Down To Earth: From NASA to your bedroom

Down to Earth explores the tech intended for space. This week, Stuart Higgins investigates how NASA's memory foam made its way into our homes...

Stuart - What happens when the science and technology of space comes down to Earth?

Hi I’m Dr Stuart Higgins and welcome to Down to Earth from the Naked Scientists. A mini series all about the space tech that’s being used back down on Earth.

This episode we’re talking about the grand-daddy of space spinoffs. A story with such a soft ending it might just send you to sleep. Yes… we’re talking about memory foam.

Back in the 1960s, NASA wanted to improve the survival rates of aircraft passengers during crashes. Even if the aircraft fuselage doesn’t break up during a crash, the sudden deceleration can still cause severe injuries. Aeronautical engineer, Charles Yost, came up with a solution. In 1962 he’d been part of the team that developed the parachute system for the Apollo command module for it’s return to Earth. But his solution for improving crash safety was something altogether more squishy…

He developed a special plastic foam that could be used in seat cushions to absorb the energy of an impact, helping to protect passengers. You could think of plastics as being made up of lots of interlocking chains, a bit like a tangled plate of spaghetti. The overall properties of the material depend, in part, on just how tangled up those chains are.

Yost trapped a gas inside the plastic as it was being formed, turning it into a bubble filled structure and fundamentally altering its material properties. What was really interesting about the foam he created is that it was visco-elastic, meaning that it behaves a bit like a thick viscous material like honey but, over time, also bounces back elastically into it’s original shape. This technology went on to become the basis for the memory foam mattress. These are made from polyurethane which, surprisingly, is the same plastic used in skateboard's wheels. But with the right processing, what is a hard durable plastic can become a springy foam that temporarily holds the shape of objects pressed into it.

So, presumably, NASA astronauts have some of the comfiest memory foam mattresses in the solar system - right? Well… not exactly. In fact, memory foam mattresses never made it to space. You don’t need a mattress when you’re sleeping in zero G - just a sleeping bag. And, although the foam was initially developed by Yost and NASA, the mattresses came much later. Although, coincidently, nowadays NASA make astronauts who’ve just returned to Earth walk around on a memory foam surface. They use it to test how well the astronauts can balance to see how they’re coping with gravity again.

You might say that the memory foam surface is helping astronauts by putting the spring back in their step.

That was Down to Earth from the Naked Scientists and join me again soon to learn about more space technology that’s changing lives back on earth.