Alex_DeltaDev 🎮🚀🟠Apr 10

Just about couldn't believe this Artemis reentry map when I saw it earlier tonight. Orion flying directly over South Australia TWICE. 🌏

This is a very interesting map though - Orion does not make any sharp turns.. so... something unintuitive is happening here. #Space #Artemis #NASA

Show threadAlex_DeltaDev 🎮🚀🟠Apr 10

I did some digging to understand this properly.
(See the image below, Orion does not make any sharp turns during its approach and re-entry - so what is going on here??)

The way to think about it is that there are 2 phases of trajectory making up this path - both relative to the Earth's surface ..

Show threadAlex_DeltaDev 🎮🚀🟠Apr 10
1) For the first part of the map Orion is seemingly moving East to West, this is only because Orion is still far from Earth, and going slower than the Earth is spinning (Earth is spinning towards the East). So the East->West movement across the map is moreso Earth spinning as Orion approaches ..
Show threadAlex_DeltaDev 🎮🚀🟠Apr 10
2) Then the 2nd part to the map - where Orion has gotten close enough on approach that it falls deeper into Earths gravity well and speeds up very quickly. It speeds up to the point its travelling faster than Earth's spin, which is why we see its trajectory moving North-East ..
Show threadAlex_DeltaDev 🎮🚀🟠
Very unintuitive, very crazy space stuff. Great to be able to understand it because I don't think this is something most people would get right away.
Apr 10 at 5:11amWeb
Show threadAlex_DeltaDev 🎮🚀🟠Apr 10
GIF for a better visual of what is going on here: https://mastodon.social/@Alex_ADEdge/116378699014529094