It was August when I last wrote about Nasa’s Artemis mission and the ongoing delays of launching. Those delays kept on coming but wahey, the rocket finally lifted off this week and the Artemis Orion craft is finally on its way to the moon. Apparently it will be tomorrow when the ship reaches its closest proximity to the moon, 80 miles, before heading into orbit.

The latest official Nasa update talks of the tests they’ve been doing along the way - solar power, WiFi signal, radiator systems and navigation guidance. The navigation stuff is particularly interesting:

As part of planned testing throughout the mission, the guidance, navigation, and control officer, also known as GNC, performed the first of several tests of the star trackers that support Orion’s navigation system. Star trackers are a navigation tool that measure the positions of stars to help the spacecraft determine its orientation. In previous flight days, engineers evaluated initial data to understand star tracker readings correlated to thruster firings.

Engineers hope to characterize the alignment between the star trackers that are part of the guidance, navigation and control system and the Orion inertial measurements units, by exposing different areas of the spacecraft to the Sun and activating the star trackers in different thermal states.

I’m keeping track of the progress of the mission via Space.com’s excellent live updates and hope there’s more fascinating stuff coming up!