MELOS ("Mars Exploration with a Lander-Orbiter Synergy") is a proposed Japanese planetary exploration mission under assessment and consideration, that would investigate the evolution of Martian atmosphere, the water and climate of Mars.
The mission's objective is to increase understanding on the composition of the interior and surface of Mars, as well as its atmosphere and surrounding space.
The MELOS mission would consist of an orbiter and up to 4 small landers; all elements would be launched together on the same rocket. The orbiter would study the atmosphere, its and interactions with the solar wind, and image the current weather. Each of the four stationary landers would be deployed on pre-determined landing sites and perform different measurements:
This lander would analyse soil near a methane vent. The proposed method is to use fluorochrome dye and a microscope to stain and scan for proteins and cellular membranes. The target sensitivity would be 10 cells / 1 g of soil (compared to 104 cells / 1 g in Earth desert). It would also detect other organic biosignatures or biomolecules.
This proposed mission by the Japan Aerospace Exploration Agency (JAXA), aims to understand the geological evolution of Mars and to answer the fundamental question "Why (and how) is Mars different from the Earth?" MELOS would also attempt to determine if Mars had a warm and wet environment in its early stages.