Advanced environmental monitoring and control technologies are required for future human exploration of the solar system, where the spacecraft air supply must be recycled for continuous use over a period of months to years. Primary target compounds and 180-day Spacecraft Maximum Acceptable Concentration (SMAC's) limits have been identified for several classes of contaminants. For the identified major species, O2, CO, CO2 and CH4, room-temperature, near-IR tunable diode laser absorption sensors have already been demonstrated with ∼1 ppm-meter detection limits (at or below many of the current SMAC limits) and continuous response band widths on the order of 1 Hz. Additional sensitivity can be achieved using compact long pathlength multipass optical cells. These new generation diode laser sensors use communications-type diode lasers in compact, fiber-coupled packages ideal for remote and autonomous sensor applications. In this paper we will describe extensions of these diode laser sensor concepts for sensitive monitoring of a second class of contaminants, trace volatile hydrocarbons species. We will also describe results from a technology insertion demonstration of selected species detection at the NASA Johnson human habitat simulation.