SpaceX begins installation of Raptor engines for B4 booster

On August 26, 12 days after SpaceX's super heavy booster B4 booster returned from the orbital launch pad to the factory's high bay, engineers began installing 29 Raptor engines again to pave the way for possible future orbital flight tests. This is the second time this month that SpaceX has installed Raptor engines on the B4 booster, just 11 days after engineers finished removing the engines.

On August 1, SpaceX just finished installing car-sized grill wings on the B4 booster, and then began installing multiple Raptor engines at a very fast pace. Less than 24 hours later, 29 Raptor engines were attached to the super heavy rocket's propulsion structure.

Just one day later, the B4 booster was delivered and installed on the newly built orbital launch pad. Four days after the B4 booster completed its Raptor engine installation, engineers assembled the S20 Starship and B4 booster together to form a complete Starship Launch System, the tallest and largest rocket ever built. But this state lasted only an hour. spaceX then removed the S20 and B4 boosters from the launch pad and returned them to the factory for further operations.

Since the B4 booster returned to the high bay on Aug. 11, engineers first removed the 29 Raptor engines from the booster and then have been working to lay thousands of meters of piping and cabling for the massive 69-meter-tall rocket booster.

Now, just 11 days after engineers quickly removed the Raptor engines, SpaceX has begun reinstalling the Raptor on the B4 booster, with several engines not installed last time on site. It is reported that when SpaceX first installed the Raptor engines on the B4 booster, at least five of them had never been tested, making it almost inevitable that engineers would install and then remove the Raptor engines. In fact, as expected, SpaceX will have to install several new Raptor engines on the B4 booster this time.

Considering the series of matching checks already completed on the B4 booster, this means that SpaceX will conduct the first static ignition test of the booster after the installation of the 29 Raptor engines is complete. Of course, static ignition tests can be problematic and can even damage some of the Raptor engines.

Once the engine installation is complete, SpaceX will send the B4 booster from the high bay to the launch pad a second time, which could be done in the next week or two. Engineers are likely to install the B4 booster on a second suborbital test bed next to the S20 interplanetary spacecraft, though it may also return directly to the orbital launch pad.