Landsat 9 is an American Earth observation satellite. NASA is in charge of building, launching, and testing the system, while the United States Geological Survey (USGS) will process, archive, and distribute its data. It's intended as the eighth satellite in the Landsat series, Landsat 6 failed to reach orbit.

-CUTE (Colorado Ultraviolet Transit Experiment) is a 6U CubeSat set to use near-ultraviolet (NUV) transmission spectroscopy from 255 to 330 nanometers (nm) to characterize the composition and mass-loss rates of exoplanet atmospheres. (University of Colorado Boulder)

-CuPID (Cusp Plasma Imaging Detector) is a 6U Cubesat designed to test competing models of solar wind-magnetosphere coupling. It carries a wide field-of-view soft X-ray telescope, the first of its kind to be placed into orbit. In orbit, the spacecraft will measure soft X-rays emitted from the process of charge exchange when plasma from the solar wind collides with neutral atoms in the Earth’s distant atmosphere. (Boston University)

Cesium Satellites 1 and 2 are 6U CubeSats operated by CesiumAstro that host customer experiments about small satellite communication and are set to demonstrate technologies like dynamic waveform switching and dynamic link optimization.
With the launch of Mission 1, Cesium will have a complete commercial phased array communication system as well as an inter-satellite link in LEO.