Complex sentence: They are designed to be fired in a range of 1 AU or less, however variants exist that can reach upto 3 AU, once fired a smart missile can be "called home" or neutralized during flight.
Split into simpler sentences: They are designed to be fired in a range of 1 AU or less, however variants exist that can reach upto 3 AU. Once fired a smart missile can be "called home" or disarmed during flight.