After a long phase of extensive upgrade work of "Stage Zero" at SpaceX's orbital launch site in Starbase, Boca Chica, crews are now preparing Ship 24 and Booster 7 for a potential launch no earlier than November. What milestones have been checked off the list and what is yet to come ahead of launch?
Stage Zero Upgrades
During the past months, SpaceX's test launch site at Boca Chica has seen extensive work on ground infrastructure, often referred to as "Stage Zero". The main focus has been the orbital launch mount, an immensely complex structure, on which the rocket will be staged for launch as well as for testing. Not only has it to withstand big forces and high temperatures without being damaged, the orbital launch mount includes several systems that are crucial for testing and launches, such as fuel and pressure lines, hold down clamps and fire suppression systems. Although the OLM has been installed for several months now, recent work was being executed to increase robustness and reliability as well as to prevent mishaps such as unwanted explosions.
In September, new plumbing was added for a new more extensive water system. This system, officially called "Fire and Detonation Suppression" includes nitrogen pressure valves to increase the effect of limited water output. On September 21-22, this new system was tested. As a side note, the orbital launch pad at Cape Canaveral will feature a more extensive water deluge system with huge water pipes having already been installed. After that, installation of blast shielding continued. In order to prepare the OLM for launch, more covers, side and flame protections still have to be installed.
Meanwhile, the orbital tank farm has seen some work as well, the focus being the Methane side, where SpaceX appeared to experience some problems. Pump installation has to be completed and likely, more subcoolers will be installed. For testing and launch, the tank farm will likely see a significant increase in deliveries of Methane, Oxygen, Nitrogen and Helium. Finally, on the Orbital Launch and Integration tower (OLIT) scaffolding and construction equipment has to be removed.
Starship 7/24
Booster 7 and Ship 24 have been around for quite a while now. Both vehicles have undergone an extensive testing program including several setbacks. Booster 7 was first rolled out to the pad on March 31. Since then, it has been cryogenically proof testes several times, four static fires and eight spin prime tests have been conducted. Ship 24 was rolled out on May 26 for the first time. On September 8, all six engines have been static fired. Meanwhile, Booster 7 has yet to conduct a full 33-engine static fire.
On October 11, Ship 24 was finally stacked onto Booster 7 after a failed attempt the night before that also damaged several tiles on Ship 24. The issue likely was linked to the previously installed felt that should soften the impact of a booster on the chopsicks during a catch attempt. Before lifting, SpaceX made some short term fixes on the chopsticks. However, the stacking didn't appear to be satisfactory - after realignment and integration checks on October 12 and after some testing, which was likely aborted, Ship 24 was destacked on October 16, and on October 20, it was stacked onto Booster 7 for a second time.
Testing Program
Starship 7/24's testing program began on October 24 with a cryogenic proof test during which both LOX tanks frosted up partially. On this occasion, the Ship quick disconnect (QD) was tested for the first time. Thermal imagery showed residual LOX/LN2 in the Ship the next morning, possibly indicating issues with detanking, which however are unconfirmed. Nevertheless, this confirms Elon Musk's tweet that SpaceX still plans to launch B7 and S24 for the first orbital launch.
On October 26, SpaceX continued to test the fully stacked Starship with methane being loaded onto Booster 7's methane tank. This goes in line with an incremental approach on this early testing in order to minimize risk as many of the procedures are being carried out on new hardware for the first time. Elon Musk explained this approach:
Bearing in mind this, it is very difficult to predict, how long it will take until SpaceX is ready for a first orbital test launch. As soon as partial load tests are complete, a full wet dress rehearsal is expected during which the rocket would be completely fuelled. Furthermore, a 33-engine static fire with Booster 7 is expected as well. From the perspective of regulatory approval, the FAA is continuing to work with SpaceX within the licensing process. It is unknown, when a launch license can be issued.
Further reading and resources
Wiki article: https://starship-spacex.fandom.com/wiki/Starship_7/24
Readiness sheet (@GrandpaJoe42): https://docs.google.com/spreadsheets/d/1s11hPjPhCHZGLoiOr5tanhtJd4-m5dK6NpZlMXOFvuc/edit#gid=0
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