Atomic Oxygen and Helium have not been measured in-situ since the early 1980s during the era of the Dynamics Explorer. Hydrogen has never been directly measured in-situ over the mission region. By providing measurements over Arecibo, Wisconsin, Kitt Peak, and Cerro Tololo, ExoCube will aid in the inter-comparison and validation of ground-based observations from the respective sites. These measurements are performed using passive optical interferometry and photometry of neutral airglow emissions as well as active ISR to characterize the local ionosphere.
