This Guy Found Space Shuttle Debris On The Beach

When you go on a walk on the beach, you expect it to be calming and relaxing with just you and a few other people who are there for the same reason you are. But when Reddit user newroot went for a walk on the beach, he came across something that was definitely unexpected. I don't know what I would do if I came across this. I might run the other way, but I'm sure glad he stopped and took pictures to share with us all!
While going for a walk, he found this odd shaped piece of metal.
It looks like a panel of some sort, but what does this wording mean?
The panel has definitely seen better days, as it's very scratched up.
How in the world did this panel end up here?
A better look at the underside of the panel, with wires and electronics hanging out.
There was some tubing and wires that were exposed, but since it wasn't connected to anything, he figured it was okay to get a little closer.
You can see the word "space" on the panel. Makes you wonder. It sure looks like this panel is missing from somewhere important.
There is some crazy insulation on the underside of the panel.

A closer look at this panel. I wonder what he was thinking when he found this just sitting there.
Well now it's starting to make sense. It definitely is the panel from this!
How did this panel end up missing? This seems like it would be a very important piece that they should have recovered.