We have generated predictions for observing Phobos transits during the period 2012–2014 using the Mars Science Laboratory. We describe how the detections of Phobos eclipses can be used as an alternative procedure to determine the coordinates of the rover. We present a numerical simulation to analyse the sensitivity of the precise observed contact times to the coordinate determination. The numerical results show that after four days of eclipse observations for 1 min each day, within the 25 × 20 km2 landing site ellipse, the position of the lander can be determined to within an ellipse of 40 × 60 m2 for uncertainties of 1 s in eclipse time observations. A 20 × 15 m2 ellipse is estimated if a 0.1-s time precision can be gathered.