How it works
Remote Agent is made up of three components which each play a significant, integral role in controlling the spacecraft:
- Planner and Scheduler (PS)--produces flexible plans, specifying the basic activities that must take place in order to accomplish the mission goals.
- Smart Executive (EXEC)--carries out the planned activities.
- Mode Identification and Recovery (MIR)-- monitors the health of the spacecraft and attempts to correct any problems that occur.
These three parts work together and communicate with each
other to make sure the spacecraft accomplishes
the goals of the mission:
- EXEC requests a plan from PS.
- PS produces a plan for a given time period based on the general mission goals and the current state of the spacecraft.
- EXEC receives the plan from PS, fills in the details of the plans, (eg., determines what spacecraft system actions must take place to complete the planned activities), and commands spacecraft systems to take the necessary actions.
- MIR constantly monitors the state of the spacecraft. It identifies failures and suggests recovery actions.
- EXEC executes the recovery action or requests a new plan from PS which will take into account the failure.
The parts of Remote Agent are constantly communicating (using inter-process communication) with each other and with external components of the spacecraft. MIR receives information regarding the state of different components from monitors located throughout the spacecraft. PS must receive information from planning experts in order to generate the plan. For example, the navigation system reports to PS regarding the spacecraft's current position, and the attitude-control system tells PS how long it will take to turn the spacecraft to a new position. Finally, EXEC sends commands to other pieces of flight software which in turn control the spacecraft's systems or flight hardware.
- NASA Official: Michael Shafto
- Curator: ASANI Solutions