• Pending FAA approval, Starship ready to sport upgrades for upcoming te

    From NasaSpaceFlight@1337:1/100 to All on Fri Sep 22 17:45:03 2023
    Pending FAA approval, Starship ready to sport upgrades for upcoming test flight

    Date:
    Fri, 22 Sep 2023 17:34:50 +0000

    Description:
    Following Starships debut during Integrated Flight Test One (IFT 1), SpaceX
    is ready to improve The post Pending FAA approval, Starship ready to sport upgrades for upcoming test flight appeared first on NASASpaceFlight.com .

    FULL STORY ======================================================================

    Following Starships debut during Integrated Flight Test One (IFT 1), SpaceX is ready to improve on the vehicles objectives by employing a vast series of upgrades. Most of the enhancements have been made to the launch site and Booster 9, which, in turn, are waiting for final regulatory approval.

    Changes to Booster



    Booster 7 and 9 have several significant differences, starting with the changeover from Raptor 2 to Raptor 2.1, which uses electric TVC (Thrust
    Vector Control) over the previous hydraulic system. This removes two
    hydraulic power units (HPUs) from the boosters aft.

    Electric TVC uses electric linear actuators to move the center 13 raptors on a booster rather than with hydraulic actuators. This has multiple benefits; first off, SpaceX can get rid of the HPUs that were at the bottom of the booster, thus reducing weight, and secondly, electric TVC can allow for quick and smoother gimbaling action during flight. Raptor 2.1 with an Electric TVC Actuator (Credit: Jack Beyer for NSF)

    Removing the need for the HPUs also helps reduce complexity and increase reliability, along with a mass of tubing inside the engine bay replaced by wire harnesses.

    See Also SpaceX Starship Section L2 SpaceX/Starship Section Click here to Join L2

    Booster 9 also had its Raptors and its valves upgraded after IFT 1, and the upgrades consisted of modifying the methane turbopumps and manifolds with new seals to reduce the amount of Methane leakage into the engine compartment. This had caused fires in B7s engine compartment during the first flight test.

    A possible reason why SpaceX has an issue with methane leakage compared to other rockets could be the high pressure that Raptor operates at in its Methane turbopumps, hot gas manifold, and the Main Combustion Chamber (MCC). This results in more pressure on the seals and causes leakage.

    To help mitigate the methane buildup in the engine compartment, removal of the small chines on the side of the booster and replacing them with larger chines that include upgraded purge tanks have been employed.

    These larger purge tanks will allow SpaceX to better control methane buildup within the engine compartment during flight and static fires. Part of this system is the addition of 18 vents to the engine section of Booster 9, which can be seen in action during static fire testing.



    The gas used for this system is believed to be CO2, which is beneficial for extinguishing fires.

    The engine shielding for Booster 9 has also been upgraded when compared to Booster 7. Unlike previously, where the it was retrofitted on the booster
    over time, Booster 9 has been designed with upgraded shielding from the
    start. SpaceX is slowly simplifying the design to make it easier to access engines and perform maintenance.

    Booster 9 also has a major internal change over Booster 7, with a newly designed methane transfer tube after Booster 7s imploded during a cryo test. The new transfer tube has many more reinforcement stringers than its predecessor.

    Ship 26 vs Ship 28

    Another change to Booster 9 is the four new vents at the top of the interstage. These vents are piped from the top of the methane tank and allow SpaceX to better control the methane tank pressure.

    After the flight termination system (FTS) on IFT-1 failed to destroy the
    full stack, SpaceX upgraded the FTS on Booster 9 by adding another explosive charge on the methane tank just above the common dome.

    With this extra charge, SpaceX should be able to destroy the common dome and methane tank in such a way that mixes both the methane and liquid oxygen, which hopefully results in a larger explosion, thus destroying the entire booster. The larger FTS plates on Booster 9 (Credit: Jack Beyer for NSF)

    Hot staging upgrade

    One of the most obvious changes to Booster 9 was the addition of a hostage vent ring on the top that will allow SpaceX to fire the ships engines while still attached to the booster. This simplifies the separation mechanism and allows the ship to always be under acceleration, thus allowing it to perform better and not incur losses due to gravity. The dunes of Boca Chica beach provide nice foreground for Starship full stack photography. @NASASpaceflight

    Metal prints of this shot available here: https://t.co/XtDkvepUER pic.twitter.com/tWek2OYkVi

    Sean Doherty (@SeanKD_Photos) September 9, 2023



    This ring has a steep dome with a flat top for shielding and is heavily reinforced under the shielded section. The steep dome allows for the exhaust gases from the raptor engines to be directed outwards and through the vented ring section to prevent buildup inside the interstage.

    The hot stage ring attaches to the booster using the ship clamp system, allowing for easy installation and removal so technicians can access the
    grind fin motors and avionics located on the forward dome of Booster 9. In order for the ship to attach to the booster, the ring has a set of ship
    clamps on top. Booster 9 has her crown and is ready to roll in the coming days.

    Hot Staging ring set to make its debut. Awesome photo by Jack Beyer ( @thejackbeyer ). #NeverStopThrusting ! pic.twitter.com/6lNDIZXMPX

    Chris Bergin NSF (@NASASpaceflight) August 18, 2023



    The ring was removed this week at the launch site, but is expected to be reinstalled in the coming days.

    Changes to Ship

    Ship 24 and Ship 25 had many upgrades over Ship 20, with the intro of Raptor 2s on a vehicle for the first time, a heat shield actually made out of tiles, and a payload bay although it would be welded shut.

    There are a few differences between Ship 24 and Ship 25, although they are basically sister ships. Both ships use HPUs for TVC, and they both have the same payload section compared to Ship 28, which appears to have a functioning payload bay door. 3 more engines for the meaning of life pic.twitter.com/nt7T2TPt05

    Elon Musk (@elonmusk) July 10, 2023



    The main reason Ship 24s and Ship 25s payload section and door were welded shut was because SpaceX figured they might not survive flight loads, so they decided to weld those shut while they came up with a solution.

    After Ship 25s static fire, SpaceX removed all of the engine shielding and replaced it with thicker shielding to help protect the engines and ship
    during hot staging. This was added to the ship while parked in the rocket garden.

    SpaceX has also added extra vents above the engine shielding false floor on Ship 25. This is for purging the engine skirt around the engines to prevent Methane buildup.

    Two more vent lines have also been added to the engine section of Ship 25. However, it is currently unknown if these are related to the engine chill system, but these new lines dont have pipe extensions like the engine chill lines on Ship 24. Ship 25 during lift Operations (Credit: Jack Beyer for NSF)

    Ship 25s FTS received an upgrade just like Booster 9, with an extra charge just above the common dome.

    With all these changes, SpaceX hopes to advance its objectives during the next flight. Reaching stage separation and ignition of the ship would be a
    big win for the program. Anything more than that would be icing on the cake.

    (Lead image: Ship 25 and Booster 9 full stack. Credit: Mary for NSF)



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    Link to news story: https://www.nasaspaceflight.com/2023/09/starship-upgrades-upcoming-test-flight /


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