  The high number of objects in the LEO is a risk that collisions between
sub-orbital or escape velocity objects with an orbiting object of satellites
occur when two satellites collide while orbiting the earth. One of the
approaches to avoid collisions is a robotic configuration of satellite
constellations. Satellite constellations should not be confused with satellite
clusters, which are groups of satellites moving in close proximity to each
other in nearly identical orbits; nor with satellite series or satellite
programs, which are generations of satellites launched successively; nor with
satellite fleets, which are groups of satellites from the same manufacturer or
operator that operate an independent system. CfEOS constellations designed for
geospatial applications and Earth observation. Unlike a single satellite, a
constellation can provide permanent global or near-global coverage anywhere on
Earth. CfEOS constellations are configured in sets of complementary orbital
planes and connect to ground stations located around the globe. This paper
describes the GNC analysis, the orbit propagation and robotic systems
configuration for Collision-free Earth observation satellites (CfEOS)
constellations.
