Booster 12’s Testing Campaign for Flight 5

Written by @Phantimeball23 (https://x.com/phantime23ball?s=21)

Ahead of the fifth integrated flight of Starship, which will be Starship’s most dynamic and challenging mission, Booster 12 has performed numerous tests on the OLM, which will pair up with Ship 30, to hopefully lift off from Starbase, Texas, in a few weeks.

Testing Campaign

The preliminary testing of Booster 12 began with a rollout to Massey’s in the early hours of December 29, 2023, more than a month after the second integrated flight test. Booster 12 had no engines at this time. It arrived at Massey’s a few hours later to perform cryogenic proof testing. After the new year arrived, Booster 12 conducted a cryo test on January 10th, where only the methane tank was filled with liquid nitrogen. The test ran through the next day, where it was detanked and finished testing for the day. Booster 12 performed another cryogenic test on January 12th, where the liquid oxygen tank was fully filled and the methane tank was partially filled. 

Booster 12 was rolled back to the build site on January 19th for its engine and hardware installation.

After the third integrated flight test, Elon Musk expressed his desire for a potential booster catch in a hands-on Starship update on April 5th. He explained that if the booster on the fourth flight completed splashdown with a virtual tower, which it successfully did, they would perform a booster catch on Flight 5. For the tower and the chopstick arms that will hopefully catch Booster 12, they underwent many upgrades for a planned booster catch. It had already done slap and lift point tests on the test article Booster 14.1 in June, which was significantly shorter than other boosters.

But after a few months of upgrades, Booster 12 rolled out on July 10th without its hot stage ring to begin its final engine testing before flight. Booster 12 was lifted onto the OLM shortly after arriving at the launch pad. On July 11th, it did a venting test near the top of the booster. The road opened shortly after this test.  The next day, the tank farm spooled up, and Booster 12 began to load cryogenic liquid into its liquid oxygen tank, filling and draining to different levels of the tanks. The booster was detanked, and testing was concluded for the day. On July 13th, it was filled with cryogenics, and it conducted a spin prime test, where the engine turbopumps spin up to flight speed but there is no ignition of the engine itself. Interestingly, the last time a spin prime test was done was with Booster 9 in 2023. Boosters 10 and 11 did not perform spin prime tests. After this, it was detanked, and the road was opened. On July 16th, Booster 12 finally performed a full-duration, 33 engine static firing. This tests how the engine will hopefully work during flight.

And that’s where we are today.

What’s next for Booster 12?

After teams have checked out the data and they are happy with it, Booster 12 will roll back to the build site and get its own hot stage ring, a necessary part of the booster that acts as a heat shield against the forces of the ship and the heat of hot staging. The hot staging is a temporary fix and will be jettisoned after the boostback burn when in flight to save mass during the final stretch of the mission. Then, it will roll back to the launch site, be mounted on the OLM, and be stacked alongside Ship 30 to perform a wet dress rehearsal, and hopefully after that, we can expect a liftoff and a tower catch.