The SNIPE mission aims to elucidate microscale (100 m - 10 km) structures in the topside ionosphere (below altitude of 1000 km), especially the fine-scale morphology of high-energy electron precipitation, cold plasma density/temperature, field-aligned currents, and electromagnetic waves. Hence, the mission will observe microscale structures of the following phenomena in geospace: high-latitude irregularities, such as polar-cap patches; field-aligned currents in the auroral oval; electromagnetic ion cyclotron (EMIC) waves; hundreds of keV electron precipitations, such as electron microbursts; subauroral plasma density troughs; and low-latitude plasma irregularities, such as ionospheric blobs and bubbles.