Satellite Missions for Earth and Planetary Exploration

Remote sensing technologies have evolved in different fields and are now used in research and applications in many different areas. Many of these have evolved from the laboratory to the field, then to airborne systems and, ultimately, to satellite missions, particularly for Earth Observation but also for space research and multiple experiments in space conditions.

Scientific research and related operational applications in many areas now depend on the availability of data provided by satellites orbiting the Earth. The regular provision of appropriate data has to find a balance between maintaining the long-term continuity of the same data – typically by a series of identical successive satellites – and the introduction of innovation by means of completely new remote sensing techniques and new products that enhance the capabilities of existing techniques. Most space agencies offer both type of missions, with an operational branch oriented to provide routine data for operational applications, and more scientifically technically challenging and innovative missions dedicated to offering cutting-edge data for new science and applications. On top of the institutional data provided by space agencies, there are many commercial missions providing, in most cases, high spatial resolution land images in addition to operational services oriented toward air quality monitoring or other environmental applications demanded by society. Some local agencies and private companies also provide data from national missions. While some of these were initially conceived to satisfy specific national needs by their respective countries, the global accessibility provided by the satellites represent an additional source of data for global applications.

Users need to be well aware of the existing planned and long-term future remote sensing capabilities. To plan future research and to provide a long-term view for operational applications, users need to be continuously updated about current and planned satellite missions, including technical details about the capabilities of each mission, the products released to the users by each one of the missions, and the appropriate calibration and validation tools put in place by satellite operators to guarantee the consistency and adequacy of the derived products. While space agencies and satellite data providers have such information, for users, it is sometimes difficult to get access. This Section provides a forum to disseminate precise information in a rigorous manner about current and future satellite missions.

However, remote sensing techniques are not restricted to Earth Observation. The same techniques are applied to the research of other planets in our Solar System and astrophysical exploration. The parallel development of techniques used in different fields definitely benefits multidisciplinary research. Some approaches, initially conceived for medical imaging techniques or laboratory research, are now used as remote sensing techniques for quite different fields of applications, and new satellite missions exploiting such synergistic approaches are emerging.

The opportunity to develop remote sensing techniques for Earth Observation and the unique possibility to validate such techniques with reference field measurements on Earth is also an opportunity to export and extrapolate the techniques validated for Earth Observation to the planetary exploration through missions travelling to other Solar System planets. Also for missions addressing the search for exoplanets outside the Solar System and the characterization of such exoplanet conditions by means of remote sensing techniques to determine the capability to support life in such exoplanet environments. Comparative planetology, search for life conditions in other planets, and space exploration in general, all use remote sensing techniques which are quite similar to those used in Earth Observation and other fields, but the potential synergy and comparative analysis is poorly exploited. Many of the things learned from Earth Observation can be extended to general planetary research through interdisciplinary approaches.

This dedicated Special Section of Remote Sensing is intended to cover a broad range of satellite missions addressing the usage of remote sensing techniques not only for Earth Observation but also for planetary exploration, astrophysical research, and in general missions that use remote sensing techniques developed and validated for Earth Observation for the science and exploration of extraterrestrial environments.

Topics may include, but are not limited to, the following:

• Existing and planned operational missions for Earth Observation
• Existing and planned scientific missions for Earth Observation
• New mission concepts addressing innovative technologies for Earth Observation
• Space agencies plans for medium- and long-term satellite missions for Earth Observation
• Commercial and private sector missions for Earth Observation
• Requirements from users about future satellite mission
• New sensors and detector technologies for advanced satellite missions
• Advanced data analysis techniques for high-data-rate satellite missions
• Long time series versus technological innovation in satellite missions
• Calibration and validation aspects in the planning of satellite missions
• Using remote sensing techniques for comparative planetology in the Solar System
• Exploration missions to other Solar System planets
• Exoplanet research with spectroscopy and other remote sensing techniques
• Search for life conditions in extraterrestrial environments using remote sensing techniques
• Future technology developments for new advanced satellite mission concepts