NASA's early period of Mars remote sensing was highlighted by the Mariner (4, 6, 7) flybys and the Mariner 9 and Viking (1, 2) orbiters. In the mid 1990s, NASA returned to Mars with orbiters designed to take advantage of technological breakthroughs in imaging and spectroscopy. Mars Global Surveyor's Mars Orbiter Camera took 1.4 m/pixel resolution images while the Mars Orbiter Laser Altimeter's measurements produced highly accurate 3D relief maps. Mars Odyssey's Thermal Emission Imaging System provided data on surface infrared properties and Odyssey's neutron spectrometer measured up to 50% H2O in the shallow subsurface. The Mars Reconnaissance Orbiter was launched in August 2006. MRO is equipped with six remote sensing instruments: (1) High Resolution Imaging Science Experiment will achieve sub-meter stereo image resolution; (2) Compact Reconnaissance Imaging Spectrometer for Mars will perform 18 m/pixel, 544 channel, infrared and thermal surface analyses; (3) the Context Camera will take regional context images with 6 m/pixel resolution; (4) Mars Color Imager will produce daily global images of the atmosphere and surface; (5) Mars Climate Sounder will study the temperature, dust, ice and water vapor content of the atmosphere as a function of altitude; and, (6) the Shallow Subsurface Radar will explore regional subsurface stratigraphy down to a kilometer. Future trends in Mars remote sensing will be considerably aided by telecommunications bandwidth improvements. The trend toward higher resolution and wider wavelength spectrometer investigations (with increased channels) will continue. Subsurface sounding to determine stratigraphy will improve and should take on a more prominent role.