You are looking at a NASA coin set.
This is a 5 coin set.
The coins in the set are Antiqued Solid Bronze.
They are "Maiden Flights" coins.
The set includes the following:
Columbia~1981
Challenger~1983
Discovery~1984
Athantis~1985
and Endeavor~1985
It also has a sheet with flight information on the back.
A piece of NASA history!