The light elements H, C, N, O and S are important for propellant production and life support in space. These light elements occur on Mars, and may occur on the martian moons Phobos and Deimos, in forms that would allow their collection as gasses. The martian north pole apparently contains large amounts (/approximately/10/sup 13/ MT) of H/sub 2/O but has not been probed or sampled. The martian atmosphere is relatively well known; a MW-scale plant could produce 1000 MT of O/sub 2/ per Earth-year by dissociation of CO/sub 2/ from the martian atmosphere. A plant of about 3 MW power might produce 1000 MT of H/sub 2/ plus O/sub 2/ per Earth-year by extracting and dissociating water from the martian moons (if they are chondritic), but more data and process development are needed before such a plant can be considered with certainty. 5 refs., 2 tabs
