Featured Image Source: Lab Padrevia YouTube
SpaceX is in the process of developing its next-generation spacecraft-rocket duo, Starship. Designed to carry out long-duration missions to Mars with one hundred passengers aboard. Starship’s first crewed flight is already booked by a fashion entrepreneur, Yusaku Maezawa, who dreams of going to the moon. He is partially funding the spacecraft’s development. His circumlunar voyage is scheduled for 2023. NASA recently selected SpaceX to develop a Starship Lunar Lander to take crew and cargo to the moon. Starship prototypes are actively under construction in South Texas. SpaceX is building a production line of Starships to test-out in the assembly facility at Boca Chica Beach. Engineers are currently working on the fourth test vehicle manufactured this year, referred to as Starship SN4.
4.9 bar. Kind of a softball tbh, but that’s enough to fly!— Elon Musk (@elonmusk) April 27, 2020
Starship SN4 underwent a series of pressurization tests, conducted to determine if the stainless-steel test vehicle can withstand highly pressurized propellant and high-stress conditions it would experience during flight. On April 26, SpaceX performed the first cryogenic test on SN4. It was the first time a large-scale vehicle passed the test without collapsing. The founder and chief engineer at SpaceX Elon Musk, shared Starship SN4 endured a pressure strength of 4.9 bar – “4.9 bar. Kind of a softball tbh [to be honest], but that’s enough to fly!” Musk previously said Starship needs to withstand a pressure of at least ~6 bar, which is needed for orbital flight, and ~8.5 bar is the strength to carry out crewed flights.
After the successful test, SpaceX ignited Starship’s Raptor engine for the first time. It roared to life on May 5th during a static-fire test. SN4’s propellant tanks were filled with cryogenic methane and liquid oxygen. The single Raptor engine was ignited at about for about four seconds as the vehicle was held-down to the launch pad. The engine can produce 200 tons of thrust at full throttle. That day, Musk announced: “Starship SN4 passed static fire.”Then, on May 7th, SpaceX teams at Boca Chica conducted another successful static-fire test (shown in the video above). Musk said via Twitter the test was conducted with the header tank– “Yes. Static fire feeding from fuel header vs main tank,” he wrote. The fuel header tank is smaller in the center of the main propellant tank dome that feeds the Raptor engine.
Yes. Static fire feeding from fuel header vs main tank.— Elon Musk (@elonmusk) May 7, 2020
Tonight, May 9, SpaceX is actively preparing Starship SN4 to conduct another cryogenic pressure test (video below). It appears the company aims to reach a higher bar strength this time around. During the test, SN4 will be filled up with sub-cooled liquid nitrogen to pressurize the structure. If the test vehicle withstands the test and does not collapse under pressure, it will take flight. The first test flight will be a low altitude ‘hop’ test of 150-meters above Boca Chica beach.
Boca Chica residents set up cameras to watch SpaceX operations from the launch pad live. You can watch Starship SN4's cryogenic pressure test in the video below.