Advanced Thin Ionization Calorimeter

The Advanced Thin Ionization Calorimeter (ATIC) is a balloon-borne instrument flying in the stratosphere over Antarctica to measure the energy and composition of cosmic rays.

Antarctic logistics are provided by the National Science Foundation and its contractor Raytheon Polar Services Corporation.

[3][4] Earlier in the year, the satellite PAMELA had found excess positrons (the antiparticle of the electron) in the cosmic ray signal, also believed to originate from dark matter interactions.

[1] On the other hand, in November 2008 the Milagro experiment reported cosmic ray "hotspots" in the sky, possibly supporting astrophysical objects as sources of the surplus electrons.

[5] In May 2009, observations by the Fermi space telescope were reported which did not support the spike of high-energy electrons seen by ATIC.