NASA descends on Icelandic lava field to prepare for Mars To prepare for the next mission to Mars in 2020, NASA has taken to the lava fields of Iceland to get its new robotic space explorer ready for the job. With its black basalt sand, wind-swept dunes and craggy peaks, the Lambahraun lava field at the foot of Iceland's second biggest glacier, Langjokull, was chosen as a stand-in for the Red Planet's surface.