The development of Monolithic Microwave Integrated Circuit technology at the end of the last century led to the ability to perform multiple system functions in compact integrated circuits. This, coupled with extraordinary noise performance achievable with InP high electron mobility transistors at millimeter wavelengths, has revolutionized receiver technology for remote sensing applications, particularly in Earth Science and astrophysics. This talk will explore recent developments in instruments enabled by this technology as well as future prospects for state-of-the-art short-gate high electron mobility transistor devices.