1. Rinse satsuma sections in cold water. Drain; freeze 30 minutes or until firm.
2. Place crushed ice in a martini shaker. Add gin, juice, and Grand Marnier to shaker; shake well. Strain 1/2 cup gin mixture into each of 2 martini glasses. Add 4 frozen satsuma sections to each glass. Garnish with rind, if desired.