This site from NASA presents a comprehensive overview of the Mars Astrobiology Research and Technology Experiment (MARTE) project, which is developing drilling, sample handling, and instrument technologies relevant to searching for life in the Martian subsurface, and demonstrating them in a field test at a site with a Mars-analog subsurface biosphere on Earth. The site highlights the many problems inherent to drilling for subsurface life on Mars, and tracks the Rio Tinto project in Spain which is seen as a proxy for future Mars missions.