Polar is one of four spacecraft in the Global Geospace Science (GGS) program. These are among the spacecraft (Wind, Geotail, SOHO, and Cluster) in the International Solar Terrestrial Physics (ISTP) program. POLAR measures solar wind entry, ionospheric output, and the depositions of energy into the neutral atmosphere at high latitudes.
Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 variants ("Light" and "Heavy"). The rocket flew its final mission ICESat-2 on 15 September 2018, earning the launch vehicle a streak of 100 successful missions in a row, with the last failure being GPS IIR-1 in 1997.