Humanity's explorer? Perhaps in a generic, species sense.
The Curiosity rover is a product of NASA, its subcontractors and the American people.
Might as well call it "Earthling Emissary".
The techies of Engadget self-identify as citizens of the world.
Associating themselves with "America" would be exclusionary, racist, jingoistic, nationalistic, and imply that they are in agreement with American cultural imperialism.