SpaceX is outfitting Starship, Super Heavy with dozens of Raptor engines

New photos shared by SpaceX show that the company has almost completed installing a total of 39 upgraded Raptor engines on a new spacecraft and its Super Heavy booster.

These prototypes — known as Ship 24 and Booster 7 — could be tasked with supporting Starship’s first orbital launch attempt sometime later this year if both pass the upcoming testing campaigns without major issues. Whether that’s a likely outcome remains uncertain, but recent advances suggest it won’t be long before the prospects of both prototypes come into clearer focus.

After several rounds of proof testing and two trips to and from SpaceX’s Orbital Launch Site (OLS) Starbase, Texas, in March, April and May, Super Heavy Booster 7 (B7) made its third trip to the pad on June 23.

“SpaceX used the six weeks that Booster 7 spent in a factory assembly shop to complete the installation of aerocovers, surfaces known as chines or strakes, car-sized grid fins, Starlink internet dishes and—most importantly—33 upgraded Raptor V2 engines . Combined, Booster 7 could generate up to 7600 tons (~16.8 million lbf) of thrust at or before launch. Crucially, SpaceX also completed the installation of most of Booster 7’s Raptor heat shield during the same period, completing the work in six weeks that took Booster 4 nearly half a year. With its heat shield and all 33 Raptors mostly in place, Booster 7 should be ready to launch static fire tests almost as soon as it is installed on the starbase orbital launch mount.”

Teslarati.com – June 24, 2022

Booster 7 is waiting for its next round of testing. (NASA Spaceflight – bocachicagal)

Building, qualifying, shipping and installing 33 new Raptor 2 engines on Super Heavy B7 was already an impressive feat and resulted in the most powerful (potentially) rocket booster ever built. On July 2, two photos released by SpaceX showed Booster 7’s near-complete engine section, while also revealing that the company had completed the installation of all six of Starship S24’s Raptor engines — and even part of the ship’s aft thermal protection.

The differences between Ship 24 and Ship 20, the only other Starship prototype that has six Raptors installed, are already visible. The most notable change is the addition of a metal frame that covers the full width of the ship’s stern – most likely intended to support flat sections of insulation and thermal protection that partially seal delicate engine, plumbing, pressure vessel and avionics components in the Starship’s stern. This additional shielding should help limit the extreme conditions the hardware will experience during ground testing and possibly in flight.

Shipping on August 20, 2021. (SpaceX – Elon Musk)
Shipping on July 24, 2022. (SpaceX)

Super Heavy Booster 7 has already completed a significant number of tests, including four cryogenic proofs (cryoproofs) and a Raptor thrust simulation test. Since its third return to the pad, SpaceX has conducted several ambiguous tests, none of which appeared to involve a cryogenic propellant charge. It’s possible that these tests focused more on Booster 7’s pressurization system, perhaps filling its tanks with the hot oxygen and methane gases it will eventually use to pressurize its tanks. It’s likely SpaceX will want to put Booster 7 through at least one successful wet dress rehearsal – using real liquid methane and oxygen fuel – before attempting to static fire one of its 33 Raptors. Neither is Booster 7’s rear thermal protection system fully completed, requiring technicians to complete the installation of several more panels before static fire testing can be performed.

SpaceX technicians manipulate one of the dozens of heat shield panels that will eventually protect Super Heavy B7’s Raptors from themselves. (NASASpaceflight – Bocachicagal | July 3, 2022)

In addition to B7, Starship S24 has gone through a whole series of cryosafety and Raptor thrust simulation tests, which it survived without irreparable problems. The ship was then returned to an assembly bay on June 9, where workers installed heat shield tiles, finished the ship’s engine section, and did dozens of other, less visible, finishing jobs. SpaceX also recently completed the modification of one of its two suborbital test and launch mounts for Starship static fire tests, with the other mount being modified semi-permanently to allow for cryo-tightness and thrust simulation testing of future prototypes.

SpaceX has requested approval for road closures – each a potential 12-hour test window – on July 5, 6, 7, 11 and 12.

SpaceX is outfitting Starship, Super Heavy with dozens of Raptor engines