SpaceX’s latest starship test tank – SN 7.1 – is the second in a series of two planned prototypes, both designed to test the feasibility of using a new steel alloy to build future starships and super heavy boosters . CEO Elon Musk says SpaceX is technically optimizing its own steel alloy for starship production but Musk’s comments and results from the SN7 test in June 2020 fluctuated the 304L with slight metallic twins Points.
Prior to the SN7’s test operation, Musk revealed that the main purpose of the new alloy was to reduce the brittleness of the stars’ tanks and any adjacent steel components under cryogenic conditions (i.e. extreme cold). Ultimately, SN7 confirmed that the behavior of the new alloy was far more forgiving under cryogenic loads, which were believed to be record pressures before tank pressures burst on 24 June.
Following in the footsteps of the SN7, the SN 7.1 is very close to an actual starship prototype.
“The SN7.1 is significantly more complex than its sibling and will test a ~ 304L raptor mount (thrust puck) and skirt section. Forces and general conditions will include those new parts that were subject to SN7 significantly different than all of them, meaning that 304L steel is actually worse in some scenarios.
With any luck, however, the SN7.1’s test campaign – scheduled to begin as of 9pm CDT (UTC-5), Sept. 10 – will be an impeccable success, proving that SpaceX’s new steel alloy is all Application is better than 301 related to starship. If so, the Starship SN8 – the first complete new-alloy prototype – will likely be fully equipped with a Noscon and header tank before acceptance testing begins later this month. ”
Teslarati.com – September 10, 2020
For SN7.1, the increased flexibility can theoretically be a mixed bag. SpaceX is believed to have built a thrust puck out of 304L-adjacent steel, which may eventually lead to excessive forces that will be subjected to it. At full throttle, the thrust of the three Raptor engines will compress the thrust puck – a cone whose dimensions are almost identical to a large circular table – with a force equivalent to a weight of ~ 600 metric tons (1.3 million lb).
On September 10, SpaceX inserted SN7.1 through its Pace, performing cryogenic proof tests with liquid nitrogen (LN2), while the tank is still a simple steel frame used to support it during production and transportation Was founded on. This simple decision provides a brief glimpse at the comprehensive plan that allows SpaceX to optimize for speed and efficiency while still conducting successful tests. While SpaceX can technically install the SN 7.1 accurately for a newly launched mount custom-built testing, the company has left the tank on its build stand – much cheaper and far easier than the former.
Technically, going directly to the launch mount makes the testing process a bit simpler, but a tank burst during a root cryogenic proof test can cause extensive damage or damage to the mount, creating a complete replacement. Requires weeks of work. After the SN7.1 successfully completed cryogenic pressure testing on September 10, SpaceX removed it directly from its work and installed it on a custom-built launch mount.
On September 14 as a 9pm CDT (UTC-5), SpaceX will once again load SN7.1 with liquid nitrogen. This time, the tank – after reaching a flight pressure of 7.5 to 8+ bars (110–120 + psi) will be subjected to simulated thrust of three raptor engines by a series of hydraulic wraps. Based on the public program of road closures, at least two trials are planned. Firstly, the SN 7.1 will be put through a series of raptor thrust scenarios and profiles, which are required for orbital starship flights under the same tank pressure. If that test is successful, SpaceX may take the SN 7.1 back to its work before intentionally pressurizing the tank, until it explodes sometime around 17 September.
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