Overview

The ISS-IMAP (International Space Station - Ionosphere, Mesosphere, upper Atmosphere, and Plasmasphere mapping) is a mission aimed at observing the Earth’s upper atmosphere from the International Space Station (ISS). The mission’s objective is to provide detailed observations of airglow and plasma distributions in the Earth’s mesosphere and thermosphere, thereby elucidating the physical phenomena in these regions. The mission was launched on July 21, 2012, by the HTV-3 vehicle and concluded its late operational observations on August 24, 2015. The primary research institutions involved include Kyoto University, ISAS/JAXA, Tohoku University, the University of Tokyo, Nagoya University, Seikei University, Rikkyo University, Kyushu University, NICT, the Electronic Navigation Research Institute, and Komazawa University.

Observation Instruments

VISI (Visible and near-Infrared Spectral Imager)

VISI is an instrument designed to observe airglow in the Earth’s mesosphere and thermosphere using visible and near-infrared light. It primarily observes O2 airglow at a wavelength of 762nm. This instrument is capable of wide-field observations, allowing it to capture detailed concentric structures of airglow in the Earth’s atmosphere. The observational capabilities of VISI have enabled the collection of extensive data that was previously unattainable through ground-based observations.

EUVI (Extreme Ultraviolet Imager)

EUVI is an instrument that observes the Earth’s thermosphere and plasmasphere using extreme ultraviolet light. By utilizing the ultraviolet wavelength band, this instrument provides detailed observations of plasma distributions in the Earth’s upper atmosphere. The observations made by EUVI have yielded new insights into the structure and dynamics of the Earth’s plasmasphere.

Results

The ISS-IMAP mission has produced several significant scientific results. Notably, observations by VISI have, for the first time, detailed the concentric structures of airglow in the mesosphere. On June 1, 2013, from 04:33 UT to 04:49 UT, concentric structures of O2 airglow (762nm) were observed over North America. This data has provided crucial information for understanding the overall structure of airglow in the mesosphere.

Additionally, the ISS-IMAP mission has demonstrated the effectiveness of visible and near-infrared imaging observations of the upper atmosphere from space. While ultraviolet light, which is unaffected by the Earth’s surface, has traditionally been used, observations in the visible and near-infrared spectrum have provided new data, contributing to a deeper understanding of the Earth’s upper atmosphere.

These results serve as essential foundational data for understanding the dynamics of the Earth’s atmosphere and plasma, and they are expected to be extensively utilized in future research.