Chandrayaan -1 spacecraft launch countdown

The 52-hour countdown for the Chandrayaan 1 launch started at 5.22AM, on October 20, 2008, at the Sriharikota spaceport. India’s lunar mission Chandrayaan-1 is on board the polar satellite launch vehicle (PSLV-C11).

Chandrayaan-1 will be launched approximately at 6:20 AM on October 22, 2008.

Chandrayaan 1 will be launched by ISRO on a two-year mission to perform high-resolution remote sensing of the moon in the visible, near-infrared (NIR), low-energy X-ray and high-energy X-ray regions.

Chandrayaan-1 Photo

Chandrayaan 1 spacecraft picture that was unveiled by the Indian Space Research Organization (ISRO) Satellite Centre in Bangalore, India.

The Chandrayaan-1 spacecraft viewed from behind a glass at ISRO center in Bangalore, India.

Chandrayaan-1 has 11 scientific instruments. The Chandrayaan-1 spacecraft is shaped like a cuboid with a solar panel jutting out from one side. The spacecraft weighs 1400 kg at the time of the launch and 590 kg when in orbit.

The Chandrayaan-1 has been built mainly using composites and aluminum honeycomb material. The thermal subsystem of the Chandrayaan-1 comprises of paints, tapes, multi-layer insulation blanket, optical solar reflectors, heat pipes, heaters and temperature controllers. These ensure that the Chandrayaan-1 functions optimally and the temperature is maintained as required.

Below, is a photo of the Chandrayaan-1 ready for launch.

Chandrayaan-1 launch photo

A single solar panel powers the Chandrayaan-1 during all phases of the mission. It generates a maximum of 700 W. During eclipse, a 36 Ampere-Hour (AH) Lithium ion battery provides power to the spacecraft. The solar panel will be stowed on the south deck of the spacecraft, during launch.

Chandrayaan-1 has a dual gimballed antenna for payload data transmission. The steering of the antenna and the solar array are controlled by the mechanisms subsystem of Chandrayaan-1.

A sophisticated Telemetry, Tracking and Command subsystem of Chandrayaan-1, in S-band frequency, ensures that detailed information about spacecraft health and its position in space is communicated to Earth.

Chandrayaan-1 receives, modifies and retransmits radio waves sent by ground antennas that helps establish its position and orbit at a given instant of time.

Chandrayaan-1 ground dish antenna

During its orbit, Chandrayaan-1 sends photos and other scientific information to earth through the X-band in the microwave region.

The Chandrayaan-1 will able to receive and execute commands communicated from the Chandrayaan-1 spacecraft control centre.

The Chandrayaan-1 is a 3-axis stabilized spacecraft that has two sun and star sensors, gyroscopes that give the orientation reference for Chandrayaan-1 in space, and four reaction wheels.

The spacecraft carries three SSRs (Solid State Recorders) for gathering data.
The first has a capacity to store 32 GB data. It stores science payload data. The second SSR, that stores science payload data and attitude information, satellite house keeping, and auxiliary data, has a storage capacity of SSR-2 is 8GB.

The third SSR is an independent SSR that stores M3 (Moon Mineralogy Mapper) payload and has a capability to store 10GB.

A photo of the rocket for the Chandrayaan-1 launch is shown below.

Photo: The rocket, that will carry the Chandrayaan-1, is ready to launch at the Satish Dhawan center.

Picture: Chandrayaan-1 PSLV-C11

Picture: Chandrayaan-1 Terrain Mapping Camera and Hyper Spectral Imager payload models