Workers in the Payload Hazardous Servicing Facility guide as it is lowered onto the lander base petal for installation.

Workers in the Payload Hazardous Servicing Facility guide the Mars Exploration Rover 1 (MER-1) as it is lowered onto the lander base petal for installation. The MER Mission consists of two identical rovers, landing at different regions of Mars, designed to cover roughly 110 yards each Martian day over various terrain. Each rover will carry five scientific instruments that will allow it to search for evidence of liquid water that may have been present in the planet's past. The first rover has a launch window opening June 5, and the second rover a window opening June 25. The rovers will be launched from Cape Canaveral Air Force Station.