a b s t r a c t The next step in the exploration of Mars should include a strong and comprehensive life detection component. We propose a mission called BOLD: Biological Oxidant and Life Detection mission. The scientific objectives of the BOLD mission are to characterize habitability of the martian surface and to search for evidence of extinct or extant life. In contrast to the Viking mission, which was designed to detect heterotrophic life on Mars, the BOLD mission incorporates a more comprehensive search for autotrophic microorganisms, as well as detecting a variety of biomarkers and understanding their environment. Six miniature landers are envisioned for BOLD that utilize either an orbital (e.g. Viking) or direct entry (e.g., MER, Phoenix) mission architecture. The number of landers will provide mission redundancy, and each will incorporate a Mars Soil Analyzer, a Multispectral Microscopic Imager, a Nanopore-ARROW that detects biopolymers with single molecule resolution, an Atmospheric Structure and Surface Environment Instrument, a Fluorescent Stain experiment, and a Chirality experiment. A terrain navigation system, coupled with robust propulsion, permits a landing accuracy on the order of meters if required to meet the science objectives. The probes will use existing orbiters for commu-nication relay if the orbiter architecture proves too ambitious.