The NASA Orion spacecraft just hit a huge milestone

NASA's Orion spacecraft has held up to huge extremes of temperature and more, acing its testing at one of the US space agency's most impressive facilities, as the capsule prepares to head to the Moon. The test process took four months, a vital safety precaution ahead of the Artemis I mission. Success there paves the way for NASA's manned mission to Mars.

It's an important milestone for Orion, and one which – despite the coronavirus pandemic shutting down or impeding several ongoing NASA projects – the space agency completed ahead of schedule. The tests are designed to replicate some of the extreme conditions that the spacecraft, and eventually its human occupants, will encounter on their way to the Moon and beyond.

It all takes places at NASA's Plum Brook Station in Sandusky, Ohio. There, the agency has access to the world's largest vacuum chamber, into which Orion was sealed. With all the air removed, to simulate the vacuum of space, first the spacecraft faced thermal extremes.

The chamber can be lowered to -250 degrees Fahrenheit, or raised to 300 degrees. That way, NASA can emulate the sort of environments that Orion will have to perform in as it flies in and out of sunlight and shadow. It's not an even heating or cooling, either, with a special "Heat Flux" system able to apply excessive temperatures to specific parts of the spacecraft to make sure it all holds up.

After that came the electromagnetic interference and compatibility test. That takes advantage of the highly specific controls NASA has over conditions within the Plum Book Station chamber, with liberty to either cut all radio frequencies or introduce very specific ones for testing. Orion's electronics had to hold up during a battering of these, similar to what it might encounter on its flight to the Moon and back.

Now that it has checkmarks all down the report card, Orion can make its journey back to the Kennedy Space Center. Even that will be a spectacle, since the size of the spacecraft – and the fact it can't be easily dismantled – means NASA needs a huge plane for it.

That's the Super Guppy, a custom plane that was used to bring Orion to Sandusky in the first place. Resembling a regular quad-propeller aircraft but with a hugely swollen upper section, the Super Guppy was constructed by Aero Spacelines for transporting large items when road and rail simply aren't flexible enough.

Part of what makes the Super Guppy special is the vast interior. Its cargo area is 25 feet in diameter and 111 feet long, accessed by a hinged nose that opens a full 110-degrees. An electric winch installed in the aircraft's floor works with special rails and rollers, slowly bringing Orion into the belly of the plane where it's locked in automatically by hydraulic pins.

When back at Kennedy, NASA will be able to undertake the final assembly and checkout process. That will see Orion gain its four solar arrays, which will help keep the spacecraft powered during the mission to the Moon.

That'll be atop the Space Launch System (SLS) rocket, and initially Orion won't have any human occupants. Instead, NASA plans to make an unscrewed test flight around the Moon, and then bring Orion back to Earth to demonstrate each element is working as intended. After that, a manned return to the Moon is scheduled, and beyond that Orion and the SLS will form the backbone of NASA's crewed mission to Mars.