Re: Third Solar Sail?
IKAROS was interplanetary, not Earth orbit. NanoSail-D's launch failed, but its understudy (NanoSail-D2) deployed in LEO a couple years later after a hiccup or two.
"Only the power of sunlight" is a key phrase; NanoSail was battery powered, LightSail is powered by solar cells, the batteries are only there for use during eclipse conditions. This is pure marketing pedantry IMO, and has no place in science.