After arriving and installing a new Raptor engine on the Starhopper vehicle at SpaceX's test facility in Boca Chica, Texas – preparations are in full swing for a Static Fire test that will be required before it is expected to be a 20 meter jump for the vehicle this week.
Continuation of Starhopper testing will facilitate the further development of Raptor, the orbital Starship spacecraft and Super Heavy Booster.
Raptor is SpaceX's floating methane and oxygen powered rocket engine, under development for The Starship and Super Heavy Vehicles.
The engine that recently arrived in Boca Chica is the sixth full-scale Raptor building, followed by previous buildings that reached various stages of testing.
Raptor Serial No. 1
SN-4 was at one time intended to operate the upcoming jump tests. But having faced problems in McGregor, the engine was only used for fit control and Thrust Vector Control (TVC) testing in Boca Chica.
The engine was installed on the Starhopper vehicle and ordered to gimbal in different directions at different speeds. After these tests, the engine was removed and sent away, and Starhopper was waiting for another Raptor.
However, Raptor SN-5 also entered McGregor. Two seconds in a scheduled 50-second trial fire, the engine was damaged beyond repair. The frequency resulted in changes to engine SN-6, which had to pass testing in McGregor before being sent to Boca Chica.
The first and second test firing of SN-6 went well and lasted for 20 and 10 seconds, respectively. The third firing lasted 50 seconds before a "soft interrupt" occurred. However, the test program continued and the engine was shut down with a fourth time for a period of 65 seconds. In the fifth and final firing, Raptor broke for 85 seconds, a new record for the Raptor engine.
Having received his McGregor test program, Raptor SN-6 was sent to Boca Chica and installed on the Starhopper vehicle.
The engine was first used for further TVC tests. Now it will be used for the next phase of Starhopper tests, which gradually come closer to firing the engine and eventually flying untethered over the launch plate.
The first test case Starhopper fueled with liquid methane and oxygen and put through Ox spin prime and Fuel spin prime testing – effectively testing how to start turbines, as needed before testing the combustion.
When this is finished nominally, Raptor's combustor will itself be tested, but without igniting the engine completely. Only after successful combustion test will the SpaceX teams move towards the static fire test, which will take place earlier than Tuesday.
Starhopper has already conducted two such static fire tests using the Raptor SN-2. pad. After a successful static fire test, the teeth will be removed and Starhopper will be ready to fly untethered for the first time. This is currently no earlier than Wednesday.
The first free flow reaches a height of 20 meters. The vehicle will also "divert" sideways, similar to the early aircraft on SpaceX's Grasshopper test vehicle, which informed about the development of the reusable Falcon 9 booster. Starhopper will then return to the same pillow to shore.
Still ahead in the Starship development process, progress on both orbital prototypes continues, under construction in Texas and Florida. Construction of Mk. 1 prototype in Boca Chica continues with the addition of several stainless steel rings.
The last rings have had a protective cover, removed after the ring is welded to the cylinder.
The Boca Chica layer also builds a windbreak structure that will be covered by the fabric once finished. The purpose of the construction is understood to be protection against coastal wind, which affects the welding quality between each steel part.
The plans for these orbital Starship prototypes are fluid. They can also not represent the latest design of the operational Starship vehicle, as SpaceX CEO Elon Musk has stated further design changes have been made to the find / legs.
An official update of Musk, both on the vehicle's design and launch plans, is expected after Starhopper's first untethered test flight.
Although Musk noted, the jump will be webcast by SpaceX – which has many internal cameras around the pad that can be fed into a live stream – no official word on this option has yet been given.