A Research and Technology Operating Plan (RTOP) is an internal NASA funding mechanism that is used to assign funding to a NASA center for the purpose of carrying out a specific research task. An RTOP is what NASA's Science Mission Directorate uses instead of a grant to fund PI led research investigations at NASA Centers. NASA also uses RTOPs to apply funding to the JPL contract to carry out PI led research tasks at JPL. RTOPs are issued directly from NASA Headquarters to the recipient center or JPL.