Down to Earth: from spacesuits to stadium roofs - beta cloth

How does a material developed for NASA spacesuits get onto stadium roofs back here on Earth? Here's Stuart Higgins...

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

Welcome to Down to Earth from the Naked Scientists. The mini series that explores the spinoffs from space technology that are being used on Earth. I’m Doctor Stuart Higgins.

This episode: how materials used in spacesuits developed for NASA for the Apollo missions continue to be used in stadium roofs around the world.

January 27th, 1967. A fire breaks out during testing of the Apollo I command module. The first of the missions aiming to take astronauts to the moon. Spreading rapidly through the flammable materials inside the spacecraft the fire kills the three astronauts onboard.

The tragedy led NASA to search for new fireproof materials for their spacesuits. Nylon had been used throughout the command module but had melted during the fire and the existing spacesuits failed to provide adequate protection.

A solution was proposed by two companies working with NASA. A new kind of fabric based upon woven glass fibre and coated with a non-stick plastic polytetrafluoroethylene, otherwise known as teflon. The called the new material “Beta Cloth” and it formed the outer shell of the updated spacesuits giving ten times greater fire resistance compared to what had been before.

And while spacesuit materials have moved on since the Apollo era, beta cloth found a new lease of life back on Earth as construction material. Walter Bird, an aeronautical engineer, realised the potential of beta cloth as an architectural building material, and in 1956, formed a company to take the tech further. The company specialises in tensile structures where the building materials are continuously held in constant tension.

They’re most commonly seen today as the curving tent-like roofs on structures like the O2 stadium in London, and many other sports stadiums around the world.  The tightly woven glass fibres give the material its structural integrity, while the teflon coating reduces the ability of dirt and grime to stick to the roof allowing most of it to wash off when it rains.

The teflon polymer is made up of a long chain of carbon atoms each attached to atoms of fluorine. The configuration of electrons in the fluorine atom make it highly electronegative meaning it can strongly attract other electrons towards it. It’s the incredibly strong bond between carbon and fluorine atoms in the plastic that gives the useful non-stick properties.

Also when used in beta cloth, teflon’s white colour has the advantage of helping to reflect sunlight stopping things getting too warm inside buildings. The flexibility and strength of the material, along with its rapid installation, allows architects to explore different and interesting designs in their structures and has furthered its use.

So that's how a material originally developed for spacesuits for Apollo astronauts has become a widespread building material throughout the world.