Why SpaceX’s spacecraft is made of stainless steel according to Elon Musk

In January 2019, Elon Musk was interviewed by “Popular Mechanics”, the long-running magazine that focuses on science and technology. During the interview, he said Starship’s hull would be made of stainless steel instead of carbon fiber, mainly because it was cheaper. But it also had some added benefits.

According to Musk, carbon fiber is incredibly expensive, costing around $135 per kilogram (or 2.2 pounds). Not only that, but up to 35% of the material was wasted and thrown away just during the cutting and shaping process. In the end, it was actually costing SpaceX nearly $200 for every kilogram of carbon fiber material. Stainless steel costs less than a coffee pod for a Starbucks brewer at just $3 a kilo (via Space).

Not only that, but stainless steel has a much higher melting point, making it a more robust material for the heat it would encounter when re-entering. Musk said carbon fiber has a “steady state operating temperature” of around 300 degrees Fahrenheit, with some shapes reaching 400 degrees. You can go beyond that, but only for a short time, and even then it starts to break down and weaken. Stainless steel can withstand temperatures as high as 1,600 degrees Fahrenheit (via Space).

In the end, it was obvious for the company to switch to the shiny material, which is much cheaper and more durable. And yes, it looks suspiciously like Flash Gordon’s spaceship from the 1930s. Or a grain silo. But if it takes you into space, does it really matter?