Early this morning SpaceX launched Starship for the fourth time and it was easily the most impressive one yet. The last flight was back in March earlier this year and ended a bit early with both the booster and upper stage being destroyed.
This time around, however, the company made a few key changes and upgrades to the entire vehicle and mission plan that helped Starship reach a couple of significant new milestones. Here I will go more in-depth into the fourth flight, exactly what happened, what to expect in the near future, and more.
Fourth Launch Attempt
Despite what looks like a cloudy day, SpaceX confirmed that the weather was a go among other final launch countdown factors. There was an available hold time at T-0:40 seconds however they passed right through it as everything was in order and looking good for launch. Seconds before the clock hit zero you could hear the Raptor engines beginning to startup and the water deluge was also activated. The engines then lit creating a massive plume as Starship began to leave the ground. In the initial seconds, the graphic at the bottom which shows the 33 Raptor engines indicated that all 33 engines were running.
That was until around T + 0:03 when a single Raptor on the outer ring was shown as not running. Despite this, the vehicle easily cleared the tower and began accelerating and gaining altitude with 32 active engines. This was confirmed just around 40 seconds into the flight when a camera view from the ground confirmed that 1 of the engines was indeed out. Either way, at T + 1:00 you could hear mission controllers call out that the vehicle had reached Max Q. This is the moment of peak of mechanical stress on the rocket. 10 seconds later and Starship was supersonic.
The livestream included a few different angles with cameras looking down from the top of the booster, the top of the ship, and the ground as well. Over the next minute and a half Starship kept gaining altitude and speed with the remaining 32 engines operating as expected. The next mission milestone occurred at T + 2:46 seconds when the booster main engine cutoff occurred. Here all the engines expect the three in the center shutoff. Only seconds later the ship ignited all 6 of its raptor engines while still attached to the booster before finally seaparting and beginning to accelerate. This immediately led to the booster flip maneuver in order to orient itself for a return toward the launch site. At T + 2:57 all 13 of Super Heavy’s inner Raptor Engines lit and the boostback burn began. This burn continued for nearly a minute until T + 3:47 when the engines were shutoff. In the video you can see the graphic shows an initial shutdown of the 10 Raptors in the middle ring and then soon after the three very center engines follow suit.
Then, just past 4 minutes into the flight we got an incredible view of the Booster’s hot stage ring being jettisoned. This was unique to this test flight as SpaceX wanted to reduce weight and confirmed it’s a temporary fix. Either way, it went very smoothly. Over the next two minutes or so, the booster was just coasting back toward Earth while the upper stage continued its burn. At T + 6:12 we got an incredible view of the top of the booster showcasing some of the plumbing and mechanics for the grid fins. Also, just a few seconds later, it looks like you can see the hot stage ring in the background as Super Heavy flies past it.
By T + 6:39 the booster was transonic and within the atmosphere preparing for a landing. This is around the point in the last launch where it experienced a RUD. Starting at around T + 7:05 you could see the grid fins working hard to keep the booster in the correct orientation. Seconds later 12 of the booster’s engines ignited as it passed through the clouds, with the graphic showing one missing. A small explosion paired with some debris was also seen. Soon after the middle ring of engines shutdown leaving the inner three Raptors to slow the stage apart of the landing burn. As it passed through the clouds we got a view of the ocean and as it approached, you could see the water being disturbed with Super Heavy only feet above it. The booster then touched down in the ocean vertically before slowing tipping on its side in one piece.
This officially marked the completion of the booster’s mission and the live stream then switched over to the upper stage. That entire time the upper stage had been gaining speed and altitude with its 6 engines lit. That was until T + 8:09 when the three Raptor vacuum engines shut down followed by the inner engines soon after. Over the next 30-plus minutes the upper stage was coasting around globe getting closer to its planned reentry point. At T + 45:23 onboard cameras showed plasma starting to buildup around the vehicle. This time around, the vehicle looked very stable, unlike the last attempt. In fact, certain moments in the livestream almost looked frozen but were actually just a stable view.(52:30) The vehicle then passed through 65km which is where contact was lost on the last launch. The next few minutes consisted of continued reentry as Starship got closer to its landing location.
Everything looked to be going perfectly until around T + 57:17. Here it looked like you could start to see a weak point in the flap as plasma began making its way through. Over the next minute, this got worse until it started to strip away shielding and metal from below. It’s important to point out that once there is a single weak point, in most cases, this would mean the entire vehicle is at risk, or at least in this specific instance, the entire flap. For the next couple minutes, more material was stripped away until the camera was covered in debris and you could hardly see. At this point, the vehicle was still over 50 km high and had quite a journey still ahead of it. At T + 59:25 you can cleary see the camera crack.
From here the video signal with starship would drop out occasionally. Thankfully it came back as the vehicle made its final approach. At approximately T + 1:04:00 in the camera cleared up enough to show the same flap with a significant chunk missing from reentry. Despite this, the flap managed to keep actuating during the approach. By now the vehicle was within 10 km and not far away from its scheduled flip maneuver and attempted landing. With 1km left, you could barely see anything with the exception of some sparks flying by. Then, at T + 1:05:40, the engines lit as confirmed by SpaceX mission control along with the light shown in the camera feed. The graphic highlighting the ship’s orientation at the bottom showed it quickly flip from horizontal to vertical as we have seen in some of the original 10 and 15-km test flights. It’s nearly cut in half flap kept moving to help orient and land the vehicle. Even though the engine graphic depicted 0 engines lit, the SpaceX comms along with the video feed paint a different picture. We then got one last view of what looks like the vehicle slowly impacting the water with the lowest speed at 2 km/h. The orientation graphic also showed the vehicle going back to horizontal which would make sense after touching down in the water. SpaceX even confirmed that the landing burn shutdown was commanded.
Soon after the company tweeted saying, “Splashdown confirmed! Congratulations to the entire SpaceX team on an exciting fourth flight test of Starship!” With that confirmed, this flight was a massive success for the company. Before the launch the company was quoted saying, “The fourth flight test turns our focus from achieving orbit to demonstrating the ability to return and reuse Starship and Super Heavy. The primary objectives will be executing a landing burn and soft splashdown in the Gulf of Mexico with the Super Heavy booster, and achieving a controlled entry of Starship.” While there was a missing engine on Super Heavy, and Starship’s entry was a bit more eventful than hoped, both of these goals were met.
On the last flight, Super Heavy failed to complete a landing burn and broke up before impacting the water. As for the ship, it was destroyed around 65 km high. This time, the booster had a practically perfect landing and the ship managed to splash down even with some serious damage. In regard to this, SpaceX stressed before the launch that they had a few tests in mind related to the heat shield. For example, the ship was actually missing a few tiles on purpose. They pointed out that SpaceX had installed one thin tile and removed two entire tiles to collect data on how the ship held up in those areas. In other words, there’s still a lot of unknowns related to the reentry process and the best method to protect Starship. Despite this, the company is obviously on the right track considering the ship made it back in just about one piece.
In one final quote the company said, “The fourth flight of Starship will aim to bring us closer to the rapidly reusable future on the horizon. We’re continuing to rapidly develop Starship, putting flight hardware in a flight environment to learn as quickly as possible as we build a fully reusable transportation system designed to carry crew and cargo to Earth orbit, the Moon, Mars and beyond” they said.
Conclusion
SpaceX’s Starship just launched a fourth time and it was by far the most entertaining mission yet. Practically all of the company’s mission objectives were met and they got a wealth of data to use in future attempts. We will have to wait and see how it progresses and the impact it has on the space industry.