Starship Flight 4 milestones effect changes in Starship Flight 5

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Following the highly successful achievements of Booster 11 and Ship 29 on SpaceX’s Starship Flight 4, engineers are already applying lessons learned from the mission ahead of the next flight, including large-scale changes to the Thermal Protection System (TPS). . Although Elon Musk thinks the next flight is a month away, the pairing of Flight 5 requires reapplying stronger plates before its mission.

Starship Flight 4 Summary

Expectations on launch day were high, as SpaceX hoped for a soft landing of Booster 11 and surviving the maximum heat of reentry for Shuttle 29. The tank farm road closure and calming went as planned and the weather was near perfect. for a departure.

Shuttle 29 and Booster 11 lifted off at 7:50 a.m. Central Time. Immediately, Booster 11 shut down Engine 15, which is in the outer ring, a departure from the previous two flights, in which all 33 were in motion. However, this did not affect the booster’s ascent, with the booster completing the uphill trip without further problems.

Then came staging, where Shuttle 29 smoothly departed from Booster 11. Just a few seconds later, Booster 11 returned and restarted its ten internal thrust-burn engines.

Unlike the last flight, all 13 engines operated for the entire duration of the burn before shutting down. SpaceX does this to return to the launch site for a capture, but in this case, the target was 20 kilometers offshore in the Gulf of Mexico.

Shortly after the quick burn, SpaceX debuted a new step in the launch: Teams removed the hot ring of the stage on top of Booster 11. This was likely done to reduce mass on top of the vehicle to allow for a glide softer back. To aid this process, SpaceX installed several pneumatic thrusters to push the ring away from the booster. It works in the same way as the Falcon 9’s interstage thruster system to eject the second stage before Merlin vacuum ignition.

Then would come a shuttle engine cutoff and a nominal suborbital insertion, meaning Shuttle 29 hit the correct trajectory. Shortly thereafter, Booster 11 would fire the inner 13 engines for an initial landing burn before switching to the inner three.

However, shortly after power-up, Engine 8 in the inner ring of 10 exploded, but the booster continued to operate. Then Booster 11 cemented itself in history by becoming 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 at sea.

Looking back, Ship 29, which was in its coastal phase, had problems with the camera connection, but these were resolved in time for re-entry. After the coast phase, the spacecraft was oriented for reentry, which appeared to have a high angle of attack, like the Space Shuttle. This is very slowly starting to bleed off speed with the hull before it jumps and loses even more speed.

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

Slowly, as with Ship 28, Ship 29 began to take on a plasma glow as the ship hit the atmosphere at over 16,000 miles per hour. This is because the air heats up so much due to friction 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, as Spacecraft 29 passes through the atmosphere, plasma continues to be created. This is the first time the human race has seen reentry plasma directly from external cameras. Ship 29 would make it through peak heating, thus fulfilling one of its primary objectives. However, during re-entry, the front right flap, as seen on the external camera, completely melted the lower actuation arm and the plasma also ate a good portion of it.

However, despite damage to the flap and every other system, Ship 29 would successfully make it through reentry. Then, even after everything it had been through, Ship 29 performed a “roll and burn” maneuver, the first time a ship had done one since SN15 over three years earlier. The maneuver was a success, with the ship landing in the ocean and capsizing intact.

Flight 4 matters and what it means for Flight 5

Looking ahead to Flight 5, SpaceX likely won’t need to make any significant changes to the booster after it successfully landed on target, as confirmed by SpaceX CEO Elon Musk. With this success, SpaceX will attempt to perform a capture of Booster 12 during Flight 5. The external engine on ascent and the exploded engine on landing burn will be investigated internally for causes.

Booster 12, which has been in Mega Bay 1 since January 23, 2024, is waiting its turn for a static fire. Currently, there is no timetable for when it might launch, as SpaceX has begun removing the retaining clips on the Orbital Launch Mount (OLM) once again.

Ship 29 to Ship 30 is a completely different matter. Now that Ship 29 had successfully re-entered and completed the spin and burn, many issues needed to be corrected. First, the plasma burned through the crash seals and nearly cut off a crash. SpaceX will have to find a way to reinforce these areas for future flights. Second, while the heat shield allowed the ship to survive, there are still significant issues to correct.

Because of these issues, Ship 30 is already removing the heat shield plates and underlying blankets and eventually replacing them. The bottom blankets will be replaced by a new ablative material that may have debuted on Ship 29. As stated by Elon Musk, the plates are being upgraded to a newer, much stronger design. Although Ship 29 completed the roll and burn maneuver, it was several kilometers from the target due to collision damage.

Adrian Beil for NSF received a response from the Federal Aviation Administration (FAA) regarding a potential error investigation into Flight 4: “The FAA evaluated the operations of the SpaceX Starship Flight 4 mission. All flight events for Starship and Super Heavy appear that they occurred within the scope of planned and authorized activities. With no mishap investigation needed, SpaceX can proceed with Flight 5, however there is no word on whether or not the current license can be used for a booster capture.

Overall, the launch preparations for Flight 5 will be interesting to watch as SpaceX prepares for a capture and aims for a much better re-entry performance.

Ship 30 plate removal in progress (Credit: Mary/BocaChicaGal for NSF)

Orbital launch pad B

Construction of the upcoming Orbital Launch Pad (OLP) is gaining speed. SpaceX has the final two sections, along with the stick wings and undercarriage, on their way from Florida. With the arrival of these parts, SpaceX will only be missing one quick-detach wing of the shuttle. There is still one on Roberts Road, where SpaceX has built OLP parts. However, this wing may need updating and will probably be built from scratch on the Sanchez site.

As for when the tower can begin to be assembled, crews have made significant progress on the foundation, with the tower’s pile cap being poured and parts for the crane needed to assemble the tower arriving. Unlike the last two towers, SpaceX will not use the Liebherr LR11350 crane but a Demag CC 8800-1, which has more lifting capacity.

Orbital launch pad B shedding of the cluster cap (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 steel protection. The Orbital Launch Mount (OLM) will be located to the south, providing some incredible views once a vehicle is placed on this new launch pad.

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

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