Mars Explorer Rover (MER) project officials have determined they may not be able to take the design of the Pathfinder airbag landing system and “build it to spec” for the twin 2003 MER missions as planned. While still early in development, it appears there could be at least minor changes to the landing system’s parachute, solid rocket braking motors or possibly the airbags themselves to accommodate the heavier payload weight, and weight margin, for the 2003 mission. Officials plan to firm up the baseline in January when a project review is scheduled.