La nacelle PILOT est rattachée au ballon auxiliaire avant son lâcher

The PILOT gondola is attached to the auxiliary balloon prior to release, at the Alice Springs launch facility in Australia. The 800.000 cu. m load-carrying stratospheric balloon, 50 times larger than the auxiliary balloon, will take over and lift the gondola, which weighs 1,058 kg, to an altitude of several tens of kilometres. Auxiliary balloons are used to raise delicate equipment off the ground, with the main balloon taking over afterwards. The PILOT astronomical science gondola, with a telescope payload, has been designed for use in studying the origins of the universe. Its purpose is to measure submillimetric polarised emissions from interstellar dust. More specifically, the project aims to map the magnetic fields in the interstellar clouds of the Milky Way, and study their role in star formation These unprecedented measurements are being made using a stratospheric balloon to which the instrument gondola is attached. Measurements are more economical and simpler to perform using balloons than using satellites. Launched to a height of 40 km on 16 April 2017, PILOT gathered data that would have been impossible to collect using ground-based telescopes, as the Earth's atmosphere partially blocks cosmic radiation.