Division — Mechanical Systems

Deals with the design of the spacecraft configuration that can sustain sthe structural and thermal loads as well as the propulsion system design.

Structure

The structure subsystem is responsible for the design of the satellite bus. The team analyzes structural loads during launch condition and makes sure the design is robust, and economical. The design takes into account the mass and volume constraints provides by ISRO and ensures the components are placed in a manner suitable to the various subsystems.

Exploded view of Satellite Structure
Exploded view of Satellite Structure

The structural frame is made of aluminum and contains one body mounted and two deployable solar panels. The structural subsystem is responsible for design (CAD) and placement of all the other components in spacecraft.

Thermal

The thermal system is responsible to maintain operational temperatures of the individual components and the spacecraft as a whole within the respective survival ranges in all the mission phases. With the mission featuring trans-liberation cruise, lunar orbiting and Earth orbiting phases, the spacecraft faces a broad spectrum of thermal and radiation scenarios. The thermal system design a suitable thermal control system after analysing all the thermal loads. The plasma radiation analysis and the protection of electronics from the acquired radiation dose is also included in the subsystem’s work.

Internal views for lunar phase results (temperature in °C) and Heat Flux (W/mm2)
Internal views for lunar phase results (temperature in °C) and Heat Flux (W/mm2)

Propulsion

PPS Thruster
PPS Thruster

The propulsion subsystem deals with the selection of a suitable propellant to provide the thrust for orbital manoeuvres and reaction control. The propulsion engineer also designs the tanks and schematics for storage and efficient use of propellant respectively. SRMSAT - 2 uses a chemical bipropellant system which utilizes hydrazine as a fuel and nitrogen tetroxide (NTO) as an oxidizer. The propulsions system is pressure fed and uses helium as a pressurizer, to supply propellant to one primary thruster and 4 smaller reaction control thrusters.