Many of the research objectives of planetary science are achieved through planetary exploration, for which the development of scientific instruments for planetary missions is the prime focus of this section. In the last two decades, ISRO has been actively working on planetary exploration missions, and several planetary missions are planned for the future. PRL has played a crucial role in planning and executing these missions and also actively contributing in the development of scientific instruments to study the surface, subsurface and atmosphere of the planetary bodies. PRL has developed scientific instruments for Chandrayaan-1 (High Energy X-ray Spectrometer - HEX), Chandrayaan-2 (Solar X-ray monitor - XSM), Chandrayaan-2&3 (Alpha Particle X-ray Spectrometer - APXS and Chandra’s Surface Thermophysical Experiment – ChaSTE) and Aditya L1 (Aditya Solar wind Particle EXperiment – ASPEX) missions. Several scientific instruments are being developed for the upcoming Venus Orbiter, ISRO-JAXA Rover, Mars Orbiter Mission - 2 and other upcoming planetary/space missions.