to measure 70m (230 ft) tall, Super Heavy – just the first stage of the Starship launch vehicle – will already be as tall as an entire Falcon 9 or Falcon Heavy and weigh roughly three times more than the latter triple-booster rocket when fully fueled. At liftoff, Super Heavy will produce more than triple the thrust of Falcon Heavy and double the thrust of Saturn V, the most powerful liquid-fueled rocket to reach orbit.
Thanks to the sheer size of the booster, SpaceX’s existing Starship-sized vehicle/vertical assembly building (VAB) is far too small for Super Heavy and is even too short to fully stack a ~50m Starship. SpaceX’s contractor of choice started assembling that VAB around January 15th and the facility was able to begin supporting its first Starship stacking and welding operations on March 2nd, just a month and a half later, with the structure fully completed by March 18th. As such, assuming the in-work foundation is as close to completion as it seems and SpaceX uses the same contractor for the next building, Super Heavy’s VAB could be ready to build the first massive booster prototype as early as July or August. Things could take a bit longer given that Musk says the booster VAB will be 81m (265 ft) tall, nearly twice the height of Starship’s VAB, but likely by no more than a few weeks.
That timeline meshes well with a senior SpaceX engineer and executive’s recent suggestion that the first orbital Starship launch attempt could still happen before the end of the year. Of course, for Super Heavy to become a genuine priority for SpaceX and receive the resources necessary to achieve that extremely ambitious goal, Starship will have to perform almost flawlessly during a series of increasingly challenging tests planned over the next few months. First up, SpaceX needs to finish repairing the launch pad after Starship SN4 exploded during testing and Starship SN5 needs to be transported to the pad to complete acceptance tests, static fire(s), and its first 150m (~500 ft) hop test. After that, SpaceX will either move on to a 2 km (1.25 mi) hop or a more ambitious 20 km (12.5 mi) flight designed to test Starship’s skydiver-like approach to landing.
If Starship SN5 or SN6 manage to complete those aforementioned tests, the horse may actually be in front of the cart for Super Heavy prototype production and Starship’s first orbital launch attempt.
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