Valeriano Claros-Guerra served as INTA Deputy Director and as Operations and Communications Supervisor at Maspalomas Tracking Station, part of NASA's Manned Spaceflight Network on Gran Canaria, from 1969 to 1975. He supported a number of space programmes, including Apollos 10 through to 17 (including the historic Apollo 11 Moonlanding on 20 July 1969), ERTS (Earth Resources) and Skylabs 1 and 2.
He joined ESA in 1989, serving as Director of the Villafranca del Castillo Tracking Station and as ESA's Representative in Spain, until 2004. In the late 1990s, Claros oversaw the planning and construction of ESA's Deep Space Antenna (DSA) Network, taking part in commissioning the 35 m DSA stations at New Norcia, Australia, and Cebreros, Spain.
In his final year with ESA, he served as Station Manager at Cebreros station. He retired from ESA in 2005.