Starship 4 flight milestones effect will change to flight 5 ship

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Following the highly successful milestones achieved by Booster 11 and Ship 29 on SpaceX’s 4th flight, engineers are already implementing lessons learned from the mission, including extensive changes to the Thermal Protection System (TPS), ahead of the next flight. Although Elon Musk thinks the next flight is a month away, the Flight 5 pairing requires stronger tiles to be reused before its mission.

Starship Flight Summary 4

Expectations were high on launch day as SpaceX hoped for a mild splashdown of Booster 11 and surviving the peak heat to return to Ship 29. The road closure and tank farm cooling went according to plan and the weather was near perfect for launch.

Ship 29 and Booster 11 launched at 7:50 a.m. CET. Booster 11 had engine 15, which is in the outer ring, shut down immediately, a departure from the last two flights in which all 33 were running. However, this did not affect the booster’s climb, with the booster completing the uphill run without further problems.

Then came commissioning, where Ship 29 smoothly pulled away from Booster 11. Mere seconds later, Booster 11 turned and restarted its inner ten engines for a reburn.

Unlike the previous flight, all 13 engines ran throughout the burn before shutting down. SpaceX does this to return to the launch site for a catch, but in this case the target was 20 kilometers off the coast in the Gulf of Mexico.

Shortly after increasing the backburn, SpaceX debuted a new step at launch: The teams dropped a hot ring on top of Booster 11. This was presumably done to reduce weight on top of the vehicle to allow for a smoother slide back. To help this process, SpaceX installed several pneumatic thrusters to push the ring away from the booster. It works the same way as the thrust system in the Falcon 9’s intermediate stage to push the second stage off before igniting the Merlin Vacuum.

Next should come the ship’s engine shutdown and nominal suborbital insertion, indicating that ship 29 has hit the correct trajectory. Shortly thereafter, Booster 11 fired the inner 13 engines for an initial landing burn before switching to the inner three.

However, just after ignition, the engine 8 in the inner ring 10 exploded, but the booster continued to run. After that, Booster 11 made history as the first Super Heavy Booster in the Starship program to complete a landing in the Gulf of Mexico. After shutting down the engine, Booster 11 capsized and was lost in the sea.

In retrospect, ship 29, which was in the coast phase, had problems downloading the camera, but these were resolved in time for the return. After the coast phase, the ship oriented to return, which appeared to have a high angle of attack, like a space shuttle. Too slowly it begins to lose speed with the ship’s body before heeling over and losing even more speed.

That was the beginning of the questions: Will the heat shield last? Will the ship be able to maintain control during the return? Will Starlink provide an uninterrupted signal via re-entry?

Slowly, as with Ship 28, Ship 29 began to receive a plasma glow as the ship hit the atmosphere at over 26,000 kilometers per hour. This happens because the friction heats up the air enough that it forms into another state of matter called plasma, which is made up of charged particles caused by the incredible energy around the vehicle.

Now that Ship 29 is passing through the atmosphere, the plasma continues to accumulate. This is the first time the human race has seen plasma reentry live from external cameras. Ship 29 would undergo peak heating, fulfilling one of its primary objectives. However, during the return, the starboard forward flap, as seen on the external camera, completely melted the lower control arm and the plasma ate a good chunk of it as well.

However, despite the damage to the flap and any other systems, Ship 29 would successfully manage the return. Then, even after everything she had been through, Ship 29 performed a flip and burn maneuver, the first a ship had done since SN15 over three years ago. The maneuver was successful, the ship landed on the ocean and capsized intact.

Flight 4 issues and what it means for Flight 5

As for the outlook for Flight 5, SpaceX probably won’t need to make any significant changes to the booster since it successfully landed on the target, as confirmed by SpaceX CEO Elon Musk. With this success, SpaceX will attempt to intercept Booster 12 during Flight 5. The engine shutdown during ascent and the blown engine during burn landing will be investigated internally as to the causes.

Booster 12, which has been in Mega Bay 1 since January 23, 2024, bides its time for static fire. There is currently no timetable for when it could be launched, as SpaceX has begun removing the retaining clips on the Orbital Launch Mount (OLM) again.

Ship 29 to Ship 30 is a completely different matter. Now, while Ship 29 had gone through the reentry and completed the capsize and burnout, there were many issues that needed to be fixed. First, the plasma burned through the flap seals and nearly severed the flap. SpaceX will have to find a way to strengthen these areas for future flights. Second, although the heat shield allowed the ship to survive, there are still significant issues that need to be fixed.

Because of these problems, the heat shield linings and bottom blankets have already been removed and possibly replaced on the Lodi 30. The backing blankets would be replaced with a new ablative material that may have debuted on Lodi 29. As reported by Elon Musk, the tiles are being upgraded to a newer, much stronger design. Although Ship 29 completed the roll-and-fire maneuver, it was several kilometers off target due to flap damage.

Adrian Beil for NSF received a response from the Federal Aviation Administration (FAA) regarding a possible accident investigation for Flight 4: “The FAA has evaluated the operations of SpaceX Starship Flight 4. All flight events for both Starship and Super Heavy appear to have occurred within planned and authorized activities.” Without the need for an accident investigation, SpaceX can proceed with Flight 5, but there is no word on whether the current license can be used to catch the booster.

All in all, the preparation for the launch of Flight 5 will be interesting to see how SpaceX prepares for the catch and strives for a much better performance during the return.

Collection of 30 tiles in progress (Credit: Mary/BocaChicaGal for NSF)

Orbital Launch Pad B

Construction of the next Orbital Launch Pad (OLP) is gathering pace. SpaceX has the final two sections on their way from Florida, along with the sticks and the trolley. With the arrival of these parts, SpaceX will only be missing the ship’s quick-detach arm. One is still on Roberts Road where SpaceX makes OLP parts. However, this arm may need updating and will likely be built entirely new at the Sanchez site.

As for when the tower might begin assembling, teams have made significant progress on the foundation, with the tower lid being poured and the crane parts needed to stack the tower arriving. Unlike the last two towers, SpaceX will not use a Liebherr LR11350 crane, but a Demag CC 8800-1, which has a larger lifting capacity.

Orbital Launch Pad B Pile Cap Pour (Credit: Mary/BocaChicaGal for NSF)

An interesting new note about this tower is that the foundation will have hollow steel columns filled with concrete rather than concrete that needs to add steel shielding. The Orbital Launch Mount (OLM) will be located to the south and will provide incredible views once the vehicle is stacked on this new launch pad.

Main image: Ship 29 and Booster take off for Starship Flight 4. Credit: Mary/BocaChicaGal for NSF

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