"Following the identification of corrosion on HALO, a comprehensive investigation was promptly initiated. Preliminary findings indicate that the issue likely results from a combination of factors, including aspects of the forging process, surface treatment, and material properties."
The Starship rocket system splits in two after takeoff. The upper spacecraft would head to Earth orbit to serve as that depot, ready to carry nothing but fuel. The towering Super Heavy rocket booster, meanwhile, would return to the launch site so it can be reused.