Starship Flight 4 landmarks affect Starship Flight 5

Following the highly successful completions of Booster 11 and Ship 29 on SpaceX’s Starship Expedition 4, engineers are already implementing lessons learned from the mission ahead of the next flight, including extensive changes to the Thermal Protection System (TPS). Although Elon Musk believes the next flight will take a month, Flight 5’s coupling requires stronger slabs to be reapplied before its mission.

Starship voyage 4 rundown

Expectations for launch day were high, with SpaceX hoping for a soft landing for Booster 11 and surviving the peak reentry heat of Ship 29. The tank farm road was closed and quiet as planned, and the weather was nearly perfect for the launch.

Ship 29 and Booster 11 lifted off at 7:50 a.m. central time. Immediately, Engine 15, located in the outer ring, was shut down in Booster 11, a deviation from the previous two flights, in which all 33 flights were in operation. However, this did not affect the booster’s climb, as the booster completed the journey uphill without any further problems.

Spacecraft Flight 4 takes off in slow motion.@NASASspaceflight pic.twitter.com/clfCwkBKVZ

– Sean Doherty (SeanKD_Photos) June 6, 2024

Then came the staging phase, as Ship 29 smoothly lifted away from Booster 11. Just seconds later, Booster 11 flipped over and restarted the ten internal engines in order to burn off the rear booster.

Unlike the last flight, all thirteen engines ran for the full duration of the burn before shutting down. SpaceX does this to return to the launch site for a hunting opportunity, but in this case, the target was 20 kilometers offshore in the Gulf of Mexico.

Shortly after the rear booster burn, SpaceX debuted a new launch move: Teams eliminated the hot staging ring at the top of Booster 11. This was likely to reduce mass at the top of the vehicle to allow for a smoother slide back. To aid in this process, SpaceX installed two air thrusters to push the ring away from the booster. It works in the same way as the Falcon 9’s interstage propulsion system to push the second stage out of the way before the Merlin Vacuum ignites.

Abandon the hot phase pic.twitter.com/J48QtQD1Ae

— SpaceX (@SpaceX) June 6, 2024

Next would come the ship’s engine cut-off and nominal suborbital input, meaning Ship 29 was on track. Shortly after, Booster 11 will start its 13 internal engines for the initial landing burn before switching to its three internal engines.

However, immediately after ignition, the No. 8 engine exploded in the No. 10 inner ring, but the booster continued to operate. Booster 11 then cemented itself in history as the first very 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.

Very intense subsidence burn and soft splash in the Gulf of Mexico pic.twitter.com/lnjCSk2Cz6

— SpaceX (@SpaceX) June 8, 2024

Looking back, Ship 29, which was in its coastal phase, had camera downlink issues, but these were resolved in time for re-entry. After the coast phase, the ship steered itself back, which appeared to have a high angle of attack, like a space shuttle. This began to bleed very slowly from the ship’s hull before slipping and losing further speed.

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

Slowly, just as with Ship 28, Ship 29 began to have a plasma glow as the ship slammed into the atmosphere at over 26,000 kilometers per hour. This happens because the air gets too hot due to friction, creating another state of matter called plasma, which consists of charged particles generated by the incredible energy surrounding the vehicle.

The spacecraft performed a controlled re-entry, successfully passed peak heating and maximum aerodynamic pressure phases, and demonstrated the ability to control the vehicle using its flaps while descending through the atmosphere at hypersonic speeds. pic.twitter.com/p8bC9UweLx

— SpaceX (@SpaceX) June 6, 2024

Now, as Ship 29 passes through the atmosphere, the plasma continues to accumulate. This is the first time mankind has seen return plasma live from external cameras. Ship 29 will pass peak heating, thus completing one of its primary goals. However, during re-entry, the lower actuator arm of the right front fender completely melted, as seen on the exterior camera, and the plasma also ate a good portion of it.

However, despite damage to the flap and any other systems, Ship 29 was able to successfully pass the re-entry process. Then, even after everything she had been through, the ship performed 29 flip and burn maneuvers, the first time a ship had performed the maneuver since SN15 more than three years ago. The maneuver was successful, as the ship landed in the ocean and capsized intact.

Issues for Journey 4 and what they mean for Journey 5

Given Flight 5, SpaceX likely does not need to make any significant changes to the booster because it successfully landed on the target, as SpaceX CEO Elon Musk confirmed. With this success, SpaceX will attempt to capture Booster 12 during Flight 5. The engine during ascent and the engine that exploded during landing will be examined internally to find out the causes.

Booster 12, which has been in Mega Bay 1 since January 23, 2024, is waiting for its turn to start a stationary fire. Currently, there is no timeline for when it might roll out as SpaceX has begun removing the clamps on the Orbiting Launch Pad (OLM) again.

The booster landing was on target, and the ship’s landing was several kilometers away due to flap damage, but both were soft landings

– Elon Musk (@elonmusk) June 8, 2024

Ship 29 to Ship 30 is another matter entirely. Now, while Ship 29 had successfully passed reentry and completed the core and burn process, several issues needed to be corrected. First, the plasma burned through the flap seals and nearly severed the flap. SpaceX will need to find a way to enhance these areas for future flights. Second, while the heat shield allowed the ship to survive, there were still important issues to be corrected.

Because of these issues, Ship 30 has already begun removing and eventually replacing heat shield tiles and core blankets. The core blankets will be replaced with a new material that may have debuted on Ship 29. As Elon Musk mentioned, the tiles are being upgraded to a newer, much stronger design. Although Ship 29 completed the flip and burn maneuver, it was a few kilometers off target due to flap damage.

BREAKING: FAA Won’t Order Investigation of Starship’s IFT-4 Sorry

“The Federal Aviation Administration has evaluated SpaceX Starship Flight 4 mission operations. All flight events for both Starship and Super Heavy appear to have occurred within the scope of planned and authorized activities.”

– Adrian Bale (BCCarCounters) June 12, 2024

NSF’s Adrian Beil obtained a response from the Federal Aviation Administration (FAA) regarding a possible investigation into the Flight 4 accident: “The FAA has evaluated operations for the SpaceX Starship Flight 4 mission. All flight events for both Starship and Super Heavy appear to have occurred within Planned and authorized activities. With no mishap investigation required, SpaceX can proceed with Starship Flight 5. However, there is no information on whether or not the current license could be used for the booster hunt The launch site is not listed in the current license, and SpaceX will likely need another modification.

Overall, Flight 5’s launch preparations will be interesting as SpaceX prepares for the hunt and aims to perform much better during reentry.

Orbital launch pad b

The process of building the next Orbital Launch Platform (OLP) is gaining speed. SpaceX has the final two sections, along with the chopsticks arms and rover, on their way from Florida. With the arrival of these parts, SpaceX will only be missing the vehicle’s quick disconnect arm. There’s still one on Roberts Street, where SpaceX builds OLP parts. However, this arm may need to be updated and will likely have to be built new from scratch at the Sanchez site.

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

B Pile Cap Pour orbital launch pad (Image credit: Mary/BocaChicaGal for NSF)

An interesting new note about this tower is that the foundation will have hollow steel columns filled with concrete instead of concrete which needs to add steel armor. The Orbiter Launch Pad (OLM) will be positioned to the south, providing stunning views once the vehicle is stacked on this new launch pad.

Main image: Ship 29 and booster lift off for Starship Flight 4. Image credit: Mary/BocaChicaGal for NSF