Starting with just 1/2 C of juice in a 4 C glass measuring cup add the gelatin and give it a stir.
Let it sit for 5 mins to "bloom"
Microwave it until it's melted, about 1 min on high
Add the sugar and stir until it's dissolved.
Add the rest of the juice and stir
Prepare a 9x13 glass pan by spraying it with cooking spray
Pour the juice into the pan and refrigerate until set
cut into cubes and serve