Aspirations and outlook for nasa cosmic ray research on balloons and in space

Abstract

The cosmic-ray community has produced a steady stream of science results with both space- based and balloon-borne experiments. Low-energy cosmic rays have been studied with satellites since the dawn of the space age, but stratospheric balloons have provided all of the direct high- energy data. Results extending beyond 1014 eV from balloon flights in Antarctica now overlap indirect ground based observations in the energy range below the knee (~ 3 x 1015 eV). Ultra long-duration balloon flights with super-pressure balloons might allow direct observations to reach 1015 eV within the next decade, but larger aperture space missions with longer exposures may be needed to connect cosmic ray composition to supernovae. Space instruments looking down on the Earth's atmosphere, creating a detector as wide as the Earth, could provide information about astrophysical accelerators involving the intense gravity around black holes, neutron stars, and the largest electromagnetic fields known. © 2009 The Physical Society of Japan.