The sub- systems were added to the spacecraft, along with the other instruments, to perform the specific functions of controlling data transfer and the direction of the spacecraft.
The main sub- systems included in the spacecraft are;
- Flight Data Subsystem- it provides engineering and science data for transmission. It also formats the data for transmission.
- Command Computer Subsystem- it enables sequencing and control functions. Command decoding and fault detection are its main functions.
- Attitude and Articulation Control Subsystem- it maintains the direction of the spacecraft and upholds the pointing of the high gain antenna towards Earth.