Casolba: Balloon Calibration of Solar Cells Etienne Rapp, Valérie Pichetto, Christian Elisabelar, Carsten Baur, Denis Bausch and Maxime Jeunet E3S Web Conf., 16 (2017) 02001 Published online: 23 May 2017 DOI: 10.1051/e3sconf/20171602001