Mars express orbit design

Abstract This paper gives a survey of the orbit design, mission analysis aspects for Mars Express, the ESA mission to Mars. The emphasis is on those features which are unconventional. These are: the launch window with only 9 flight programs on the Fregat launcher upper stage for 30 launch days, and the re-targeting and Planetary protection strategy during the cruise; the delivery of the Beagle 2 lander to its entry corridor and the spacecraft re-targeting after lander separation; the capture strategy which reaches an orbit around Mars also in the case of a main engine failure; a plane turn manoeuvre during the injection sequence, and the selection of a nearly resonant eccentric orbit, using the J 2 effect of Mars to create global coverage from low altitudes at balanced sun illumination conditions for optical and radar payload, and to provide regular communications relay contacts to the lander.