  A major feature of the energy spectrum of the cosmic radiation above
10$^{19}$ eV is the increasing fraction of heavy nuclei with respect to light
nuclei. This fact, along with other simple assumptions, is adopted to calculate
the energy spectrum of the cosmic radiation up to 2.4$\times$10$^{21}$ eV. The
predicted spectrum maintains the index of 2.67 observed at lower energies which
is the basic, known, empirical well-assessed feature of the physical mechanism
accelerating cosmic rays in the Galaxy. Indeed above 10$^{19}$ eV the injection
of nuclei is inhibited by some filter and this inhibition causes a staircase
profile of the energy spectrum. It is argued that particle injection failure
versus energy commences with protons, followed by Helium and then by other
heavier nuclei up to Uranium. Around 7.5$\times$10$^{20}$ the cosmic radiation
consists solely of nuclei heavier than Copper and the estimated intensity is
1.8$\times$10$^{-30}$ particles/GeV s sr m$^2$.
