This paper delves into the iterative evolution of microelectromechanical system (MEMS) Microvalve (MV) and pre-concentrator (PC) generations designed for the Spacecraft Atmosphere Monitor (S.A.M.) instrument, a critical component of the International Space Station’s (ISS) air quality monitoring system. Covering design, simulation, and characterization, this paper includes the latest generation of PC and MV that meets and exceeds all key performance requirements of S.A.M. Deployed on the ISS in 2023, MV XXI exemplifies ongoing advancements in MV technology for space applications.