The future high energy nuclear cosmic ray flux measurements in the upper atmosphere will require large, and thus accurate, corrections for reliable Top of Atmosphere (galactic) fluxes to be derived. In this perspective, the atmospheric corrections are evaluated from the transport calculations of the flux in the atmosphere. The contributions of these corrections to the accuracy of the experimental results are discussed for the B/C and subFe/Fe elements ratios, over the kinetic energy range 10 - 10**4 GeV/n. These contributions become largely dominant at the highest energies investigated. The results and the prospects for the galactic flux measurements will be discussed in the presentation.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 4 (HE part 1), pages 613-616