An exceptionally important stage in the building of the Orion spacecraft has finally been completed. Heat shielding to protect the craft from the intense temperatures of an atmospheric reentry has been tiled to its outside, preparing Orion for the live testing that it will undergo by the end of this year.

According to NASA, the black tiles that are now plating the Orion spacecraft are the same ones that protected the belly of NASA's not-retired space shuttles as they returned from taxi missions to the International Space Station.

Due to the shuttles' significant size and general surface area, they collected a lot more drag and entered the atmosphere at a slower speed that the smaller Orion craft is expected to enter at. The shuttles still traveled at a whopping 17,000 mph as they plummeted through Earth's atmosphere, but the Orion is expected to handily top that, coming in at 20,000 mph on its first flight test. That test is due to occur later this December.

The 970 black tiles in all are expected to act as both a powerful insulator and even a physical shield against small space debris as the craft heads back home. Easily withstanding up to 4,000 degrees Fahrenheit, the tiles make up Orion's cone-shaped back shell. Directly beneath that shell, nothing is expected to get hotter than about 300 degrees - heat that of course won't even make its way to the very inside of the craft, where astronauts and/or valuable cargo are held.

One main concern is that the current tiling design won't be enough to turn away space debris or trapped and super-heated gas. If something manages to punch through the plating, the craft would be in a world of trouble. December will act as the gauntlet to make sure the shielding does its job.

"We have models that estimate how hot it will get to make sure it's safe to fly," Joseph Olejniczak, manager of Orion aerosciences, said in a statement, "but with the data we'll gather from these tiles actually coming back through Earth's atmosphere, we'll make new models with higher accuracy."