Friday, October 31, 2008

India's Mission Moon



First Time MOON MEETS INDIA so close - by Chandrayaan - I


India's first Moon mission, Chandrayaan is all set to add a golden chapter to India's space endeavour when it takes off from the Satish Dhawan Space Centre at Sriharikota on October 22.

Here's all that you wanted to know about India's first Moon mission

What is Chandrayaan-1?

Chandrayaan-1 is a scientific investigation -- by spacecraft -- of the Moon. The name Chandrayaan means Chandra (Moon), Yaan (vehicle). Chandrayaan-1 is the first Indian planetary science and exploration mission.

When, and from where, Chandrayaan-1 will be launched?

Chandrayaan-1 will be launched on October 22, 2008 from Satish Dhawan Space Centre at Sriharikota (SHAR).
The launch of Chandrayaan-1 takes place from the Second Launch Pad at Satish Dhawan Space Centre, SHAR, Sriharikota in the Nellore district of Andhra Pradesh state. Sriharikota is situated at a distance of about 80 km to the North of Chennai.

Chandrayaan-1 spacecraft begins its journey from earth onboard India's Polar Satellite Launch Vehicle (PSLV-C11) and first will reach a highly elliptical Initial Orbit (IO). In the Initial Orbit, the perigee (nearest point to earth) is about 250 km and apogee (farthest point from the earth) is about 23,000 km.

After circling the Earth in its Initial Orbit for a while, Chandrayaan-1 spacecraft is taken into two more elliptical orbits whose apogees lie still higher at 37,000 km and 73,000 km respectively. This is done at opportune moments by firing the spacecraft's Liquid Apogee Motor (LAM) when the spacecraft is near perigee.

Subsequently, LAM is fired again to take Chandrayaan-1 spacecraft to an extremely high elliptical orbit whose apogee lies at about 387,000 km.

In this orbit, the spacecraft makes one complete revolution around the Earth in about 11 days. During its second revolution around the Earth in this orbit, the spacecraft will approach the Moon's North pole at a safe distance of about a few hundred kilometers since the Moon would have arrived there in its journey round the Earth.

Once the Chandrayaan-1 reaches the vicinity of the Moon, the spacecraft is oriented in a particular way and its LAM is again fired. This slows down the spacecraft sufficiently to enable the gravity of the moon to capture it into an elliptical orbit.

Following this, the height of the spacecraft's orbit around the moon is reduced in steps. After a careful and detailed observation of perturbations in its intermediate orbits around the moon, the height of Chandrayaan-1 spacecraft's orbit will be finally lowered to its intended 100 km height from the lunar surface.

Later, the Moon Impact Probe will be ejected from Chandrayaan-1 spacecraft at the earliest opportunity to hit the lunar surface in a chosen area. Following this, cameras and other scientific instruments are turned ON and thoroughly tested. This leads to the operational phase of the mission. This phase lasts about two years during which Chandrayaan-1 spacecraft explores the lunar surface with its array of instruments that includes cameras, spectrometers and SAR.
Chandrayaan-1 is the first spacecraft mission of ISRO beyond Earth orbit. Chandrayaan-1 will be followed by Chandrayaan-2 which features a lander and a rover. India and Russia will jointly participate in this project. However, there may be a provision to accommodate payloads from other space agencies as happened in Chandrayaan-1. This apart, studies are being conducted by ISRO on sending unmanned spacecraft to planet Mars as well as to asteroids and comets. Through such programmes, ISRO intends to undertake the exploration of space besides its primary mission of developing and utilising space technology for the overall development of the country.

How long will it take Chandrayaan-1 to get to Moon?

It will take about 5� days for Chandrayaan-1 to get to the Moon.

How close to Moon will Chandrayaan-1 come while orbiting the Moon?

Chandrayaan-1 spacecraft will be in a 100 km polar orbit around the Moon.

What are Chandrayaan' s scientific goals? The Chandrayaan-1 mission is aimed at high-resolution remote sensing of the Lunar surface in visible, near Infrared, low energy X-rays and high-energy X-ray regions.

Specific scientific goals are:
To prepare a three-dimensional atlas (with a high spatial and altitude resolution of 5-10m) of both near and far side of the moon.

To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of elements such as Magnesium, Aluminum, Silicon, Calcium, Iron and Titanium with a spatial resolution of about 20 km and high atomic number elements such as Radon, Uranium & Thorium with a spatial resolution of about 40 km.

By simultaneous photo geological and chemical mapping we will be able to identify different geological units, which will test the hypothesis for the origin and early evolutionary history of the moon and help in determining the nature of the lunar crust.

The primary objectives of Chandrayaan-1 are:
1. To expand scientific knowledge about the moon
2. To upgrade India's technological capability
3. To provide challenging opportunities for planetary
research to the younger generation of Indian scientists


Chandrayaan-1 aims to achieve these well defined objectives through high resolution remote sensing of the moon in the visible, near infrared, microwave and X-ray regions of the electromagnetic spectrum. With this, preparation of a 3-dimensional atlas of the lunar surface and chemical mapping of entire lunar surface is envisaged.