Phoenix - the first Mars scout mission (a mid-term report)

As the first of the new Mars scouts missions, the Phoenix project was selected by NASA in August of 2003. Over its initial 18 months, the project has completed its advertised formulation phase activities, and has recently been approved for continuation to formulation, culminating in a launch planned for August 3, 2007. The Mars scouts missions are principle investigator (PI) led, lower cost missions, intended to be responsive to previous discoveries of the Mars Program. Mr. Peter Smith from the University of Arizona is the PI for Phoenix. Phoenix "follows the water" responding directly to the recently published data from Dr. William Boynton, PT (and Phoenix co-I) of the Mars Odyssey gamma ray spectrometer (GRS). GRS data indicate extremely large quantities of water ice (up to 50% by mass) within the upper 50 cm of the northern polar regolith. Phoenix will fly the inherited Mars surveyor program 2001 lander, and will land within this north polar region (65N - 72N) identified by GRS and provide in-situ confirmation of this extraordinary find. Our mission will investigate water in all its phases, and will investigate the history of water as evidenced in the soil characteristics that will be carefully examined by the powerful suite of onboard instrumentation. Access to the critical subsurface region expected to contain this information is made possible by a third generation robotic arm capable of excavating the expected Martian regolith to a depth of 1m. Phoenix has four primary science objectives: 1) determine the polar climate and weather, interaction with the surface, and composition of the lower atmosphere around 70deg N for at least 90 sols focusing on water, ice, dust, noble gases, and C0₂ and determine the atmospheric characteristics during descent through the atmosphere; 2) characterize the geomorphology and active processes shaping the northern plains and the physical properties of the near surface regolith focusing on the role of water; 3) determine the aqueous mineralogy and chemistry as well as the adsorbed gases and organic content of the regolith. Verify the Odyssey discovery of near-surface ice. 4) characterize the history of water, ice, and the polar climate. Determine the past and present biological potential of the surface and subsurface environments. This paper covers the mission design, progress made in the formulation phases, key system trades, future plans and challenges