@pedlefson Thanks for reaching out!
At this time Kelty does not make a footprint for their Discovery line of tents. If you'd like to use a tarp, the dimensions of the 6 person tent are 10.8' x 9', so the Outdoor Products All Purpose Tarp might work in the 10' x 8' model. You could also make your own footprint out of a sheet of plastic and a grommet kit.
Hopefully this helps!