original_query: What was the purpose of the Imaging Photopolarimeter on Pioneer 10 and Pioneer 11?
query: What was the purpose of the Imaging Photopolarimeter (IPP) on the Pioneer 10 and Pioneer 11 missions?
answer: The Lunar and Planetary Laboratory was responsible for the IPP (Imaging Photopolarimeter) on both Pioneer 10 and Pioneer 11, operating the instrument.