The world’s largest heat shield, measuring 16.5 feet in diameter, has been successfully attached to the Orion spacecraft. The heat shield is made from a single seamless piece of Avcoat ablator. It will be tested on Orion’s first flight in December 2014 as it protects the spacecraft from temperatures reaching 4000 degrees Fahrenheit.

The uncrewed flight, dubbed Exploration Flight Test-1(EFT-1), will test the spacecraft for eventual missions that will send astronauts to an asteroid and eventually Mars. EFT-1 will launch an uncrewed Orion capsule 3,600 miles into space for a four-hour mission to test several of its most critical systems. After making two orbits, Orion will return to Earth at almost 20,000 miles per hour, before its parachutes slow it down for a landing in the Pacific Ocean.