Sample Analysis at Mars (SAM)

PI: Paul Mahaffy, Goddard Space Flight Center

Official SAM Page - Click Here

The Sample Analysis at Mars (SAM) Suite Investigation in the MSL Analytical Laboratory is designed to address the present and past habitability of Mars by exploring molecular and elemental chemistry relevant to life. SAM addresses carbon chemistry through a search for organic compounds, the chemical state of light elements other than carbon, and isotopic tracers of planetary change.

SAM is a suite of three instruments, a Quadrupole Mass Spectrometer (QMS), a Gas Chromatograph (GC), and a Tunable Laser Spectrometer (TLS). The QMS and the GC can operate together in a GCMS mode for separation (GC) and definitive identification (QMS) of organic compounds. The TLS obtains precise isotope ratios for C and O in carbon dioxide and measures trace levels of methane and its carbon isotope.

Three questions about the ability of Mars to support past, present, or future life are addressed by SAM's five science goals as stated in the table below.

The three SAM instruments are supported by a sample manipulation system (SMS) and a Chemical Separation and Processing Laboratory (CSPL) that includes high conductance and micro valves, gas manifolds with heaters and temperature monitors, chemical and mechanical pumps, carrier gas reservoirs and regulators, pressure monitors, pyrolysis ovens, and chemical scrubbers and getters. The Mars atmosphere is sampled by CSPL valve and pump manipulations that introduce an appropriate amount of gas through an inlet tube to the SAM instruments. The solid phase materials are sampled by transporting finely sieved materials to one of 74 SMS sample cups that can then be inserted into a SAM oven and thermally processed for release of volatiles. The SAM mechanical configuration and a top level schematic of its sample flow configuration are illustrated below.

The illustration of the mechanical configuration of SAM shows the three instruments and several elements of the Chemical Separation and Processing Laboratory.

The path of solid and gas samples delivered by MSL subsystems to the SAM instruments is shown. Arrows designate the direction of gas and solid transport.

SAM Experiment Sequences

SAM is designed to deliver nine data set types that are acquired via the experiment sequences described in following table. These experiment sequences may utilize different elements of the SAM suite. In addition to these science sequences, the SAM vacuum elements will be cleaned as necessary during the course of the mission by in situ bakeout.