On August 26, Starship completed his tenth test flight Ameriting at a precise point of the Indian Ocean. The images emitted live Spacex were impressive: the largest ship in the world was successfully stopped over water after an aggressive re -entry maneuver. However, something else caught attention: A worrying orange strip that walked most of the fuselage.
Three small rusty tiles. Shortly after the flight, Elon Musk clarified in his X profile that the orange tone was oxide from test metal tiles on the side of the ship. But it has been Bill Gerstenmaier, a NASA ex -director veteran who works as head of construction and flight reliability of Spacex, who has given all the details.
The thermal shield It is still the greenest part of Starship. The current design consists of thousands of ceramic tiles, most in hexagonal form, glued one next to the other without leaving holes. On flight 10 (and on the three previous failed flights, Actually) Spacex placed three metal tiles on the ship to check If they contributed adequate thermal controlsince they would be easier to manufacture and more durable than the ceramics. It turns out that they are not. All that oxide It was created by those three small metal tiles.
A failed, but very useful experiment. As you collect Ars TechnicaGerstenmaier told a conference that metal tiles did not work very well. They oxidized extremely fast with atmospheric oxygen.
Although metal tiles failed in their target, the experiment was very useful for data collection. He showed that ceramic tiles are still the option to follow for the thermal shield, and helped Spacex rule out an alternative development route without putting the ship at risk, which had enough protection underneath.
The interesting thing was the white spots. Although the orange color was the most striking, the most valuable fact for Spacex engineers was in other areas of the thermal shield: white spots that appeared near the nose and other parts of the ship. Musk had already advanced that these spots were due to Isolation of the areas where Spacex had removed tiles deliberately To test Starship’s limits.
Gerstenmaier confirmed that they were the remains of an ablative material, derived from that used in Dragon capsules, which in Starship is found everywhere under the tiles. “What this shows us is that the heat is entering between the tiles, it sneaks below, and this ablative structure is consumed. So we learned that we need to seal the tiles.”
The solution: seal every tile. Now the main challenge of Starship’s thermal shield is not that tiles detach (a problem that seems solved, since almost all remained in place), but to prevent the incandescent plasma of the reentry from filtering through the tiny together between them. For Spacex, that has been the great learning of flight 10.
True to its style of breaking things and iterates fast, the company already has a solution that will test on the next flight. And, how could it be otherwise, they have put a peculiar name: “Crunch Wrap”. It is not a filling like the one used by the space ferry; It is a sealing wrapping around each tile.
“It’s like a gift paper that wraps every tile,” Gerstenmaier described. “These tiles are subject mechanically, a robot fits them. When we push the tile, this small gift paper is based around the sides of each one, and then we cut it on the surface.”
Back to the ring. After three failed flights, flight 10 has shown that the Starship is again on track. Spacex put the ship to the limit and it responded as planned, threatening just 3 meters from its target. The oxide was the visual test of a discarded path, but what has been learned about the heat leaks paid the way for the next great improvement, bringing a little more closer to make a totally reusable rocket.
The plan for flight 11, which could take place in October judging by recent tests in Starbase, is to apply this technique throughout the thermal shield. “We are going to put ‘Crunch Wrap’ everywhere and see if we can get a better seal and performance of the tiles,” Gerstenmaier said.
Image | Spacex
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