def test_sees(self):
sat1 = Satellite('SAT1', 0, 0, 1 + earth.radius * sqrt(2))
sat2 = Satellite('SAT2', 0, pi, 1 + earth.radius * sqrt(2))
sat3 = Satellite('SAT2', 0, pi/2, 1 + earth.radius * sqrt(2))
self.assertFalse(sat1.sees(sat2))
self.assertTrue(sat1.sees(sat3))
self.assertTrue(sat2.sees(sat3))
