make a simple syrup by placing the water and sugar in a small saucepan and bring to a boil, stirring to completely dissolve the sugar. Remove from heat, place in an airtight container and chill until cold.
Place the chilled cantaloupe cubes, cold simple syrup, and lemon juice in a blender. Puree until very smooth.
Freeze in an ice cream maker according to manufacturers direction,
When thick and frozen, scoop into a container and freeze overnight.