The lower half of the Columbus logo consists of a lighter blue circle symbolising Earth. This is surrounded by a darker blue ellipse which signifies the initial orbit of the Space Shuttle that transported Columbus after launch. Above these, the International Space Station is shown at its higher orbiting altitude.
The white stripe across Earth symbolises two things. Firstly, it symbolises the path from east to west, which Christopher Columbus took on his way to the Americas. Secondly, it symbolises the path of the Columbus laboratory from west to east from the launch pad in Florida, USA, into orbit and to the International Space Station, following an orbital path symbolised by the stars.
The stars (10 gold and one blue) symbolise the 11 ESA Member States that contributed to ESA's human spaceflight programme at the time of launch. With the last star being the central part of the Space Station, the stars also symbolise how the Columbus laboratory, following its orbital journey, is an integral part of the International Space Station.
The final star also symbolises the spark of genius inherent in the groundbreaking science that takes place in the laboratory.