Entry, Descent, and Landing Operations Analysis for the

The Mars Phoenix lander was launched August 4, 2007 and remained in cruise for ten months before landing in the northern plains of Mars in May 2008. The one-month Entry, Descent, and Landing (EDL) operations phase prior to entry consisted of daily analyses, meetings, and decisions necessary to determine if trajectory correction maneuvers and envi-ronmental parameter updates to the spacecraft were required. An overview of the Phoenix EDL trajectory simulation and analysis that was performed during the EDL approach and operations phase is described in detail. The evolution of the Monte Carlo statistics and foot-print ellipse during the final approach phase is also provided. The EDL operations effort ac-curately delivered the Phoenix lander to the desired landing region on May 25, 2008. Nomenclature E = atmospheric entry time EDL = entry, descent, and landing EPU = environmental parameter update L = spacecraft landing time MOLA = Mars Orbiter Laser Altimeter OD = orbit determination r = radial distance to the center of Mars TCM = trajectory correction maneuver Vh = horizontal velocity Vv = vertical velocity γ = inertial flight path angle I