In December 2012 through January 2013 and December 2013 through January 2014, the Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) mission was also conducted under this program.
This passage describes the BARREL mission being a part of a larger program, which was conducted over two distinct timeframes: December 2012 to January 2013 and December 2013 to January 2014.