From the launch of its first module in 1998, to its first onboard crew in 2000, to today’s expansive labyrinth of space laboratories and solar arrays, the International Space Station is a technological marvel and an icon of human innovation. The ISS is well known as a research facility for medicine, biology, physical science, physiology, space flight, and cutting-edge engineering.
But did you know the ISS is home to a unique collection of facilities that can be used for Earth observing instruments. These include the Columbus – External Payload Facility (Columbus-EPF), the Expedite the Processing of Experiments to the Space Station Logistics Carrier (ELC), the Japanese Experiment Module – Exposed Facility (JEM-EF) and the Window Observational Research Facility (WORF). The Columbus-EPF, ELC and JEM-EF support external payloads, which means remote sensing instruments can be mounted on the outside of the ISS. And the WORF supports internal payloads by providing a very high optical quality optical window through which instruments can view the Earth below.
Advantages of using the ISS as a remote sensing platform include the capacity to install new instruments with relative ease (at least compared with launching free flying satellites), the ability to remove instruments and transport them to ground for post-mission analysis, and in some cases the option for crew interaction with the instrument while onboard the station. The ISS also has a unique orbit that differs from most Earth observing satellites, thus allowing image collection at different times of the day and under different illumination conditions than would otherwise be possible. These same orbit characteristics; however, can also be a disadvantage with respect to image uniformity and operational requirements. Additionally, in some cases the solar arrays can interfere with observations during certain situations. Nonetheless, the ISS is an excellent facility to test new instruments and explore new remote sensing capabilities.
So what are some of the instruments that have flown on the ISS? There are HICO (Hyperspectral Imager for the Coastal Ocean) and RAIDS (Remote Atmospheric and Ionospheric Detection System), which are integrated into a single payload installed on the JEM-EF. As the name implies, HICO is a hyperspectral instrument that has been optimized for imaging the nearshore aquatic environment. RAIDS is used for measuring the major constituents of Earth’s upper atmosphere, specifically the thermosphere and the ionosphere. There is also the EVC (Earth Viewing Camera), which is part of the European Technology Exposure Facility (EuTEF) deployed on Columbus-EPF. EVC is a commercial off-the-shelf digital camera used to capture color images of the Earth’s surface. A final example is ISSAC (International Space Station Agricultural Camera), which is installed as an internal payload on WORF. ISSAC is a multispectral camera measuring wavelengths in the visible and near infrared that primarily targets agricultural areas in the northern Great Plains. ISSAC is also particularly exciting, since it was largely built and operated by students at the University of North Dakota.
Those are just a few of the exciting instruments on the ISS. There are many others… and more instruments planned for future missions.
Are you involved in instrument development or image analysis related to the ISS? We’d love to hear your thoughts and stories and share them with the community.
For more about the ISS: http://www.nasa.gov/mission_pages/station/main/