PoGOLite (The Polarised Gamma-ray Observer) [1][2] is a balloon-borne astroparticle physics experiment which is to measure polarisation in hard X-rays and soft gamma-rays.

The pathfinder instrument containing 61 PDCs and 30 SAS detectors was scheduled to be launched from the Esrange facility in northern Sweden during summer 2011.

The main targets of the pathfinder experiment are the Crab Pulsar and the high-mass X-ray binary system Cygnus X-1, which are two of the brightest objects in the energy range of PoGOLite.

However, it was brought back down by 7:00 am from an altitude of 35 km, because of a helium leak.

A second attempt was scheduled for July 2012 but was cancelled because of bad weather.