you can also usually find these on cargo ships traveling thru the sector map.
I never do these either since they've removed them from the ship replicator, but i am wondering that if you keep some in the bank if it'll take them from there. Does with "crafting" supplies at least. Anyone try this?
I love these missions!
When I get one I fly around the system collecting resources then I go to talk to the people on the planet in order to know who it is I'm laughing at as I warp out of the system never to return!