Although SpaceX’s revolutionary spacecraft Starship is preparing to move humanity to Mars, it is literally a critical problem in the target of reusability. Elon Musk, the CEO of the company, announced that the biggest obstacle to Starship’s reusability is the heat shields.

Starship moves at extreme speeds in the atmosphere during the return to Earth. In the meantime, the friction causes excessive temperature on the outer surface of the vehicle and leads to flames. At this point, the orbit heat shield, which is activated, enables the vehicle to go down to the ground safely. However, so far, no company has developed a completely reusable heat shield.

SpaceX has not yet solved the heat shield problem

According to Musk’s statements, the heat shield used by SpaceX consists of extremely thin glass fibers and aluminum oxide fibers. These materials are resistant to high temperatures, but they are also very fragile. The surface of the heat shield is also strengthened by special coatings. These coatings help to maintain the integrity of the structure as well as increasing temperature resistance. However, the tremors experienced by the vehicle during the launch and re -entry can lead to cracking or breaking of this fragile structure.

Another problem encountered during the assembly of the heat shield is the expansion and shrinkage effects in different parts of the vehicle. Starship’s fuel tanks shrink when extremely cold cryogenic fuel is loaded. At the entrance to the atmosphere again, the temperature expands as it increases. These temperature fluctuations change the gaps between heat shield panels by 10-20 percent. If the panels are placed in the end, this expansion causes breaks.

Musk emphasizes that it is extremely complex to find the right material combination for heat shield. Materials need to have a perfect structure at the molecular level and mounted flawlessly. “This is a very difficult problem that no one has solved before.” Musk says that SpaceX continues to work intensively to overcome this obstacle.