Mars Polar Lander. Artwork of the Mars Polar Lander on its way to Mars. The Mars Polar Lander is due for launch in January 1999. This light- weight spacecraft is designed to study the soil and weather on Mars. It also has several imaging systems which will be used to photograph the terrain. A robot arm will be used to collect soil samples for on-board analysis. These will be tested for water. Also on this mission are two New Millennium Project Microprobes (orange, under the lander's solar panels). These will detach before touchdown, and bury probes in the Martian soil, which will look for water in the deeper layers.