Space Plasma Detectors on NEXTSat-1 for Ionospheric Measurements

This paper describes the Space Plasma Detectors (SPD) on board the Next Generation Small Satellite-1 (NEXTsat-1), which will observe the thermal plasmas of the ionosphere, especially the plasma irregularities in the low and the middle latitude regions. A SPD consists of a disk-type Langmuir Probe (LP), a Retarding Potential Analyzer (RPA), and an Ion Drift Meter (IDM), which will measure the electron densities and temperatures, the ion densities and temperatures as well as the ion components, and the ion drift velocities, respectively. Whereas SPD employ conventional designs, a high cadence of nominal 100 msec will enable us to study small-scale structures of irregularities, such as plasma bubbles and blobs, with a spatial resolution of less than a kilometer at an altitude of ~ 575 km. Furthermore, the high-resolution mode of the LP operating at a 20 msec cadence will provide data on the electron density and temperature variations with an even better spatial resolution. The NEXTSat-1 is scheduled for launch in early 2018.