Jyunmi Hatcher

The vehicle management computers themselves are a generational leap over anything humans have flown before.

According to Lockheed Martin, each of Orion's redundant flight computers is approximately 20,000 times faster than the computer on Apollo and 25 times faster than the flight computers on the International Space Station.

Orion's internal data network is a gigabit ethernet, the same basic network technology in modern offices, and can move data roughly a thousand times faster than the systems on the space shuttle and ISS.

There are five independent flight computers on board, not because anyone expects to use all five at once, but because deep space is a hostile environment for electronics.

High energy particles from cosmic radiation can flip individual bits inside a processor at any time.

The defense is called triple modular redundancy.

Critical calculations run on three processors simultaneously.

The results are compared, and if one disagrees with the other two, the outlier gets outvoted and ignored.

For navigation, Orion's guidance, navigation and control system known as GNC combines two inertial measurement units, optical star trackers and optical navigation cameras that photograph the moon and earth against the background stars.

GPS doesn't work beyond Earth orbit.

Satellites are too far below and their geometry is just wrong for tracking spacecraft at lunar distances.

So Orion has to know where it is by combining what its gyroscopes and accelerometers measure with what its cameras can see in the sky.

The system handles this continuously without requiring ground input.

Scott Modesset, Lockheed Martin's Artemis II mission manager, described the significance of the avionics during the original power on test.

He says, firing up the avionics inside a spacecraft that will send humans back to the moon for the first time in 50 years is a significant event.

Our test team and flight systems all did their jobs and performed expectedly well during the tests.

The crew has been actively flying Orion at intervals during the mission to test its manual handling characteristics.

It's part of the test flight purpose.

But the spacecraft has handled most of the operation workload itself.

Mission Commander Reed Weissman told the BBC before launch, it is a test mission and we are ready for every scenario.