The Chief's responsibilities include managing Astronaut Office resources and operations and helping to develop operating concepts and assignments for astronaut flight crew.

[1] When Deke Slayton was grounded from the Mercury Seven due to a heart condition, he took on the position of Coordinator of Astronaut Activities and informally held the title of "chief astronaut".

His responsibilities included monitoring the coordination, scheduling, and control of all activities involving NASA astronauts.

This included monitoring the development and implementation of training programs to assure the flight readiness of pilot and non-pilot personnel for space flights; furnishing pilot evaluations applicable to the design, construction, and operations of spacecraft systems and related equipment; and providing scientific and engineering observations to facilitate mission planning, formulation of operational procedures, and selection and conduct of experiments for each flight.

[3] The Chief of the Astronaut Office often returns to active duty once their term is complete.