On Sept 30, 2015, NASA selected Lucy (along with 4 other exciting proposed missions) as a potential Discovery mission out of a group of 28 proposed missions. The Lucy team was then instructed to carry out in-depth concept design studies. At this point the main parameters of the mission as well as the science goals that the mission are finalized.
During Phase A the Lucy team developed final mission concept, system-level requirements, needed system technology developments, and program/project technical management plans. During this time the Lucy team was focused on showing the feasibility of the proposed mission and establishing the baseline compatibility with NASA’s strategic plans.
On January 4, 2017 NASA selected Lucy (along with Psyche) to be the next Discovery class missions. This allowed Lucy to move on to Phase B.