1. Bring first 4 ingredients to a boil in a saucepan; cook 1 minute or until sugar dissolves. Remove from heat. Place pan in a large ice-filled bowl for 15 minutes or until sugar mixture cools completely, stirring occasionally.
2. Place cantaloupe, vodka, and juice in a food processor; process until smooth. Strain cantaloupe mixture through a sieve over a bowl; discard solids. Add sugar mixture and cream to cantaloupe mixture; stir well.
3. Pour cantaloupe mixture into the freezer can of an ice-cream freezer; freeze according to manufacturer's instructions. Spoon sherbet into a freezer-safe container; cover and freeze 1 hour or until firm.