NASA’s innovative use of polyurethane foam has played a critical role in space shuttle missions. Specifically engineered to insulate the external fuel tank, a 2.5cm layer of polyurethane foam helps maintain the extreme cold needed for 1.5 million litres of liquid hydrogen at -252°C. This specialised foam not only provides superior insulation but also contributes to the structural integrity of the tank, all while keeping the weight to a minimum.
Polyurethane foam’s effectiveness stems from its unique composition. NASA developed a blend of polyols that self-adheres to the tank’s aluminium surface without the need for adhesives. Its closed-cell structure traps vapor and prevents air infiltration, creating a tight seal that withstands the rigors of launch and re-entry.
The space shuttle’s external fuel tank, the largest part of the shuttle, benefits greatly from this lightweight insulation. Despite the tank’s massive size and weight (almost 800,000kg when full!) the polyurethane foam adds minimal mass while ensuring the fuel remains at optimal temperatures. The foam’s durability also means it can endure the extreme conditions of both launch and atmospheric re-entry.
NASA’s innovative use of polyurethane shows the immense potential for new applications yet to be explored. When it comes to finding new uses for polyurethane, the sky, or should we say space, is the limit.
Read more about the use of polyurethane in space travel here!
