The Chandrayaan-1: The Spacecraft
 
 
Chandrayaan-1 spacecarft undergoing prelaunch
tests at SDSC SHAR
 
Chandrayaan-1 spacecraft on top of PSLV-C11 fourth stage
with Payload fairing partially covering it
 

Chandrayaan-1 spacecraft carrying 11 scientific instruments weighed about 1380 kg at the time of its launch and is shaped like a cuboid with a solar panel projecting from one of its sides. The state of the art subsystems of the spacecraft, some of them miniaturised, facilitate the safe and efficient functioning of its array of scientific instruments.

The spacecraft structure was mainly built using composites and Aluminium honeycomb material. The Thermal subsystem consisting of paints, tapes, multi layer insulation blanket, optical solar reflectors, heat pipes, heaters and temperature controllers, ensures the proper functioning of the spacecraft by keeping its temperature within acceptable limits. The Mechanisms subsystem of Chandrayaan-1 spacecraft took care of the deployment of its solar panel and the steers of the dual gimballed antenna.

The spacecraft is powered by a single solar panel generating a maximum of 700 W. A 36 Ampere-Hour (Ah) Lithium ion battery supplies power when the solar panel is not illuminated by the sun. The Telemetry, Tracking and Command subsystem of Chandrayaan-1 working in S-band takes care of radioing the detailed spacecraft health information, facilitating the knowledge about spacecraft's position in space and allows the reception and execution of commands coming from Earth by the spacecraft.

Sun and star sensors as well as gyroscopes provide the orientation reference for spacecraft in space. The Attitude and Orbit Control subsystem, essentially the brain of Chandrayaan-1, consisting of a Bus Management Unit (BMU), reaction wheels and thrusters, ensures the proper orientation and stability of the spacecraft as well as in changing its orbit during different phases of its flight.

To make Chandrayaan-1 spacecraft to escape from orbiting Earth and to travel towards the moon, its liquid apogee motor (LAM) was used. Liquid propellants needed for LAM as well as thrusters were stored onboard the spacecraft.

Chandrayaan-1 spacecraft's Communications subsystem transmits the precious information gathered by its scientific instruments to Earth in 'X-band' through its Dual Gimballed Antenna.

Chandrayaan-1 spacecraft was built at ISRO Satellite Centre, Bangalore with contributions from ISRO/Department of Space (DOS) establishments like Vikram Sarabhai Space Centre (VSSC), Liquid Propulsion Systems Centre (LPSC) and ISRO Inertial Systems Unit (IISU) of Tiruvananthapuram, Space Applications Centre (SAC) and Physical Research Laboratory (PRL) of Ahmedabad and Laboratory for
Electro-optic Systems (LEOS) of Bangalore.