NASA’s Ionospheric Connection Explorer satellite (ICON) is scheduled to launch next month for a two-year mission to gather information on weather and other physical processes within the ionosphere — the frontier of space, where Earth’s weather and space weather meet. A central component of the ICON satellite’s instrument package is the Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI), developed by a team at the U.S. Naval Research Laboratory and Jenoptik, which built the imaging optics. MIGHTI represents a significant advancement in Michelson interferometer design. Ordinarily, interferometers have a single mirror attached to an adjustable motorized bracket. The mirror is moved and a reading is taken; then the mirror is moved again and another reading is taken, and so on. Because the device will be launched into space on a rocket, the delicate moving interferometer parts have been replaced by fixed tilted gratings, resulting in a robust, monolithic element known as a Doppler Asymmetric Spatial Heterodyne (DASH) interferometer. In this design, each grating groove acts as a mirror, so the device can take measurements without the need for precision adjustment. New insights into space’s frontier MIGHTI will be used to measure wind speeds, directions, and temperatures within the critical altitude zone between 90 and 300 km to gain a better picture of the weather patterns that occur within that space. Changes in density within the ionosphere can have a significant effect on our weather, radio signals, GPS, and other technologies used by low-orbiting satellites, spacecraft, and the International Space Station, all of which travel through that portion of the atmosphere. The ICON satellite will orbit the Earth at a 27° inclination at an altitude of 575 km, placing it in position to observe the ionosphere around the equator, one of the most problematic areas for technology passing through. The satellite was selected for development in 2013 as part of the long-running NASA Explorers Program. Total budget for the project, excluding the Pegasus XL delivery rocket, was $200 million.