Following established processes of NASA's Science Mission Directorate, the science planning process began with the establishment of a science definition team, which was tasked to outline the mission's objectives and the strategies to achieve them, including developing a realistic surface operations scenario, suggestions for threshold science measurements that would meet the proposed objectives, and a proof-of-concept instrument suite. NASA then openly competed the opportunity for the mission's specific payload and science instruments. NASA selected seven science instruments. On the basis of this selection, the Mars 2020 rover would study diverse rocks and soils to understand past habitable conditions on Mars and to seek signs of ancient microbial life, monitor weather and dust in the Martian atmosphere, and test the ability to extract oxygen from the Red Planet's carbon-dioxide atmosphere to prepare for future human exploration. Rock-studying instruments would assist scientists in understanding which samples would be most promising for the Mars 2020 rover to core, collect, and cache (store).