COSMO-SkyMed

COSMO-SkyMed (COnstellation of small Satellites for the Mediterranean basin Observation) is an Earth observation satellite system funded by the Italian Ministry of Research and Ministry of Defence and conducted by the Italian Space Agency (ASI), intended for both military and civilian use.

The space segment of the system includes four identical medium-sized satellites equipped with synthetic aperture radar (SAR) sensors with global coverage of the planet. Observations of an area of interest can be repeated several times a day in all-weather conditions. The imagery will be applied to defense and security assurance in Italy and other countries, seismic hazard analysis, environmental disaster monitoring, and agricultural mapping.

Space segment

The four satellites are in sun-synchronous polar orbits with a 97.9° inclination at a nominal altitude of 619 km and an orbital period of 97.2 minutes. The local time ascending node at the equator is 06:00. The expected operating life of each satellite is estimated to be 5 years. Each satellite repeats the same ground track every 16 days, and all of the satellites follow the same ground track. They cross the equator at 06:00 and 18:00 local-time each day. The satellites are phased in the same orbital plane, with COSMO-SkyMed's 1, 2 and 4 at 90° to each other and COSMO-SkyMed 3 at 67.5° from COSMO-SkyMed 2. This results in varied intervals between the satellites along the same ground track of between 1 and 15 days. The sun-synchronous orbit is used to keep the solar cells illuminated at all times.